Factors associated with prolonged work absence after occupational injuries in Chile

Background Prolonged work absence following an occupational injury has important personal, social, and economic consequences, including social isolation, depression, reduced income, and diminished quality of life. Despite its relevance, the demographic, clinical, and injury-related factors associated with prolonged work absence remain insufficiently understood. This study aimed to identify these factors using administrative data from Mutual de Seguridad de Chile (2011–2024). Methods An explanatory full-cohort study was conducted using administrative records from 130,752 eligible occupational injury cases. Prolonged work absence was defined as time loss of at least 90 days (3 months). A probit model was estimated using the full cohort, and average marginal effects (AMEs) were calculated to quantify the adjusted association between each predictor and the probability of prolonged work absence. All explanatory variables were operationalized as dichotomous measures. Model performance was evaluated using goodness-of-fit statistics, including the area under the receiver operating characteristic (ROC) curve. Results Prolonged work absence was observed in 6,228 cases (4.8% of the cohort). The probit model demonstrated excellent discriminative ability, with an area under the ROC curve of 0.91. A higher probability of prolonged work absence was associated with being male (0.6% points), having multiple diagnoses (3.0% points), sustaining a severe injury (11.3% points), having a disability of at least 15% (57.6% points), injuries affecting the nervous system (9.1% points) or genitourinary system (4.3% points), falls (0.9% points), machine-related injuries (0.2% points), and employment in small and medium-sized enterprises (0.3% points). Compared with workers aged 45 years or older, younger workers had significantly lower probabilities of prolonged work absence. Conclusion Prolonged work absence following occupational injuries in Chile is associated with demographic, clinical, injury-related, and workplace characteristics, with injury severity and disability demonstrating the strongest associations. These findings may support the early identification of workers at increased risk of prolonged absence and inform targeted prevention, rehabilitation, and return-to-work strategies. Strengthening occupational health protection systems may further facilitate recovery and promote a timely and sustainable return to work.