Jennifer L. Smith|Sudhakar Selvaraj|Mansur Rabiu|Fatima Kyari|Anthony W. Solomon|Clare Gilbert
Multilevel Analysis of Trachomatous Trichiasis and Corneal Opacity in Nigeria: The Role of Environmental and Climatic Risk Factors on the Distribution of Disease
London School of Hygiene & Tropical Medicine|Global Brain Health Institute|University of California, San Francisco|University of Aberdeen|Saudi Center for Disease Prevention and Control|University of Abuja|London School of Hygiene & Tropical Medicine|London School of Hygiene & Tropical Medicine|London School of Hygiene & Tropical Medicine
distribution trachoma nigeria spatially heterogeneous largescale trends observed across country local variation within areas relative contributions individual clusterlevel risk factors geographic distribution disease remain largely unknown primary aim analysis assess relationship climatic factors trachomatous trichiasis tt andor corneal opacity co due trachoma nigeria accounting effects individual risk factors spatial correlation addition explore relative importance variation risk trichiasis andor corneal opacity ttco different levels data 2007 national blindness visual impairment survey used analysis included nationally representative sample adults aged 40 years complete data available 304 clusters selected using multistage stratified clusterrandom sampling strategy participants 13543 individuals interviewed examined ophthalmologist presence absence tt co addition fieldcollected data remotely sensed climatic data extracted cluster used fit bayesian hierarchical logistic models disease outcome risk ttco associated factors individual cluster levels approximately 14 total variation attributed cluster level beyond established individual risk factors age gender occupation strong evidence environmentalclimatic factors clusterlevel lower precipitation higher land surface temperature higher mean annual temperature rural classification also associated greater risk ttco study establishes importance largescale risk factors geographical distribution ttco nigeria supporting anecdotal evidence environmental conditions associated increased risk context highlighting potential use improving estimates disease burden large scales