Physiotherapy utilisation and costs before lumbar spine surgery: a retrospective analysis of workers compensation claims in Australia.

Background: Understanding how much physiotherapy people receive before lumbar spine surgery could give insight into what people and clinicians consider an adequate trial of non-operative management. The aim of this study was to investigate physiotherapy utilisation and costs before lumbar spine surgery under a workers' compensation claim in New South Wales (NSW), Australia.

Methods: Using data from the NSW State Insurance Regulatory Authority, we audited physiotherapy billing codes used before surgery for people who received lumbar spine surgery from 2010 to 2018. We summarised, separately for fusion and decompression, the time from initiation of physiotherapy to surgery, number of physiotherapy sessions people received before surgery, total cost of physiotherapy before surgery, and time from injury date to initiation of physiotherapy. All analyses were descriptive.

Results: We included 3070 people (800 had fusion, 2270 decompression). Mean age (standard deviation, SD) was similar between those who received fusion and decompression [42.9 (10.4) vs. 41.9 (11.6)]. Compared to people who had fusion, those who had decompression were more likely to not have any physiotherapy before surgery (28.4% vs. 15.4%), received physiotherapy for a shorter duration before surgery [median (interquartile range, IQR): 5 (3 to 11) vs. 15 (4-26) months], were less likely to have physiotherapy for ≥2 years before surgery (5.6% vs. 27.5%), had fewer physiotherapy sessions before surgery [mean (SD): 16 (21) vs. 28 (35) sessions], were less likely to have > 50 physiotherapy sessions before surgery (6.8% vs. 18.1%), and had lower total physiotherapy-related costs [mean (IQR): $1265 ($0-1808) vs. $2357 ($453-2947)]. Time from injury date to first physiotherapy session was similar between people who had fusion and decompression [median (IQR): 23 (9-66) vs.19 (7-53) days].

Conclusions: There is variation in physiotherapy utilisation and costs before lumbar spine surgery for people funded by NSW Workers' Compensation. Some people may not be receiving an adequate trial of physiotherapy before surgery, particularly before decompression surgery. Others may be receiving an excessive amount of physiotherapy before surgery, particularly before fusion.