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1.  An underlying diagnosis of osteonecrosis of bone is associated with worse outcomes than osteoarthritis after total hip arthroplasty 
Background
Well-designed studies of complications and readmission rates in patients undergoing total hip arthroplasty (THA) with osteonecrosis are lacking. Our objective was to examine if a diagnosis of osteonecrosis was associated with complications, mortality and readmission rates after THA.
Methods
We analyzed prospectively collected data from an integrated healthcare system’s Total Joint Replacement Registry of adults with osteonecrosis vs. osteoarthritis (OA) undergoing unilateral primary THA during 2001–2012, in an observational cohort study. We examined mortality (90-day), revision (ever), deep (1 year) and superficial (30-day) surgical site infection (SSI), venous thromboembolism (VTE, 90-day), and unplanned readmission (90-day). Age, gender, race, body mass index, American Society of Anesthesiologists class, and diabetes were evaluated as confounders. We used logistic or Cox regression to calculate odds or hazard ratios (OR, HR) with 95% confidence intervals (CI).
Results
Of the 47,523 primary THA cases, 45,252 (95.2%) had OA, and 2,271 (4.8%) had osteonecrosis. Compared to the OA, patients with osteonecrosis were younger (median age 55 vs. 67 years), and were less likely to be female (42.5% vs. 58.3%) or White (59.8% vs. 77.4%). Compared to the OA, the osteonecrosis cohort had higher crude incidence of 90-day mortality (0.7% vs. 0.3%), SSI (1.2% vs. 0.8%), unplanned readmission (9.6% vs. 5.2%) and revision (3.1% vs. 2.4%). After multivariable-adjustment, patients with osteonecrosis had a higher odds/hazard of mortality (OR: 2.48; 95% CI:1.31–4.72), SSI (OR: 1.67, 95%CI:1.11–2.51), unplanned 90-day readmissions (OR: 2.20; 95% CI:1.67–2.91) and a trend towards higher revision rate 1-year post-THA (HR: 1.32; 95% CI: 0.94–1.84), than OA patients.
Conclusions
Compared to OA, a diagnosis of osteonecrosis was associated with worse outcomes post-THA. A detailed preoperative discussion including the risk of complications is needed for informed consent from patients with osteonecrosis.
Electronic supplementary material
The online version of this article (doi:10.1186/s12891-016-1385-0) contains supplementary material, which is available to authorized users.
doi:10.1186/s12891-016-1385-0
PMCID: PMC5223478  PMID: 28068972
Total hip replacement; Readmission; Osteoarthritis; Osteonecrosis; Arthroplasty; Joint replacement; Diagnosis; Risk factor
2.  When patients write the guidelines: Patient panel recommendations for the treatment of RA 
Arthritis care & research  2015;68(1):26-35.
Background
How best to involve patients in the development of clinical practice guideline (CPG) recommendations is not known. We sought to determine the feasibility and value of developing CPG recommendations based on a voting panel composed entirely of patients, with the ultimate goal of comparing the patients’ recommendations to ones developed by a physician-dominated voting panel on the same clinical questions.
Methods
Ten patients with rheumatoid arthritis completed eight hours of training on evidence-based medicine and guideline development. They constituted a voting panel and, with two American College of Rheumatology staff with expertise in CPG development and a physician facilitator, subsequently met at a face-to-face meeting to develop recommendations. They applied the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology to formulate recommendations on 18 questions for which there was evidence warranting moderate or high confidence.
Results
The patient panel developed recommendations for 16 of the 18 questions; for the other two, the panel thought there were insufficient data to support a recommendation. For 13 of the 16 questions, the patient panel recommended the same course of action as did the physician-dominated panel. Differences were due to how the two panels valued the balance between benefits and harms.
Conclusion
Patient and physician-dominated panels developed the same recommendations for most questions for which there was evidence warranting moderate to high confidence. Additional experiences are necessary to advance the evidence necessary to determine what panel composition is optimal to produce the best guidelines.
doi:10.1002/acr.22758
PMCID: PMC4715535  PMID: 26545701
3.  Gout: will the “King of Diseases” be the first rheumatic disease to be cured? 
BMC Medicine  2016;14:180.
Gout is the most common inflammatory arthritis in adults in the Western world. Characterized by hyperuricemia and the effects of acute and chronic inflammation in joints and bursa, gout leads to an agonizing, chronically painful arthritis. Arthritis can also be accompanied by urate nephropathy and subcutaneous urate deposits (tophi). Exciting new developments in the last decade have brought back the focus on this interesting, crystal-induced chronic inflammatory condition. New insights include the role of NALP3 inflammasome-induced inflammation in acute gout, the characterization of diagnostic signs on ultrasound and dual-energy computed tomography imaging modalities, the recognition of target serum urate less than 6 mg/day as the goal for urate-lowering therapies, and evidence-based treatment guidelines. A better understanding of disease mechanisms has enabled drug discovery – three new urate-lowering drugs have been approved in the last decade, with several more in the pipeline. We now recognize the important role that environment and genetics play in the causation of gout. A focus on the cardiac, renal, and metabolic comorbidities of gout will help translational research and discovery over the next decade.
doi:10.1186/s12916-016-0732-1
PMCID: PMC5105252  PMID: 27832792
Gout; Urate-lowering therapy; Serum urate; Lesinurad; Allopurinol
4.  Are There Modifiable Risk Factors for Hospital Readmission After Total Hip Arthroplasty in a US Healthcare System? 
Background
Although total hip arthroplasty (THA) is a successful procedure, 4% to 11% of patients who undergo THA are readmitted to the hospital. Prior studies have reported rates and risk factors of THA readmission but have been limited to single-center samples, administrative claims data, or Medicare patients. As a result, hospital readmission risk factors for a large proportion of patients undergoing THA are not fully understood.
Questions/purposes
(1) What is the incidence of hospital readmissions after primary THA and the reasons for readmission? (2) What are the risk factors for hospital readmissions in a large, integrated healthcare system using current perioperative care protocols?
Methods
The Kaiser Permanente (KP) Total Joint Replacement Registry (TJRR) was used to identify all patients with primary unilateral THAs registered between January 1, 2009, and December 31, 2011. The KPTJRR’s voluntary participation is 95%. A logistic regression model was used to study the relationship of risk factors (including patient, clinical, and system-related) and the likelihood of 30-day readmission. Readmissions were identified using electronic health and claims records to capture readmissions within and outside the system. Odds ratio (OR) and 95% confidence intervals (CIs) were calculated. Of the 12,030 patients undergoing primary THAs included in the study, 59% (n = 7093) were women and average patient age was 66.5 years (± 10.7).
Results
There were 436 (3.6%) patients with hospital readmissions within 30 days of the index procedure. The most common reasons for readmission were infection and inflammatory reaction resulting from internal joint prosthetic (International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9-CM] 996.66, 7.0%); other postoperative infection (ICD-9-CM 998:59, 5.5%); unspecified septicemia (ICD-9-CM 038.9, 4.9%); and dislocation of a prosthetic joint (ICD-9-CM 996.42, 4.7%). In adjusted models, the following factors were associated with an increased likelihood of 30-day readmission: medical complications (OR, 2.80; 95% CI, 1.59-4.93); discharge to facilities other than home (OR, 1.89; 95% CI, 1.39–2.58); length of stay of 5 or more days (OR, 1.80; 95% CI, 1.22–2.65) versus 3 days; morbid obesity (OR, 1.74; 95% CI, 1.25–2.43); surgeries performed by high-volume surgeons compared with medium volume (OR, 1.53; 95% CI, 1.14–2.08); procedures at lower-volume (OR, 1.41; 95% CI, 1.07–1.85) and medium-volume hospitals (OR, 1.81; 95% CI, 1.20–2.72) compared with high-volume ones; sex (men: OR, 1.51; 95% CI, 1.18–1.92); obesity (OR, 1.32; 95% CI, 1.02–1.72); race (black: OR, 1.26; 95% CI, 1.02–1.57); increasing age (OR, 1.03; 95% CI, 1.01–1.04); and certain comorbidities (pulmonary circulation disease, chronic pulmonary disease, hypothyroidism, and psychoses).
Conclusions
The 30-day hospital readmission rate after primary THA was 3.6%. Modifiable factors, including obesity, comorbidities, medical complications, and system-related factors (hospital), have the potential to be addressed by improving the health of patients before this elective procedure, patient and family education and planning, and with the development of high-volume centers of excellence. Nonmodifiable factors such as age, sex, and race can be used to establish patient and family expectations regarding risk of readmission after THA. Contrary to other studies and the finding of increased hospital volume associated with lower risk of readmission, higher volume surgeons had a higher risk of patient readmission, which may be attributable to the referral patterns in our organization.
Level of Evidence
Level III, therapeutic study.
Electronic supplementary material
The online version of this article (doi:10.1007/s11999-015-4278-x) contains supplementary material, which is available to authorized users.
doi:10.1007/s11999-015-4278-x
PMCID: PMC4586234  PMID: 25845947
5.  Increasing comorbidity is associated with worsening physical function and pain after primary total knee arthroplasty 
Background
Previous studies suggested that pre-operative comorbidity was a risk factor for worse outcomes after TKA. To our knowledge, studies have not examined whether postoperative changes in comorbidity impact pain and function outcomes longitudinally. Our objective was to examine if increasing comorbidity postoperatively is associated with worsening physical function and pain after primary total knee arthroplasty (TKA).
Methods
We performed a retrospective chart review of veterans who had completed Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Short Form-36 (SF36) surveys at regular intervals after primary TKA. Comorbidity was assessed using a variety of scales: validated Charlson comorbidity index score, and a novel Arthroplasty Comorbidity Severity Index score (Including medical index, local musculoskeletal index [including lower extremity and spine] and TKA-related index subscales; higher scores are worse ), at multiple time-points post-TKA. We used mixed model linear regression to examine the association of worsening comorbidity post-TKA with change in WOMAC and SF-36 scores in the subsequent follow-up periods, controlling for age, length of follow-up, and repeated observations.
Results
The study cohort consisted of 124 patients with a mean age of 71.7 years (range 58.6–89.2, standard deviation (SD) 6.9) followed for a mean of 4.9 years post-operatively (range 1.3–11.4; SD 2.8). We found that post-operative worsening of the Charlson Index score was significantly associated with worsening SF-36 Physical Function (PF) (beta coefficient (ß) = -0.07; p < 0.0001), SF-36 Bodily Pain (BP) (ß = -0.06; p = 0.002), and WOMAC PF subscale (ß = 0.08; p < 0.001; higher scores are worse) scores, in the subsequent periods. Worsening novel medical index subscale scores were significantly associated with worsening SF-36 PF scores (ß = -0.03; p = 0.002), SF-36 BP (ß = -0.04; p < 0.001) and showed a non-significant trend for worse WOMAC PF scores (ß = 0.02; p = 0.11) subsequently. Local musculoskeletal index subscale scores were significantly associated with worsening SF-36 PF (ß = -0.05; p = 0.001), SF-36 BP (ß = -0.04; p = 0.03) and WOMAC PF (ß = 0.06; p = 0.01) subsequently. None of the novel index subscale scores were significantly associated with WOMAC pain scores. TKA complications, as assessed by TKA-related index subscale,  were not significantly associated with SF-36 or WOMAC domain scores.
Conclusions
Increasing Charlson index as well as novel medical and local musculoskeletal index subscale scores (from novel Arthroplasty  Comorbidity Severity Index) post-TKA correlated with subsequent worsening of physical function and pain outcomes post-TKA. Further studies should examine which comorbidity management could have the greatest impact on these outcomes.
Electronic supplementary material
The online version of this article (doi:10.1186/s12891-016-1261-y) contains supplementary material, which is available to authorized users.
doi:10.1186/s12891-016-1261-y
PMCID: PMC5055707  PMID: 27717340
Comorbidity; Physical Function; Pain; Primary Total Knee Arthroplasty; TKA; Worsening
6.  2015 Gout Classification Criteria: An American College Of Rheumatology-European League Against Rheumatism Collaborative Initiative 
Objective
Existing gout classification criteria have suboptimal sensitivity and/or specificity, and were developed at a time when advanced imaging was not available. The current effort was undertaken to develop new classification criteria for gout.
Methods
An international group of investigators, supported by the American College of Rheumatology (ACR) and European League Against Rheumatism (EULAR) conducted the following studies: a systematic literature review of advanced imaging, a diagnostic study in which monosodium urate (MSU) crystals in synovial fluid or tophus was the gold standard, a ranking exercise of paper patient cases, and a multi-criterion decision analysis exercise. These data formed the basis for developing the classification criteria, which were tested in an independent dataset.
Results
The entry criterion for the new classification criteria requires at least one episode of peripheral joint or bursal swelling, pain, or tenderness. The presence of MSU crystals in a symptomatic joint/bursa (i.e., synovial fluid) or in a tophus is a sufficient criterion for gout classification, and does not require further scoring. The domains of the new classification criteria include clinical (pattern of joint/bursa involvement, characteristics and time-course of symptomatic episodes), laboratory (serum urate, MSU-negative synovial fluid aspirate), and imaging (double-contour sign on ultrasound or urate on DECT, radiographic gout-related erosion). The sensitivity and specificity of the criteria are high: 92% and 89%, respectively.
Conclusions
The new classification criteria, developed using a data-driven and decision-analytic approach, have excellent performance characteristics and have incorporated current state-of-the-art evidence regarding gout.
doi:10.1002/art.39254
PMCID: PMC4566153  PMID: 26352873
7.  Allopurinol reduces the risk of myocardial infarction (MI) in the elderly: a study of Medicare claims 
Background
Previous observational studies that have examined the association of allopurinol with myocardial infarction (MI) have provided contradictory results. One study showed that allopurinol reduced the risk, while another study showed an increased risk with allopurinol. Therefore, our objective was to assess whether allopurinol use is associated with a reduction in the risk of MI in the elderly.
Method
We used the 2006–2012 5 % random sample of Medicare beneficiaries to study the association of new allopurinol initiation and the risk of incident MI in a cohort study. Multivariable-adjusted Cox regression models adjusted for age, gender, race, and Charlson index, in addition to various cardio-protective medications (beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, diuretics, statins). We calculated hazard ratios (HRs) with 95 % confidence intervals (CIs). Sensitivity analyses adjusted for coronary artery disease (CAD) risk factors, including hypertension, hyperlipidemia, diabetes, and smoking.
Results
Of the 29,298 episodes of incident allopurinol use, 1544 were associated with incident MI (5.3 % episodes). Allopurinol use was associated with reduced hazards of MI, with a HR of 0.85 (95 % CI, 0.77 to 0.95). Compared to no allopurinol use, longer durations of allopurinol use were associated with a lower HR of MI: 1–180 days, 0.98 (95 % CI, 0.84 to 1.14); 181 days to 2 years, 0.83 (95 % CI, 0.72 to 0.95); and >2 years, 0.70 (95 % CI, 0.56 to 0.88). Other factors associated with a higher hazard of MI were: age 75 to <85 years and ≥85 years, male gender, higher Charlson index score, and the use of an ACE inhibitor. Adjustment for CAD risk factors confirmed these findings.
Conclusion
Incident allopurinol use was associated with a reduction in the risk of incident MI in the elderly. Longer durations of allopurinol use reduced the risk of incident MI incrementally. Future studies should assess the underlying mechanisms for MI prevention and assess the risk-benefit ratio for allopurinol use.
Electronic supplementary material
The online version of this article (doi:10.1186/s13075-016-1111-1) contains supplementary material, which is available to authorized users.
doi:10.1186/s13075-016-1111-1
PMCID: PMC5032238  PMID: 27655429
Allopurinol; Myocardial infarction; MI; Risk factor; Pharmacoepidemiology; Elderly; Predictor; Coronary artery disease; CAD
8.  Using serum urate as a validated surrogate end point for flares in patients with gout: protocol for a systematic review and meta-regression analysis 
BMJ Open  2016;6(9):e012026.
Introduction
Gout is the most common inflammatory arthritis in men over 40 years of age. Long-term urate-lowering therapy is considered a key strategy for effective gout management. The primary outcome measure for efficacy in clinical trials of urate-lowering therapy is serum urate levels, effectively acting as a surrogate for patient-centred outcomes such as frequency of gout attacks or pain. Yet it is not clearly demonstrated that the strength of the relationship between serum urate and clinically relevant outcomes is sufficiently strong for serum urate to be considered an adequate surrogate. Our objective is to investigate the strength of the relationship between changes in serum urate in randomised controlled trials and changes in clinically relevant outcomes according to the ‘Biomarker-Surrogacy Evaluation Schema version 3’ (BSES3), documenting the validity of selected instruments by applying the ‘OMERACT Filter 2.0’.
Methods and analysis
A systematic review described in terms of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines will identify all relevant studies. Standardised data elements will be extracted from each study by 2 independent reviewers and disagreements are resolved by discussion. The data will be analysed by meta-regression of the between-arm differences in the change in serum urate level (independent variable) from baseline to 3 months (or 6 and 12 months if 3-month values are not available) against flare rate, tophus size and number and pain at the final study visit (dependent variables).
Ethics and dissemination
This study will not require specific ethics approval since it is based on analysis of published (aggregated) data. The intended audience will include healthcare researchers, policymakers and clinicians. Results of the study will be disseminated by peer-reviewed publications.
Trial registration number
CRD42016026991.
doi:10.1136/bmjopen-2016-012026
PMCID: PMC5051435  PMID: 27650765
GOUT; BIOMARKER; RHEUMATOLOGY; SURROGATE; OUTCOME
9.  Risk of serious infections with immunosuppressive drugs and glucocorticoids for lupus nephritis: a systematic review and network meta-analysis 
BMC Medicine  2016;14(1):137.
Background
To perform a systematic review and network meta-analysis (NMA) to compare the risk of serious infections with immunosuppressive medications and glucocorticoids in lupus nephritis.
Methods
A trained librarian performed two searches: (1) PubMed for all lupus nephritis trials from the end dates for the systematic review for the 2012 American College of Rheumatology (ACR) lupus nephritis treatment guidelines and the 2012 Cochrane Systematic Review on treatments for lupus nephritis, to September 2013; and (2) PubMed and SCOPUS for all lupus trials (excluding lupus nephritis) from inception to February 2014, to obtain additional trials for harms data in any lupus patient. The search was updated to May 2016. Duplicate title/abstract review and duplicate data abstractions by two abstractors independently was performed for all eligible studies, including those studies abstracted for the 2012 ACR lupus nephritis treatment guidelines and the 2012 Cochrane Systematic Review on lupus nephritis treatments. We performed a systematic review and a Bayesian NMA, including randomized controlled trials (RCTs) of immunosuppressive drugs or glucocorticoids in patients with lupus nephritis assessing serious infection risk. Markov chain Monte Carlo methods were used to model 95 % credible intervals (CrI). Sensitivity analyses examined the robustness of estimates.
Results
A total of 32 RCTs with 2611 patients provided data. There were 26 two-arm, five three-arm, and one four-arm trials. We found that tacrolimus was associated with significantly lower risk of serious infections compared to glucocorticoids, cyclophosphamide (CYC), mycophenolate mofetil (MMF), and azathioprine (AZA) with odds ratios (95 % CrI) of 0.33 (0.12–0.88), 0.37 (0.15–0.87), 0.340 (0.18–0.81), and 0.32 (0.12–0.81), respectively. Conversely, CYC low dose (LD), CYC high dose (HD), and HD glucocorticoids were associated with higher odds of serious infections compared to tacrolimus, ranging from 4.84 to 12.83. We also found that MMF followed by AZA (MMF-AZA) was associated with significantly lower risk of serious infections as compared to CYC LD, CYC HD, CYC-AZA, or HD glucocorticoids with odds ratios (95 % CrI) of 0.09 (0.01–0.76), 0.07 (0.01–0.54), 0.14 (0.02–0.71), and 0.03 (0.00–0.56), respectively. Estimates were similar to pair-wise meta-analyses. Sensitivity analyses that varied estimate (odds ratio vs. Peto’s odds ratio), method (random vs. fixed effects model), data (sepsis vs. serious infection data; exclusion of observational studies), treatment grouping (CYC and CYC HD as a combined treatment group vs. separate), made little/no difference to these estimates.
Conclusions
Tacrolimus and MMF-AZA combination were associated with lower risk of serious infections compared to other immunosuppressive drugs or glucocorticoids for lupus nephritis. In conjunction with comparative efficacy data, these data can help patients make informed decisions about treatment options for lupus nephritis.
PROSPERO registration
CRD42016032965
Electronic supplementary material
The online version of this article (doi:10.1186/s12916-016-0673-8) contains supplementary material, which is available to authorized users.
doi:10.1186/s12916-016-0673-8
PMCID: PMC5022202  PMID: 27623861
Network meta-analysis; Serious infections; Immunosuppressive drugs; Glucocorticoids; Lupus nephritis; Lupus; Tacrolimus; Cyclophosphamide; Mycophenolate mofetil
10.  Comparative effectiveness of immunosuppressive drugs and corticosteroids for lupus nephritis: a systematic review and network meta-analysis 
Systematic Reviews  2016;5(1):155.
Background
There is a lack of high-quality meta-analyses and network meta-analyses of immunosuppressive drugs for lupus nephritis. Our objective was to assess the comparative benefits and harms of immunosuppressive drugs and corticosteroids in lupus nephritis.
Methods
We conducted a systematic review and network meta-analysis (NMA) of trials of immunosuppressive drugs and corticosteroids in patients with lupus nephritis. We calculated odds ratios (OR) and 95 % credible intervals (CrI).
Results
Sixty-five studies that met inclusion and exclusion criteria; data were analyzed for renal remission/response (37 trials; 2697 patients), renal relapse/flare (13 studies; 1108 patients), amenorrhea/ovarian failure (eight trials; 839 patients) and cytopenia (16 trials; 2257 patients). Cyclophosphamide [CYC] low dose (LD) and CYC high-dose (HD) were less likely than mycophenolate mofetil [MMF] and azathioprine [AZA], CYC LD, CYC HD and plasmapharesis less likely than cyclosporine [CSA] to achieve renal remission/response. Tacrolimus [TAC] was more likely than CYC LD to achieve renal remission/response. MMF and CYC were associated with a lower odds of renal relapse/flare compared to PRED and MMF was associated with a lower rate of renal relapse/flare than AZA. CYC was more likely than MMF and PRED to be associated with amenorrhea/ovarian failure. Compared to MMF, CYC, AZA, CYC LD, and CYC HD were associated with a higher risk of cytopenia.
Conclusions
In this systematic review and NMA, we found important differences between immunosuppressives used for the treatment of lupus nephritis. Patients and physicians can use this information for detailed informed consent in a patient-centered approach. Study limitations of between-study clinical heterogeneity and small sample size with type II error must be considered when interpreting these findings.
Systematic review registration
PROSPERO: CRD42016032965
Electronic supplementary material
The online version of this article (doi:10.1186/s13643-016-0328-z) contains supplementary material, which is available to authorized users.
doi:10.1186/s13643-016-0328-z
PMCID: PMC5020478  PMID: 27619512
Network meta-analysis; Immunosuppressive drugs; Glucocorticoids; Lupus nephritis; Lupus; Renal remission; Renal relapse; Tacrolimus; Cyclophosphamide; Mycophenolate mofetil
11.  Allopurinol and the risk of stroke in older adults receiving medicare 
BMC Neurology  2016;16(1):164.
Background
Previous studies of allopurinol and stroke risk have provided contradictory findings, ranging from a protective effect to an increased risk. Our objective was to assess whether allopurinol use is associated with the risk of stroke in the elderly.
Methods
We used the 5 % random sample of Medicare beneficiaries from 2006–2012 to study the association of new allopurinol initiation and incident stroke. We used multivariable-adjusted Cox regression models adjusted for age, gender, race, Charlson index, and cardio-protective medications (beta-blockers, ACE inhibitors, diuretics, statins) to calculate hazards ratio (HR) with 95 % confidence intervals (CI). Sensitivity analyses adjusted for coronary artery disease (CAD) risk factors including hypertension, hyperlipidemia, diabetes, and smoking instead of Charlson index.
Results
Among 28,488 eligible episodes of incident allopurinol, 2,177 ended in incident stroke (7.6 % episodes). In multivariable-adjusted analyses, allopurinol use was associated with 9 % lower hazard ratio for stoke, 0.91 (95 % CI, 0.83 to 0.99). Compared to no allopurinol use, allopurinol use durations of 181 days to 2 years, 0.88 (95 % CI, 0.78 to 0.99) and >2 years, 0.79 (95 % CI, 0.65 to 0.96) were significantly associated with lower multivariable-adjusted hazard of stroke. Sensitivity analyses adjusted for CAD risk factors confirmed these findings. In subgroup analyses, significant associations were noted between allopurinol use and the risk of ischemic stroke, 0.89 (95 % CI, 0.81 to 0.98); associations were not significant for hemorrhagic stroke, 1.01 (95 % CI, 0.79 to 1.29).
Conclusions
Allopurinol use is associated with lower risk of stroke overall, more specifically ischemic stroke. This association is evident after 6-months of allopurinol use, and the hazard reduction increases with longer duration of use. Future studies need to examine underlying mechanisms.
Electronic supplementary material
The online version of this article (doi:10.1186/s12883-016-0692-2) contains supplementary material, which is available to authorized users.
doi:10.1186/s12883-016-0692-2
PMCID: PMC5015204  PMID: 27604082
Allopurinol; Stroke; Elderly; Medicare; Ischemic stroke; Urate-lowering therapy; Hyperuricemia; Age; Race; Gender
12.  2015 Gout Classification Criteria: An American College of Rheumatology/European League Against Rheumatism Collaborative Initiative 
Objective
Existing criteria for the classification of gout have suboptimal sensitivity and/or specificity, and were developed at a time when advanced imaging was not available. The current effort was undertaken to develop new classification criteria for gout.
Methods
An international group of investigators, supported by the American College of Rheumatology and the European League Against Rheumatism, conducted a systematic review of the literature on advanced imaging of gout, a diagnostic study in which the presence of monosodium urate monohydrate (MSU) crystals in synovial fluid or tophus was the gold standard, a ranking exercise of paper patient cases, and a multicriterion decision analysis exercise. These data formed the basis for developing the classification criteria, which were tested in an independent data set.
Results
The entry criterion for the new classification criteria requires the occurrence of at least 1 episode of peripheral joint or bursal swelling, pain, or tenderness. The presence of MSU crystals in a symptomatic joint/bursa (i.e., synovial fluid) or in a tophus is a sufficient criterion for classification of the subject as having gout, and does not require further scoring. The domains of the new classification criteria include clinical (pattern of joint/bursa involvement, characteristics and time course of symptomatic episodes), laboratory (serum urate, MSU‐negative synovial fluid aspirate), and imaging (double‐contour sign on ultrasound or urate on dual‐energy computed tomography, radiographic gout‐related erosion). The sensitivity and specificity of the criteria are high (92% and 89%, respectively).
Conclusion
The new classification criteria, developed using a data‐driven and decision analytic approach, have excellent performance characteristics and incorporate current state‐of‐the‐art evidence regarding gout.
doi:10.1002/art.39254
PMCID: PMC4566153  PMID: 26352873
13.  How often is the office visit needed? Predicting total knee arthroplasty revision risk using pain/function scores 
Background
Most patients have favorable outcomes after primary total knee arthroplasty (TKA). Well-validated methods to predict the risk of poor outcomes have not been developed or implemented. Several patients have annual clinic visits despite well-funcitoning TKA, as a routine practice, to detect early failure requiring revision surgery. It is not known whether assessment of pain and function can be used as a predictive tool for early failure and revision to guide practice. Our objective was to determine whether pain and function can predict revision after TKA.
Methods
We retrospectively studied data from a large prospectively gathered TKA registry to examine changes in outcome scores for primary TKAs undergoing revision compared to those not requiring revision to determine the factors that are predictive for revision.
Results
Of the 1,012 patients, 721 had had a single-sided primary TKA and had American Knee Society (AKS) Scores for three or more visits. 46 patients underwent revision, 23 acutely (fracture, traumatic component failure or acute infection) and 23 for latent causes (late implant loosening, progressive osteolysis, or pain and indolent infection). Mean age was 70 years for the non-revision patients, and 64 years for those revised. Both AKS Clinical and AKS Function Scores for non-revised patients were higher than in revision patients, higher in acute revision compared to latent revision patients. Significant predictors of revision surgery were preoperative, 3- and 15-month postoperative AKS Clinical Scores and 3-month AKS Function Scores. At 15-month post-TKA, a patient with a low calculated probability of revision, 32 % or less, was unlikely to require revision surgery with a negative predictive value of 99 %.
Conclusion
Time dependent interval evaluation post-TKA with the AKS outcome scores may provide the ability to assign risk of revision to patients at the 15-month follow-up visit. If these findings can be replicated using a patient-reported measure, a virtual follow-up with patient-reported outcomes and X-ray review may be an alternative to clinic visit for patients doing well.
Electronic supplementary material
The online version of this article (doi:10.1186/s12913-016-1669-y) contains supplementary material, which is available to authorized users.
doi:10.1186/s12913-016-1669-y
PMCID: PMC4995795  PMID: 27553056
Total knee arthroplasty; TKA; Revision risk; Pain; Function; American Knee Society Scores; AKS scores
14.  Persisting Racial Disparities in Total Shoulder Arthroplasty Utilization and Outcomes 
Objective
The purpose was to study whether racial disparities in total shoulder arthroplasty (TSA) utilization and outcomes have declined over time.
Methods
We used the US Nationwide Inpatient Sample from 1998 to 2011.We used chi-squared test to compare characteristics, Cochran-Armitage test to compare utilization rates, and Cochran-Armitage test and logistic regression to compare time-trends in outcomes by race.
Results
From 1998 to 2011, 176,141 Whites and 7694 Blacks underwent TSA. Compared to Whites, Blacks who underwent TSA were younger (69.1 vs. 64.2 years; p<0.0001), more likely to be female (54.9 vs. 71.0 %; p<0.0001), and have rheumatoid arthritis or avascular necrosis as the underlying diagnosis (1.7 vs. 3.0%and 1.7 vs. 6.1 %; p<0.0001 for both) and a Deyo-Charlson index of 2 or higher (8.5 vs. 16.7 %; p<0.0001). Compared to Whites, Blacks had much lower TSA utilization rate/100,000 in 1998 (2.97 vs. 0.83; p<0.0001) and in 2011 (12.27 vs. 3.33; p<0.0001); racial disparities increased from 1998 to 2011 (p<0.0001). A higher proportion of Blacks than Whites had a hospital stay greater than median in 1998–2000, 62 vs. 51.4 % (p=0.02), and in 2009–2011, 34.4 vs. 27.3 % (p<0.0001); disparities did not change over time (p=0.31). These disparities in utilization were borderline significant in adjusted analyses. There were no racial differences in proportion discharged to inpatient medical facility in 1998–2000, 15.2 vs. 15.0 % (p=0.95), and in 2009–2011, 12.3 vs. 11.1%(p=0.37), respectively.
Conclusions
We found increasing racial disparities in TSA utilization. Some disparities in outcomes exist as well. Patients, surgeons, and policy-makes should be aware of these findings and take action to reduce racial disparities.
doi:10.1007/s40615-015-0138-3
PMCID: PMC4581980  PMID: 26413459
Race; Total shoulder arthroplasty; TSA; Utilization; Outcomes; Mortality; Hospital stay; Discharge; Time-trends
15.  An Internet Survey of Common Treatments used by Patients with Gout Including Cherry extract and Juice and other dietary supplements 
doi:10.1097/RHU.0000000000000246
PMCID: PMC4974079  PMID: 26010189
Gout; cherry extract; cherry juice; complementary medicine; allopurinol; febuxostat; Internet study; survey; natural supplements
16.  Imaging as an Outcome Measure in Gout Studies: Report from the OMERACT Gout Working Group 
The Journal of rheumatology  2015;42(12):2460-2464.
Objective
The gout working group at the Outcome Measures in Rheumatology (OMERACT) 12 meeting in 2014 aimed to determine which imaging modalities show the most promise for use as measurement instruments for outcomes in studies of people with chronic gout and to identify the key foci for future research about the performance of these imaging techniques with respect to the OMERACT filter 2.0.
Methods
During the gout session, a systematic literature review of the data addressing imaging modalities including plain radiography (XR), conventional computed tomography (CT), dual-energy computed tomography (DECT), magnetic resonance imaging (MRI), and ultrasound (US) and the fulfillment of the OMERACT filter 2.0 was presented.
Results
The working group identified 3 relevant domains for imaging in gout studies: urate deposition (tophus burden), joint inflammation, and structural joint damage.
Conclusion
The working group prioritized gaps in the data and identified a research agenda.
doi:10.3899/jrheum.141164
PMCID: PMC4966884  PMID: 25641895
GOUT; OUTCOME MEASURES; MEDICAL IMAGING; OMERACT
17.  Emergency Department and Inpatient Healthcare utilization due to Hypertension 
Background
Hypertension is one of the commonest chronic diseases, yet limited data are available for related health care utilization. Our study objective was to describe the emergency department (ED) and subsequent hospitalization related health care utilization and charges due to hypertension in the U.S.
Methods
We used the National ED sample (NEDS) to study hypertension-related utilization and charges. Multivariable-adjusted linear or logistic regression was used to assess hypertension-associated ED and hospitalization outcomes (disposition, length of stay, charges), adjusted for patient demographic, comorbidity and hospital characteristics.
Results
There were 0.92, 0.97 and 1.04 million ED visits (0.71–0.77 % of all ED visits) with hypertension as the primary diagnosis in 2009, 2010 and 2012, respectively; 23 % resulted in hospitalization. ED charges were $2.00, $2.27 and $2.86 billion, and for those hospitalized, total charges (ED plus inpatient) were $6.62, $7.09 and $7.94 billion, in 2009, 2010 and 2012, respectively. Older age (50 to 65 years), female sex, metropolitan area residence, South or West U.S. hospital location, private insurance and the presence of congestive heart failure were each associated with higher charges for an ED visit with hypertension as the primary diagnosis. Younger age, metropolitan residence, Medicaid insurance, hospital location in the Northeast and co-existing diabetes, gout, coronary heart disease, chronic obstructive pulmonary disease, hyperlipidemia and osteoarthritis were associated with higher risk, whereas male sex was associated with lower risk of hospitalization after ED visit for hypertension. In 2012, 71.6 % of all patients hospitalized with hypertension as the primary diagnosis were discharged home. Older age, metropolitan residence and most comorbidities were associated with lower odds, whereas male sex, payer other than Medicare, South or West U.S. hospital location were associated with higher odds of discharge to home.
Conclusions
Hypertension is associated with significant healthcare burden in the U.S. Future studies should assess strategies to reduce hypertension-associated cost and health care burden.
Electronic supplementary material
The online version of this article (doi:10.1186/s12913-016-1563-7) contains supplementary material, which is available to authorized users.
doi:10.1186/s12913-016-1563-7
PMCID: PMC4962411  PMID: 27461237
Emergency department; Hospitalization; Health care utilization; Charges; Hypertension; Predictors; Hospital discharge; Predictors
18.  The risk of serious infection with biologics in treating patients with rheumatoid arthritis: A Systematic Review and Meta-analysis 
Lancet (London, England)  2015;386(9990):258-265.
Background
Serious infections are a major concern for patients considering treatmentsfor rheumatoid arthritis (RA). Evidence is inconsistent on whether biologicsare associated with an increased risk of serious infection compared to traditional disease-modifying anti-rheumatic drugs (DMARDs).
Methods
A systematic literature search was undertaken using MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and www.clinicaltrials.gov from inception through February 11, 2014. Search terms included biologics, rheumatoid arthritis and their synonyms. Trials were eligible for inclusion if they included any of the biologics and reported serious infections. The risk of bias was assessed using the Cochrane Risk of Bias Tool. We conducted a Bayesian network meta-analysis,using a binomial likelihood model, of published trials to assess the risk of serious infections of biologics in RA patients, compared to traditional DMARDs.
Findings
The systematic review identified 106 trials that included RA patients on biologic and reported on serious infections. Compared to traditional DMARDs, standard-dose biologic (odds ratio [OR],1.31; 95% credible interval [CrI], 1.09 to 1.58) andhigh-dose biologic (OR, 1.90; 95% Crl, 1.50 to 2.39) were associated with an increased risk of serious infections, while low-dose biologics (OR, 0.93; 95% CrI, 0.65 to 1.33) were not. The risk was lower in patients who are methotrexate naïve compared withtraditional DMARD- or anti-TNF-biologic-experienced. The absolute increase in the number of serious infectionsper 1000 patients treated each year compared to traditional DMARDs ranged from 6 for standard-dose biologic to 55 for combination biologic therapy.
Interpretation
Standard-dose and high-dose biologics (with/without traditional DMARDs) are associated with an increase in serious infections compared to traditional DMARDs in RA, while low-dose biologics are not.Clinicians should discuss the balance between benefit and harm with the individual RA patient before initiating biologic therapy.
Funding
Rheumatology division at the University of Alabama at Birmingham.
doi:10.1016/S0140-6736(14)61704-9
PMCID: PMC4580232  PMID: 25975452
rheumatoid arthritis; serious infection; harms; biologics; anti-TNF biologic; non-TNF biologic; methotrexate; DMARD; network meta-analysis; NMA; systematic review; meta analysis
19.  Clinically important improvement thresholds for Harris Hip Score and its ability to predict revision risk after primary total hip arthroplasty 
Background
Some aspects of validity are missing for the Harris Hip Score (HHS). Our objective was to examine the clinically meaningful change thresholds, responsiveness and the predictive ability of the HHS questionnaire.
Methods
We included a cohort of patients who underwent primary total hip arthroplasty (THA) and responded to the HHS preoperatively and at 2- or 5-year post-THA (change score) to examine the clinically meaningful change thresholds (Minimal clinically important improvement, MCII; and moderate improvement), responsiveness (effect size (ES) and standardized response mean (SRM)) based on pre- to post-operative change and the predictive ability of change score or absolute postoperative score at 2- and 5-years post-THA for future revision.
Results
Two thousand six hundred sixty-seven patients with a mean age of 64 years completed baseline HHS; 1036 completed both baseline and 2-year HHS and 669 both baseline and 5-year HHS. MCII and moderate improvement thresholds ranged 15.9–18 points and 39.6–40.1 points, respectively. ES was 3.12 and 3.02 at 2- and 5-years; respective SRM was 2.73 and 2.52. There were 3195 hips with HHS scores at 2-years and 2699 hips with HHS scores at 5-years (regardless of the completion of baseline HHS; absolute postoperative scores). Compared to patients with absolute HHS scores of 81–100 (score range, 0–100), patients with scores <55 at 2- and 5-years had higher hazards (95 % confidence interval) of subsequent revision, 4.34 (2.14, 7.95; p < 0.001) and 3.08 (1.45, 5.84; p = 0.002), respectively. Compared to HHS score improvement of  >50 points from preoperative to 2-years post-THA, lack of improvement/worsening or 1–20 point improvement were associated with increased hazards of revision, 18.10 (1.41, 234.83; p = 0.02); and 6.21 (0.81, 60.73; p = 0.10), respectively.
Conclusions
HHS is a valid measure of THA outcomes and is responsive to change. Both absolute HHS postoperative scores and HHS score change postoperatively are predictive of revision risk post-primary THA. We defined MCID and moderate improvement thresholds for HHS in this study.
doi:10.1186/s12891-016-1106-8
PMCID: PMC4901425  PMID: 27286675
Harris Hip Score; Total Hip Arthroplasty; Responsiveness; Discriminant ability; Predictability; Clinically important improvement; Minimal clinically important improvement; MCII; Minimal clinically important difference; MCID
20.  VALIDATION OF ADMINISTRATIVE CODES FOR CALCIUM PYROPHOSPHATE DEPOSITION: A Veterans Administration study 
Background
Despite high prevalence, progress in calcium pyrophosphate deposition (CPPD) has been limited by poor awareness and absence of validated approaches to study it in large datasets.
Objectives
We aimed to determine the accuracy of administrative codes for the diagnosis of CPPD as a foundational step for future studies.
Methods
We identified all patients with an International Classification of Diseases-9-common modification (ICD-9-CM) code for chondrocalcinosis (712.1–712.39) or pseudogout/other disorders of mineral metabolism (275.49), and randomly selected a comparison group with gout (274.00–03 or 274.8–9), or rheumatoid arthritis (714.0) from 2009–2011 at a VA medical center. Each patient was categorized as having definite, probable, possible CPPD or absence of CPPD based on the McCarty and Ryan criteria using chart abstracted data including crystal analysis, radiographs, and arthritis history.
Results
249 patients met the clinical gold standard criteria for CPPD based on medical records, while 48 patients met definite criteria, 183 probable, and 18 met possible criteria. The accuracy of administrative claims with a code of 712 or 275.49 for definite or probable CPPD was: 98% sensitivity (95% CI, 96%–99%), 78% specificity (74%–83%), 91% positive predictive value and 94% negative predictive value.
Conclusions
A single administrative code 275.49 or 712 accurately identifies patients with CPPD with a positive predictive value of 91%. These findings suggest that administrative codes have strong clinical accuracy and merit further validation to allow adoption in future epidemiologic studies of CPPD.
doi:10.1097/RHU.0000000000000251
PMCID: PMC4694041  PMID: 26010181
Calcium pyrophosphate; chondrocalcinosis; ICD-9-CM code; veterans; CPPD disease
21.  Chondroitin for osteoarthritis 
Background
Osteoarthritis, a common joint disorder, is one of the leading causes of disability. Chondroitin has emerged as a new treatment. Previous meta-analyses have shown contradictory results on the efficacy of chondroitin. This, in addition to the publication of more trials, necessitates a systematic review.
Objectives
To evaluate the benefit and harm of oral chondroitin for treating osteoarthritis compared with placebo or a comparator oral medication including, but not limited to, nonsteroidal anti-inflammatory drugs (NSAIDs), analgesics, opioids, and glucosamine or other “herbal” medications.
Search methods
We searched seven databases up to November 2013, including the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, CINAHL, EMBASE, Science Citation Index (Web of Science) and Current Controlled Trials. We searched the US Food and Drug Administration (FDA) and European Medicines Agency (EMEA) websites for adverse effects. Trial registers were not searched.
Selection criteria
All randomized or quasi-randomized clinical trials lasting longer than two weeks, studying adults with osteoarthritis in any joint, and comparing chondroitin with placebo, an active control such as NSAIDs, or other “herbal” supplements such as glucosamine.
Data collection and analysis
Two review authors independently performed all title assessments, data extractions, and risk of bias assessments.
Main results
Forty-three randomized controlled trials including 4,962 participants treated with chondroitin and 4,148 participants given placebo or another control were included. The majority of trials were in knee OA, with few in hip and hand OA. Trial duration varied from 1 month to 3 years. Participants treated with chondroitin achieved statistically significantly and clinically meaningful better pain scores (0–100) in studies less than 6 months than those given placebo with an absolute risk difference of 10% lower (95% confidence interval (CI), 15% to 6% lower; number needed to treat (NNT) = 5 (95% CI, 3 to 8; n = 8 trials) (level of evidence, low; risk of bias, high); but there was high heterogeneity between the trials (T2 = 0.07; I2 = 70%, which was not easily explained by differences in risk of bias or study sample size). In studies longer than 6 months, the absolute risk difference for pain was 9% lower (95% CI 18% lower to 0%); n = 6 trials; T2 = 0.18; I2 = 83% ), again with low level of evidence.
For the Western Ontario and McMaster Universities Osteoarthritis Index Minimal Clinically Important Improvement (WOMAC MCII Pain subscale) outcome, a reduction in knee pain by 20% was achieved by 53/100 in the chondroitin group versus 47/100 in the placebo group, an absolute risk difference of 6% (95% CI 1% to 11%), (RR 1.12, 95% CI 1.01 to 1.24; T2 = 0.00; I2 = 0%) (n = 2 trials, 1253 participants; level of evidence, high; risk of bias, low).
Differences in Lequesne’s index (composite of pain, function and disability) statistically significantly favoured chondroitin as compared with placebo in studies under six months, with an absolute risk difference of 8% lower (95% CI 12% to 5% lower; T2= 0.78; n = 7 trials) (level of evidence, moderate; risk of bias, unclear), also clinically meaningful. Loss of minimum joint space width in the chondroitin group was statistically significantly less than in the placebo group, with a relative risk difference of 4.7% less (95% CI 1.6% to 7.8% less; n = 2 trials) (level of evidence, high; risk of bias, low). Chondroitin was associated with statistically significantly lower odds of serious adverse events compared with placebo with Peto odds ratio of 0.40 (95% CI 0.19 to 0.82; n = 6 trials) (level of evidence, moderate). Chondroitin did not result in statistically significant numbers of adverse events or withdrawals due to adverse events compared with placebo or another drug. Adverse events were reported in a limited fashion, with some studies providing data and others not.
Comparisons of chondroitin taken alone or in combination with glucosamine or another supplement showed a statistically significant reduction in pain (0–100) when compared with placebo or an active control, with an absolute risk difference of 10% lower (95% CI 14% to 5% lower); NNT = 4 (95% CI 3 to 6); T2 = 0.33; I2 = 91%; n = 17 trials) (level of evidence, low). For physical function, chondroitin in combination with glucosamine or another supplement showed no statistically significant difference from placebo or an active control, with an absolute risk difference of 1% lower (95% CI 6% lower to 3% higher with T2 = 0.04; n = 5 trials) (level of evidence, moderate). Differences in Lequesne’s index statistically significantly favoured chondroitin as compared with placebo, with an absolute risk difference of 8% lower (95% CI, 12% to 4% lower; T2 = 0.12; n = 10 trials) (level of evidence, moderate). Chondroitin in combination with glucosamine did not result in statistically significant differences in the numbers of adverse events, withdrawals due to adverse events, or in the numbers of serious adverse events compared with placebo or with an active control.
The beneficial effects of chondroitin in pain and Lequesne’s index persisted when evidence was limited to studies with adequate blinding or studies that used appropriate intention to treat (ITT) analyses. These beneficial effects were uncertain when we limited data to studies with appropriate allocation concealment or a large study sample (> 200) or to studies without pharmaceutical funding.
Authors’ conclusions
A review of randomized trials of mostly low quality reveals that chondroitin (alone or in combination with glucosamine) was better than placebo in improving pain in participants with osteoarthritis in short-term studies. The benefit was small to moderate with an 8 point greater improvement in pain (range 0 to 100) and a 2 point greater improvement in Lequesne’s index (range 0 to 24), both likely clinically meaningful. These differences persisted in some sensitivity analyses and not others. Chondroitin had a lower risk of serious adverse events compared with control. More high-quality studies are needed to explore the role of chondroitin in the treatment of osteoarthritis. The combination of some efficacy and low risk associated with chondroitin may explain its popularity among patients as an over-the-counter supplement.
doi:10.1002/14651858.CD005614.pub2
PMCID: PMC4881293  PMID: 25629804
22.  Do pessimists report worse outcomes after total hip arthroplasty? 
Background
Seligman’s theory of causal attribution predicts that patients with a pessimistic explanatory style will have less favorable health outcomes. We investigated this hypothesis using self-reported hip pain and hip function 2- years after total hip arthroplasty (THA).
Methods
Most THA patients had completed the Minnesota Multiphasic Personality Inventory (MMPI) during their usual clinical care long before THA (median, 14.7 to 16.6 years). Scores from the MMPI Optimism-Pessimism (PSM) scale were used to categorize patients as pessimistic (t-score >60) or non-pessimistic (t score ≤60). Outcomes were self-reported: (a) moderate-severe pain, (b) absence of “much better” improvement compared to preoperative hip function, and (c) moderate-severe activity limitation. Multivariable logistic regression was adjusted for gender, age and other covariates. Odds ratios (OR) with 95 % confidence intervals (CI) are presented.
Results
We identified 507 patients with 565 primary THAs with an MMPI prior to primary THA, of whom 441 patients with 488 primary THAs had responded to hip pain and function follow-up surveys at 2-years post-surgery. Similarly, 202 patients with 235 revision THAs had an MMPI prior to surgery, of whom 172 patients with 196 revision THAs completed 2-year surveys. Among those with primary THA, pessimists reported (a) a non-significant trend toward more moderate-severe pain at 2-years with OR (95 % CI; p-value), 2.16 (0.90, 5.20; p = 0.08; reference, none-mild pain),; (b) no significant difference for absence of “much better” improvement in hip function at 2-years, 1.87 (0.77, 4.52; p = 0.16; reference, much better hip function); and (c) significantly higher rate of moderate-severe activity limitation at 2-years, 2.90 (1.25, 6.70; p = 0.01). Among revision THA cohort, pessimists reported no significant differences from non-pessimists in moderate-severe pain, improvement in hip function or moderate-severe functional limitation at 2-years.
Conclusions
A pessimistic explanatory style was associated with moderate-severe activity limitation and a non-significant trend towards moderate-severe pain post-THA.
doi:10.1186/s12891-016-1045-4
PMCID: PMC4857442  PMID: 27146803
Pessimism; Total hip arthroplasty; THA; Outcomes; Psychological risk factor; Pessimistic style
23.  Hospital Volume Predicts Outcomes and Complications after Total Shoulder Arthroplasty in the United States 
Arthritis care & research  2015;67(6):885-890.
Objective
To assess the association of hospital procedure volume for total shoulder arthroplasty (TSA) with patient outcomes and complications.
Methods
We used the U.S. Nationwide Inpatient Sample (NIS) from 1998–2011 to study the association of hospital annual TSA procedure volume with patient characteristics and TSA outcomes, including discharge disposition (home vs. inpatient facility), length of index hospitalization, post-arthroplasty periprosthetic fracture and revision. Annual hospital TSA volume was categorized as <5, 5–9, 10–14, 15–24 and ≥25 TSA procedures annually.
Results
Patients receiving TSA at higher volume hospitals were more likely to be female (p<0.0001) and White (p<0.0001). Compared to low volume hospitals (<5, 5–9, 10–14 procedures annually), patients receiving TSA at higher volume hospitals (15–24, ≥25) had significantly lower likelihood of: (1) being discharged to an inpatient medical facility, 16.5%, 13.4%, 13.0%, 12.7% and 11.5% (p<0.0001); (2) hospital stay >median, 46.6%, 40.4%, 36.6%, 34.4% and 29.2% (p<0.0001); (3) post-arthroplasty fracture, 1.2%, 0.8%, 0.9%, 0.6% and 0.8% (p=0.0004); (4) blood transfusion, 8%, 7.1%, 6.7%, 7.1% and 5.5% (p=0.006); and (5) TSA revision, 0.5%, 0.3%, 0.2%, 0.3%, 0.3% (p=0.045), respectively.
Conclusions
In this study, we found that higher annual hospital TSA volume was associated with better TSA outcomes in the U.S. These findings document the impact of annual hospital TSA volume on TSA outcomes. Patients, surgeons and policy-makers should be aware of these findings and take them into account in decision-making, policy decisions and resource allocation.
doi:10.1002/acr.22507
PMCID: PMC4418937  PMID: 25370499
hospital volume; total shoulder arthroplasty; TSA; utilization; outcomes; mortality; hospital stay; discharge; fracture; blood transfusion; revision
24.  Sex Differences in Characteristics, Utilization and Outcomes of patient undergoing Total Elbow Arthroplasty: A Study of the U.S. Nationwide Inpatient Sample 
Clinical rheumatology  2014;35(3):723-731.
Objective
To compare patient characteristics, utilization rates and outcomes after total elbow arthroplasty (TEA) by sex.
Methods
We used the Nationwide Inpatient Sample from 1998-2011 to study sex-related time-trends in patient characteristics, comorbidity and outcomes after TEA. We used chi-square test, analysis of variance and the Cochran-Armitage test to assess differences in utilization rates and characteristics over time by sex and logistic regression to compare mortality, discharge disposition and the length of hospital stay by sex.
Results
Overall TEA utilization increased significantly from 0.45 in 1998 to 0.96 per 100,000 in 2011 (p<0.0001). The utilization rates were significantly higher in females compared to males throughout the study period: 0.62 vs. 0.29 in 1998 (p<0.0001) and 1.31 vs. 0.70 in 2011 (p<0.0001). Compared to males, females undergoing TEA were more likely to be White (79.7% vs. 71.4%; p<0.0001), have rheumatoid arthritis (16.7% vs. 8.1%; p<0.0001) and have Deyo-Charlson index of 2 or more (11.3% vs. 5.9%; p<0.0001) and were older (63.5 vs. 51.4 years; p<0.0001). Compared to males undergoing TEA, females had significantly lower mortality, 0.1% vs. 0.4% (p=0.03); lower proportion were discharged to home, 81.9% vs. 89.6% (p<0.0001) and fewer had index hospital stay above the median, 30.0% vs. 33.0% (p=0.01); most differences were significant after multivariable adjustment.
Conclusions
TEA utilization in the U.S. more than doubled in the last 14 years, with rates higher in females than males. Females had better outcomes after TEA than men. Preoperative risk communication should be sex-specific based on these data.
doi:10.1007/s10067-014-2778-9
PMCID: PMC4400189  PMID: 25316506
Sex; total elbow arthroplasty; TEA; utilization; outcomes; mortality; hospital stay; discharge
25.  Gout-related inpatient utilization: a study of predictors of outcomes and time trends 
Background
To assess inpatient healthcare burden of gout in the USA after an Emergency Department (ED) visit and the predictors of gout-related hospitalizations.
Method
We used the 2009, 2010 and 2012 US National ED Sample (NEDS) data to examine the time trends in inpatient visits with gout as the primary diagnosis. We used the 2012 NEDS data to assess multivariable-adjusted predictors of length of hospital stay, discharge to home (versus other) and total charges for gout-related inpatient visits.
Results
Of the 205,152 ED visits for gout as the primary diagnosis in 2012, 7.7 % resulted in hospitalization. In 2009, 2010 and 2012, 63 %, 63 % and 64.5 % of hospitalized patients were discharged home; respective durations of hospital stay were 4.15, 4.00 and 3.86 days. Older age 50 to <65 years (ref <50), renal failure, heart failure, osteoarthritis and diabetes were associated with a longer hospital stay and self-pay/uninsured status, hospital location in the Midwest or Western USA with a shorter hospital stay for gout. Similar factors were associated with total charges for gout-related admissions. Older age (65 to <80 and ≥80, relative to <50 years), diabetes, self-pay/no charge insurance status, metropolitan area residence, and a longer length of hospital stay were associated with lower odds of discharge to home; and self-pay/no charge (uninsured) status was associated with higher odds of discharge to home, compared to Medicare coverage.
Conclusions
Using a national sample, we noted declining duration of hospital stay and identified factors associated with the length of hospital stay, discharge to home and charges for gout hospitalization following an ED visit. Future studies should examine whether better management of comorbidities in patients with gout can further reduce utilization and cost of gout-related hospitalizations.
doi:10.1186/s13075-016-0936-y
PMCID: PMC4774040  PMID: 26935737
Gout; Inpatient utilization; Hospitalization; Comorbidity; Predictors; Length of stay; Hospital discharge; Resource utilization; Charges

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