Measuring working alliance and technical alliance from the perspective of healthcare professionals working with people with mild intellectual disabilities: Adaptation, factor structure and reliability

Background
The establishment of a valuable and meaningful working alliance between people with mild intellectual disabilities (IDs) and healthcare professionals is critically important for improving both the quality of life and impact of therapy for people with mild IDs. Measuring the working alliance as a treatment or support component is therefore of utmost relevance. In light of the increased use of eHealth tools, it is also essential to measure the alliance using these tools, which is referred to as technical alliance. There was a lack of validation of these two measurements for healthcare professionals working with people with mild IDs, which this study sought to address.

Method
Both the validated Working Alliance Inventory – Short Form – MID (WAI-SF-MID) and Technical Alliance Inventory – Short Form – MID (TAI-SF-MID) for general patient populations were adapted for healthcare professionals working with people with mild IDs. A two-step approach was conducted to systematically adapt both measurements with an expert group of healthcare professionals. Confirmatory factor analysis was conducted to test a three-factor structure for both the WAI-SF-MID (N = 199) and the TAI-SF-MID (N = 139), and internal consistency was determined for both scales.

Results
An acceptable-to-good model fit was found for both the WAI-SF-MID and the TAI-SF-MID; confirmatory factor analysis confirmed a three-factor model for both measurements. Cronbach's alpha and McDonald's omega were excellent for both total scales (≥0.90) and acceptable to good for sub-scales of both versions.

Conclusion
Both the WAI-SF-MID and the TAI-SF-MID are promising measurements for determining healthcare professionals' perspective on the (digital) working alliance with people with mild IDs.