Background The prevalence of depression is high and the elderly have an increased risk of developing a chronic course. International data suggest that depression in the elderly is under-recognised, the latency before clinicians provide a treatment plan is longer, and elderly patients with depression are not offered psychotherapy to the same degree as younger patients. Although recommendations for the treatment of elderly patients with depression exist, health care professionals adhere to these recommendations to a limited degree only. Investigators conducted a systematic review to identify recommendations for managing depression in the elderly and prioritised six recommendations. Investigators identified and prioritised determinants of practice related to implementation of these recommendations in primary care, and subsequently discussed and prioritised interventions to address the identified determinants. The objective of this study is to evaluate the effectiveness of these tailored implementation interventions to implement six recommendations for the management of elderly patients with depression in primary care.

Methods/design Investigators will conduct a pragmatic cluster randomised trial comparing implementation of the six recommendations using tailored interventions with usual care. Investigators will randomize 80 municipalities into one of two groups: an intervention group, to which investigators will deliver tailored interventions to implement the six recommendations, and a control group, to which investigators will not deliver any intervention. Investigators will randomise municipalities rather than patients, individual clinicians or practices because we will deliver the intervention for the first three recommendations at the municipal level and investigators want to minimise the risk of contamination across practices for the other three recommendations. The primary outcome is the proportion of general practitioners' behaviours which are consistent with the recommendations.

Discussion This trial will investigate whether a tailored implementation approach is an effective strategy to improve collaborative care in the municipalities and health care professionals' practice towards elderly patients with depression in primary care. The effectiveness evaluation described in this protocol will be accompanied with a process evaluation exploring why and how the interventions were effective or ineffective.

Inclusion Criteria:

Home-dwelling patients aged 65 or higher, who have a diagnosis of depression, according to International Statistical Classification of Diseases and Related Health Problems, Tenth Revision

Exclusion Criteria:

Patients will be excluded if they have a diagnosis of dementia, bipolar disorder or reside in nursing homes or is assessed by their practitioner to have low life expectancy.