Systematic depression screening in high-risk patients attending primary care: a pragmatic cluster-randomized trial

BACKGROUND: Systematic screening for depression in high-risk patients is recommended but remains controversial. The aim of this study was to assess the effectiveness of such screening in everyday clinical practice on depression recognition. METHODS: A pragmatic, cluster randomized, controlled study that randomized primary care physicians (PCPs) in Spain either to an intervention or control group. The intervention group (35-PCPs) received training in depression screening and used depression screening routinely for at least 6 months. The control group (34-PCPs) managed depression in their usual manner. Adherence to (1–6; never-very frequently), feasibility (1–4; unfeasible-very feasible), and acceptance (1–5; very poor-very good) of the screening were evaluated. Underrecognition (primary outcome) and undertreatment rates of major depressive disorder (MDD) in the two groups were compared 6 months after randomization in a random sample of 3737 patients assigned to these PCPs using logistic regression adjusting for the clustering effect. RESULTS: No significant differences were found for recognition rates (58.0% vs. 48.1% intervention vs. control; OR [95%CI] 1.40 [0.73-2.68], p = 0.309). The undertreatment rate did not differ significantly either (p = 0.390). The mean adherence to depression screening was 4.4 ± 1.0 (‘occasionally’), the mean feasibility was 3.1 ± 0.5 (‘moderately feasible’), and the mean acceptance was 4.2 ± 0.6 (‘good’). CONCLUSIONS: This research was not able to show effectiveness of the systematic screening for MDD in high-risk patients on depression recognition in primary care. The poor adherence to screening implementation could partially explain the results. These reflect the difficulties of putting into practice the clinical guidelines usually based on interventional research. TRIAL REGISTRATION: Clinicaltrials.gov NCT01662817