Survival and Factors Associated with Mortality Among Infants with Anorectal Malformation: A Population- Based Study from A Middle-Income Country

Abstract

Abstract Limited data on the survival of anorectal malformation (ARM) patients from lower-and-middle income countries is available. This retrospective population-based study from the State of Johor, Malaysia, determines the incidence, mortality rate, and survival of ARM patients and factors associated with mortality. Kaplan-Meier survival analysis was used to estimate the survival of ARM patients at 1-, 5- and 10- years. In addition, multivariate cox-regression analysis was used to analyze mortality-related factors. There were 175 ARM patients among 803850 live births, giving an overall ARM incidence of 2.2 (95% confidence interval [CI], 1.9 to 2.5) per 10,000 live births. The male-to-female ratio was 1.5: 1. There was 122 (69%) non-isolated ARM, of which 41 were Down syndrome and 34 had VACTERL. Seventy-three (41.7%) had CHD, with 38 severe and 35 non-severe CHD. Overall, 33 (18.9%) patients died, with a median age of death of 5.7 months (Interquartile range 25 days to 11.2 months). The overall estimated 1-, 5- and 10-year survival rate for ARM patients was 82.3% (95% CI, 76.0% – 88.6%), 77.3% (95% CI, 70.4% - 84.2%), and 77.3% (95% CI, 70.4%- 84.2%), respectively. Univariate analysis shows that non-isolated ARM, VACTREL association, and severe CHD were associated with mortality. However, only severe CHD is the independent factor associated with mortality, with a hazard ratio of 4.03 (95% CI: 1.93-8.42). Conclusion: CHD is common among ARM patients, and one in five ARM patients had a severe cardiac defect, significantly affecting their survival.