Development and validation of the Out-of-Hospital Adherence Questionnaire for Stroke Patients (OHAQ-SP).

Background: The extent of rehabilitation of stroke patients outside the hospital is contingent upon their dedication to rehabilitative exercises, adherence to a suitable diet, and medication protocols. Therefore, multiple aspects of compliance must be assessed. Questionnaires are indirect measurements that are economical and easy to use. However, questionnaires should meet specific criteria to minimize errors and ensure reprehensibility of the results.

Objective: To develop a new questionnaire-based assessment tool for out-of-hospital treatment adherence in stroke patients and to evaluate the psychometric properties and feasibility of the questionnaire by conducting preliminary measurements in the stroke population. The questionnaire should have at least one validity measure and one reliability measure.

Methods: A preliminary "OHAQ-SP" was developed based on a literature review and two rounds of Delphi expert consultation. Between April 1 and July 2022, 308 stroke patients revisited the neurology departments of four Grade A tertiary hospitals in Shanghai using the convenience sampling approach. Various statistical methods, such as item analysis, correlation analysis, exploratory factor analysis, confirmatory factor analysis, and the internal consistency measure Cronbach's α coefficient, were employed to assess the reliability and validity of the questionnaire.

Results: A total of 290 questionnaires were collected; the Cronbach's α coefficients were 0.936, 0.862, 0.916, and 0.928 for the different sections, and the overall Cronbach's α coefficient for the entire scale was 0.902. The results of the confirmatory factor analysis were CMIN/DF = 2.490, RMR = 0.05, GFI = 0.901, NFI = 0.927, IFI = 0.955, and RMSEA = 0.054. The standardized loading values varied between 0.717 and 0.916. The combined reliabilities of the four dimensions were 0.936, 0.864, 0.917, and 0.929, respectively. The average variance extraction values for the four dimensions are 0.676, 0.614, 0.611, and 0.652, respectively.

Conclusion: The OHAQ-SP is a reliable and accurate instrument for evaluating medication use, nutritional status, and behavior throughout the out-of-hospital rehabilitation phase.