The heterogeneous effect of short-term transfers for improving ART adherence among HIV-infected Tanzanian adults

Abstract

A recently concluded randomized study in Tanzania found that short-term conditional cash and food transfers significantly improved HIV-infected patients’ possession of antiretroviral therapy (ART) and reduced patient loss to follow-up (LTFU) (McCoy et al., 2017). We examined whether these transfers had differential effects within population subgroups. In the parent study, 805 individuals were randomized to one of three study arms: standard-of-care (SOC) HIV services, food assistance, or cash transfer. We compared achievement of the medication possession ratio (MPR) ≥ 95% at 6 and 12 months and patient LTFU at 12 months between those receiving the SOC and those receiving food or cash (combined). Using a threshold value of p<0.20 to signal potential effect measure modifiers (EMM), we compared intervention effects, expressed as risk differences (RD), within subgroups characterized by: sex, age, wealth, and time elapsed between HIV diagnosis and ART initiation. Short-term transfers improved 6 and 12-month MPR ≥ 95% and reduced 12-month LTFU in most subgroups. Study results revealed wealth and time elapsed between HIV diagnosis and ART initiation as potential EMMs, with greater effects for 6-month MPR ≥ 95% in the poorest patients (RD: 32, 95% CI: (9, 55)) compared to those wealthier (RD: 16, 95% CI: (5, 27); p=0.18) and in newly diagnosed individuals (<90 days elapsed since diagnosis) (RD: 25, 95% CI: (13, 36)) compared to those with ≥90 days (RD: 0.3, 95% CI (−17, 18); p=0.02), patterns which were sustained at 12 months. Results suggest that food and cash transfers may have stronger beneficial effects on ART adherence in the poorest patients. We also provide preliminary data suggesting that targeting interventions at patients more recently diagnosed with HIV may be worthwhile. Larger and longer-term assessments of transfer programs for the improvement of ART adherence and their potential heterogeneity by sub-population are warranted.

A Cascade of Interventions to Promote Adherence to Antiretroviral Therapy in African Countries

“…However, innovative interventions are needed for young people who are stable on ART, reducing the need for frequent clinic visits which impact on education, domestic responsibilities and social activities and can thus be a barrier to ART adherence. ] **Trial also reported in "Target population: all PLHIV prescribed ART" [57] For PLHIV initiated on ART but have disengaged from care, providing cash incentives shows distinct promise in improving retention in HIV care, for perinatal women living with HIV and those who are food insecure [83 •• , 84 •• ]. Amounts needed to make a difference are likely to be small, covering transport costs of getting to clinics and possibly making a minimal contribution to basic food items [81].…”

“…However, in this study, food insecurity was not assessed which may limit the findings [ 56 ]. However, in Tanzania, conditional food and cash transfers did have a beneficial effect on ART adherence at 6 months (95% medication possession ratio) (adjusting for site, 58% (95% CI = 50, 66) SoC versus 76% (95% CI = 72, 80) intervention) particularly for food-insecure patients and those newly diagnosed [ 57 ].…”

“… *Trial also reported in “Target population: PLHIV initiated on treatment who disengage from care or are lost to follow-up (LTFU)” [ 84 •• ] **Trial also reported in “Target population: all PLHIV prescribed ART” [ 57 ] …”

Durability of effects from short-term economic incentives for clinic attendance among HIV positive adults in Tanzania: long-term follow-up of a randomised controlled trial

“…In addition, we explored effect heterogeneity across the same subgroups as in an analysis of the original trial results (sex, age, wealth index and treatment delay between HIV diagnosis and ART initiation) with a Wald test of the interaction term at alpha=0.20, while expecting these analyses to be underpowered. 22 …”

The Utilisation of Payment Models Across the HIV Continuum of Care: Systematic Review of Evidence

“…Of the 23 articles included, 15 (65%) articles reported randomised clinical trials [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33], 4 (17%) non-randomised empirical studies [34][35][36][37] and 4 (17%) quantitative descriptive studies with cost-effectiveness analyses [38][39][40][41].…”