Integrating a Stepped Care Model of Screening and Treatment for Depression Into Malawi's National HIV Care Delivery Platform

BACKGROUND

Major depressive disorder imposes catastrophic health and economic impacts in Malawi, and throughout sub-Saharan Africa. Depression is a leading cause of disability in Malawi. Yet, best evidence suggests that over 90% of individuals with the condition receive no treatment (1). The cost of inaction is liable to have wide-ranging impacts. In terms of health, depression-when untreated-typically observes a recurrent trajectory across the lifespan, and is associated with significant depreciation in quality of life. Depression also indirectly impacts other health outcomes, including HIV outcomes such as adherence to antiretroviral therapy and health-seeking behavior. In terms of social ecology, depression affects interpersonal relationships, engagement in household activities, and labor force participation. The World Economic Forum has estimated a $30 trillion loss over a twenty-year span due to neglected treatment of neuropsychiatric conditions, largely due to lost labor force participation (2).

Integrating depression care into Neno's HIV platform represents a cost-effective, scalable solution in Neno District, Malawi, consistent with best practices. Over the past 10 years, Malawi has enrolled over a million individuals in antiretroviral therapy. Current enrollment levels stand at 580,000. This has been achieved by introducing a framework of HIV care delivery, the basis of which is a network of 706 HIV clinics throughout the country. Over this same timeframe, HIV has evolved from an acute condition with poor prognosis, to a chronic condition with vastly improved survival rates. Given this context, the HIV system is a strategic point of entry for screening and treating depression, as it represents a leveragable chronic care system. In Neno District, HIV facilities have already transitioned into an integrated chronic care platform for treating conditions like diabetes, hypertension, asthma and epilepsy. Likewise, community health screenings, routine in Malawi, could be leveraged to screen for depression.

Overarching Objective. Evaluate a clinical model of screening and treatment for depression in terms of 'real world' effectiveness and cost-effectiveness at reducing depression in Neno District.

Objective 1. Determine the implementation strategy effectiveness-in terms of improved depression (PHQ-9), daily functioning (WHODAS), and overall health (EQ5D)-of introducing a stepped model of depression care (behavioral therapy and antidepressant therapy) among adults receiving integrated chronic care in Neno District, Malawi between July 1, 2021-June 30, 2025.

Objective 2. Determine the cost-effectiveness the stepped model of depression care (behavioral therapy and antidepressant therapy) among adults receiving integrated chronic care in Neno District, Malawi between July 1, 2021-June 30, 2025.

Objective 3: Assess positive externalities associated with depression care, including improved wellbeing among household members of treated patients, and improved physical health outcomes among patients receiving depression care.

Objective 4: Inspect mediators and moderators of improved depression care, including a dose effect from level of treatment received (number of behavioral therapy sessions), reduced internalized mental health stigma, and improved perceived social support.

RATIONALE

The framework strategically addresses the bi-directionality of depression and HIV outcomes. A broad literature throughout sub-Saharan Africa has outlined the impact of HIV-including HIV-related stigma, reduced quality of life and ability to maintain employment-on elevated depression levels (3). Depression, in turn, predicts HIV-related outcomes such as adherence to ART. As such, targeting depression care among a population that includes HIV+ individuals in Malawi should yield significant benefits in terms of HIV-related outcomes. Outside sub-Saharan Africa, there is increasing evidence that integrative health services represents stronger value for money than stand-alone models.

Research examining the benefits and costs of treating neuropsychiatric conditions, including depression, suffers two key limitations. First, evaluations have only measured individual-level, direct treatment effects. This approach under-appreciates the social ecology of mental health: that individuals are typically situated within families, and families within communities. From this lens, neuropsychiatric disorders have shown adverse effects-in terms of burden of care and emotional wellbeing-on household members. Previously, the investigators showed that, when individuals' mental health improves through treatment, indirect benefits are observed among household members (4). Likewise, measurement limited to direct treatment effects overlooks indirect benefits to overall health, including for comorbid conditions such as HIV, that may result from mental health intervention. A second shortcoming is that evaluations have focused on measuring costs of standalone interventions, which are costlier than those that leverage existing systems. For instance, interventions for youth have often integrated within school systems to lower costs. In Malawi, the national HIV system-already transitioning to an integrated chronic care platform in Neno District-holds potential to treat depression at lower costs by building on established systems of longitudinal care.

In terms of historical objectives, a preponderance of mental health evaluations in low-resource settings has stopped at the point of measuring effectiveness, rather than cost-effectiveness, with a few exceptions by project members. The consequences are marked: In settings of financial constraint such as Neno District, Malawi, resources allocated to a particular program necessarily means resources allocated away from another. As such, assessing intervention costs are fundamental for determining scalability. A collaborative care model of treatment for depression and comorbid conditions such as HIV and diabetes has the potential to overcome resource constraints, which cost-effectiveness analysis would demonstrate.

The investigators will evaluate an evidence-based stepped care model of depression treatment integrated into Neno's HIV system, assessing health outcomes and cost-effectiveness, inclusive of direct and indirect benefits. Partners In Health (PIH), in collaboration with the Malawian Ministry of Health, has operated in Neno District-home to 165,000 Malawians-for 12 years. The investigators proposed to integrate a stepped care model for depression-combining antidepressant therapy (ADT) with group-based Problem Management Plus (PM+), the elements of which have been successfully instituted by the research team in low-resource settings, ranging from Rwanda to Haiti. The proposed study will evaluate a model that trains clinical staff situated in clinics to screen and diagnose depression, and administer PM+ among those with a diagnosis of moderate or severe depression. Over five weekly 1.5-2.5 hour group sessions, the behavioral intervention combines empirically-based treatment components such as psychoeducation, strategic problem solving, and behavioral activation (5). This will be coupled with antidepressant therapy (ADT) among those with severe depression.

To assess intervention benefits, the investigators will measure patient outcomes for depression every 3 months-including baseline, post-intervention, 6-months, and 12-months follow-up-as well as markers of comorbid conditions: including viral load and ART adherence among those are HIV+ (71% of the sample) as well as other disease-specific outcomes such as systolic blood pressure for hypertensive patients (17% of sample) and hemoglobin A1C for diabetic patients (2% of sample)-supported by an electronic medical records system. Importantly, to quantify indirect benefits of depression care, the investigators will also interview household members at baseline and 6-months follow-up to evaluate burden of care, including emotional distress and missed days of work. The investigators will convert direct and indirect benefits to quality-adjusted life years (QALYs).

METHODS

Design of Study. We will implement a stepped-wedge cluster randomized trial of an evidence-based intervention for depression care within Neno's HIV system, currently undergoing transition to a chronic care platform, examining depression symptoms and outcomes of comorbid conditions, inclusive of HIV, across 14 facilities rolled-out clinic-wide in five steps over 15 months (6). This design is a gold standard experimental approach aligned with PIH's clinical goal to implement depression care permanently throughout Neno District, and is a methodological framework on which we have unique expertise, including locally.

Place of Study. This study will take place in Neno District, a catchment area of 165,000 Malawians, where 12,186 are enrolled in integrated chronic care-including for HIV. Five-year retention in ART in Neno District is 80%, while five-year mortality is close to 15%. The viral suppression rate is 83%. These figures signify Neno as high performing but also underscores significant room for improvement-particularly among the most vulnerable, such as those with depression. As such, we do not anticipate a ceiling effect for measuring HIV outcomes among those concurrently enrolled in depression care. This is also true for other chronic conditions: e.g. only 60% of hypertensive patients currently have controlled systolic blood pressure (<140 mm Hg). Successes to-date have been achieved through modest human resource investments such as CHWs, suggesting replicability nationally. This has been supported by the investigators' past cost-effectiveness analyses.

Target Population. The investigators intend to recruit at least 420 adults with depression for participation in this study, beginning July 1, 2021 and continuing through June 30, 2025. This number is based on the sample size needed for us to determine the effectiveness of the depression treatment, as well as the prevalence of depression in Malawi: At each ICC clinic, 200-1,800 patients are seen on a quarterly basis. The investigators anticipate 10%-12% of all patients (n=12,186) will screen positive for depressive symptoms, and 6% will be diagnosed with moderate/severe depression. Prior studies in Malawi have found acceptance of research study participation is 90% or higher. In addition, the investigators will be conducting interviews with 210 households among half of participants-in order to determine whether the intervention improves quality of life within households.

Sampling Techniques and Tools. The full study period is January 1, 2021 through June 30, 2025. The first six months will be preparation. Beginning July 1, 2021, all adults attending integrated chronic care clinics will be screened for depression symptoms using the PHQ-2 by existing clinical officers. Consistent with the prior screening literature, those with a score > 2 will complete remaining questions of the PHQ-9; and a score >9 will trigger administration of a brief diagnostic interview--adapted from the CIDI 3.0--by a trained counselor. Those with PHQ-9<10 (no/mild depression) will receive a psychoeducation session, but will not be enrolled-based on limited availability of health professionals and need-based prioritization. Those with moderate/severe depression (PHQ-9>9, corresponding to diagnosis of major depression) will be eligible for cohort enrollment. Screening, diagnosis and enrollment will occur continuously across all facilities over the full trial period; those who meet diagnostic criteria will be enrolled. Treatment will be rolled-out progressively: patients in each cluster's cohort will be initiated into the intervention: Three facilities will begin treatment immediately (Step 1), with remaining facilities will initiate treatment at three- (Step 2), six- (Step 3), nine- (Step 4) or twelve-months (Step 5) later. The stepped-wedge approach enables all facilities throughout Neno District to implement the model, as such maintaining equipoise. Assessment of patients on outcome measures will occur at every 3 months.

Sample Size Determination. The investigators assume n=30 enrollees per facility (total n=420), based on depression prevalence in Malawi. The investigators further assume loss to follow-up of 15%, based on intervention trials that the investigators have conducted in similar settings. To account for clustering, the investigators calculated detectable differences using an intracluster correlation coefficient (ICC) of 0.05 within treatment group and 0.01 within rollout step, based on depression treatment studies in multiple developing countries, including the investigators' pilot work. Based on this, the investigators find n=420 enrollees to be sufficient (power > 0.80; (alpha=.05; 2-tailed) for detecting a clinically meaningful standardized effect size of 0.5 (Cohen's d) for primary outcomes, including accounting for cluster autocorrelation. This is not separated by modality (though the investigators will explore this): it is to assess overall effectiveness of the stepped care model.

Data Collection Techniques and Tools. Over the 15-month roll-out period, primary outcomes (PHQ-9, WHODAS, EQ5D) will be measured at three-month intervals among all participants from point of enrollment, consistent with the three-month increments between steps (see above). Three-month increments will coincide with treatment initiation, post-intervention, 6 months and 12 months follow-up. In the event an enrolled individual no longer meets criteria at treatment initiation, the individual will leave the cohort and not be eligible for treatment but will continue to be evaluated every three months for future eligibility. Given that screening, diagnosis and enrollment will occur at all facilities over the full trial period, the investigators expect any reduction in patients enrolled in the cohort due to lagged treatment initiation will be offset by newly-identified individuals over this same period. This is consistent with an open cohort design for stepped-wedge trials. Ultimately, this approach enables all facilities to implement the model, maintain equipoise, and create control sites by randomizing roll-out sequence. Measurement intervals are consistent with best practices in outcomes tracking, including past trials. Interviews with household members will be conducted at treatment initiation and 6-month follow-up, among 210 randomized households.

Data Analysis. Analysis will assume a mixed-effects longitudinal regression framework, which the team has implemented in similar contexts. To account for nesting of patients within treatment groups and clusters, as well as time points (autocorrelation), patient, patient group and cluster will be incorporated as random effects, while cluster assignment and covariates are included as fixed effects-using STATA's MIXED command. The investigators will run sensitivity analyses to test if data are missing at random (MAR), and examine stigma and social support as moderators, as well as potential mediation using causal mediation analysis.

Effectiveness. The investigators will use linear mixed-effects regression analysis to test differences between study arms on change in primary outcomes. Models will adjust for patient demographics, as well as stigma and social support. Analysis will assume an intention-to- treat (ITT) framework, with and without multiple imputation analysis. In addition to ITT, the investigators will perform a 'completers only' analysis to exam outcomes among those who adhered to treatment, and examine dose response.

Cost-effectiveness. Health measures will be converted to QALYs using the EQ5D-3L cross-walk between domain-specific outcomes. This approach has been utilized and published on previously. QALY estimates will be related to base case and treatment cost estimates. For formal CEA, the investigators will use a gold standard Markov chain Monte Carlo (MCMC) simulation-based approach in TreeAge, from a societal perspective. For sensitivity analyses, the investigators will vary discount rates from 0-5%, based on health-adjusted life expectancy. Unit of interest is the incremental cost-effectiveness ratio (ICER) of cost per QALY, comparing the cost of integrated chronic care before and after introduction of the depression treatment.

PROTOCOL

Evidence-based treatment of depression. Drawing from a manual-driven framework of enhanced Problem Solving Therapy (PST) known as Problem Management Plus (PM+), developed by the WHO for low-resource settings, the investigators will implement a gold standard, stepped approach to treatment for depression. The model will follow a group format, based on three considerations: this lowers costs of human resources, which is essential when considering national scalability; it provides peer support during treatment; and it is culturally appropriate for the setting. These considerations have been sources of advocacy for the group model by WHO. In settings where group format has been implemented, results have been comparable to individual format. Local counselors will administer PST in five 1.5-2.5 hour sessions, with 6-8 participants per group, consistent with WHO guidelines. Among those with PHQ-9>15, antidepressant therapy (ADT) will be offered following WHO mhGAP procedures.

Depression screening. The investigators will screen patients ages 18+ enrolled in ICC clinics in Neno District, beginning the first quarter of Y2. Screening, diagnosis and enrollment into the treatment cohort will occur continuously across facilities, administered by data clerks and counsellors trained on the PHQ-2 and PHQ-9, respectively (6). Screening will also occur every 3 months among individuals in the active cohort to determine current treatment eligibility status. The PHQ-2 assesses frequency of depressed mood and anhedonia, and has been implemented throughout Africa. Use of PHQ-2 as a first step has will save time: the investigators are screening 12,186 adults. The selected threshold allows high sensitivity. Patients who screen positive with the PHQ-2 (score >2; range: 0-6) will immediately receive remaining PHQ-9 questions, on which a score > 9 (range: 0-27) represents a possible depressive disorder. Those with PHQ-9<10 will receive a psychoeducation session from the clinical officer, using a manual on which they have been trained. Those with PHQ>9 (moderate/severe depression) will be referred to a counselor to administer the diagnostic protocol.

Depression diagnosis. Counselors will review PHQ-9 scores and administer a brief diagnostic interview--based on the Comprehensive International Diagnostic Interview (CIDI)--to diagnose depression: 5 of 9 symptoms present and functional impairment. All patients will be evaluated for suicide risk and whether immediate intervention is warranted. If so, they will be referred to the supervising physician at the health facility, triggering an emergency protocol. Patients will be assigned to one of three categories: mild, moderate and severe depression. Those with a negative diagnosis will not be eligible for the intervention, and will undergo PHQ-2 screenings at subsequent visits for eligibility. Those with a positive diagnosis and PHQ-9>10 will be eligible. Those with PHQ-9 10-14 will be offered PST alone. Those with PHQ-9>15 (moderate-to-severe depression) will be offered PST and ADT as joint treatment, with the alternative to choose a single modality. Pregnant women with severe depression will also be eligible for ADT. Best evidence, including recent systematic reviews, does not find increased risk for mother or infant with appropriately administered ADT, and there are significant potential benefits of improved wellbeing of the mother.

Psychoeducation and treatment selection. Counselors will inform patients on availability of PST and ADT, outline potential benefits and risks, provide an overview of the study, and acquire informed consent. Those who decline care will be offered psychoeducation and referred to available resources. Among those who elect PM+, the first PM+ session will also incorporate in-depth psychoeducation. Patients with a PHQ-9 score of 10-14 will be provided the option of ADT but recommended PM+ instead, given that behavioral therapy has established efficacy and avoids potential side effects of ADT. Patients with PHQ-9 > 15 will also be given the options of PST, ADT, or both, and recommended both. At facilities randomized to administer the intervention immediately, patients will be informed of date, time and location of their first PM+ session.

Problem Management Plus (PM+). Counselors (n=8) will receive intensive training in Year 1 by to administer PM+ using a manualized approach. Training and supervision are described below. PM+ is a WHO-enhanced framework of Problem Solving Therapy (PST) for implementation by lay personnel in low-resource settings like Neno, designed to be conducted in five weekly 1.5-2.5 hour sessions. Elements of PM+, including sequential problem solving, have been applied by the research team in numerous settings with marked success, including in Lilongwe. This district-wide randomized trial leveraging Neno's existing infrastructure would represent a critical evidential support for WHO's agenda to expand the model globally. Modules include: psychoeducation, managing problems, behavioral activation, social support strengthening, and stress reduction.

Antidepressant Therapy (ADT). The investigators expect 20-25% of study participants-i.e. those who meet diagnostic criteria-to have moderately severe or severe depression and opt to enroll in ADT. Fluoxetine, a serotonin selective reuptake inhibitor (SSRI), and amitriptyline, a tricyclic antidepressant (TCA), are part of Malawi's national formulary. Neno District has a robust supply chain, which will reduce stock-out. Potential side effects of ADT are modest but include nausea, insomnia, and nervousness and will be communicated to participants prior to initiation. There is modest evidence ADT may increase risk of suicidality; this risk will be stated in informed consents, counselors will be trained to identify this risk, and will be formally assessed during outcome assessments, with the potential to trigger protocol for suicidal ideation. Benefits of ADT often outweigh risk of harm and negative impact of untreated depression. Fluoxetine is typically the first drug of choice because it is better tolerated.

Dosing Algorithm: Daily dose will commence at 20 mg of fluoxetine, or 25 mg of amitriptyline. Dose increments and levels are the same for each drug. At monthly follow-up visits, a dose increment or medication change may be considered based on measures of treatment response and side effects, using the Antidepressant Side Effect Checklist. This algorithm-based process will be repeated bi-weekly until the patient is fully responding to treatment for a period of three months (PHQ-9 < 5). Dose escalations of more than one increment and medication changes will be reviewed with the doctor-in-charge.

MEASUREMENT

Primary Outcomes. Measures will include surveys, laboratory assays, pharmacy data, and data abstracted from medical charts and the Depression Care Registry. Survey measures that have not been translated into Chichewa in the course of prior research will be translated using standard translation, back-translation methods, and will be administered at each assessment, unless otherwise noted.

Depression symptoms. Depression symptoms will be measured with the PHQ-9, which has been translated previously and locally-validated. The investigators have elected to use PHQ-9 because it has been implemented throughout sub-Saharan Africa, including Malawi, where the scale has shown high sensitivity responding to treatment, as well as concurrent and predictive validity. It contains nine four-point ordinal response items on topics such as hopelessness, psychosomatic response (e.g. sleeplessness, loss of appetite) and anhedonia.

Functional impairment. Functional impairment including aspects of daily functioning, correspond to DSM diagnostic criteria. The investigators will evaluate this using the 12-item WHO Disability Assessment Schedule 2.0 (WHODAS). The WHODAS has been validated in a diverse range of sub-Saharan African contexts, including Malawi, and covers topics like completing household chores, concentrating, and maintaining relationships.

Overall health. A health profile will be generated for each individual using the EQ-5D-3L, previously validated in Malawi. This survey determines patients' overall health at time of interview and offers a cross-walk to quality-adjusted life years (QALYs).

Secondary Outcomes. Secondary outcomes will constitute those measuring indirect benefits and costs of treatment. Indirect benefits will be incorporated into cost-effectiveness estimates by internalizing improvements among comorbid conditions such as HIV and hypertension, as well as reduced household burden of care.

ART adherence. ART adherence will be measured in terms of whether HIV+ enrollees have returned to an IC3 for antiretrovirals (ARVs) within the past three months, an approach considered more reliable than self-reports. This interval overlays with clinical protocols throughout Malawi in terms of the duration for which ARVs are supplied.

Viral load. Viral load will be measured as part of HIV+ patients' clinical assessment pre-intervention, post-intervention, 6- and 12-month follow-up, consistent with ongoing care at IC3s. This is considered a key metric for determining treatment plans and is highly sensitive to compliance with prescribed ART regimens.

HIV disease staging. Staging will be evaluated every three months among HIV+ enrollees, consistent with IC3 visits. This approach to tracking disease progression is commonly used in low-resource settings.

Chronic care outcomes. Chronic care outcomes on hypertension, type-2 diabetes, and epilepsy will be abstracted from electronic medical records. Systolic blood pressure and adherence to antihypertensive medication (measured by medicine pickups) will be measured among those with hypertension. Among those with type-2 diabetes, adherence to quarterly visits and A1C (or random blood sugar) levels will be abstracted. Among those with epilepsy, the investigators will catalog number of reported seizures in past quarter, and adherence to antiepileptics as measured by quarterly medicine pickups.

Household burden of care. Lastly, household burden of care will be evaluated with household members using a locally-adapted version of the Burden Assessment Schedule (BAS), previously implemented by the team. The survey assesses dimensions of emotional and functional burden of care, including missed work, guilt and worry.

Mediators and Moderators. Analyses will also include three mediators/moderators assessing potential pathways by which depression treatment leads to alleviation of depression symptoms, including enhanced social support, reduced HIV and depression-related stigma, and performance of psychosocial counsellors as quantified by fidelity to PM+ protocols.

Perceived social support. Social support strengthening is a focus of PM+. This will be measured with the Multidimensional Scale of Perceived Social Support (MSPSS), previously validated, to assess support before and after care.

Perceived stigma. Self-perceived stigma is associated with HIV status and depression, including in Malawi. The investigators will adapt the AIDS-Related Stigma Scale (ARSS) and Internalizing Stigma of Mental Illness (ISMI) scale in Year 1 of the project-both designed for use in community-based settings in sub-Saharan Africa.

PM+ fidelity. Fidelity checklist scores will be generated for each counsellor by a lead clinical officer or supervisor. Research has shown that fidelity protocols are predictive of patient outcomes in the context of depression care.

Household Interviews. Adult household members of participants-one per household-will be identified for participation based referral by the study participant and/or self-identification as a social support in close contact with the study participant. This individual will be informed that the research team is conducting a broad study on the relationship between individual and household health. Household interviews will chiefly comprise a subset of the battery administered to participants: specifically, the PHQ-9, WHODAS, and EQ-5D-3L (primary outcomes). In addition, household members will complete the BAS, as described above.

Process Evaluation. In the final year of the project, the investigators will conduct qualitative interviews to assess provider and patient experiences on their perceived effects of the intervention, as well as implementation barriers and strategies used to solve them. The goal is to identify key lessons learned, and to ready the intervention tools for scale-up at end of study.

Provider experience: In Year 5, the investigators will interview 10 clinical officers who prescribed ADT, as well as psychosocial counsellors who led PM+ sessions as well as diagnosed patients. In addition to discussing perceived strengths and weakness of the intervention and its implementation, the investigators will also discuss the training and supervision process, as well as provider job satisfaction and burnout.

Patient experience: A random sample of 20 participants (10 male, 10 female) will be interviewed after their final study assessment to assess their experiences with the intervention - including logistical aspect of participation, impact on personal mental health and wellbeing, as well as changes in relationships at the household level.