Evaluating the role of levels of exposure to a task shared depression counselling intervention led by behavioural health counsellors: outcome and process evaluation

BACKGROUND: In the context of a large treatment gap for common mental disorders (CMDs) and shortage of mental health specialists in low- and middle-income countries, there is increasing evidence of the effectiveness of task sharing of counselling interventions to increase access to mental health care for CMDs at primary health care level. This study evaluated the relationship between levels of exposure to a task-shared counselling intervention and psychosocial outcomes (depression, functional disability, internalised stigma and social support) in chronic care service users with comorbid depression in South Africa guided by the Medical Research Council process evaluation framework. Implementation and participant-level factors that promote greater exposure were also investigated. METHOD: The study design was a cohort study comprising of 173 participants referred by primary health care nurses for the task-shared counselling intervention. The study site comprised four primary health care facilities in a sub-district of the Dr. Kenneth Kaunda district in the North West Province of South Africa. The participants were assessed for psychosocial outcomes at three time points: baseline, 3 months and at 12 months. The number of counselling sessions each participant was exposed to was collected for each participant. Linear regression models were used to test the influence of counselling exposure on each of the psychosocial variables between baseline and endline. In-depth qualitative interviews were conducted on 29 randomly selected participants, stratified according to exposure to counselling sessions, and analysed using framework analysis. FINDINGS: Findings from the cohort study indicated a significant reduction in depression severity at 12 months. Internalised stigma and functional disability improved from baseline to endline. Participants receiving 5–8 sessions have the greatest reduction in PHQ9 scores from baseline to endline (β = − 2.46, 95% CI − 5.06 to 0.15) compared to those with 0 sessions (β = − 0.51, 95% CI − 3.62 to 2.60, p = 0.064). The WHODAS scores decreased significantly more from baseline to endline among those who received 5–8 sessions (β = − 10.73, 95% CI − 19.86 to 1.59) compared to those with 0 sessions (β = 2.25, 95% CI − 8.65 to 13.14, p = 0.021). No significant differences as a function of levels of counselling exposure from baseline to endline was observed for OSS-3 scores. An improvement in ISMI scores from 1–4 sessions to 5–8 sessions was found (β = − 4.05, 95% CI − 7.30 to − 0.80, p = 0.015). The qualitative process evaluation indicated that the service was acceptable and accessible; but that session attendance was hindered by women’s’ caregiving burden, poor counsellor attributes and poor referral processes. CONCLUSION: Exposure to a greater number of sessions (5–8 sessions) was found to optimize functional ability, reduce stigma, and potentially reduce depression symptoms. In order to enhance session attendance, lay counsellor delivered psychosocial interventions need to pay attention to (i) counsellor selection criteria, particularly person-centred care qualities; and (ii) strengthening referral processes in contexts where mental health literacy is low.