Patterns of Mental Health Service Use in Australian Workers with Low Back Pain: A Retrospective Cohort Study.

Purpose: To describe the volume, timing and provider of mental health services provided to workers with accepted low back pain (LBP) claims, and to identify determinants of service volume and time to first mental health service.

Methods: Using claim and service-level workers' compensation data from four Australian states (Queensland, South Australia, Western Australia, Victoria) for LBP claims with at least one mental health service lodged between 1 July 2011 and 30 June 2015. Mental health services occurring 30 days prior to 730 days following claim acceptance were examined. Outcomes were number of mental health services and time (weeks) from claim acceptance to first service, calculated overall, by provider and interaction type, and by independent variables (age group, sex, time loss duration, financial year of lodgement, jurisdiction, socioeconomic status, remoteness). Negative binomial and Cox regression models examined differences between service volume and time to first service by independent variables, respectively.

Results: Of workers with LBP claims who accessed mental health services, psychologist services were most common (used by 91.2% of workers) and 16% of workers saw multiple provider types. Number of services increased with time loss duration, as did time to first service. Victorian workers had the most services, yet accessed them latest.

Conclusions: Psychologist services were most common, longer duration claims used more mental health services but accessed them later, and there were a number of jurisdictional differences. Results suggest opportunities for workers' compensation authorities to provide, to those who may benefit, greater and earlier access to mental health care.