OPS 11: Health effects of climate change in low- and middle-income countries, Room 114, Floor 1, August 27, 2019, 10:30 AM - 12:00 PM
Background: The frequency and intensity of flooding are projected to increase in a changing climate, which may have great implications for diarrhea. Yet the causal relationship between flood and diarrhea remains uncertainties and very limited study had detected its modifiers.
Methods: Daily number of diarrheal cases and meteorological data from June 18th 2013 to August 31th 2017 and background data of flood in Anhui province were obtained. The differences-in-differences (DID) approach with propensity score matching were applied to examined the causal effects of the 2016 flood in Anhui during flooding and in post-flood period. The difference-in-difference-in-difference (DDD) analysis was deployed to detect the modifiers of flood’s impacts, including gender, age, occupation and community health resource.
Results: During the study period, 359,580 cases of diarrhea occurred in Anhui province, with an average of 258.6 cases per day. The adjusted DID model estimated that the flood had immediately increased the risk of dysentery (RR: 1.29, 95% CI: 1.14 – 1.46) and have caused 21% increase of all-cause diarrhea in post-flood period, with 49%, 36%, 9% of risk increasing for Typhoid and Paratyphoid, Dysentery, Other Infectious Diarrhea. The DDD model showed that the flood had posed a higher risk to males, under 5 and 5-14-years old children, and non-farmers. People belonged to county with high density of health professionals had a significantly lower risk of diarrhea during flooding (RR: 0.81, 95% CI: 0.67 - 0.99) and in post-flood period (RR: 0.83, 95% CI: 0.74 - 0.92).
Conclusions: Flooding has increased the risk of diarrhea and the effects were modified by age, gender, occupation and density of health professionals. Our findings recommended using DID design to detect causal effect of floods and other climate extremes and highlighted the protective effects of community health workforce on the health impacts posed by flooding.