Cost and cost effectiveness of reactive case detection (RACD), reactive focal mass drug administration (rfMDA) and reactive focal vector control (RAVC) to reduce malaria in the low endemic setting of Namibia: an analysis alongside a 2×2 factorial design cluster randomised controlled trial

Abstract

Objectives: To estimate the cost and cost effectiveness of reactive case detection (RACD), reactive focal mass drug administration (rfMDA) and reactive focal vector control (RAVC) to reduce malaria in a low endemic setting.

Setting: The study was part of a 2×2 factorial design cluster randomised controlled trial within the catchment area of 11 primary health facilities in Zambezi, Namibia.

Participants: Cost and outcome data were collected from the trial, which included 8948 community members that received interventions due to their residence within 500 m of malaria index cases.

Outcome measures: The primary outcome was incremental cost effectiveness ratio (ICER) per in incident case averted. ICER per prevalent case and per disability-adjusted life years (DALY) averted were secondary outcomes, as were per unit interventions costs and personnel time. Outcomes were compared as: (1) rfMDA versus RACD, (2) RAVC versus no RAVC and (3) rfMDA+RAVC versus RACD only.

Results: rfMDA cost 1.1× more than RACD, and RAVC cost 1.7× more than no RAVC. Relative to RACD only, the cost of rfMDA+RAVC was double ($3082 vs $1553 per event). The ICERs for rfMDA versus RACD, RAVC versus no RAVC and rfMDA+RAVC versus RACD only were $114, $1472 and $842, per incident case averted, respectively. Using prevalent infections and DALYs as outcomes, trends were similar. The median personnel time to implement rfMDA was 20% lower than for RACD (30 vs 38 min per person). The median personnel time for RAVC was 34 min per structure sprayed.

Conclusion: Implemented alone or in combination, rfMDA and RAVC were cost effective in reducing malaria incidence and prevalence despite higher implementation costs in the intervention compared with control arms. Compared with RACD, rfMDA was time saving. Cost and time requirements for the combined intervention could be decreased by implementing rfMDA and RAVC simultaneously by a single team.

Trial registration number: NCT02610400; Post-results.

Keywords: EPIDEMIOLOGY; HEALTH ECONOMICS; Health policy; Public health.

Figure 1

Cost category breakdown for RACD, rfMDA and RAVC. RACD, reactive case detection; RAVC, reactive focal vector control; rfMDA, reactive focal mass drug administration.

Figure 2

Start-up and recurrent costs by comparison groups for cost per event (A), cost per person (B) and cost per PAR (C). PAR, population at risk; RACD, reactive case detection; RAVC, reactive focal vector control; rfMDA, reactive focal mass drug administration.

Figure 3

ICER of RACD vs rfMDA, no RAVC vs RAVC and RACD only vs rfMDA+RAVC per incident case averted, prevalent infection averted and DALY averted. DALY, disability-adjusted life years; ICER, incremental cost effectiveness ratio; RACD, reactive case detection; RAVC, reactive focal vector control; rfMDA, reactive focal mass drug administration.

Figure 4

Tornado diagram of change in the ICER per incident case averted for rfMDA vs RACD (A), RAVC vs no RAVC (B) and rfMDA+RAVC vs RACD only (C). The values in brackets are the range over which the parameter was varied. The vertical line is the baseline value of the ICER per incident case averted. The blue bars show the direction and magnitude of change in the ICER, when the input variable is set to its lower value and the red bars show the direction and magnitude of change when the input variable is set to its higher value. Marginal changes in the ICER are not visible on the graph. CHW, community health worker; DALY, disability-adjusted life years; ICER, incremental cost effectiveness ratio; RACD, reactive case detection; RAVC, reactive focal vector control; rfMDA, reactive focal mass drug administration.