Exploring risk factors associated with catastrophic health expenditure on diarrhea management in Karachi, Pakistan, 2022-2024.

Catastrophic health expenditure (CHE) is a situation where a household's out-of-pocket medical payments are excessively high relative to its income, potentially leading to impoverishment. This study explores the risk factors associated with CHE in the management of diarrhea among children enrolled in Enterics for Global Health (EFGH) facilities in Karachi, Pakistan. We conducted a secondary analysis of data from 1,400 children presenting with diarrhea at Pakistan EFGH facilities. We estimated households' direct medical and non-medical costs per diarrheal episode. CHE was defined as healthcare expenditures exceeding 10% of total monthly household expenditure. Risk factors for CHE were assessed using univariate and multivariate regression models. CHE was observed in 9 (0.6%) households. Children experiencing severe diarrhea were 9.53 times (95%CI:1.93-46.91, p = 0.006) more likely to incur CHE compared to those with mild cases. Children with Cryptosporidium had a 7.08 times higher risk (95%CI:1.46-34.38, p = 0.015) compared to non- cryptosporidium. Children with moderate or severe wasting were 5.47 and 9.71 times more likely to experience CHE compared to those without wasting (95%CI:1.01-29.69, p = 0.011 and 1.64-57.6, p = 0.012, respectively). Similarly, moderately underweight children were 5.4 times more likely to experience CHE compared to their non-underweight counterparts (95%CI:1.01-29.69, p = 0.043). After adjusting for diarrhea severity, the risk of CHE among households where the father's education was limited to Quranic schooling was 8.4 times higher compared to no formal education (95%CI:1.13-62.49, p = 0.038). Estimates were based on a small number of CHE events and had wide confidence intervals. Although rare, CHE remains a potential risk for the vulnerable population. While limited statistical power due to small sample sizes warrants cautious interpretation of our risk ratios, our analyses suggest that severe diarrhea, malnutrition, and Cryptosporidium infection are associated with increased risk of CHE. Improving access to affordable healthcare, vaccination and nutritional programs, water, sanitation, and hygiene (WASH) practices, and financial support could reduce the impact of CHE.