# Regression Analysis of Dependent Binary Data for Estimating Disease Etiology from Case-Control Studies

## TL;DR

This paper extends a statistical model to incorporate covariate effects in disease cause estimation from case-control studies, improving accuracy and inference of disease etiology.

## Contribution

It introduces a regression framework for nested partially-latent class models that accounts for covariates and control data, enhancing disease etiology estimation.

## Key findings

- Less biased estimation of population etiologic fractions (PEFs).
- More valid inference compared to models ignoring covariates.
- Application reveals disease etiology dependence on season, age, severity, and HIV status.

## Abstract

In large-scale disease etiology studies, epidemiologists often need to use multiple binary measures of unobserved causes of disease that are not perfectly sensitive or specific to estimate cause-specific case fractions, referred to as "population etiologic fractions" (PEFs). Despite recent methodological advances, the scientific need of incorporating control data to estimate the effect of explanatory variables upon the PEFs, however, remains unmet. In this paper, we build on and extend nested partially-latent class model (npLCMs, Wu et al., 2017) to a general framework for etiology regression analysis in case-control studies. Data from controls provide requisite information about measurement specificities and covariations, which is used to correctly assign cause-specific probabilities for each case given her measurements. We estimate the distribution of the controls' diagnostic measures given the covariates via a separate regression model and a priori encourage simpler conditional dependence structures. We use Markov chain Monte Carlo for posterior inference of the PEF functions, cases' latent classes and the overall PEFs of policy interest. We illustrate the regression analysis with simulations and show less biased estimation and more valid inference of the overall PEFs than an npLCM analysis omitting covariates. A regression analysis of data from a childhood pneumonia study site reveals the dependence of pneumonia etiology upon season, age, disease severity and HIV status.