Risk Factors and Predictors of Pneumonia Among Under-Five Children in Sana'a City, Yemen: A Multicenter Case-Control Study.

Background: Pneumonia is a major cause of preventable morbidity and mortality among under-five children, particularly in low-resource and conflict-affected countries. However, evidence from Yemen remains scarce. This study examined child-related, maternal, and environmental factors possibly associated with pneumonia among under-five children in Sana'a City, Yemen. Methods: An unmatched multicenter case-control study was conducted among 302 children aged 2-59 months at five tertiary hospitals from August to December 2023. The study included 151 children admitted to pediatric wards with pneumonia and 151 controls attending outpatient clinics for non-respiratory conditions and without clinical evidence of pneumonia. Data on potential factors associated with pneumonia were collected using a structured interviewer-administered questionnaire. Univariable binary logistic regression was used to assess associations, and variables with Results: In univariable analysis, low birthweight, prematurity, acute malnutrition, recent upper respiratory tract infection (URTI), having a household contact with respiratory infection, and poor ventilation in the cooking area were significantly associated with pneumonia. In multivariable analysis, acute malnutrition (adjusted odds ratio [AOR] = 1.9, 95% CI: 1.12-3.36; Conclusion: Acute malnutrition, recent URTI, and household contact with respiratory infection show independent associations with pneumonia among under-five children attending tertiary hospitals in Sana'a. These findings highlight child nutrition, early recognition and management of URTI, and household infection-prevention practices as priorities in this resource-limited, conflict-affected setting. However, these hospital-based case-control findings require confirmation in longitudinal, population-based studies before they can inform context-specific prevention strategies.