Task Sharing for the Care of Severe Mental Disorders in a Low-income Country

Background and rationale Task sharing mental health care through integration of mental health into primary health care (PHC) is advocated as a means of narrowing the treatment gap for mental disorders in low-income countries. In Ethiopia, it is estimated that only around 10% of people with severe mental disorders (SMDs) ever receive evidence-based treatment for their condition, largely due to scarcity of specialist mental health services. A task-sharing model of mental health care in PHC would be more affordable and accessible to the majority of persons with SMD who do not currently receive evidence-based mental health care. Furthermore, task sharing mental health care with PHC is about to be scaled up in Ethiopia in line with the National Mental Health Strategy. However, the effectiveness of the task sharing model of mental health care for people with SMD has not been evaluated systematically in a low-income country. In this study we propose to investigate non-inferiority of a task sharing model of mental health care in PHC compared to a less accessible, but more specialist, psychiatric nurse-led model of care. The specialist model of care has been demonstrated to be acceptable and associated with improved clinical outcomes for persons with SMD engaged in the service in Ethiopia thus making this an appropriate comparison model against which to evaluate non-inferiority of the task sharing model.

Methods Setting Meskan and Mareko districts, Gurage Zone, and Silti Zone, Southern Nations, Nationalities and People's Region, Ethiopia.

Design A parallel group, randomized, single-blinded, controlled non-inferiority trial.

Participants Adults (aged between 25 and 65 years) with severe mental disorders (DSM-IV diagnoses of schizophrenia or schizoaffective disorder, bipolar disorder or major depressive disorder) of a severity requiring continuing care who were (1) identified during a population-based survey carried out between 1998 and 2001, and are still under active follow-up, or (2) recruited from Butajira hospital psychiatric outpatient clinic.

Participants will be recruited and randomised in two phases. Phase 1 will include participants who are clinically stable, not pregnant or breastfeeding, not on depot medication and who have no co-morbid substance use or complex medical conditions. After a three month evaluation period, and if no safety or quality issues arise, the study will proceed to Phase 2. Phase 2 will include participants who have more complex needs or are less clinically stable.

New intervention Participants in the new intervention arm will receive a task sharing model of locally-delivered mental health care integrated into PHC. The intervention will be offered for 18 months.

Comparison intervention Participants in the active control arm will receive the established model of specialist mental health care delivered by psychiatric nurses at an out-patient clinic within Butajira general hospital and supported by outreach from project workers.

General objective To determine the acceptability, affordability, effectiveness and sustainability of mental health care for persons with SMD delivered by trained and supervised non-specialist, primary health care workers compared with an existing psychiatric nurse-led service.

Specific objectives For persons suffering from SMD in Butajira, Ethiopia,

1. To determine the effectiveness and cost-effectiveness of task sharing mental health care with PHC, compared to psychiatric nurse-led mental health care, on the primary outcome measure of symptom severity and on a series of secondary outcome measures.
2. To examine factors influencing the implementation of the task sharing intervention and future scale up, by examining feasibility, sustainability, quality, and safety, and by qualitative exploration of the experience of task sharing from the perspectives of both PHC workers and patients.

Hypothesis Persons with SMD who receive mental health care task-shared with PHC will have a non-inferior clinical outcome, defined as a difference in the mean symptom score on the Brief Psychiatric Rating Scale, expanded version (BPRS-E), of no more than six points higher, compared to persons with SMD who receive a psychiatric nurse-led model of mental health care, after 12 months of care under the comparison service models.

Sample size A total of 324 participants (162 in each arm) will be required to detect a six point higher mean BPRS-E score in the new intervention arm compared to the active control arm, at 90% power and 95% confidence, allowing for 30% refusals and loss to follow-up (n = 124 for Phase 1 and n = 200 for Phase 2).

Randomisation Sequence generation: Computerized generation of randomization list. Blocked randomization stratified by health centre catchment area.

Allocation concealment: Labelled, sealed envelopes containing cards with intervention allocation administered by an independent clinician.

Implementation: Enrollment will occur after participants have been screened for eligibility, given informed consent (or permission given by guardian) and undergone baseline evaluation. After enrollment, an independent clinician will inform the participant of their allocation status.

Concealment Partial concealment. Outcome assessment and data analysis will be carried out by investigators who are masked to the intervention allocation of participants.

Statistical methods Intention to treat will be the primary approach to data analysis, but per protocol analyses will also be used as this is thought to more conservative in the case of non-inferiority trials. The primary outcome measure will be analysed using linear regression adjusting for baseline symptom severity measured using BPRS-E.