Cross-Sectional Reference Data From 29 European Countries for 6 Frequently Used Depression Measures

Cross-sectional reference values are needed to enable adequate interpretation of individual and group-level scores of frequently used depression measures in research and clinical practice.

To provide age-, sex- and country-specific reference values for the PROMIS depression metric as well as 6 frequently used depression measures.

Within the cross-sectional European Health Interview Survey (EHIS) wave 3, depressive symptoms were assessed using Patient Health Questionnaire (PHQ)-8 in a general European population from 2018 to 2020. PHQ-8 data were used to score depression severity on the Patient Reported Outcomes Measurement Information System (PROMIS) depression T-score metric and estimated reference scores for 6 other measures. EHIS wave 3 had response rates ranging from 12% to 78% with 22 countries having a response rate of over 50%. PHQ-8 responses from the general population across 29 European countries were analyzed from March to October 2023.

Completion of EHIS.

PROMIS depression T-score estimates.

A total of 287 530 participants from the general population (156 655 [54.1%] were female) provided PHQ-8 responses. The median (IQR) PROMIS depression T-score of the overall European population was 45.33 (39.11-51.68), 44.11 (38.06-50.40) for male participants, and 46.37 (40.00-52.76) for female participants. Lowest scores were observed in Serbia with a median (IQR) of 40.81 (35.45-46.59) and highest were observed in Iceland (48.60 [42.60-54.45]).

In this cross-sectional study of depressive symptom scores in the general population, scores differed by age, sex, and country. Item response theory modeling and quantile regression enabled modeling of depression questionnaire reference data on a common, instrument-independent metric.