Stability of the effects of guideline training in primary care on the identification of depressive disorders

Background: Depressive disorders are a highly important group in primary care. However, patients with depressive disorders are often not diagnosed correctly. There is evidence that detection and correct diagnosis rates can be improved by implementing diagnostic guidelines within practical skills training. Aim: To analyse short- and medium-term effects of guideline training on the identification of depressive syndromes by GPs. Methods: In a naturalistic controlled clinical trial, 2585 primary care patients were screened for depressive disorders, and GPs' diagnoses (n = 29) were assessed. Evidence-based guidelines for depressive disorders were implemented, and training for diagnostic skills was given within a multifaceted intervention. The primary outcome was the identification of depressive patients, assessed as the congruence between GPs' diagnoses and patients' self-assessment. Results: Following the training, the identification rate of depressive disorders improved significantly in the intervention group. The improvement increased further in the 1-year follow-up, although this was not statistically significant. At the same time, the diagnostic odds ratios indicate no alteration of diagnostic accuracy, i.e. correct allocation of depressive versus non-depressive patients. Although the odds ratios of the improvements do speak in favour of intervention, this could not be statistically verified. Conclusions: Guideline implementation improves the accuracy of GPs' diagnostic behaviour regarding depressive disorders in the short term and possibly in the medium term. Limitations result from the naturalistic design of the study.