Measurement properties of depression questionnaires in patients with diabetes: a systematic review

Purpose To conduct a systematic review on measurement properties of questionnaires measuring depressive symptoms in adult patients with type 1 or type 2 diabetes. Methods A systematic review of the literature in MEDLINE, EMbase and PsycINFO was performed. Full text, original articles, published in any language up to October 2016 were included. Eligibility for inclusion was independently assessed by three reviewers who worked in pairs. Methodological quality of the studies was evaluated by two independent reviewers using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist. Quality of the questionnaires was rated per measurement property, based on the number and quality of the included studies and the reported results. Results Of 6286 unique hits, 21 studies met our criteria evaluating nine different questionnaires in multiple settings and languages. The methodological quality of the included studies was variable for the different measurement properties: 9/15 studies scored 'good' or 'excellent' on internal consistency, 2/5 on reliability, 0/1 on content validity, 10/10 on structural validity, 8/11 on hypothesis testing, 1/5 on cross-cultural validity, and 4/9 on criterion validity. For the CES-D, there was strong evidence for good internal consistency, structural validity, and construct validity; moderate evidence for good criterion validity; and limited evidence for good cross-cultural validity. The PHQ-9 and WHO-5 also performed well on several measurement properties. However, the evidence for structural validity of the PHQ-9 was inconclusive. The WHO-5 was less extensively researched and originally not developed to measure depression. Conclusion Currently, the CES-D is best supported for measuring depressive symptoms in diabetes patients.