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1.  Association between Drug Insurance Cost Sharing Strategies and Outcomes in Patients with Chronic Diseases: A Systematic Review 
PLoS ONE  2014;9(3):e89168.
Background
Prescription drugs are used in people with hypertension, diabetes, and cardiovascular disease to manage their illness. Patient cost sharing strategies such as copayments and deductibles are often employed to lower expenditures for prescription drug insurance plans, but the impact on health outcomes in these patients is unclear.
Objective
To determine the association between drug insurance and patient cost sharing strategies on medication adherence, clinical and economic outcomes in those with chronic diseases (defined herein as diabetes, hypertension, hypercholesterolemia, coronary artery disease, and cerebrovascular disease).
Methods
Studies were included if they examined various cost sharing strategies including copayments, coinsurance, fixed copayments, deductibles and maximum out-of-pocket expenditures. Value-based insurance design and reference based pricing studies were excluded. Two reviewers independently identified original intervention studies (randomized controlled trials, interrupted time series, and controlled before-after designs). MEDLINE, EMBASE, Cochrane Library, CINAHL, and relevant reference lists were searched until March 2013. Two reviewers independently assessed studies for inclusion, quality, and extracted data. Eleven studies, assessing the impact of seven policy changes, were included: 2 separate reports of one randomized controlled trial, 4 interrupted time series, and 5 controlled before-after studies.
Findings
Outcomes included medication adherence, clinical events (myocardial infarction, stroke, death), quality of life, healthcare utilization, or cost. The heterogeneity among the studies precluded meta-analysis. Few studies reported the impact of cost sharing strategies on mortality, clinical and economic outcomes. The association between patient copayments and medication adherence varied across studies, ranging from no difference to significantly lower adherence, depending on the amount of the copayment.
Conclusion
Lowering cost sharing in patients with chronic diseases may improve adherence, but the impact on clinical and economic outcomes is uncertain.
doi:10.1371/journal.pone.0089168
PMCID: PMC3965394  PMID: 24667163
2.  Benefits and harms of statin therapy for persons with chronic kidney disease: A systematic review and meta-analysis 
Annals of internal medicine  2012;157(4):263-275.
Background
Statins have uncertain benefits in chronic kidney disease (CKD) as individual trials may have insufficient power to determine whether treatment effects differ with severity of CKD.
Purpose
To summarize the benefits and harms of statin therapy for adults with CKD and examine whether effects of statins vary by kidney disease stage.
Data Sources
Cochrane and EMBASE databases (inception to February 2012).
Study Selection
Randomized trials comparing effects of statins with placebo, no treatment or another statin on mortality and cardiovascular outcomes.
Data Extraction
Two independent reviewers extracted data and assessed risk of bias.
Data Synthesis
Eighty trials (n=51,099) compared statin with placebo or no treatment. Treatment effects varied with stage of CKD. In persons not on dialysis, statins reduced all-cause (relative risk, 0·81, 95% confidence interval, 0·74-0·88) and cardiovascular (0·78, 0·68-0·89) mortality and cardiovascular events (0·76, 0·73-0·80) in moderate-high quality evidence. For persons on dialysis, statins had little or no effect on all-cause (0·96, 0·88-1·04) or cardiovascular (0.94, 0.82-1.07) mortality or cardiovascular events (0·95, 0·87-1·03) in moderate-high quality evidence. Effects of statins in kidney transplant recipients were uncertain. Statins had little or no effect on cancer, myalgia, liver function, or withdrawal from treatment, although adverse events were evaluated systematically in fewer than half of trials.
Limitations
Reliance on post hoc subgroup data for earlier stages of CKD and lack of data for primary and secondary prevention.
Conclusions
Statins lower mortality and cardiovascular events in persons with early stages of CKD, have little or no effect in persons on dialysis, and have uncertain effects in kidney transplant recipients.
doi:10.7326/0003-4819-157-4-201208210-00007
PMCID: PMC3955032  PMID: 22910937
3.  Age and the Association of Kidney Measures with Mortality and End-Stage Renal Disease 
Context
Chronic kidney disease (CKD) is prevalent in older individuals, but the risk implications of low estimated glomerular filtration rate (eGFR) and high albuminuria across the full age range are controversial.
Objective
To evaluate possible effect modification (interaction) of age on the association of estimated GFR and albuminuria with clinical risk examining both relative and absolute risk.
Design, Setting, Participants
We investigated 2,051,244 participants from 33 general population or high-risk (of vascular disease) cohorts and 13 CKD cohorts from Asia, Australesia, Europe, and North/South America conducted during 1972–2011 with mean follow-up time of 5.8 years (range 0–31 years).
Main Outcome Measures
Hazard ratios (HRs) of mortality and end-stage renal disease (ESRD) according to eGFR and albuminuria were meta-analyzed across age categories after adjusting for sex, race, cardiovascular disease, diabetes, systolic blood pressure, cholestserol, body mass index, and smoking. Absolute risks were estimated using HRs and average incidence rates.
Results
Mortality (112,325 deaths) and ESRD (8,411 events) risk were higher at lower eGFR and higher albuminuria in every age category. In general/high-risk cohorts, relative mortality risk for reduced eGFR decreased with increasing age: e.g., adjusted HRs (95% CI) at eGFR 45 vs. 80 ml/min/1.73m2 were 3.50 (2.55–4.81), 2.21 (2.02–2.41), 1.59 (1.42–1.77), and 1.35 (1.23–1.48) in age categories 18–54, 55–64, 65–74 and 75+ years, respectively (P-values for age interaction <0.05). Absolute risk differences for the same comparisons were higher at older age (9.0 [95% CI, 6.0–12.8], 12.2 [10.3–14.3], 13.3 [9.0–18.6], and 27.2 [13.5–45.5] excess deaths per 1,000 person-years, respectively). For increased albuminuria, reduction of relative risk with increasing age were less evident, while differences in absolute risk were higher in the older age categories (7.5 [95% CI, 4.3–11.9], 12.2 [7.9–17.6], 22.7 [15.3–31.6], and 34.3 [19.5–52.4] excess deaths per 1,000 person-years, respectively by age category, at ACR 300 mg/g compared to 10 mg/g). In CKD cohorts, adjusted relative hazards of mortality did not decrease with age. In all cohorts, ESRD relative risks and absolute risk differences at lower eGFR or higher albuminuria were comparable across age categories.
Conclusions
Both low eGFR and high albuminuria were independently associated with mortality and ESRD regardless of age across a wide range of populations. Mortality showed lower relative risk but higher absolute risks differences at older age.
doi:10.1001/jama.2012.16817
PMCID: PMC3936348  PMID: 23111824
4.  Diabetes Guidelines 
doi:10.1503/cmaj.113-2103
PMCID: PMC3576447  PMID: 23423276
5.  Association between First Nations ethnicity and progression to kidney failure by presence and severity of albuminuria 
Background:
Despite a low prevalence of chronic kidney disease (estimated glomerular filtration rate [GFR] < 60 mL/min per 1.73 m2), First Nations people have high rates of kidney failure requiring chronic dialysis or kidney transplantation. We sought to examine whether the presence and severity of albuminuria contributes to the progression of chronic kidney disease to kidney failure among First Nations people.
Methods:
We identified all adult residents of Alberta (age ≥ 18 yr) for whom an outpatient serum creatinine measurement was available from May 1, 2002, to Mar. 31, 2008. We determined albuminuria using urine dipsticks and categorized results as normal (i.e., no albuminuria), mild, heavy or unmeasured. Our primary outcome was progression to kidney failure (defined as the need for chronic dialysis or kidney transplantation, or a sustained doubling of serum creatinine levels). We calculated rates of progression to kidney failure by First Nations status, by estimated GFR and by albuminuria category. We determined the relative hazard of progression to kidney failure for First Nations compared with non–First Nations participants by level of albuminuria and estimated GFR.
Results:
Of the 1 816 824 participants we identified, 48 669 (2.7%) were First Nations. First Nations people were less likely to have normal albuminuria compared with non–First Nations people (38.7% v. 56.4%). Rates of progression to kidney failure were consistently 2- to 3-fold higher among First Nations people than among non–First Nations people, across all levels of albuminuria and estimated GFRs. Compared with non–First Nations people, First Nations people with an estimated GFR of 15.0–29.9 mL/min per 1.73 m2 had the highest risk of progression to kidney failure, with similar hazard ratios for those with normal and heavy albuminuria.
Interpretation:
Albuminuria confers a similar risk of progression to kidney failure for First Nations and non–First Nations people.
doi:10.1503/cmaj.130776
PMCID: PMC3903763  PMID: 24295865
7.  Comparison of risk prediction using the CKD-EPI equation and the MDRD Study equation for estimated glomerular filtration rate 
JAMA : the journal of the American Medical Association  2012;307(18):10.1001/jama.2012.3954.
Context
The CKD-EPI equation more accurately estimates glomerular filtration rate (eGFR) than the MDRD Study equation using the same variables, especially at higher GFR, but definitive evidence of its risk implications in diverse settings is lacking.
Objective
To evaluate risk implications of eGFRCKD-EPI compared to eGFRMDRD in populations with a broad range of demographic and clinical characteristics.
Design, Setting, and Participants
Meta-analyses based on data from 1,130,472 adults (aged 18 years or older) from 25 general population, 7 high-risk (of vascular disease), and 13 chronic kidney disease (CKD) cohorts. Data transfer and analyses were conducted between March 2011 and March 2012.
Main Outcome Measures
All-cause mortality (84,482 deaths from 40 cohorts), cardiovascular mortality (22,176 events from 28 cohorts), and end-stage renal disease (ESRD) (7,644 events from 21 cohorts) during 9.4 million person-years of follow-up (median of mean follow-up time across cohorts was 7.4 years).
Results
eGFR was classified into six categories (≥90, 60-89, 45-59, 30-44, 15-29, and <15 ml/min/1.73m2) by both equations. Compared to eGFRMDRD, 24.4% and 0.6% of participants from general population cohorts were reclassified to a higher and lower eGFR category by the CKD-EPI equation, respectively, and the prevalence of CKD stage 3-5 (eGFR <60 ml/min/1.73m2) was reduced from 8.7% to 6.3%. 34.7% of participants with eGFRMDRD 45-59 were reclassified to eGFRCKD-EPI 60-89 and had lower incidence rates (per 1,000 person-years) of outcomes compared to those not reclassified (9.9 vs. 34.5 for all-cause mortality, 2.7 vs. 13.0 for cardiovascular mortality, and 0.5 vs. 0.8 for ESRD). The corresponding adjusted hazard ratios were 0.80 (95% confidence interval, 0.74 to 0.86) for all-cause mortality, 0.73 (0.65 to 0.82) for cardiovascular mortality, and 0.49 (0.27 to 0.88) for ESRD. Similar findings were observed in other eGFRMDRD categories. Net reclassification improvement (NRI) based on eGFR categories was significantly positive for all outcomes (range from 0.06 to 0.13, all P<0.001). NRI was similarly positive in most subgroups defined by age (< and ≥65 years), sex, race/ethnicity (white, Asian, and black), and presence or absence of diabetes and hypertension. The results in high-risk and CKD cohorts were largely consistent with the general population cohorts.
Conclusions
The CKD-EPI equation classified fewer individuals as CKD and more accurately categorized the risk for mortality and ESRD than did the MDRD Study equation across a broad range of populations.
doi:10.1001/jama.2012.3954
PMCID: PMC3837430  PMID: 22570462
8.  Patterns of engagement with the health care system and risk of subsequent hospitalization amongst patients with diabetes 
Background
Re-hospitalization is common among patients with diabetes, and may be related to aspects of health care use. We sought to determine the association between patterns of health care engagement and risk of subsequent hospitalization within one year of discharge for patients with diabetes.
Methods
We identified adults with incident diabetes in Alberta, Canada, who had at least one hospitalization following their diabetes diagnosis between January 1, 2004 and March 31, 2011. We used Cox regression to estimate the association between factors related to health care engagement (prior emergency department use, primary care visits, and discharge disposition (i.e. whether the patient left against medical advice)) and the risk of subsequent all-cause hospitalization within one year.
Results
Of the 33811 adults with diabetes and at least one hospitalization, 11095 (32.8%) experienced a subsequent all-cause hospitalization within a mean (standard deviation) follow-up time of 0.68 (0.3) years. Compared to patients with no emergency department visits, there was a 4 percent increased risk of a subsequent hospitalization for every emergency department visit occurring prior to the index hospitalization (adjusted Hazard Ratio [HR]: 1.04; 95% CI: 1.03–1.05). Limited and increased use of primary care was also associated with increased risk of a subsequent hospitalization. Compared to patients with 1–4 visits, patients with no visits to a primary care physician (adjusted HR: 1.11; 95% CI: 0.99–1.25) and those with 5–9 visits (adjusted HR: 1.06; 95% CI: 1.00–1.12) were more likely to experience a subsequent hospitalization. Finally, compared to patients discharged home, those leaving against medical advice were more likely to have a subsequent hospitalization (adjusted HR: 1.74; 95% CI: 1.50–2.02) and almost 3 times more likely to have a diabetes-specific subsequent event (adjusted HR: 2.86; 95% CI: 1.82–4.49).
Conclusions
Patterns of health care use and the circumstances surrounding hospital discharge are associated with an increased risk of subsequent hospitalization among patients with diabetes. Whether these patterns are related to the health care systems ability to manage complex patients within a primary care setting, or to access to primary care services, remains to be determined.
doi:10.1186/1472-6963-13-399
PMCID: PMC3851786  PMID: 24103159
Diabetes; Administrative data; Hospitalization
9.  Associations of kidney disease measures with mortality and end-stage renal disease in individuals with and without diabetes: a meta-analysis 
Lancet  2012;380(9854):1662-1673.
Background
Chronic kidney disease is characterised by low estimated glomerular filtration rate (eGFR) and high albuminuria, and is associated with adverse outcomes. Whether these risks are modified by diabetes is unknown.
Methods
We did a meta-analysis of studies selected according to Chronic Kidney Disease Prognosis Consortium criteria. Data transfer and analyses were done between March, 2011, and June, 2012. We used Cox proportional hazards models to estimate the hazard ratios (HR) of mortality and end-stage renal disease (ESRD) associated with eGFR and albuminuria in individuals with and without diabetes.
Findings
We analysed data for 1 024 977 participants (128 505 with diabetes) from 30 general population and high-risk cardiovascular cohorts and 13 chronic kidney disease cohorts. In the combined general population and high-risk cohorts with data for all-cause mortality, 75 306 deaths occurred during a mean follow-up of 8·5 years (SD 5·0). In the 23 studies with data for cardiovascular mortality, 21 237 deaths occurred from cardiovascular disease during a mean follow-up of 9·2 years (SD 4·9). In the general and high-risk cohorts, mortality risks were 1·2–1·9 times higher for participants with diabetes than for those without diabetes across the ranges of eGFR and albumin-to-creatinine ratio (ACR). With fixed eGFR and ACR reference points in the diabetes and no diabetes groups, HR of mortality outcomes according to lower eGFR and higher ACR were much the same in participants with and without diabetes (eg, for all-cause mortality at eGFR 45 mL/min per 1·73 m2 [νs 95 mL/min per 1·73 m2], HR 1·35; 95% CI 1·18–1·55; νs 1·33; 1·19–1·48 and at ACR 30 mg/g [νs 5 mg/g], 1·50; 1·35–1·65 νs 1·52; 1·38–1·67). The overall interactions were not significant. We identified much the same findings for ESRD in the chronic kidney disease cohorts.
Interpretation
Despite higher risks for mortality and ESRD in diabetes, the relative risks of these outcomes by eGFR and ACR are much the same irrespective of the presence or absence of diabetes, emphasising the importance of kidney disease as a predictor of clinical outcomes.
doi:10.1016/S0140-6736(12)61350-6
PMCID: PMC3771350  PMID: 23013602
10.  Comparison of Concurrent Complications of CKD by 2 Risk Categorization Systems 
Background
Using both estimated glomerular filtration rate (eGFR) and proteinuria to classify the severity of chronic kidney disease (CKD) has been proposed. The utility of a staging system incorporating both eGFR and proteinuria for guiding evaluation of concurrent CKD complications is not known.
Study design
Cross-sectional analysis
Setting & participants
30,528 participants in the US National Health and Nutrition Examination Survey conducted in 1988–1994 and 1999–2006 (n=8,242 for hyperparathyroidism).
Predictors
Classification system that uses both eGFR and proteinuria (alternative) and a system that primarily uses eGFR (NKF-KDOQI; the National Kidney Foundation's Kidney Disease Outcomes Quality Initiative)
Outcomes
Prevalence of anemia, acidosis, hyperphosphatemia, hypoalbuminemia, hyperparathyroidism and hypertension
Measurements
GFR estimated from the CKD-Epidemiology Collaboration (CKD-EPI) equation and proteinuria assessed using urine albumin-creatinine ratio (ACR)
Results
The prevalence of hypoalbuminemia, hypertension and hyperparathyroidism increased with more severe CKD using the NKF-KDOQI system. For example, the prevalence of hyperparathyroidism was 9.1%, 11.1%, 28.2% and 72.5% for Stages 1, 2, 3 and 4, respectively. Similarly the prevalence of anemia, acidosis and hyperphosphatemia increased progressively from Stage 2 through 4. With the alternative system, the prevalence of anemia, hyperphosphatemia, hypertension and hyperparathyroidism was lower in Stage 3 compared to Stage 2. For example, the prevalence of hyperparathyroidism was 13.5%, 40.3%, 22.2%, and 63.4% for stages 1, 2, 3 and 4, respectively. Applying the alternative system, participants without each complication were more likely to be appropriately reclassified to lower stages (for example, overall net reclassification index of −6.5% for hyperparathyroidism). However, participants with complications (except for hypoalbuminemia) were more likely to be inappropriately reclassified to lower stages.
Limitations
Use of single creatinine to estimate GFR and single measure to assess ACR. Small number of participants with CKD Stage 4.
Conclusions
The NKF-KDOQI system may better identify patients with certain concurrent CKD complications compared to systems using eGFR and proteinuria.
doi:10.1053/j.ajkd.2011.09.021
PMCID: PMC3288542  PMID: 22113126
11.  Association between perceived unmet health care needs and risk of adverse health outcomes among patients with chronic medical conditions 
Open Medicine  2013;7(1):e21-e30.
Background
Adults with chronic medical conditions are more likely to report unmet health care needs. Whether unmet health care needs are associated with an increased risk of adverse health outcomes is unclear.
Methods
Adults with at least one self-reported chronic condition (arthritis, chronic obstructive pulmonary disease, diabetes mellitus, heart disease, hypertension, mood disorder, stroke) from the 2001 and 2003 cycles of the Canadian Community Health Survey were linked to national hospitalization data. Participants were followed from the date of their survey until March 31, 2005, for the primary outcomes of all-cause and cause-specific admission to hospital. Secondary outcomes included length of stay, 30-day and 1-year all-cause readmission to hospital, and in-hospital death. Negative binomial regression models were used to estimate the association between unmet health care needs, admission to hospital, and length of stay, with adjustment for socio-demographic variables, health behaviours, and health status. Logistic regression was used to estimate the association between unmet needs, readmission, and in-hospital death. Further analyses were conducted by type of unmet need.
Results
Of the 51 932 adults with self-reported chronic disease, 15.5% reported an unmet health care need. Participants with unmet health care needs had a risk of all-cause admission to hospital similar to that of patients with no unmet needs (adjusted rate ratio [RR] 1.04, 95% confidence interval [CI] 0.94–1.15). When stratified by type of need, participants who reported issues of limited resource availability had a slightly higher risk of hospital admission (RR 1.18, 95% CI 1.09–1.28). There was no association between unmet needs and length of stay, readmission, or in-hospital death.
Interpretation
Overall, unmet health care needs were not associated with an increased risk of admission to hospital among those with chronic conditions. However, certain types of unmet needs may be associated with higher or lower risk. Whether unmet needs are associated with other measures of resource use remains to be determined.
PMCID: PMC3654502  PMID: 23687534
12.  Association of enrolment in primary care networks with diabetes care and outcomes among First Nations and low-income Albertans 
Open Medicine  2012;6(4):e155-e165.
Background
The prevalence of diabetes mellitus and its complications is higher among First Nations people and people with low socio-economic status (SES). Previous studies in Alberta have shown that provision of care through Primary Care Networks (PCNs) is associated with better quality of care and better outcomes for people with diabetes, possibly because of greater utilization of chronic disease management programs. However, it is unknown whether First Nations individuals and those in lower SES groups experience these benefits.
Methods
We used administrative and laboratory data for a population-based cohort analysis of Alberta residents under 65 years of age with diabetes. The primary outcome, assessed over a 1-year period, was admission to hospital or emergency department visit for a diabetes-specific ambulatory care sensitive condition (ACSC). Secondary outcomes were 2 quality-of-care indicators (likelihood of measurement of glycated hemoglobin [HbA1c] and or retinal screening) and 2 measures of health care utilization (visits to specialist and primary care physicians). We used negative binomial regression to determine the association between care within a PCN and hospital admission or emergency department visit for diabetes-specific ACSCs. We also assessed outcomes in 3 populations of interest (individuals receiving a health care subsidy [household income less than $39 250 and not eligible for Income Support], those receiving Income Support, and First Nations individuals) relative to the remainder of the population, controlling for whether care was provided in a PCN and adjusting for several baseline characteristics.
Results
We identified a total of 106 653 patients with diabetes eligible for our study, of whom 43 327 (41%) received care in a PCN. Receiving care through a PCN was associated with lower rates of ACSC-related hospital admission or emergency department visits for all groups of interest, which suggests that PCNs had similar effects across each group. However, regardless of where care was provided, First Nations and low-SES patients had more than twice the adjusted rates of hospital admission or emergency department visits for diabetes-specific ACSCs than the general population and were less likely to receive guideline-recommended care, including measurement of HbA1c and retinal screening.
Interpretation
Care in a PCN was associated with lower risks of hospital admission or emergency department visits for diabetes-specific ACSCs, even within vulnerable groups such as First Nations people and those of low SES. However, differences in outcomes and quality-of-care indicators persisted for First Nations individuals and those of low SES, relative to the general population, irrespective of where care was provided.
PMCID: PMC3654512  PMID: 23687531
14.  Incidence and causes of end-stage renal disease among Aboriginal children and young adults 
Background:
Although Aboriginal adults have a higher risk of end-stage renal disease than non-Aboriginal adults, the incidence and causes of end-stage renal disease among Aboriginal children and young adults are not well described.
Methods:
We calculated age- and sex-specific incidences of end-stage renal disease among Aboriginal people less than 22 years of age using data from a national organ failure registry. Incidence rate ratios were used to compare rates between Aboriginal and white Canadians. To contrast causes of end-stage renal disease by ethnicity and age, we calculated the odds of congenital diseases, glomerulonephritis and diabetes for Aboriginal people and compared them with those for white people in the following age strata: 0 to less than 22 years, 22 to less than 40 years, 40 to less than 60 years and older than 60 years.
Results:
Incidence rate ratios of end-stage renal disease for Aboriginal children and young adults (age < 22 yr, v. white people) were 1.82 (95% confidence interval [CI] 1.40–2.38) for boys and 3.24 (95% CI 2.60–4.05) for girls. Compared with white people, congenital diseases were less common among Aboriginal people aged less than 22 years (odds ratio [OR] 0.56, 95% CI 0.36–0.86), and glomerulonephritis was more common (OR 2.18, 95% CI 1.55–3.07). An excess of glomerulonephritis, but not diabetes, was seen among Aboriginal people aged 22 to less than 40 years. The converse was true (higher risk of diabetes, lower risk of glomerulonephritis) among Aboriginal people aged 40 years and older.
Interpretation:
The incidence of end-stage renal disease is higher among Aboriginal children and young adults than among white children and young adults. This higher incidence may be driven by an increased risk of glomerulonephritis in this population.
doi:10.1503/cmaj.120427
PMCID: PMC3470642  PMID: 22927509
15.  Bariatric Surgery: A Systematic Review of the Clinical and Economic Evidence 
Journal of General Internal Medicine  2011;26(10):1183-1194.
CONTEXT
Use of bariatric surgery for severe obesity has increased dramatically.
OBJECTIVE
To systematically review 1. the clinical efficacy and safety, 2. cost-effectiveness of bariatric surgery, and 3. the association between number of surgeries performed (surgical volume) and outcomes.
DATA SOURCES
MEDLINE (from 1950), EMBASE (from 1980), CENTRAL, EconLit, EURON EED, Harvard Center for Risk Analysis, trial registries and HTA websites were searched to January 2011.
STUDY SELECTION
1. Randomized controlled trials (RCTs) and 2. cost-utility and cost-minimisation studies comparing a contemporary bariatric surgery (i.e., adjustable gastric banding, Roux-en-Y gastric bypass, sleeve gastrectomy) to another contemporary surgical comparator or a non-surgical treatment or 3. Any study reporting the association between surgical volume and outcome.
DATA EXTRACTION
Outcomes included changes in weight and obesity-related comorbidity, quality of life and mortality, surgical complications, resource utilization, and incremental cost-utility.
RESULTS
RCT data evaluating mortality and obesity-related comorbidity endpoints were lacking. A small RCT of 16 patients reported that adjustable gastric banding reduced weight by 27% (p < 0.01) compared to diet-treated controls over 40 weeks. Six small RCTs reported comparisons of commonly used, contemporary procedures. Gastric banding reduced weight to a lower extent than gastric bypass and sleeve gastrectomy and resulted in shorter operating times, fewer serious complications, lower weight loss efficacy, and more frequent reoperations compared to gastric bypass. Sleeve gastrectomy and gastric bypass reduced weight to a similar extent. A 2-year RCT in 50 adolescents reported that gastric banding substantially reduced weight compared to lifestyle modification (35 kg vs. 3 kg; p <0.001). Based on findings of 14 observational studies, higher volume centers and surgeons had lower mortality and complication rates. Surgery resulted in long-term incremental cost–utility ratios of $ <1.000–$40,000 (2009 USD) per quality-adjusted-life-year compared with non-surgical treatment.
CONCLUSIONS
Contemporary bariatric surgery appears to result in sustained weight reduction with acceptable costs but rigorous, longer-term (≥5 year) data are needed and a paucity of RCT data on mortality and obesity related comorbidity is evident. Procedure-specific variations in efficacy and risks exist and require further study to clarify the specific indications for and advantages of different procedures.
doi:10.1007/s11606-011-1721-x
PMCID: PMC3181300  PMID: 21538168
randomized controlled trials; clincical evidence; economic evidence; systematic review
16.  Evaluating the impact of a novel restricted reimbursement policy for quinolone antibiotics: A time series analysis 
Background
Publicly-funded drug plans often use prior authorization policies to limit drug prescribing. To guide physician prescribing of a class of antibiotics with broad antimicrobial activity (quinolone antibiotics) in accordance with new prescribing guidelines, Alberta’s provincial health ministry implemented a new mechanism for formulary restriction entitled the optional special authorization (OSA) program. We conducted an observational study to determine the impact of this new formulary restriction policy on antimicrobial prescription rates as well as any clinical consequences.
Methods
Quinolone antibiotic use, and adherence with quinolone prescribing guidelines, was assessed before and after implementation of the OSA program in patients with common outpatient infections using an administrative data cohort and a chart review cohort, respectively. At the same time this policy was implemented to limit quinolone prescribing, two new quinolone antibiotics were added to the formulary. Using administrative data, we analysed a total of 397,534 unique index visits with regard to overall antibiotic utilization, and through chart review, we analysed 1681 charts of patients with infections of interest to determine the indications for quinolone usage.
Results
Using segmented regression models adjusting for age, sex and physician enrollment in the OSA program, there was no statistically significant change in the monthly rate of all quinolone use (−3.5 (95% CI −5.5, 1.4) prescriptions per 1000 index visits) following implementation of the OSA program (p = 0.74). There was a significant level change in the rate of quinolone antibiotic use for urinary tract infection (−33.6 (95% CI: -23.8, -43.4) prescriptions and upper respiratory tract infection (−16.1 (95%CI: -11.6, -20.6) prescriptions per 1000 index visits. Among quinolone prescriptions identified on chart review, 42.5% and 58.5% were consistent with formulary guidelines before and after the implementation of the OSA program, respectively (p = 0.002). There was no change in hospitalization, mortality or use of physician services after implementation of the OSA program.
Conclusions
Despite the addition of two new quinolone antibiotics to the formulary, we found that there was no change in the use of quinolones after implementation of a new formulary restriction policy for outpatients with common outpatient infections.
doi:10.1186/1472-6963-12-290
PMCID: PMC3470979  PMID: 22935100
Formulary restriction; Antibiotic; Prior authorization; Prescription drugs
17.  Association between chronic conditions and perceived unmet health care needs 
Open Medicine  2012;6(2):e48-e58.
Background
Although effective treatments exist, many Canadians with chronic medical conditions do not receive the full care they require, possibly as a consequence of limited accessibility or availability. A commonly used indicator of inadequate access to or availability of care is the perception of unmet health care needs. The objective of this study was therefore to determine the association between chronic conditions and perceived unmet health care needs.
Methods
We extracted data for adult respondents from the combined 2001, 2003 and 2005 cross-sectional cycles of the Canadian Community Health Survey. Multivariate logistic regression was used to estimate the association between 7 high-prevalence and high-impact chronic conditions (arthritis, chronic obstructive pulmonary disease/emphysema, diabetes, heart disease, hypertension, mood disorder and stroke) and perceived unmet health care needs in the prior 12 months, adjusting for sociodemographic variables, health behaviours, health status and survey cycle.
Results
Of the 360 105 adult respondents, 12.2% reported an unmet health care need. Compared with those without chronic conditions, respondents with at least one condition were more likely to report an unmet need (adjusted odds ratio [OR] 1.51, 95% confidence interval [CI] 1.45–1.59). Those with mood disorders were almost twice as likely to report an unmet need (OR 1.94, 95% CI 1.78–2.12), while those with diabetes or hypertension were less likely to report an unmet need (diabetes OR 0.85, 95% CI 0.76–0.94; hypertension OR 0.96, 95% CI 0.89–1.04). Furthermore, the likelihood of an unmet need increased with the number of chronic conditions (OR 1.71, 95% CI 1.56–1.88 for 3 or more conditions). Respondents with chronic conditions were more likely than those without to report an unmet need related to resource availability (OR 1.14, 95% CI 1.06–1.22).
Interpretation
Adults with chronic medical conditions are more likely to report an unmet health care need, and the likelihood increases with an increasing number of conditions. Whether these unmet needs are associated with worse outcomes, and whether interventions targeted to address these needs may improve outcomes for Canadians with chronic disease, remain to be determined.
PMCID: PMC3659214  PMID: 23696769
19.  Enrolment in primary care networks: impact on outcomes and processes of care for patients with diabetes 
Background:
Primary care networks are a newer model of primary care that focuses on improved access to care and the use of multidisciplinary teams for patients with chronic disease. We sought to determine the association between enrolment in primary care networks and the care and outcomes of patients with diabetes.
Methods:
We used administrative health care data to study the care and outcomes of patients with incident and prevalent diabetes separately. For patients with prevalent diabetes, we compared those whose care was managed by physicians who were or were not in a primary care network using propensity score matching. For patients with incident diabetes, we studied a cohort before and after primary care networks were established. Each cohort was further divided based on whether or not patients were cared for by physicians enrolled in a network. Our primary outcome was admissions to hospital or visits to emergency departments for ambulatory care sensitive conditions specific to diabetes.
Results:
Compared with patients whose prevalent diabetes is managed outside of primary care networks, patients in primary care networks had a lower rate of diabetes-specific ambulatory care sensitive conditions (adjusted incidence rate ratio 0.81, 95% confidence interval [CI] 0.75 to 0.87), were more likely to see an ophthalmologist or optometrist (risk ratio 1.19, 95% CI 1.17 to 1.21) and had better glycemic control (adjusted mean difference −0.067, 95% CI −0.081 to −0.052).
Interpretation:
Patients whose diabetes was managed in primary care networks received better care and had better clinical outcomes than patients whose condition was not managed in a network, although the differences were very small.
doi:10.1503/cmaj.110755
PMCID: PMC3273535  PMID: 22143232
22.  A systematic review on the effect of sweeteners on glycemic response and clinically relevant outcomes 
BMC Medicine  2011;9:123.
Background
The major metabolic complications of obesity and type 2 diabetes may be prevented and managed with dietary modification. The use of sweeteners that provide little or no calories may help to achieve this objective.
Methods
We did a systematic review and network meta-analysis of the comparative effectiveness of sweetener additives using Bayesian techniques. MEDLINE, EMBASE, CENTRAL and CAB Global were searched to January 2011. Randomized trials comparing sweeteners in obese, diabetic, and healthy populations were selected. Outcomes of interest included weight change, energy intake, lipids, glycated hemoglobin, markers of insulin resistance and glycemic response. Evidence-based items potentially indicating risk of bias were assessed.
Results
Of 3,666 citations, we identified 53 eligible randomized controlled trials with 1,126 participants. In diabetic participants, fructose reduced 2-hour blood glucose concentrations by 4.81 mmol/L (95% CI 3.29, 6.34) compared to glucose. Two-hour blood glucose concentration data comparing hypocaloric sweeteners to sucrose or high fructose corn syrup were inconclusive. Based on two ≤10-week trials, we found that non-caloric sweeteners reduced energy intake compared to the sucrose groups by approximately 250-500 kcal/day (95% CI 153, 806). One trial found that participants in the non-caloric sweetener group had a decrease in body mass index compared to an increase in body mass index in the sucrose group (-0.40 vs 0.50 kg/m2, and -1.00 vs 1.60 kg/m2, respectively). No randomized controlled trials showed that high fructose corn syrup or fructose increased levels of cholesterol relative to other sweeteners.
Conclusions
Considering the public health importance of obesity and its consequences; the clearly relevant role of diet in the pathogenesis and maintenance of obesity; and the billions of dollars spent on non-caloric sweeteners, little high-quality clinical research has been done. Studies are needed to determine the role of hypocaloric sweeteners in a wider population health strategy to prevent, reduce and manage obesity and its consequences.
doi:10.1186/1741-7015-9-123
PMCID: PMC3286380  PMID: 22093544
23.  Cost-effectiveness of the use of low- and high-potency statins in people at low cardiovascular risk 
Background:
Although statins have been shown to reduce the risk of cardiovascular events in patients at low cardiovascular risk, their absolute benefit is small in the short term, which may adversely affect cost-effectiveness. We sought to determine the long-term cost-effectiveness (beyond the duration of clinical trials) of low- and high-potency statins in patients at low cardiovascular risk and to estimate the impact on Canada’s publicly funded health care system.
Methods:
Using Markov modelling, we performed a cost-utility analysis in which we compared low-potency statins (fluvastatin, lovastatin, pravastatin and simvastatin) and high-potency statins (atorvastatin and rosuvastatin) with no statins in a simulated cohort of low-risk patients over a lifetime horizon. Model outcomes included costs (in 2010 Canadian dollars), quality-adjusted life-years (QALYs) gained and the cost per QALY gained.
Results:
Over a lifetime horizon, the cost of managing a patient at low cardiovascular risk was estimated to be about $10 100 without statins, $15 200 with low-potency statins and $16 400 with high-potency statins. The cost per QALY gained with high-potency statins (v. no statins) was $21 300; the use of low-potency statins was not considered economically attractive. These results were robust to sensitivity analyses, although their use became economically unattractive when the duration of benefit from statin use was assumed to be less than 10 years.
Interpretation:
Use of high-potency statins in patients at low cardiovascular risk was associated with a cost per QALY gained that was economically attractive by current standards, assuming that the benefit from statin use would continue for at least 10 years. However, the overall expenditure on statins would be substantial, and the ramifications of this practice should be carefully considered by policy-makers.
doi:10.1503/cmaj.101281
PMCID: PMC3216439  PMID: 21989469
24.  Efficacy of statins for primary prevention in people at low cardiovascular risk: a meta-analysis 
Background:
Statins were initially used to improve cardiovascular outcomes in people with established coronary artery disease, but recently their use has become more common in people at low cardiovascular risk. We did a systematic review of randomized trials to assess the efficacy and harms of statins in these individuals.
Methods:
We searched MEDLINE and EMBASE (to Jan. 28, 2011), registries of health technology assessments and clinical trials, and reference lists of relevant reviews. We included trials that randomly assigned participants at low cardiovascular risk to receive a statin versus a placebo or no statin. We defined low risk as an observed 10-year risk of less than 20% for cardiovascular-related death or nonfatal myocardial infarction, but we explored other definitions in sensitivity analyses.
Results:
We identified 29 eligible trials involving a total of 80 711 participants. All-cause mortality was significantly lower among patients receiving a statin than among controls (relative risk [RR] 0.90, 95% confidence interval [CI] 0.84–0.97) for trials with a 10-year risk of cardiovascular disease < 20% [primary analysis] and 0.83, 95% CI 0.73–0.94, for trials with 10-year risk < 10% [sensitivity analysis]). Patients in the statin group were also significantly less likely than controls to have nonfatal myocardial infarction (RR 0.64, 95% CI 0.49–0.84) and nonfatal stroke (RR 0.81, 95% CI 0.68–0.96). Neither metaregression nor stratified analyses suggested statistically significant differences in efficacy between high-and low-potency statins, or larger reductions in cholesterol.
Interpretation:
Statins were found to be efficacious in preventing death and cardiovascular morbidity in people at low cardiovascular risk. Reductions in relative risk were similar to those seen in patients with a history of coronary artery disease.
doi:10.1503/cmaj.101280
PMCID: PMC3216447  PMID: 21989464
25.  Dialysis and transplantation among Aboriginal children with kidney failure 
Background:
Relatively little is known about the management and outcomes of Aboriginal children with renal failure in Canada. We evaluated differences in dialysis modality, time spent on dialysis, rates of kidney transplantation, and patient and allograft survival between Aboriginal children and non-Aboriginal children.
Methods:
For this population-based cohort study, we used data from a national pediatric end-stage renal disease database. Patients less than 18 years old who started renal replacement treatment (dialysis or kidney transplantation) in nine Canadian provinces (Quebec data were not available) and all three territories between 1992 and 2007 were followed until death, loss to follow-up or end of the study period. We compared initial modality of dialysis and time to first kidney transplant between Aboriginal children, white children and children of other ethnicity. We examined the association between ethnicity and likelihood of kidney transplantation using adjusted Cox proportional hazard models for Aboriginal and white children (data for the children of other ethnicity did not meet the assumptions of proportional hazards).
Results:
Among 843 pediatric patients included in the study, 104 (12.3%) were Aboriginal, 521 (61.8%) were white, and 218 (25.9%) were from other ethnic minorities. Hemodialysis was the initial modality of dialysis for 48.0% of the Aboriginal patients, 42.7% of the white patients and 62.6% of those of other ethnicity (p < 0.001). The time from start of dialysis to first kidney transplant was longer among the Aboriginal children (median 1.75 years, interquartile range 0.69–2.81) than among the children in the other two groups (p < 0.001). After adjustment for confounders, Aboriginal children were less likely than white children to receive a transplant from a living donor (hazard ratio [HR] 0.36, 95% confidence interval [CI] 0.21–0.61) or a transplant from any donor (HR 0.54, 95% CI 0.40–0.74) during the study period.
Interpretation:
The time from start of dialysis to first kidney transplant was longer among Aboriginal children than among white children. Further evaluation is needed to determine barriers to transplantation among Aboriginal children.
doi:10.1503/cmaj.101840
PMCID: PMC3134757  PMID: 21609989

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