Association between changes in function among patients with lumbar impairments classified according to the STarT Back Screening Tool and managed by McKenzie credentialed physiotherapists.

Purpose: To examine the association between functional status (FS) scores using a Patient Reported Outcome Measure (PROM) for patients with non-specific low back pain classified according to psychosocial risk using the STarT Back Screening Tool and managed by physiotherapists credentialed in McKenzie methods. Methods: Participants (n = 705) completed FS and STarT surveys at intake and discharge. Prevalence of STarT risk classifications and change in STarT risk was calculated. Regression models were developed to examine associations between baseline and change in STarT risk categories, and FS outcomes at discharge from rehabilitation services. Results: FS outcomes at discharge was not significantly different (p-values > 0.10) across baseline STarT risk subgroups after controlling for model covariates. Seventy-eight and 91.5% of medium and high-risk patients respectively decreased STarT risk. When compared with subjects whose STarT risk decreased, there was no significant difference in subjects whose STarT risk remained low. For subjects whose risk remained medium/high, or whose risk worsened, FS outcome scores were statistically significant (p < 0.001) and clinically relevant (-15.76 and -23.42 points respectively) compared to patients whose STarT risk decreased. Conclusions: Baseline STarT psychosocial risk stratifications should be interpreted cautiously to estimate the likelihood of good or poor FS outcomes at discharge from physiotherapy practice in the US when patients are managed by clinicians credentialed in McKenzie methods. Decreased STarT risk was associated with clinically important improvements in FS outcomes scores at discharge from McKenzie directed physiotherapy care.