Prognostic factors in short-term disability due to musculoskeletal disorders

To identify factors associated with poor outcome in temporary work disability (TWD) due to musculoskeletal disorders (MSDs).

We conducted a secondary data analysis of a 2-year randomized controlled trial in which all patients with TWD due to MSDs in 3 health districts of Madrid (Spain) were included. Analyses refer to the patients in the intervention group. Primary outcome variables were duration of TWD and recurrence. Diagnoses, sociodemographic, work-related administrative, and occupational factors were analyzed by Cox proportional hazards models.

We studied 3,311 patients with 4,424 TWD episodes. The following were independently associated with slower return to work: age (hazard ratio [HR] 0.99, 95% confidence interval [95% CI] 0.98-0.99), female sex (HR 0.84, 95% CI 0.78-0.90), married (HR 0.90, 95% CI 0.83-0.97), peripheral osteoarthritis (HR 0.77, 95% CI 0.6-0.9), sciatica (HR 0.59, 95% CI 0.54-0.65), self-employment (HR 0.56, 95% CI 0.48-0.65), unemployment (HR 0.41, 95% CI 0.28-0.58), manual worker (HR 0.86, 95% CI 0.79-0.94), and work position covered during sick leave (HR 0.84, 95% CI 0.77-0.92). The factors that better predicted recurrence were peripheral osteoarthritis (HR 1.75, 95% CI 1.14-2.6), inflammatory diseases (HR 1.66, 95% CI 1.009-2.72), sciatica (HR 1.30, 95% CI 1.08-1.56), indefinite work contract (HR 1.43, 95% CI 1.14-1.75), frequent kneeling (HR 1.39, 95% CI 1.15-1.69), manual worker (HR 1.19, 95% CI 1.003-1.42), and duration of previous episodes (HR 1.003, 95% CI 1.001-1.005).

Sociodemographic, work-related administrative factors, diagnosis, and, to a lesser extent, occupational factors may explain the duration and recurrence of TWD related to MSD.