Heterogeneity across outcomes reported in clinical trials for older adults with depression: a systematic survey

The objective of our study was to identify outcomes reported in trials for older adults with depression and describe outcome heterogeneity.

We searched four databases to identify trials assessing any intervention for major depressive disorder among older adults published between 2011 and 2021. We grouped reported outcomes thematically and mapped them onto core outcome areas (physiological/clinical, life impact, resource use, adverse events, and death) and used descriptive analysis to summarize outcome heterogeneity.

There were 434 total outcomes reported by 49 included trials, which were measured using 135 different outcome measurement instruments and grouped into 100 unique outcome terms. Most outcome terms mapped to the physiological/clinical core area (47%), followed by life impact (42%). More than half of all terms (53%) were reported by only a single study. Most trials (n = 31/49) reported a single, discernible primary outcome. The most commonly reported outcome "depressive symptom severity" was assessed by 36 studies using 19 different outcome measurement instruments.

There is substantial heterogeneity in the outcomes and outcome measurement instruments used in geriatric depression trials. A standard set of outcomes and accompanying measurement tools is necessary to facilitate comparison and synthesis of trial findings.