To explore definitions for multi-site pain, and compare associations with risk factors for different patterns of musculoskeletal pain, we analysed cross-sectional data from the Cultural and Psychosocial Influences on Disability (CUPID) study. The study sample comprised 12,410 adults aged 20-59 years from 47 occupational groups in 18 countries. A standardised questionnaire was used to collect information about pain in the past month at each of 10 anatomical sites, and about potential risk factors. Associations with pain outcomes were assessed by Poisson regression, and characterised by prevalence rate ratios (PRRs). Extensive pain, affecting 6-10 anatomical sites, was reported much more frequently than would be expected if the occurrence of pain at each site were independent (674 participants v 41.9 expected). In comparison with pain involving only 1-3 sites, it showed much stronger associations (relative to no pain) with risk factors such as female sex (PRR 1.6 v 1.1), older age (PRR 2.6 v 1.1), somatising tendency (PRR 4.6 v 1.3) and exposure to multiple physically stressing occupational activities (PRR 5.0 v 1.4). After adjustment for number of sites with pain, these risk factors showed no additional association with a distribution of pain that was widespread according to the frequently used American College of Rheumatology (ACR) criteria. Our analysis supports the classification of pain at multiple anatomical sites simply by the number of sites affected, and suggests that extensive pain differs importantly in its associations with risk factors from pain that is limited to only a small number of anatomical sites.

SummaryLarge international variation in the prevalence of disabling forearm and low back pain was only partially explained by established personal and socioeconomic risk factors.

Purpose This study aimed to report lifetime and 4-week low back pain (LBP) prevalence and examine factors associated with chronic LBP and back pain disability over a lifetime in a Japanese adult population. Methods In February 2011, 1,063,083 adults aged 20-79 years registered as internet research volunteers were randomly selected to participate in a questionnaire survey. The data from 65,496 respondents were analyzed to calculate age-standardized lifetime and 4-week prevalence. Chronic LBP and back pain disability were defined as LBP lasting for C3 months and a consecutive C4-day-long absence, respectively. Factors associated with chronic disabling back pain over a lifetime were examined by multiple logistic regression modeling. Results The lifetime LBP prevalence was 83 % and 4-week prevalence was 36 %; majority of the respondents had disability-free LBP. (aOR: 3.84; 95 % CI: 3.36, 4.40) were associated with chronic disabling back pain over a lifetime. Conclusions LBP is common in Japan as in other industrialized countries. The association between the advice to rest and chronic disabling back pain supports recent treatment guidelines emphasizing continuation of daily activities.

Background The CUPID (Cultural and Psychosocial Influences on Disability) study was established to explore the hypothesis that common musculoskeletal disorders (MSDs) and associated disability are importantly influenced by culturally determined health beliefs and expectations. This paper describes the methods of data collection and various characteristics of the study sample. Methods/Principal Findings A standardised questionnaire covering musculoskeletal symptoms, disability and potential risk factors, was used to collect information from 47 samples of nurses, office workers, and other (mostly manual) workers in 18 countries from six continents. In addition, local investigators provided data on economic aspects of employment for each occupational group. Participation exceeded 80% in 33 of the 47 occupational groups, and after pre-specified exclusions, analysis was based on 12,426 subjects (92 to 1018 per occupational group). As expected, there was high usage of computer keyboards by office workers, while nurses had the highest prevalence of heavy manual lifting in all but one country. There was substantial heterogeneity between occupational groups in economic and psychosocial aspects of work; three- to five-fold variation in awareness of someone outside work with musculoskeletal pain; and more than ten-fold variation in the prevalence of adverse health beliefs about back and arm pain, and in awareness of terms such as “repetitive strain injury” (RSI). Conclusions/Significance The large differences in psychosocial risk factors (including knowledge and beliefs about MSDs) between occupational groups should allow the study hypothesis to be addressed effectively.

Objectives-To assess the prevalence and correlates of regional pain and associated disability in four groups of Japanese workers.Methods-As part of a large international survey of musculoskeletal symptoms (the CUPID study), samples of nurses, office workers, sales/marketing personnel and transportation operatives in Japan completed a self-administered questionnaire (response rate 83%). The questionnaire covered experience of pain in six anatomical regions, associated disability and sickness absence, and various possible occupational and psychosocial risk factors for these outcomes. Associations with risk factors were assessed by logistic regression.Results-Analysis was based on 2290 subjects. Rates of regional pain were generally less than have been reported in the UK, with a particularly low prevalence of wrist/hand pain among office workers (6% in the past month). The strongest and most consistent risk factor for regional pain in the past month was tendency to somatise (odds ratios (95% confidence intervals) for report of ≥2 v 0 distressing somatic symptoms 3.1 (2.4-4.0) for low back pain, 2.8 (2.1-3.8) for shoulder pain, and 2.5 (1.6-4.1) for wrist/hand pain). Sickness absence for regional pain complaints in the past year was reported by 5% of participants, the major risk factor for this outcome being absence during the same period for other medical reasons (OR 3.7,).Conclusions-Japanese office workers have markedly lower rates of wrist/hand pain than their UK counterparts. In Japan, as in Western Europe, somatising tendency is a major risk factor for regional pain. Sickness absence attributed to regional pain complaints appears to be much less common in Japan than in the UK, and to be driven principally by a general propensity to take sickness absence.