Psychiatric Consultation-Liaison Intervention in Primary Care: A Pilot Study

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

2.1 Hypothesis and primary objective

2.1.1 For the Pilot study (PLIMeC-P) :

To determine whether the planned multicentric mixed method design randomized controlled trial is feasible and practicable.

• Essential activities in the PLIMeC-P will include testing procedures for assessment methods; conducting initial semi-structured individual interviews to test and adjust the moderator's guide (questions concerning PCPs, CL-psychiatrists and patients lived experience of the intervention); first evaluation and analysis of initial results. These activities will be carried out through ongoing collaboration between the study sites.

2.1.2 For the PLIMeC main study:

The primary objective is to compare the efficacy of a CL psychiatry intervention (case discussion, brief intervention, and conjoint feedback session - intervention arm) introduced in a primary care setting, with treatment as usual (TAU - control arm), for patients suffering from mental health problems. More precisely, the investigators will focus on the effect of such an intervention on the psychiatric symptoms and the quality of life of participants. The investigators hypothesize that a significant clinical change will be produced in the intervention arm in comparison with the control arm.

The secondary objective is to explore qualitatively the participants' lived experience of the management of their mental health problems in primary care and the effect of a CL psychiatry intervention on this (as well as on doctor-patient relationship), and, in parallel, the PCPs' and psychiatrists' lived experience of their collaboration (barriers and/or facilitators, needs, affects, thoughts etc.).

An exploratory objective is to investigate aspects of public health efficiency, in order to answer the question of at what level to best meet psychiatric outpatients and to where best allocate psychiatric resources. The investigators expect a high level of complexity in the basis evaluation of the clinical situations and hypothesize that healthcare professionals' collaboration will ameliorate with the CL psychiatry intervention.

2.2 Endpoints are detailed in the Outcome Measures session.

2.3 Study design

The PLIMeC multicenter study is a randomized controlled trial, with a mixed methods design (i.e., using both quantitative and qualitative assessment), including a control arm (CL-psychiatry intervention), and an intervention arm (Treatment as Usual - TAU), in primary care settings in which the intervention of a CL-psychiatrist was implemented.

A potential problem associated with the proposed study design could be the specificity of different local primary care settings (different regions, different organization, different clinical experiences of PCPs, different sizes, etc.). To minimize potential bias, first, both arms will be studied in the same primary care settings, with patients naturally seeking help at primary care practices and being randomized. Second, the investigators will use complementary qualitative data to further interpret the quantitative data (employ a mixed-method design). Finally, a variety of private primary care practices, with different demographic variables, will be included in a large region of French-speaking Switzerland for the main study (already 3 different private primary care practices, in different regions of two different cantons for the pilot study). The employment of validated questionnaires, which will be monitored during the pilot study, will also ensure the quality of our data.

In addition, the investigators are aware that the sensitivity of PCPs to mental health problems, and their training in these issues, may vary from one practitioner to another. Nevertheless, such heterogeneity characterizes the current state of practice. Consequently, the investigators do not consider this heterogeneity to be a source of bias, as the aim of the PLIMeC study is to estimate the effect of the intervention in the current healthcare context (real-world data). On the other hand, PCPs working in practices that agreed to take part in the study may be on average more sensitive to education about mental health issues than their colleagues not taking part in the study, thereby constituting a recruitment bias. In order to reduce this bias, with the pilot study (PLIMeC-P) a first analysis will be conducted of the different private primary care practices (3 practices), in different regions, with the participating PCPs. The investigators will identify the level of training and/or awareness of mental health issues among the PCPs included in the study (demographic elements collected before the start of the study) to identify trends, to better calibrate the main study, and carry out sample size calculations.

Regarding the qualitative part of the design, a potential problem could be the fact that the local PI supervises the clinical project. To minimize potential bias, reflexivity will be applied during the research process, and the investigators will ensure that the research assistant who will conduct the individual semi-structured interviews will not be directly involved in the clinical project and will have no hierarchical link with the participating PCPs and CL-psychiatrists. Moreover, to ensure the quality of our qualitative data the investigators will use a moderator guide drawn upon three previous qualitative research studies: a) a study on the referral process, as experienced by PCPs; b) a study on psychiatrist/PCP discussion groups, with a sociological perspective (observation in situ); c) a qualitative study on the experience of PCP regarding consultation-liaison psychiatry interventions in primary care. Finally, the interview guide will be monitored during the PLIMeC-P.

2.4 Regarding the study intervention, see Arms and Interventions session. 3. STUDY POPULATION AND STUDY PROCEDURES

3.1 Study population:

The study population will be composed of patients who present mental distress in primary care consultations. They will be part of the PCP patient list (new or regular patients). For the PLIMeC-P, two private primary care group practices, in the canton of Neuchâtel (in two distinct regions), and one private primary care practice, in the North Vaud (in Yverdon), will be mobilized, a total of three primary care practices, in three different regions. Participants will be indicated by their PCP working in these practices and will be enrolled by the local PIs or delegates. More precisely, firstly, the patient will be orally asked to consent in order that his/her details are communicated by the PCP to the respective local PI or delegates. Afterwards, the local PI or his/her delegates will hold recruitment, if the inclusion criteria are met and if there are no exclusion criteria, after transmitting the necessary information concerning the study to their patients. Interested patients will be asked to review the information and consent form and sign it if they consent to participate in the study.

For Inclusion and Exclusion criteria, see Eligibility session.

For the PLIMeC-P, 15 eligible participants are expected for the control arm (TAU) and 15 eligible participants for the intervention arm, with a total number of 30 participants. The investigators will include 10 participants from each of the three sites (5 participants in each arm, per site). In parallel, part of the participating patients (3 from TAU arm and 3 from the intervention arm), who will be chosen for their mixed sociodemographic characteristics, will be asked to participate in individual semi-structured interviews, in order to explore qualitatively their perception regarding usual mental health care and the proposed intervention.

Moreover, the participating PCPs and psychiatrists will also be invited to undergo individual semi-structured interviews for the qualitative part of the study, in order to obtain a global understanding of the impact of the intervention. They will decide if they want or not to participate, having all the liberty to refuse the invitation. No health-related data will be collected.

No compensation or payment is intended to be given to the participants or the collaborating PCPs.

3.2 Study procedures

Demographic data and baseline questionnaires will be addressed to the participants together with the informed consent by email or Post (depending on the participant's choice). Only participants completing the baseline assessment will be included in the study. The baseline questionnaire assessment lasts around 15 minutes. It will include demog

• The lived experience of the participants [Срок оценки: 3 months (T1) after enrolment, semi-structured interviews will be carried out for both arms (control and intervention) of participants]
• The lived experience of the implicated clinicians [Срок оценки: 6 months after the beginning of the study, semi-structured interviews will be carried out for implicated clinicians]