Table 3 PEP++ project outcomes and statistical analysis plan

To provide evidence of the effectiveness of an enhanced post-exposure prophylaxis regimen (PEP++) compared to SDR-PEP

Primary:

contacts diagnosed with leprosy

PEP++ offers a higher protection against leprosy disease manifestation than SDR-PEP

Number of persons with leprosy disease detected at 24 months after receiving prophylaxis

Descriptive statistics; Cox’ proportion hazards analysis and Poisson regression comparing rates between the intervention and control areas

To show the cost- benefit and acceptability of the enhanced chemoprophylaxis regimen

Secondary:

Cost–benefit of the enhanced regimen compared with effectiveness of SDR-PEP

PEP++ is a cost-effective strategy in leprosy control and the increased effectiveness of the intervention will justify additional costs from multiple doses

Number of contacts screened, cases prevented, and disabilities avoided against operational costs and out-of-pocket expenses

Health economic evaluation

Secondary: Acceptability of the enhanced regimen compared with SDR-PEP

The new regimen will be accepted by contacts and health professionals

Proportion of eligible close contacts who take all three doses; qualitative interview results indicating that PEP++ is acceptable

Descriptive statistics of contacts who took medication; qualitative content analysis of interviews; semi-structured interviews, FGDs

To provide evidence of increased transmission of M. leprae in cluster areas identified through GIS-based mapping compared to non-cluster areas

Secondary:

Contacts diagnosed with leprosy in identified high-transmission clusters (2014–19 index cases)

Detection of new leprosy cases will be higher in the cluster areas than in non-cluster areas due to higher local transmission and relative risk

Rate ratios of all new leprosy cases and child cases in cluster areas as compared with non-cluster areas (as a result of intervention as well as passive cases); rate ratio

Poisson regression comparing rates between cluster and non-cluster areas

To demonstrate the effectiveness of the community education and behaviour change interventions to change the perception of leprosy in the study districts

Secondary:

Levels of knowledge, attitudes, and stigma in each district

New, contextualised education materials and interventions will increase community knowledge regarding leprosy and reduce stigma so as to promote early detection

Change in KAP, EMIC-CSS and SDS scores and interviews/FGDs in all four target groups

Descriptive statistics; comparison of mean/median scores between baseline and end-line surveys; effect size; correlations between exposure to the interventions and KAP, EMIC-CSS and SDS scores; multivariate regression; qualitative content analysis of interviews, FGDs, and observations

To demonstrate proof of concept of the potential for the PEP++ approach to reduce, and ultimately stop, the transmission of M. leprae in a target area

Primary:

Detection of new autochthonous child cases of leprosy

Reduction in new case and child case detection will be higher in intervention compared with control areas;

Overall and child case detection levels will reduce against baseline (2019) detection

Rate ratio of new case and child case detection per 1,000,000 population; total number of new cases per district

Descriptive statistics, comparison of new case and child case detection rates between the intervention and control areas