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 ß=1.57, P<.05) and LBP (ß=1.42, P<.05), with age (ß=-0.07, P<.01) and baseline function (ß=0.06, P<.01) contributing to cohorts with knee and LBP, respectively. Physical therapist-level predictors included female sex (ß=6.04, P<.05), Pain Attitudes and Beliefs Scale for Physiotherapists behavioral (ß=0.65, P<.01), and Self-Efficacy in Patient-Centeredness Questionnaire (SEPCQ) Exploring Patient Perspective (ß=-0.75, P<.01) subscale scores for LBP, with SEPCQ Sharing Information and Power subscale scores (ß=0.56, P<.05) contributing to both cohorts with knee (ß=0.56, P<.05) and LBP (ß=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.

The Relationship of the Therapeutic Alliance to Patient Characteristics and Functional Outcome During an Episode of Physical Therapy Care for Patients With Low Back Pain: An Observational Study.

OBJECTIVE: Research supports the relevance of the therapeutic alliance (TA) between patients and physical therapists on outcomes, but the impact of TA during routine physical therapist practice has not been quantified. The primary objective of this study was to examine the relationship between TA assessed during a physical therapy episode of care for patients with low back pain and functional outcome at the conclusion of care. The secondary objective was to examine psychometric properties of the Working Alliance Inventory-Short Revised (WAI-SR) form, a patient-reported TA measure. METHODS: This study was a retrospective analysis of prospectively collected data from 676 patients (mean [SD] age = 55.6 [16.1] y; 55.9% female) receiving physical therapy for low back pain in 45 outpatient clinics from 1 health system in the United States. Participating clinics routinely collect patient-reported data at initial, interim, and final visits. The lumbar computer-adapted test (LCAT) was used to evaluate functional outcome. The TA was assessed from the patient's perspective at interim assessments using the WAI-SR, bivariate correlations were examined, and regression models were examined if interim WAI-SR scores explained outcome variance beyond a previously validated multivariate prediction model. Internal consistency and ceiling effects for the WAI-SR were examined. RESULTS: Interim WAI-SR scores were not correlated with patient characteristics or initial LCAT, but they were correlated with final LCAT and LCAT change from initial to final assessment. WAI-SR total score (adjusted R2 = 0.36), and Task (adjusted R2 = 0.38) and Goal subscales (adjusted R2 = 0.35) explained additional variance in outcome beyond the base model (adjusted R2 = 0.33). Internal consistency was higher for WAI-SR total score (α = .88) than for subscales (α = .76-.82). Substantial ceiling effects were observed for all WAI-SR scores (27.2%-63.6%). CONCLUSION: Findings support the importance of TA in physical therapist practice. Measurement challenges were identified, most notably ceiling effects. IMPACT: This study supports the impact of the patient-physical therapist alliance on functional outcome. Results extend similar findings from controlled studies into a typical physical therapist practice setting. Better understanding of the role of contextual factors including the therapeutic alliance might be key to improving the magnitude of treatment effect for discrete physical therapist interventions and enhancing clinical outcomes of physical therapy episodes of care.