Intervention for Antidepressant Deprescription in Primary Care: a Randomized Community Clinical Trial

MATERIAL AND METHODS Study design A randomized community clinical trial will be conducted. Population and sample The study population comes from an urban area of Cádiz, in the autonomous community of Andalusia (Spain), with a population profile characteristic of urban areas with access to primary health services. The study sample will include patients of both sexes treated in primary care in the urban area of La Laguna, Cádiz, who meet the following inclusion criteria: being of legal age (≥18 years), having received at least one prescription for an antidepressant in the year before the start of the study and having the physical capacity to go to the health center and the mental capacity to give informed consent. Patients who are minors, have changed health centers, have physical or mental disabilities (including advanced dementia, severe cognitive deficit, advanced Alzheimer's disease, and disability >70%), or are hospitalized at the time of selection are excluded. For the calculation of the sample size, the 325 antidepressant users identified in 2023 in the same primary care area were taken as a reference. Considering the expected effect of the intervention of 10% total or partial deprescription of antidepressants, a precision of 5%, and a confidence interval of 95%, a minimum sample of 98 patients was estimated to achieve clinical significance. An additional 10% was adjusted to this calculation to cover possible losses or refusals to participate in the study, resulting in a final sample of 108 patients. The selection of participants was carried out by simple random sampling, ensuring that all patients in the reference population have the same probability of being chosen, which guarantees a representative sample.

Sampling procedure Data collection will be carried out by accessing the information sources provided by the pharmacy unit of the District of Cádiz, Bahía-La Janda. In this unit, a pseudo-anonymized list of patients who have picked up antidepressants in pharmacies during the year before the start of the study will be obtained, using a mathematical coding system to preserve confidentiality.

The sample will be selected from the pseudo-anonymized list using simple random sampling. Subsequently, the list of selected patients will be sent to the address of the clinical management unit where the study will be conducted, which will be forwarded to the research team. The principal investigator will contact the selected subjects by telephone to invite them to participate in the study.

Intervention The intervention will begin with a first visit (V0), in which each participant will be provided with detailed information about the study and will be asked to sign the informed consent. In this initial visit, relevant variables will be collected through a specific questionnaire, including universal variables, sociodemographic variables, comorbidities, and possible drug interactions. In addition, questionnaires for the evaluation of anxiety and depression symptoms will be administered, such as the Hamilton scale for anxiety and the Beck Inventory for depression.

The intervention process will then consist of a series of visits scheduled in the work diary of the family doctor in charge of the deprescription. In the second visit (V1), the diagnosis and symptoms will be re-evaluated, including the detection of possible interactions or adverse reactions. If adverse effects are identified, the corresponding notification procedure will be followed and the dose will be adjusted if necessary. In a third visit (V2), a telephone follow-up will be carried out, which will include psychotherapeutic reinforcement, and in the final face-to-face visit (V3), the deprescription intervention will continue and the results will be evaluated (Figure 1).