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

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<.05) and LBP (β=1.42, P<.05), with age (β=-0.07, P<.01) and baseline function (β=0.06, P<.01) contributing to cohorts with knee and LBP, respectively. Physical therapist-level predictors included female sex (β=6.04, P<.05), Pain Attitudes and Beliefs Scale for Physiotherapists behavioral (β=0.65, P<.01), and Self-Efficacy in Patient-Centeredness Questionnaire (SEPCQ) Exploring Patient Perspective (β=-0.75, P<.01) subscale scores for LBP, with SEPCQ Sharing Information and Power subscale scores (β=0.56, P<.05) contributing to both cohorts with knee (β=0.56, P<.05) and LBP (β=0.74, P<.01). Random effects for patients nested within physical therapists were observed for both cohorts. CONCLUSIONS These findings provide preliminary evidence for inconsistent relationships among patient- and physical therapist-level factors and therapeutic alliance across cohorts with knee and LBP.