Rosie J. Lacey

The impact of workplace risk factors on the occurrence of neck and upper limb pain: a general population study

BackgroundWork-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.MethodsA cross-sectional survey was conducted of 10 000 adults in North Staffordshire, UK, in which there is a common local manual industry. The primary outcome measure was presence or absence of neck and upper limb pain. Participants were asked to give details of up to five recent jobs, and to report exposure to six work activities involving the neck or upper limbs. Psychosocial measures included job control, demand and support. Odds ratios (ORs) and population attributable fractions were calculated for these risk factors.ResultsThe age-standardized one-month period prevalence of neck and upper limb pain was 44%. There were significant independent associations between neck and upper limb pain and: repeated lifting of heavy objects (OR = 1.4); prolonged bending of neck (OR = 2.0); working with arms at/above shoulder height (OR = 1.3); little job control (OR = 1.6); and little supervisor support (OR = 1.3). The population attributable fractions were 0.24 (24%) for exposure to work activities and 0.12 (12%) for exposure to psychosocial factors.ConclusionNeck and upper limb pain is associated with both physical and psychosocial factors in the work environment. Inferences of cause-and-effect from cross-sectional studies must be made with caution; nonetheless, our findings suggest that modification of the work environment might prevent up to one in three of cases of neck and upper limb pain in the general population, depending on current exposures to occupational risk.

Predicting poor functional outcome in community-dwelling older adults with knee pain: prognostic value of generic indicators

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/m2, 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.

The Knee Clinical Assessment Study – CAS(K). A prospective study of knee pain and knee osteoarthritis in the general population: baseline recruitment and retention at 18 months

BackgroundSelective non-participation at baseline (due to non-response and non-consent) and loss to follow-up are important concerns for longitudinal observational research. We investigated these matters in the context of baseline recruitment and retention at 18 months of participants for a prospective observational cohort study of knee pain and knee osteoarthritis in the general population.MethodsParticipants were recruited to the Knee Clinical Assessment Study – CAS(K) – by a multi-stage process involving response to two postal questionnaires, consent to further contact and medical record review (optional), and attendance at a research clinic. Follow-up at 18-months was by postal questionnaire. The characteristics of responders/consenters were described for each stage in the recruitment process to identify patterns of selective non-participation and loss to follow-up. The external validity of findings from the clinic attenders was tested by comparing the distribution of WOMAC scores and the association between physical function and obesity with the same parameters measured directly in the target population as whole.Results3106 adults aged 50 years and over reporting knee pain in the previous 12 months were identified from the first baseline questionnaire. Of these, 819 consented to further contact, responded to the second questionnaire, and attended the research clinics. 776 were successfully followed up at 18 months. There was evidence of selective non-participation during recruitment (aged 80 years and over, lower socioeconomic group, currently in employment, experiencing anxiety or depression, brief episode of knee pain within the previous year). This did not cause significant bias in either the distribution of WOMAC scores or the association between physical function and obesity.ConclusionDespite recruiting a minority of the target population to the research clinics and some evidence of selective non-participation, this appears not to have resulted in significant bias of cross-sectional estimates. The main effect of non-participation in the current cohort is likely to be a loss of precision in stratum-specific estimates e.g. in those aged 80 years and over. The subgroup of individuals who attended the research clinics and who make up the CAS(K) cohort can be used to accurately estimate parameters in the reference population as a whole. The potential for selection bias, however, remains an important consideration in each subsequent analysis.

Predicting the course of functional limitation among older adults with knee pain: do local signs, symptoms and radiographs add anything to general indicators?

Objective: To determine the additional prognostic value of clinical history, physical examination and x-ray findings to a previously derived simple generic model (age, body mass index, anxiety and pain severity) in a cohort of older adults with knee pain. Methods: Prospective cohort study in community-dwelling adults in North Staffordshire. 621 participants (aged ⩾50 years) reporting knee pain who attended a research clinic at recruitment and were followed up by postal questionnaire at 18 months. Poor functional outcome was measured by the Physical Functioning Scale of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at 18-month follow-up defined in 60% of participants. Results: Three clinical history variables (bilateral knee pain, duration of morning stiffness and inactivity gelling) were independently associated with poor outcome. The addition of the “clinical history” model to the “generic” model led to a statistical improvement in model fit (likelihood ratio (LR)  = 24.84, p = 0.001). Two physical examination variables (knee tender point count and single-leg balance) were independently associated with poor outcome but did not lead to a significant improvement when added to the “clinical history and generic” model (LR = 6.34, p = 0.50). Functional outcome was significantly associated with severity of knee radiographic osteoarthritis (OA), but did not lead to any improvement in fit when added to the “generic, clinical history and physical examination” model (LR = 1.86, p = 0.39). Conclusions: 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.

Predictors of new-onset widespread pain in older adults: results from a population-based prospective cohort study in the UK.

In 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.

Sleep Disturbance and Chronic Widespread Pain

Musculoskeletal pain is common and often occurs at multiple sites. Persons with chronic widespread pain (CWP) often report disturbed sleep. Until recently, the relationship between sleep disturbance and CWP has been unclear: does poor sleep increase the risk of developing CWP, do people with CWP develop poor sleep as a consequence of their pain, or is the relationship bi-directional? In this article, we have focused on the relationship between insomnia and CWP. We briefly present descriptive epidemiological data for insomnia and CWP. We then summarise the available evidence which supports the hypothesis that the relationship is bi-directional. Finally, we discuss the clinical management of CWP and insomnia in primary care, where the vast majority of cases of CWP are managed.

Gender difference in symptomatic radiographic knee osteoarthritis in the Knee Clinical Assessment – CAS(K): A prospective study in the general population

BackgroundA recent study of adults aged ≥50 years reporting knee pain found an excess of radiographic knee osteoarthritis (knee ROA) in symptomatic males compared to females. This was independent of age, BMI and other clinical signs and symptoms. Since this finding contradicts many previous studies, our objective was to explore four possible explanations for this gender difference: X-ray views, selection, occupation and non-articular conditions.MethodsA community-based prospective study. 819 adults aged ≥50 years reporting knee pain in the previous 12 months were recruited by postal questionnaires to a research clinic involving plain radiography (weight-bearing posteroanterior semiflexed, supine skyline and lateral views), clinical interview and physical examination. Any knee ROA, ROA severity, tibiofemoral joint osteoarthritis (TJOA) and patellofemoral joint osteoarthritis (PJOA) were defined using all three radiographic views. Occupational class was derived from current or last job title. Proportions of each gender with symptomatic knee ROA were expressed as percentages, stratified by age; differences between genders were expressed as percentage differences with 95% confidence intervals.Results745 symptomatic participants were eligible and had complete X-ray data. Males had a higher occurrence (77%) of any knee ROA than females (61%). In 50–64 year olds, the excess in men was mild knee OA (particularly PJOA); in ≥65 year olds, the excess was both mild and moderate/severe knee OA (particularly combined TJOA/PJOA). This male excess persisted when using the posteroanterior view only (64% vs. 52%). The lowest level of participation in the clinic was symptomatic females aged 65+. Within each occupational class there were more males with symptomatic knee ROA than females. In those aged 50–64 years, non-articular conditions were equally common in both genders although, in those aged 65+, they occurred more frequently in symptomatic females (41%) than males (31%).ConclusionThe excess of knee ROA among symptomatic males in this study seems unlikely to be attributable to the use of comprehensive X-ray views. Although prior occupational exposures and the presence of non-articular conditions cannot be fully excluded, selective non-participation bias seems the most likely explanation. This has implications for future study design.

Pain at multiple body sites and health-related quality of life in older adults: results from the North Staffordshire Osteoarthritis Project

Objectives. Number of pain sites (NPS) is a potentially important marker of health-related quality of life (HRQoL) but remains unexplored in older people. This cross-sectional study investigated whether, in older people including the oldest old, NPS was independently associated with poorer mental and physical HRQoL and if the association was moderated by age. Methods. A postal questionnaire sent to a population sample of adults aged ≥50 years in North Staffordshire, UK, included the 12-item Short Form Health Survey (SF-12) mental component summary (MCS) and physical component summary (PCS), a blank body pain manikin, socio-demographic, health behaviour and morbidity questions. Participants shaded sites of pain lasting ≥1 day in the past 4 weeks on the manikin. OA consultation data were obtained for participants consenting to medical records review. Results. A total of 13 986 individuals (adjusted response 70.6%) completed a questionnaire, of which 12 408 provided complete pain data. The median NPS reported was 4 [interquartile range (IQR) 0–8]. General linear models showed that an increasing NPS was significantly associated with poorer MCS (β = −0.43, 95% CI −0.46, −0.40) and PCS (β = −0.87, 95% CI −0.90, −0.84). Adjustment for covariates attenuated the associations but they remained significant (MCS: β = −0.28, 95% CI −0.31, −0.24; PCS: β = −0.63, 95% CI −0.66, −0.59). The association between NPS and MCS or PCS was moderated by age, but the strongest associations were not in the oldest old. Conclusion. NPS appears to be a potentially modifiable target for improving physical and mental HRQoL in older people. Future analyses should investigate the influence of NPS on HRQoL over time in older people.

Does life course socio-economic position influence chronic disabling pain in older adults? A general population study

Background: Chronic pain is the leading cause of disability in developed countries. Prevalence is linked with socio-economic position (SEP), but little is known about the influence of SEP on disabling pain over the life course. We have investigated the influence of different life course trajectories of SEP on disabling pain (‘pain interference’) in postal surveys of adults aged ≥50 years sampled from the general population of adults registered with three UK general practices. Methods: Current pain interference was measured using the dichotomized 36-item Short-Form (SF-36) health survey. Three recalled SEP measures (age left school, longest job and current/most recent job) were dichotomized into low SEP (left school at or before minimum school leaving age; reported routine or manual occupations) and high SEP, from which eight life course SEP trajectories were constructed. Associations of (i) eight SEP trajectories and (ii) three individual SEP measures adjusted for each other, with pain interference, adjusted for potential confounders, were calculated using logistic regression. Results: A total of 2533 individuals provided data on all three SEP measures. A consistently low life course SEP trajectory was significantly associated with current pain interference compared with a high trajectory [odds ratio (OR) = 2.76, 95% confidence interval (CI): 2.19–3.47], even after adjustment for age and gender. Further adjustment reduced the association but it remained significant (OR = 2.04; 95% CI: 1.55–2.68). In the model with individual measures, low age left school (OR = 1.45; 95% CI: 1.15–1.82) and manual longest job (OR = 1.47; 95% CI: 1.13–1.91) were independently associated with pain interference. Conclusions: Our results highlight the potential for reducing chronic disabling pain in later life by addressing inequalities in both childhood education and adult occupational opportunities.

Reasons why multimorbidity increases the risk of participation restriction in older adults with lower extremity osteoarthritis: a prospective cohort study in primary care.

To determine why multimorbidity causes participation restriction in adults ages ≥50 years who consult primary care with lower extremity osteoarthritis (OA).