Development of a theory-informed questionnaire to assess the acceptability of healthcare interventions

The theoretical framework of acceptability (TFA) was developed in response to recommendations that acceptability should be assessed in the design, evaluation and implementation phases of healthcare interventions. The TFA consists of seven component constructs (affective attitude, burden, ethicality, intervention coherence, opportunity costs, perceived effectiveness, and self-efficacy) that can help to identify characteristics of interventions that may be improved. The aim of this study was to develop a generic TFA questionnaire that can be adapted to assess acceptability of any healthcare intervention.

Two intervention-specific acceptability questionnaires based on the TFA were developed using a 5-step pre-validation method for developing patient-reported outcome instruments: 1) item generation; 2) item de-duplication; 3) item reduction and creation; 4) assessment of discriminant content validity against a pre-specified framework (TFA); 5) feedback from key stakeholders. Next, a generic TFA-based questionnaire was developed and applied to assess prospective and retrospective acceptability of the COVID-19 vaccine. A think-aloud method was employed with two samples: 10 participants who self-reported intention to have the COVID-19 vaccine, and 10 participants who self-reported receiving a first dose of the vaccine.