Background: Medical certification of injured workers is a routine occurrence in most General Practitioners (GPs) offices. GPs play an important role in return-to-employment after a work-related injury.

Objectives: To examine patterns of healthcare service utilisation (HSU) in injured workers by condition and type of medical certificate issued by the GP at the initial consultation.

Methods: Zero-inflated negative binomial regression (ZINB) was conducted for major healthcare services accessed by injured workers over the 12-month period post-initial medical examination. Services included GP consultations, pharmacy, physiotherapy, occupational rehabilitation, psychology and others. Logistic regression was conducted for hospital and occupational therapy services. All models were adjusted for the injured worker's gender, age, injury type, certification type, occupation and residential location.

Findings: HSU differed according to the type of initial medical certificate and worker condition. Compared to other conditions, for unfit for work (UFW) and alternate duties (ALT) certificates, the average number of physiotherapy services was greater in workers with musculoskeletal disorders (MSD), back pains and strains and fractures. In contrast, for both UFW and ALT certificates, the mean number of psychological services was greater in mental health conditions (MHC). Workers suffering from MHCs were more likely to access pharmacy and psychological services. Workers with ALT certificates were more likely to use GPs, pharmacy and physiotherapy services. They were less likely to access occupational rehabilitation, psychology or other services.

Discussion: HSU in the 12 months post-initial medical certification varied substantially according to the worker's medical condition, certificate type, occupation, age, gender and residential location.

Conclusion: Understanding these socio-demographic characteristics that influence HSU can facilitate more appropriate resource allocation, strategic thinking on optimal use of particular health services and enable better targeting of particular provider groups for more education on the health benefits of RTW and safe work.