Collaborative Multidimensional Intervention for Depression in Chile

This study protocol aims to determine the efficacy of a collaborative multidimensional model (CMD) to improve the results of depression in primary care (PHC) in Chile. The CMD includes training of PHC teams, on the recognition of clinical, functional and psycho-biographic dimensions associated to a complex depression sub-type, difficult to treat, prevalent in PHC in Chile, for which there are no recommendations in current clinical guidelines. This model implies the implementation of a collaborative model, trauma informed care, patient- centered, that includes a case manager, the use of instruments and a close relationship between the PHC team and the specialty level. At least twelve primary care teams belonging to the Maule Region will be randomly assigned to one of the two arms of the study, the CMD group and the current standard model (SM). After the implementation of the CMD, an intentional sample of 394 participants who agreed to participate, with prior informed consent, will be evaluated by a blind research team at the beginning, at three and six months with a battery of instruments. An improvement in depressive symptoms, anxiety and functional variables is expected in participants treated in CMD versus SM. This protocol was approved by the Research Ethics Council of the University of Talca, Talca. The goal is to publish the preliminary results in December 2022.

The research design is a cluster randomized clinical trial. Inter-professional teams from at least 12 primary care centers of the Maule area will be randomized in two arms: intervention and control. The intervention arm will receive a training in the collaborative multidimensional model for depression (CMD) and the control arm will be trained in the current clinical guide (SM).

After the CMD implementation, a sample of 394 participants entered to treatment for depression at their respective center will be invited to participate. This sample has been calculated estimating a maximum error of 5 %, a confidence level of 95 %, a power of 80 % a maximum variance of 50 % and a retention of 85 %.

The patients who agreed to participate, will be treated by their respective PHC team and their therapeutic indications will be included in the official clinical records for each participant. Also these patients, after informed consent, will be evaluated by a blind external research team at the beginning, at three and six months with a battery of instrument.

The informed consents will be kept in locked folders. The data obtained by the external evaluators will be confidential, entered into a virtual spreadsheet in a coded form on a server of the U. of Talca through a personal computer. Participant's diagnoses will be coded using the MINI.

A protocol for the management of adverse situations of an emergency nature will be provided.

The results will be presented according to the CONSORT guide for randomized clinical trials, with its extensions to cluster and non-pharmacological interventions.

Analysis of the primary and secondary outcomes will be performed by intention to treat. In the initial analysis, the balance between the characteristics of the different samples will be evaluated and a linear multi-variable regression will be performed to establish differences at 3 and 6 months, adjusting the results according to the initial data, in case of imbalance for all outcomes. A sensitivity analysis based on different assumptions will also be implemented, to investigate the possible effects of missing data. Statistical analysis will be done with SPSS software.

The research protocol was approved by the Ethics Committee of the University of Talca and approved by the Agencia Nacional de Investigación y Desarrollo (ANID), the national institution that audit the project through a follow-up sheet and yearly controls.

Eligibility Criteria:
Inclusion Criteria:

* Starting the treatment for depression in Primary Care according the Health Guarantees.
* Confirmed depression diagnosis according to the Mini International Diagnostic Interview Mini International Neuropsychiatric Interview (MINI, Sheehan et al. 1998).

Exclusion Criteria:

* Sensory disability
* Inability to provide the informed consent
* not having contact phone number
* Continuing treatment for depression
* High suicidal risk
* Suspected bipolar and psychosis.