Scenario 4

Background

You have been recruited by the National Malaria Control Programme (NMCP) of Cambodia to assist with study design. The NMCP is concerned about the potential spread of mutations that affect the performance of HRP2-based rapid diagnostic tests (RDTs). pfhrp2 deletions can cause false-negative results in HRP2-based RDTs. In the last few weeks, there have been anecdotal reports of RDT failures in border towns, particularly in the Forest region. Additionally, there are concerns about the emergence of artemisinin resistance due to a new pfk13 mutation, as neighboring countries have reported its increasing prevalence. Confirming whether this rare mutation is present in Cambodia is a priority for the NMCP. The NMCP plans to conduct a cross-sectional study to estimate the prevalence of pfhrp2 deletions and detect the pfk13 mutation. The NMCP are also interested to know the prevalence of other drug resistance mutations, such as pfdhps, pfdhfr and pfcrt mutations so these are secondary outcomes of interest.

Your task

The NMCP has a budget of USD 250,000. There are four regions in Cambodia (Coastal, Highland, Forest, and Urban) each with 25 health facilities. From previous studies conducted by the NMCP, we know that the intra-cluster correlation is 0.01. Your job is to design a study powered for the following end-points:

  • Primary endpoints
    • Estimate the prevalence of pfhrp2 deletions causing false-negative RDTs
    • Detect the new pfk13 mutation associated with artemisinin resistance.
  • Secondary endpoint
    • Estimate the prevalence of pfdhps, pfdhfr and pfcrt mutations.

Each team member has key information on the epidemiological context, health facilities in each region, costing and sample size considerations (ICC, etc). Click on your role to access this information. Work in parellel (but together) to develop your study design!