The goal of this systematic review is to merge evidence from literature regarding the influence of patients’ perceived working alliance on pain and physical functioning in patients with chronic musculoskeletal pain. The intention was to conduct another review when new articles had been published. Based on the cohort studies that have been included in the research, it appears that there is evidence that working alliance contributes to pain reduction and evidence that working alliance contributes to physical functioning measured by means of questionnaires in patients with chronic musculoskeletal pain (Table 3). Additionally, there is evidence of the influence on pain interference. The influence of working alliance on treatment results is small but significant.
The results of this review underpin the results found in the previous review of Hall that working alliance had an influence on pain [4], even though the current review included an additional three studies [5, 30, 31] and did not include the results of one dissertation that was beyond the strict inclusion criteria of this review [34]. Moreover, the results resemble those in a review of the influence of working alliance in psychotherapy [3]. Taking into account the latter results, it could be concluded that there is strong evidence that a patient’s perception of working alliance has an influence on the results of therapy as evidenced by pain and physical functioning.
Patient-centred communication is related to a patient’s perceived positive working alliance [35]. Working alliance was measured in most of the included studies with the WAI that comprised agreement on goals, collaboration with tasks, and establishment of the patient-therapeutic bond [14, 15]. Constructs that are related to a sense of positive working alliance are, first, allowing patient involvement in the consultation process that may influence the WAI construct agreement on goals, second, the trust that could influence the WAI construct collaboration with tasks; and, third, emotional support that can influence the establishment of the patient-therapeutic bond [35]. It is recommended to study the relation between the latter causative factors for a positive perception of working alliance.
As in all reviews, this review could have been biased based on the included studies and the method used for this review. There could possibly have been a language bias based upon the fact that only English and Dutch studies are included. During our intensive search, there were no other studies that we could not include based on the language. The studies that were included were performed in the USA, Germany, Australia and Canada. We may have missed studies that were performed in other countries. Additionally, there was heterogeneity between the number and age of patients, the measurement instruments, the time of treatment session for gathering the information of working alliance, and the outcome measurements of especially physical activity. The number of patients differed from 53 to 688 patients and were not taken into account during analyses. Studies were not excluded based on the age of patients because there is a limited availability of studies. However, in future research concerning working alliance, it would be interesting to take the age of the patient population into consideration because the effect of age on pain sensitivity and pain perception is evident [36, 37]. Another confounding variable may possibly have been the duration of pain and pain severity at baseline. Yet the results of one study that included patients that had suffered pain for more than six months resembled the results of the other included studies [29] and there were no pregnant differences of pain severity at baseline between included studies (Table 2). It is unknown what effect the diversity of interventions and the amount and quality of communication during intervention had on the results of a patient’s perception of working alliance and therewith the results of this study. Only one study video recorded the therapist’s communication during intervention [31]. It is recommended to observe and describe the communication during intervention in future studies on working alliance. The validity and reliability of the measurement instrument of working alliance were good in four of the five studies [5, 28, 29, 31]. In one study, the PHYSAT was used that was not validated [30]. However, if the results of that study were excluded from the best evidence synthesis, it would not affect the results of the best evidence syntheses. The treatment session at which the working alliance was measured differed considerably. The point of measurement of working alliance varied from directly after the first treatment until after the therapeutic program ended. Although the measurement points differ, the influence of working alliance that was measured at the end of all of the treatment sessions was not greater than the effect of working alliance in a study that measured directly after the first session (Table 2). It would be interesting to conduct research where the moment of the application of the working alliance is the primary factor of influence. Finally, the physical activity measurements to measure treatment results of the included studies differed from questionnaires (ODI and RMDQ) to functional capacity tests. Previous studies indicated that psychosocial variables, such as working alliance, are both related to functional capacity and to pain [38, 39]. Still, this diversity of outcome measurements used in the included studies might have caused a bias on the results of this review. Another bias might have occurred while performing the method of this review. This study was originally performed by the second author who was writing a Bachelor of Science thesis of physical therapy. In a second stage, the first author repeated the search and data extraction. This process could have caused a bias although both authors are very thorough, and the first author has published several systematic reviews in peer reviewed journals. Besides the limitations, there are also strengths in this research. The research process has been performed thoroughly following certain criteria beginning with a systematic search for articles, followed by a grading of the methodological quality, and the application of best-evidence syntheses. Thus, a solid systematic review has been compiled.
A recommendation for further research is to perform additional RCT’s in which specific aspects of working alliance (agreement on goals, tasks and relation) resulting in additional information about the most active ingredient of working alliance in conjunction with specific subgroups of patients with diverse health conditions, age, specific physical therapy modalities, specific communication styles that can be recorded, and specific outcome measures such as the ODI, RMDQ or functional capacity tests.
The moment of measuring working alliance varied between being studies from directly after the first intervention until after the entire treatment period. Measuring patient’s perceptions of working alliance at these diverse points during treatment are predictive for an improved treatment outcome. Therefore, a recommendation to practice is to be sensitive to and measure a patient’s perceived working alliance during therapy in order to detect this predictive factor on therapy results. In psychotherapie, the therapist’s feedback on a patient’s perceived working alliance seems to predict improved psychological functioning [40–42]. Further study is needed on the effect of feedback on pain and physical functioning. Communication skill training might be taken into consideration since it is effective for physical therapists [43].