Patient- and Physical Therapist–Level Predictors of Patient-Reported Therapeutic Alliance: An Observational, Exploratory Study of Cohorts With Knee and Low Back Pain

Abstract

Objective: To identify patient- and physical therapist–level predictors for therapeutic alliance at the end of an episode of physical therapy for knee or low back pain (LBP). Design: Secondary analysis of observational cohort. Setting: Outpatient physical therapy clinics. Participants: Patients receiving physical therapy for knee (n=189) or LBP (n=252) and physical therapists (n=19). Candidate predictor variables included demographics, patient clinical characteristics, and physical therapist attitudes and beliefs (Pain Attitudes and Beliefs Scale for Physical Therapists) and confidence in providing patient-centered care (Self-Efficacy in Patient-Centeredness Questionnaire). Interventions: Not applicable. Main Outcome Measures: Patient-reported therapeutic alliance was measured using the 12-item Work Alliance Inventory–Short Revised (WAI-SR). Results: Final linear mixed models indicated different patient- and physical therapist–level factor contributions in predicting final WAI-SR scores across cohorts with knee and LBP. Female sex was a consistent patient-level predictor for both knee (estimated β=1.57, P