A Pilot Study on the Impact of a Psychiatric Consultation-Liaison Intervention in Primary Care Medical Consultations in French Speaking Switzerland (PLIMeC-P): A Mixed Method Randomized Controlled Trial

1. BACKGROUND AND RATIONALE

According to the WHO, mental health is a central component of personal health and well-being. Mental disorders claim a heavy toll on individuals, their families and society, and are a major public health issue. In Switzerland, 18-21% of the population suffers from psychological distress, of which 12.7% have been diagnosed with a psychiatric disorder. Primary care physicians (PCP) are usually the first contact with healthcare for patients suffering from psychological distress or mental disorders. More precisely, a prevalence of 25-60% is reported for mental disorders in primary care, and this is the case worldwide, as well as in Switzerland. More than half of those patients have no specialized psychiatric care and PCPs tend to base their treatment on pharmacotherapy, support therapy, and psycho-education. PCPs are therefore key stakeholders in the detection, prevention, and adjusted treatment management of mental disorders.

Therefore, the optimization of both the quality of primary care interventions and cooperation with psychiatric care networks are important challenges. Patients with mental disorders are often considered complex patients and tend to be frequent care users, PCPs feeling lacking competency in dealing with them. Close collaboration between psychiatrists and PCPs, and multidisciplinary interventions can reinforce PCPs' skills and help them gain confidence in managing mental disorders. A wide range of collaboration models between psychiatrists and PCP exist, the Consultation Liaison (CL) interventions being one of them. However various barriers are described regarding such a collaboration, notably because of different treatment paradigms and of lack of accessibility.

In Switzerland, CL-psychiatric interventions are mainly used in hospital settings. To introduce a model of care that offers optimal management of mental disorders in primary care, ensuring an adequate continuity and good coordination of care, for patients with complex needs, a multidisciplinary collaboration project between PCP and CL-psychiatrists has been developed in a region of French-speaking Switzerland. A CL-psychiatric consultation within primary care practices has been implemented, to promote the quality of mental health care and facilitate communication between healthcare professionals. The need for further research on the implementation of psychiatric interventions in primary care is clearly highlighted. Moreover, the experience of patients, of PCPs and of psychiatrists during such interventions is rarely investigated, whereas emotional experiences seem to present one of the central obstacles to the optimal management of mental disorders in primary care.

Our study will investigate the impact of a CL-psychiatric intervention for patients with mental health problems in private primary care group practices, in French-speaking Switzerland, using mixed methods (qualitative and quantitative). In parallel, the lived experience of PCPs and CL-psychiatrists will be investigated during their collaboration, in order to better understand the factors that influence this type of intervention and to better qualify its results. Initially, a pilot study (PLIMeC-P) of the multi-center, multi-method PLIMeC study will be conducted, to determine whether the PLIMeC study is feasible. 2. STUDY OBJECTIVES AND DESIGN