Causal variation modelling identifies large inter- and intra-regional disparities in physical therapy offered to hip fracture patients in Estonia

Purpose An essential measure of hip fracture (HF) rehabilitation, the amount of physical therapy (PT) used per patient, has been severely understudied. This study (1) evaluates post-acute PT use after HF in Estonia, (2) presents causal variation modelling for examining inter- and intra-regional disparities, and (3) analyses its temporal trends. Materials and methods This retrospective cohort study used validated population-wide health data, including patients aged >= 50 years, with an index HF diagnosed between January 2009 and September 2017. Patients' 6-month PT use was analysed and reported separately for acute and post-acute phases. Results While most of the included 11,461 patients received acute rehabilitation, only 40% of them received post-acute PT by a median of 6 h. Analyses based on measures of central tendency revealed 2.5 to 2.6-fold inter-regional differences in HF post-acute rehabilitation. Variation modelling additionally detected intra-regional disparities, showing imbalances in the fairness of allocating local rehabilitation resources between a county's patients. Conclusions This study demonstrates the advantages of causal variation modelling for identifying inter- and intra-regional disparities in rehabilitation. The analyses revealed persisting large multi-level disparities and accompanying overall inaccessibility of PT in HF rehabilitation in Estonia, showing an urgent need for system-wide improvements.