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1.  Body mass index is not a clinically meaningful predictor of patient reported outcomes of primary hip replacement surgery: prospective cohort study 
To describe whether body mass index (BMI) is a clinically meaningful predictor of patient reported outcomes following primary total hip replacement (THR) surgery
Combined data from prospective cohort studies. We obtained information from four cohorts of patients receiving primary THR for osteoarthritis: Exeter Primary Outcomes Study (n=1431); EUROHIP (n=1327); Elective Orthopaedic Centre (n=2832); and St. Helier (n=787). The exposure of interest was pre-operative BMI. Confounding variables included: age, sex, SF-36 mental health, comorbidities, fixed flexion, analgesic use, college education, OA in other joints, expectation of less pain, radiographic K&L grade, ASA grade, years of hip pain. The primary outcome was the Oxford Hip Score (OHS). Regression models describe the association of BMI on outcome adjusting for all confounders.
For a 5-unit increase in BMI, the attained 12-month OHS decreases by 0.78 points 95%CI (0.27 to 1.28), p-value 0.001. Compared to people of normal BMI (20 to 25), those in the obese class II (BMI 35 to 40) would have a 12-month OHS that is 2.34 points lower. Although statistically significant this effect is small and not clinically meaningful in contrast to the substantial change in OHS seen across all BMI groupings. In obese class II patients achieved a 22.2 point change in OHS following surgery.
Patients achieved substantial change in OHS after THR across all BMI categories, which greatly outweighs the small difference in attained post-operative score. The findings suggest BMI should not present a barrier to access THR in terms of PROMs.
PMCID: PMC4147658  PMID: 24418679
Epidemiology; Osteoarthritis; Hip replacement; Patient reported outcome; body mass index; decision making
3.  High bone mass is associated with an increased prevalence of joint replacement: a case–control study 
Rheumatology (Oxford, England)  2013;52(6):1042-1051.
Objective. Epidemiological studies have shown an association between OA and increased BMD. To explore the nature of this relationship, we examined whether the risk of OA is increased in individuals with high bone mass (HBM), in whom BMD is assumed to be elevated due to a primary genetic cause.
Methods. A total of 335 115 DXA scans were screened to identify HBM index cases (defined by DXA scan as an L1 Z-score of ≥+3.2 and total hip Z-score ≥+1.2, or total hip Z-score ≥+3.2 and L1 Z-score ≥+1.2). In relatives, the definition of HBM was L1 Z-score plus total hip Z-score ≥+3.2. Controls comprised unaffected relatives and spouses. Clinical indicators of OA were determined by structured assessment. Analyses used logistic regression adjusting for age, gender, BMI and social deprivation.
Results. A total of 353 HBM cases (mean age 61.7 years, 77% female) and 197 controls (mean age 54.1 years, 47% female) were included. Adjusted NSAID use was more prevalent in HBM cases versus controls [odds ratio (OR) 2.17 (95% CI 1.10, 4.28); P = 0.03]. The prevalence of joint replacement was higher in HBM cases (13.0%) than controls (4.1%), with an adjusted OR of 2.42 (95% CI 1.06, 5.56); P = 0.04. Adjusted prevalence of joint pain and knee crepitus did not differ between cases and controls.
Conclusion. HBM is associated with increased prevalence of joint replacement surgery and NSAID use compared with unaffected controls.
PMCID: PMC3651613  PMID: 23362220
osteoarthritis; high bone mass; bone mineral density; DXA; joint replacement
4.  Assessing function in patients undergoing joint replacement: a study protocol for a cohort study 
Joint replacement is an effective intervention for people with advanced arthritis, although there is an important minority of patients who do not improve post-operatively. There is a need for robust evidence on outcomes after surgery, but there are a number of measures that assess function after joint replacement, many of which lack any clear theoretical basis. The World Health Organisation has introduced the International Classification of Functioning, Disability and Health (ICF), which divides function into three separate domains: Impairment, activity limitations and participation restrictions. The aim of this study is to compare the properties and responsiveness of a selection of commonly used outcome tools that assess function, examine how well they relate to the ICF concepts, and to explore the changes in the measures over time.
Two hundred and sixty three patients listed for lower limb joint replacement at an elective orthopaedic centre have been recruited into this study. Participants attend the hospital for a research appointment prior to surgery and then at 3-months and 1-year after surgery. At each assessment time, function is assessed using a range of measures. Self-report function is assessed using the WOMAC, Aberdeen Impairment, Activity Limitation and Participation Restriction Measure, SF-12 and Measure Yourself Medical Outcome Profile 2. Clinician-administered measures of function include the American Knee Society Score for knee patients and the Harris Hip Score for hip patients. Performance tests include the timed 20-metre walk, timed get up and go, sit-to-stand-to-sit, step tests and single stance balance test. During the performance tests, participants wear an inertial sensor and data from motion analysis are collected. Statistical analysis will include exploring the relationship between measures describing the same ICF concepts, assessing responsiveness, and studying changes in measures over time.
There are a range of tools that can be used to assess function before and after joint replacement, with little information about how these various measures compare in their properties and responsiveness. This study aims to provide this data on a selection of commonly used assessments of function, and explore how they relate to the ICF domains.
PMCID: PMC3520823  PMID: 23148591
Joint replacement; Hip; Knee; Disability; Pain; Function; Outcome; Self-report; Performance tests; Motion analysis
5.  What proportion of patients report long-term pain after total hip or knee replacement for osteoarthritis? A systematic review of prospective studies in unselected patients 
BMJ Open  2012;2(1):e000435.
Total hip or knee replacement is highly successful when judged by prosthesis-related outcomes. However, some people experience long-term pain.
To review published studies in representative populations with total hip or knee replacement for the treatment of osteoarthritis reporting proportions of people by pain intensity.
Data sources
MEDLINE and EMBASE databases searched to January 2011 with no language restrictions. Citations of key articles in ISI Web of Science and reference lists were checked.
Study eligibility criteria, participants and interventions
Prospective studies of consecutive, unselected osteoarthritis patients representative of the primary total hip or knee replacement population, with intensities of patient-centred pain measured after 3 months to 5-year follow-up.
Study appraisal and synthesis methods
Two authors screened titles and abstracts. Data extracted by one author were checked independently against original articles by a second. For each study, the authors summarised the proportions of people with different severities of pain in the operated joint.
Searches identified 1308 articles of which 115 reported patient-centred pain outcomes. Fourteen articles describing 17 cohorts (6 with hip and 11 with knee replacement) presented appropriate data on pain intensity. The proportion of people with an unfavourable long-term pain outcome in studies ranged from about 7% to 23% after hip and 10% to 34% after knee replacement. In the best quality studies, an unfavourable pain outcome was reported in 9% or more of patients after hip and about 20% of patients after knee replacement.
Other studies reported mean values of pain outcomes. These and routine clinical studies are potential sources of relevant data.
Conclusions and implications of key findings
After hip and knee replacement, a significant proportion of people have painful joints. There is an urgent need to improve general awareness of this possibility and to address determinants of good and bad outcomes.
Article summary
Article focus
Total hip and knee replacement have good clinical outcomes.
There is a perception that some people experience long-term pain after their joint replacement.
We aim to establish the proportion of patients experiencing long-term pain after joint replacement.
Key messages
Well-conducted studies in representative populations of patients with total hip and knee joint replacement suggest that a significant proportion of people continue to have painful joints after surgery.
The proportion of people with an unfavourable long-term pain outcome in studies ranged from about 7% to 23% after hip and 10% to 34% after knee replacement. In the best quality studies, an unfavourable pain outcome was reported in 9% or more of patients after total hip and about 20% of patients after total knee replacement.
There is an urgent need to improve general awareness that some patients experience long-term pain after joint replacement and to address the determinants of good and bad outcomes.
Strengths and limitations of this study
Systematic review conducted according to established methods and guidelines identified 17 studies in representative populations of patients with total hip or knee replacement.
Pain outcome data are widely recorded as mean values but only a minority of studies reported outcomes as proportions with pain at follow-up.
The small number of studies and different pain outcome measures precluded meta-analysis, calculation of a summary estimate and exploration of sources of heterogeneity.
PMCID: PMC3289991  PMID: 22357571
7.  Exploring the relationships between International Classification of Functioning, Disability and Health (ICF) constructs of Impairment, Activity Limitation and Participation Restriction in people with osteoarthritis prior to joint replacement 
The International Classification of Functioning, Disability and Health (ICF) proposes three main constructs, impairment (I), activity limitation (A) and participation restriction (P). The ICF model allows for all paths between the constructs to be explored, with significant paths likely to vary for different conditions. The relationships between I, A and P have been explored in some conditions but not previously in people with osteoarthritis prior to joint replacement. The aim of this paper is to examine these relationships using separate measures of each construct and structural equation modelling.
A geographical cohort of 413 patients with osteoarthritis about to undergo hip and knee joint replacement completed the Aberdeen measures of Impairment, Activity Limitation and Participation Restriction (Ab-IAP). Confirmatory factor analysis was used to test the three factor (I, A, P) measurement model. Structural equation modelling was used to explore the I, A and P pathways in the ICF model.
There was support from confirmatory factor analysis for the three factor I, A, P measurement model. The structural equation model had good fit [S-B Chi-square = 439.45, df = 149, CFI robust = 0.91, RMSEA robust = 0.07] and indicated significant pathways between I and A (standardised coefficient = 0.76 p < 0.0001) and between A and P (standardised coefficient = 0.75 p < 0.0001). However, the path between I and P was not significant (standardised coefficient = 0.01).
The significant pathways suggest that treatments and interventions aimed at reducing impairment, such as joint replacement, may only affect P indirectly, through A, however, longitudinal data would be needed to establish this.
PMCID: PMC3123258  PMID: 21575238
8.  All cause and disease specific mortality in patients with knee or hip osteoarthritis: population based cohort study 
Objective To examine all cause and disease specific mortality in patients with osteoarthritis of the knee or hip.
Design Population based cohort study.
Setting General practices in the southwest of England.
Participants 1163 patients aged 35 years or over with symptoms and radiological confirmation of osteoarthritis of the knee or hip.
Main outcome measures Age and sex standardised mortality ratios and multivariable hazard ratios of death after a median of 14 years’ follow-up.
Results Patients with osteoarthritis had excess all cause mortality compared with the general population (standardised mortality ratio 1.55, 95% confidence interval 1.41 to 1.70). Excess mortality was observed for all disease specific causes of death but was particularly pronounced for cardiovascular (standardised mortality ratio 1.71, 1.49 to 1.98) and dementia associated mortality (1.99, 1.22 to 3.25). Mortality increased with increasing age (P for trend <0.001), male sex (adjusted hazard ratio 1.59, 1.30 to 1.96), self reported history of diabetes (1.95, 1.31 to 2.90), cancer (2.28, 1.50 to 3.47), cardiovascular disease (1.38, 1.12 to 1.71), and walking disability (1.48, 1.17 to 1.86). However, little evidence existed for increased mortality associated with previous joint replacement, obesity, depression, chronic inflammatory disease, eye disease, or presence of pain at baseline. The more severe the walking disability, the higher was the risk of death (P for trend <0.001).
Conclusion Patients with osteoarthritis are at higher risk of death compared with the general population. History of diabetes, cancer, or cardiovascular disease and the presence of walking disability are major risk factors. Management of patients with osteoarthritis and walking disability should focus on effective treatment of cardiovascular risk factors and comorbidities, as well as on increasing physical activity.
PMCID: PMC3050438  PMID: 21385807
9.  The effect of local anaesthetic wound infiltration on chronic pain after lower limb joint replacement: A protocol for a double-blind randomised controlled trial 
For the majority of patients with osteoarthritis (OA), joint replacement is a successful intervention for relieving chronic joint pain. However, between 10-30% of patients continue to experience chronic pain after joint replacement. Evidence suggests that a risk factor for chronic pain after joint replacement is the severity of acute post-operative pain. The aim of this randomised controlled trial (RCT) is to determine if intra-operative local anaesthethic wound infiltration additional to a standard anaethesia regimen can reduce the severity of joint pain at 12-months after total knee replacement (TKR) and total hip replacement (THR) for OA.
300 TKR patients and 300 THR patients are being recruited into this single-centre double-blind RCT. Participants are recruited before surgery and randomised to either the standard care group or the intervention group. Participants and outcome assessors are blind to treatment allocation throughout the study. The intervention consists of an intra-operative local anaesthetic wound infiltration, consisting of 60 mls of 0.25% bupivacaine with 1 in 200,000 adrenaline. Participants are assessed on the first 5 days post-operative, and then at 3-months, 6-months and 12-months. The primary outcome is the WOMAC Pain Scale, a validated measure of joint pain at 12-months. Secondary outcomes include pain severity during the in-patient stay, post-operative nausea and vomiting, satisfaction with pain relief, length of hospital stay, joint pain and disability, pain sensitivity, complications and cost-effectiveness. A nested qualitative study within the RCT will examine the acceptability and feasibility of the intervention for both patients and healthcare professionals.
Large-scale RCTs assessing the effectiveness of a surgical intervention are uncommon, particulary in orthopaedics. The results from this trial will inform evidence-based recommendations for both short-term and long-term pain management after lower limb joint replacement. If a local anaesthetic wound infiltration is found to be an effective and cost-effective intervention, implementation into clinical practice could improve long-term pain outcomes for patients undergoing lower limb joint replacement.
Trial registration
Current Controlled Trials ISRCTN96095682
PMCID: PMC3056874  PMID: 21352559
10.  Osteoarthritis of the knee in primary care 
BMJ : British Medical Journal  2007;336(7636):105-106.
Topical NSAIDS are as effective as oral NSAIDs, and patients prefer them
PMCID: PMC2206305  PMID: 18056741
11.  Unstated factors in orthopaedic decision-making: a qualitative study 
Total joint replacement (TJR) of the hip or knee for osteoarthritis is among the most common elective surgical procedures. There is some inequity in provision of TJR. How decisions are made about who will have surgery may contribute to disparities in provision. The model of shared decision-making between patients and clinicians is advocated as an ideal by national bodies and guidelines. However, we do not know what happens within orthopaedic practice and whether this reflects the shared model. Our study examined how decisions are made about TJR in orthopaedic consultations.
The study used a qualitative research design comprising semi-structured interviews and observations. Participants were recruited from three hospital sites and provided their time free of charge. Seven clinicians involved in decision-making about TJR were approached to take part in the study, and six agreed to do so. Seventy-seven patients due to see these clinicians about TJR were approached to take part and 26 agreed to do so. The patients' outpatient appointments ('consultations') were observed and audio-recorded. Subsequent interviews with patients and clinicians examined decisions that were made at the appointments. Data were analysed using thematic analysis.
Clinical and lifestyle factors were central components of the decision-making process. In addition, the roles that patients assigned to clinicians were key, as were communication styles. Patients saw clinicians as occupying expert roles and they deferred to clinicians' expertise. There was evidence that patients modified their behaviour within consultations to complement that of clinicians. Clinicians acknowledged the complexity of decision-making and provided descriptions of their own decision-making and communication styles. Patients and clinicians were aware of the use of clinical and lifestyle factors in decision-making and agreed in their description of clinicians' styles. Decisions were usually reached during consultations, but patients and clinicians sometimes said that treatment decisions had been made beforehand. Some patients expressed surprise about the decisions made in their consultations, but this did not necessarily imply dissatisfaction.
The way in which roles and communication are played out in decision-making for TJR may affect the opportunity for shared decisions. This may contribute to variation in the provision of TJR. Making the importance of these factors explicit and highlighting the existence of patients' 'surprise' about consultation outcomes could empower patients within the decision-making process and enhance communication in orthopaedic consultations.
PMCID: PMC2954986  PMID: 20849636
12.  Help-seeking behaviour among people living with chronic hip or knee pain in the community 
A large proportion of people living with hip or knee pain do not consult health care professionals. Pain severity is often believed to be the main reason for help seeking in this population; however the evidence for this is contradictory. This study explores the importance of several potential risk factors on help seeking across different practitioner groups, among adults living with chronic hip or knee pain in a large community sample.
Health care utilization, defined as having seen a family doctor (GP) during the past 12 months; or an allied health professional (AHP) or alternative therapist during the past 3 months, was assessed in a community based sample aged 35 or over and reporting pain in hip or knee. Adjusted odds ratios were determined for social deprivation, rurality, pain severity, mobility, anxiety/depression, co-morbidities, and body mass index.
Of 1119 persons reporting hip or knee pain, 52% had pain in both sites.
Twenty-five percent of them had seen a doctor only, 3% an AHP only, and 4% an alternative therapist only. Thirteen percent had seen more than one category of health care professionals, and 55% had not seen any health care professional. In the multivariate model, factors associated with consulting a GP were mobility problems (OR 2.62 (1.64-4.17)), urban living (OR 2.40 (1.14-5.04) and pain severity (1.28 (1.13-1.44)). There was also some evidence that obesity was associated with increased consultation (OR 1.72 (1.00-2.93)). Factors were similar for consultation with a combination of several health care professionals. In contrast, seeing an alternative therapist was negatively associated with pain severity, anxiety and mobility problems (adjusting for age and sex).
Disability appears to be a more important determinant of help-seeking than pain severity or anxiety and depression, for adults with chronic pain in hip or knee. The determinants of seeking help from alternative practitioners are different from determinants of consulting GPs, AHPs or a combination of different health care providers.
PMCID: PMC2793247  PMID: 19968876
13.  Measuring the ICF components of impairment, activity limitation and participation restriction: an item analysis using classical test theory and item response theory 
The International Classification of Functioning, Disability and Health (ICF) proposes three main health outcomes, Impairment (I), Activity Limitation (A) and Participation Restriction (P), but good measures of these constructs are needed The aim of this study was to use both Classical Test Theory (CTT) and Item Response Theory (IRT) methods to carry out an item analysis to improve measurement of these three components in patients having joint replacement surgery mainly for osteoarthritis (OA).
A geographical cohort of patients about to undergo lower limb joint replacement was invited to participate. Five hundred and twenty four patients completed ICF items that had been previously identified as measuring only a single ICF construct in patients with osteoarthritis. There were 13 I, 26 A and 20 P items. The SF-36 was used to explore the construct validity of the resultant I, A and P measures. The CTT and IRT analyses were run separately to identify items for inclusion or exclusion in the measurement of each construct. The results from both analyses were compared and contrasted.
Overall, the item analysis resulted in the removal of 4 I items, 9 A items and 11 P items. CTT and IRT identified the same 14 items for removal, with CTT additionally excluding 3 items, and IRT a further 7 items. In a preliminary exploration of reliability and validity, the new measures appeared acceptable.
New measures were developed that reflect the ICF components of Impairment, Activity Limitation and Participation Restriction for patients with advanced arthritis. The resulting Aberdeen IAP measures (Ab-IAP) comprising I (Ab-I, 9 items), A (Ab-A, 17 items), and P (Ab-P, 9 items) met the criteria of conventional psychometric (CTT) analyses and the additional criteria (information and discrimination) of IRT. The use of both methods was more informative than the use of only one of these methods. Thus combining CTT and IRT appears to be a valuable tool in the development of measures.
PMCID: PMC2696439  PMID: 19422677
14.  Variations in the pre-operative status of patients coming to primary hip replacement for osteoarthritis in European orthopaedic centres 
Total hip joint replacement (THR) is a high volume, effective intervention for hip osteoarthritis (OA). However, indications and determinants of outcome remain unclear. The 'EUROHIP consortium' has undertaken a cohort study to investigate these questions. This paper describes the variations in disease severity in this cohort and the relationships between clinical and radiographic severity, and explores some of the determinants of variation.
A minimum of 50 consecutive, consenting patients coming to primary THR for primary hip OA in each of the 20 participating orthopaedic centres entered the study. Pre-operative data included demographics, employment and educational attainment, drug utilisation, and involvement of other joints. Each subject completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC – Likert version 3.1). Other data collected at the time of surgery included the prosthesis used and American Society of Anaesthesiologists (ASA) status. Pre-operative radiographs were read by the same three readers for Kellgren and Lawrence (K&L) grading and Osteoarthritis Research Society International (OARSI) atlas features. Regression analyses were carried out.
Data from 1327 subjects has been analysed. The mean age of the group was 65.7 years, and there were more women (53.4%) than men. Most (79%) were ASA status 1 or 2. Reported disease duration was 5 years or less in 69.2%. Disease in other joint sites was common.
Radiographs were available in 1051 subjects and the K&L grade was 3 or 4 in 95.8%. There was much more variation in clinical severity (WOMAC score); the mean total WOMAC score was 59.2 (SD 16.1). The radiographic severity showed no correlation with WOMAC scores.
Significantly higher WOMAC scores (worse disease) were seen in older people, women, those with obesity, those with worse general health, and those with lower educational attainment.
1. Clinical disease severity varies widely at the time of THR for OA.
2. In advanced hip OA clinical severity shows no correlation with radiographic severity.
3. Simple scores of pain and disability do not reflect the complexity of decision-making about who should have a THR.
PMCID: PMC2654855  PMID: 19208230
15.  Developing and evaluating complex interventions: the new Medical Research Council guidance 
Evaluating complex interventions is complicated. The Medical Research Council's evaluation framework (2000) brought welcome clarity to the task. Now the council has updated its guidance
PMCID: PMC2769032  PMID: 18824488
16.  Complex interventions to improve physical function and maintain independent living in elderly people: a systematic review and meta-analysis 
Lancet  2008;371(9614):725-735.
In old age, reduction in physical function leads to loss of independence, the need for hospital and long-term nursing-home care, and premature death. We did a systematic review to assess the effectiveness of community-based complex interventions in preservation of physical function and independence in elderly people.
We searched systematically for randomised controlled trials assessing community-based multifactorial interventions in elderly people (mean age at least 65 years) living at home with at least 6 months of follow-up. Outcomes studied were living at home, death, nursing-home and hospital admissions, falls, and physical function. We did a meta-analysis of the extracted data.
We identified 89 trials including 97 984 people. Interventions reduced the risk of not living at home (relative risk [RR] 0·95, 95% CI 0·93–0·97). Interventions reduced nursing-home admissions (0·87, 0·83–0·90), but not death (1·00, 0·97–1·02). Risk of hospital admissions (0·94, 0·91–0·97) and falls (0·90, 0·86–0·95) were reduced, and physical function (standardised mean difference −0·08, −0·11 to −0·06) was better in the intervention groups than in other groups. Benefit for any specific type or intensity of intervention was not noted. In populations with increased death rates, interventions were associated with reduced nursing-home admission. Benefit in trials was particularly evident in studies started before 1993.
Complex interventions can help elderly people to live safely and independently, and could be tailored to meet individuals' needs and preferences.
PMCID: PMC2262920  PMID: 18313501
17.  Turning evidence into recommendations: Protocol of a study guideline development groups 
Health care practice based on research evidence requires that evidence is synthesised, and that recommendations based on this evidence are implemented. It also requires an intermediate step: translating synthesised evidence into practice recommendations. There is considerable literature on evidence synthesis and implementation, but little on how guideline development groups (GDGs) produce recommendations. This is a complex process, with many influences on communication and decision-making, e.g., the quality of evidence, methods of presentation, practical/resource constraints, individual values, professional and scientific interests, social and psychological processes. To make this process more transparent and potentially effective, we need to understand these influences. Psychological theories of decision-making and social influence provide a framework for this understanding.
This study aims to investigate the processes by which GDGs formulate recommendations, drawing on psychological theories of decision-making and social influence. The findings will potentially inform the further evolution of GDG methods, such as choice of members and procedures for presenting evidence, conducting discussion and formulating recommendations.
Longitudinal observation of the meetings of three National Institute of Health and Clinical Excellence (NICE) GDGs, one from each of acute, mental health and public health, will be tape recorded and transcribed. Interviews with a sample of GDG members at the beginning, middle, and end of the GDG's work will be recorded and transcribed. Site documents including relevant e-mail interchanges, GDG meeting minutes, and stakeholders' responses to the drafts of the recommendations will be collected. Data will be selected for analysis if they refer to either evidence or recommendations; the focus is on "hot spots", e.g., dilemmas, conflicts, and uncertainty. Data will be analysed thematically and by content analysis, drawing on psychological theories of decision-making and social influence.
PMCID: PMC2031892  PMID: 17803806
18.  "Me's me and you's you": Exploring patients' perspectives of single patient (n-of-1) trials in the UK 
Trials  2007;8:10.
The n-of-1 trial offers a more methodologically sound approach to determining optimum treatment for an individual patient than "trials of therapy" routinely conducted in clinical practice. However, such methodology is rarely used in the UK. This pilot study explores the acceptability of n-of-1 trials to patients in the UK.
Patients with osteoarthritis of the knee were recruited to their own 12-week n-of-1 trial comparing either two knee supports or an NSAID with simple analgesic. Patients were interviewed at the start and completion of their trial to explore reasons for participation, understanding of the trial design and experiences of participation. Daily diaries were completed to inform future treatment.
Nine patients participated (5 supports, 4 drugs). Patients were keen to participate, believing that the trial may lead to personal gains such as improved symptom control and quality of life. However, recruitment to the pharmacological comparison was more difficult since this could also entail risk. All patients were eager to complete the trial, even when difficulties were encountered. Completing the daily diary provided some patients with greater insight into their condition, which allowed them to improve their self-management. The n-of-1 trial design was viewed as a 'logical' design offering an efficient method of reaching a personalised treatment decision tailored to suit individual needs and preferences.
This pilot study suggests that patients perceive the n-of-1 trial as an acceptable approach to the individualisation of treatment. In addition, further benefits over and above any gained from the interventions can be derived from involvement in such a study.
PMCID: PMC1831792  PMID: 17371593
20.  Factors associated with change in pain and disability over time: a community-based prospective observational study of hip and knee osteoarthritis 
Hip and knee osteoarthritis are frequent causes of primary care consultations. They are considered slowly progressive disorders, often resulting in severe pain or disability and the need for joint replacements. There have been few longitudinal studies of progression to inform individual prognoses in primary care.
To describe the degree of progression and investigate predictors of change in hip or knee pain and disability.
Design of study
Prospective community-based cohort.
An age–sex stratified survey of 27 000 people registered with 40 general practices in Avon and Somerset yielded 2437 reporting hip and/or knee symptoms at baseline (1992–1994). A 25% random sample of 587 individuals was followed up between 1998 and 1999.
Pain or disability was measured at baseline and follow-up using the New Zealand score. For the worst joint according to the New Zealand score at baseline, hip and knee problems were analysed separately. Regression models ascertained characteristics of non-responders and factors associated with change in scores. Seven sociodemographic, seven comorbidity, and two healthcare utilisation variables were considered.
Generally pain and disability worsened over the 7 years, but 35% and 29% of those initially reporting hip and knee pain respectively had improved. Reporting ‘other health problems’ was associated with greater deterioration for both hip and knee disease, as was cardiovascular morbidity for hip disease and lower social class, being retired, hypertension, and higher body mass index for knee disease. Deteriorations in scores were strongly associated with individuals consulting their GP about joint problems.
Osteoarthritis does not invariably deteriorate, but when it does social as well as biological factors appear to be important. These findings may aid outcome prediction. Future research on osteoarthritis should be conducted within a biopsychosocial rather than a purely biological paradigm.
PMCID: PMC1463091  PMID: 15808036
disability evaluation; disease progression; New Zealand score; osteoarthritis; pain; projections and predictions
22.  What is successful ageing and who should define it? 
BMJ : British Medical Journal  2005;331(7531):1548-1551.
A definition of successful ageing needs to include elements that matter to elderly people
PMCID: PMC1322264  PMID: 16373748
23.  Characteristic and incidental (placebo) effects in complex interventions such as acupuncture 
BMJ : British Medical Journal  2005;330(7501):1202-1205.
The specific effects of non-pharmaceutical treatments are not always divisible from placebo effects and may be missed in randomised trials
PMCID: PMC558023  PMID: 15905259

Results 1-25 (50)