"Ecological study measuring association between conflict, environmental factors, and annual global cutaneous and mucocutaneous leishmaniasis incidence (2005 - 2022)" data

This repository contains one dataset: ModelVars.csv. In this study, we measured the association between conflict and leishmaniasis over 18 years while accounting for other factors, such as environmental conditions and population displacement, that are relevant to leishmaniasis’ spread.

Data Sources

Cutaneous and mucocutaneous leishmaniasis case data (case): WHO Global Health Observatory

Population (pop): World Bank

Conflict intensity (con_intens): Bertelsmann Transformation Index

Gross domestic product (gdp): World Bank

Internal displacement (displace_prop): Internal Displacement Monitoring Center

Precipitation (precip) and temperature (temp_mean, temp_range): World Bank's Climate Change Knowledge Portal

Humidity (hum_mean, hum_range): NASA's Global Land Data Assimilation System Land Surface Model

Normalized difference vegetation index (ndvi): NASA's Terra MODIS

Data Specification

• Confict intensity was lagged one year
• Displacement was included as a proportion of the total population and log-transformed
• GDP, precipitation, temperature, humidity, and NDVI were mean centered and standardized
• We included a random nation-level intercept

Model Code

We ran our model using the mgcv package in R version 4.0.4. The final model (Model C in Table 1) uses the following code:

gam(case ~ year + con_intens + displace_prop_log + gdp_scale + precip_scale + s(temp_mean_scale,k=-1) + s(temp_range_scale,k=-1) + s(ndvi_scale,k=-1) + hum_mean_scale + hum_range_scale + s(nation,bs="re"), offset=log(pop), family = nb, gamma=1.5, data=ModelVars, method="REML")