Workers who stay at work despite chronic nonspecific musculoskeletal pain: do they differ from workers with sick leave?

Purpose: Most workers with chronic nonspecific musculoskeletal pain (CMP) do not take sick leave, nor consult a health care professional or search vocational rehabilitation. Yet, the knowledge of many researchers, clinicians and policy makers is largely based on people with CMP who discontinue work. The aim of this study was to explore characteristics of workers who stay at work despite CMP, and to compare these with sick-listed workers with CMP following vocational rehabilitation.

Methods: The clinical characteristics of workers who stay at work despite CMP (n = 119) and sick-listed workers who follow vocational rehabilitation (n = 122) were described and the differences between these groups were assessed. Logistic regression analysis was used to assess differences between the groups and to determine which variables predicted group status.

Results: Workers who stayed at work despite CMP reported significantly lower levels of fear avoidance (OR = 0.94), pain catastrophizing (OR = 0.93), perceived workload (OR = 0.93), and higher pain acceptance (OR = 1.11), life control (OR = 1.62) and pain self-efficacy (OR = 1.09) compared to sick-listed workers following rehabilitation, even after controlling for confounders. The groups did not differ on physical activity level, active coping and work satisfaction. Group status was predicted best by pain intensity, duration of pain, pain acceptance, perceived workload, mental health, and psychological distress (area under the receiver operating characteristic curve = 0.91, 95% CI = 0.87-0.95).

Conclusions: A wide range of characteristics of workers who stay at work despite CMP were explored. Relevant differences from sick-listed workers with CMP were observed in all domains of the bio-psycho-social model. Six main predictors were identified that best discriminate between both groups.