Ethical guidelines in the United Kingdom require written consent from participants in epidemiologic studies for follow-up or review of medical records. This may cause bias in samples used for follow-up or medical record review. The authors analyzed data from seven general population surveys conducted in the United Kingdom (1996-2002), to which over 25,000 people responded. Associations of age, gender, and symptom under investigation with consent to follow-up and consent to review of medical records were examined. Consent to follow-up was approximately 75-95% among survey responders under age 50 years but fell among older people, particularly females. Consent to follow-up was also higher among responders who had the symptom under investigation (pooled odds ratio = 1.61, 95% confidence interval: 1.36, 1.92). Consent to review of medical records followed a similar pattern. Patterns of consent were relatively consistent and represented a high proportion of responders. Males, younger people, and subjects reporting the symptom under investigation were more likely to give consent, and these groups may be overrepresented in follow-up samples or reviews of medical records. Although consent is high among responders, the additive effect of nonresponse and nonconsent can substantially reduce sample size and should be taken into account in epidemiologic study planning.

Background: In longitudinal studies across a range of regional musculoskeletal pain syndromes, certain prognostic factors consistently emerge. They are ''generic'' in the sense that they appear to apply regardless of the particular anatomical site or underlying cause of the pain. Objective: To investigate the value of generic indicators of poor functional outcome for knee pain and osteoarthritis in the community. Methods: We conducted a population-based cohort study of adults aged >50 years with knee pain as part of the Clinical Assessment Study (Knee) (CAS(K)). At baseline, participants completed a postal questionnaire and attended a research clinic where they completed a further questionnaire and underwent structured physical examination and x rays. The 18-month follow-up was via a self-completed questionnaire. Risk ratios were calculated using Cox regression with a fixed time period assigned to each participant. Results: In total, 60% of participants experienced a poor outcome at 18 months. Twelve univariate associations were associated with poor outcome, with four variables remaining in the multivariate model (older age, being overweight or obese, having possible or probable anxiety, and more severe pain).Using a simple unweighted additive risk score (1 point each for age >60 years, body mass index >25 kg/m 2 , possible or probable anxiety, Chronic Pain Grade II-IV), 90% of participants with all four generic indicators were correctly classified.Conclusions: This study has demonstrated that generic prognostic indicators can be used to determine the prognosis of older people in the community with knee pain.

Background: Work-related neck and upper limb pain has mainly been studied in specific occupational groups, and little is known about its impact in the general population. The objectives of this study were to estimate the prevalence and population impact of work-related neck and upper limb pain.

ObjectiveIn older adults, widespread pain (WP) is common, although its etiology is unclear. This study sought to identify factors associated with an increased risk of developing WP in adults age ≥50 years.MethodsA population‐based prospective study was conducted. A baseline questionnaire was administered to subjects to collect data on pain, psychological status, lifestyle and health behaviors, and sociodemographic and clinical factors. Participants free of WP (as defined by the American College of Rheumatology 1990 criteria for fibromyalgia) were followed up for 3 years, and those with new‐onset WP at followup were identified. Logistic regression analyses were used to test the relationship between baseline factors and new‐onset WP. Multiple imputation was used to test the results for sensitivity to missing data.ResultsIn this population‐based study, 4,326 subjects (1,562 reporting no pain at baseline and 2,764 reporting some pain at baseline) participated at followup. Of these participants, 800 (18.5%) reported a status of new WP at followup (of whom, 121 [7.7%] had reported no pain at baseline and 679 [24.6%] had reported some pain at baseline). The majority of the study factors were associated with new‐onset WP. However, only a few factors showed a persistent association with new‐onset WP in the multivariate analysis, including age (odds ratio [OR] 0.97, 95% confidence interval [95% CI] 0.96–0.99), baseline pain status (OR 1.1, 95% CI 1.08–1.2), anxiety (OR 1.5, 95% CI 1.01–2.1), physical health‐related quality of life (OR 1.3, 95% CI 1.1–1.5), cognitive complaint (OR 1.3, 95% CI 1.04–1.6), and nonrestorative sleep (OR 1.9, 95% CI 1.2–2.8). These associations persisted after adjustment for the presence of diffuse osteoarthritis (OA), which led to a modest increase in model fit (C‐statistic 0.738, compared with 0.731 in the model excluding diffuse OA). The results were not sensitive to missing data.ConclusionOf the factors measured in this study, nonrestorative sleep was the strongest independent predictor of new‐onset WP.

Clinical history, physical examination and severity of radiographic knee OA are of limited value over generic factors when trying to predict which older adults with knee pain will experience progressive or persistent functional difficulties.