Test–retest reliability and measurement error of the WHO-5 Well-being Index and the Problem Areas in Diabetes questionnaire (PAID) used in telehealth among patients with type 1 diabetes

Background Patient-reported outcome (PRO) measures may be used in telehealth for the clinical assessment of mental health and diabetes distress, which are important aspects in diabetes care, but valid and reliable instruments on these topics are necessary. We aimed to evaluate the test–retest reliability and measurement error of the Danish versions of the WHO-Five Well-being Index (WHO-5) and Problem Areas in Diabetes (PAID) questionnaires used in a PRO-based telehealth intervention among patients with type 1 diabetes. A further aim was to evaluate the test–retest reliability of single items concerning patients’ symptom burden and general health status. Methods Outpatients with type 1 diabetes from the Steno Diabetes Center Aarhus, Aarhus University Hospital, Denmark, were enrolled from April 2019 to June 2020. Patients aged ≥ 18 who had type 1 diabetes for > 1 year, internet access, and the ability to understand, read, and write Danish were included. Intraclass correlation coefficients (ICC) and weighted Kappa values were used to assess test–retest reliability, and measurement error was assessed by estimating the minimal detectable change (MDC). Results A total of 146/255 (57%) patients completed the web questionnaire twice. The median response time between the two-time points was five days. The ICC of the WHO-5 scale was 0.87 (95% CI 0.82–0.90), and MDC was 18.56 points (95% CI 16.65–20.99). The ICC of the PAID scale was 0.89 (95% CI 0.84–0.92), and MDC was 11.86 points (95% CI 10.46–13.70). Overall, test–retest reliability of single symptoms and general health status items was substantial. Conclusions The WHO-5 and PAID questionnaires, and single symptoms and general health status items showed substantial test–retest reliability among patients with type 1 diabetes. Measurement error of the PAID questionnaire was considered acceptable; however, a larger measurement error of the WHO-5 questionnaire was observed. Further research is recommended to explore these findings.