Abstract
Purpose: Interest in measuring the therapeutic alliance has grown in recent years in both the clinical field and the literature. Several instruments can be used to measure the therapeutic alliance in physiotherapy, and choosing the most appropriate one is challenging. The purpose of this systematic review was to (1) identify the instruments that have been used to evaluate the therapeutic alliance in physiotherapy and (2) appraise the methodological quality of studies of the psychometric properties of these instruments. Method: The researchers carried out a systematic search in MEDLINE, SciELO, PsycINFO, Theseus, Cochrane Library, and Open Grey. Only articles published in English and Spanish were included. The articles were evaluated by two independent reviewers in accordance with the COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) and Preferred Reporting items for Systematic Review and Meta-Analysis standards, using the four-point COSMIN checklist. Results: Four studies were included in this review, and four instruments evaluated the therapeutic alliance in physiotherapy. The methodological quality of the studies was fair for most of the psychometric characteristics analyzed. Conclusions: The Working Alliance Inventory is the best instrument to measure therapeutic alliance and the measure that had the greatest number of psychometric properties evaluated against the COSMIN standard. More studies of high methodological quality are required to evaluate the psychometric properties of the instruments used to assess the therapeutic alliance in physiotherapy.