Survival and factors associated with mortality among infants with anorectal malformation: a population-based study from a middle-income country

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 803,850 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 were 122 (69%) non-isolated ARM, of which 41 were Trisomy-21 and 34 had VACTERL association. Seventy-three (42%) had congenital heart disease (CHD), with 38 severe and 35 non-severe CHD. Overall, 33 (19%) patients died, with a median age of death of 5.7 months (interquartile range (IQR) 25 days to 11.2 months). The overall estimated 1-, 5-, and 10-year survival rate for ARM patients was 82% (95% CI, 76-89%), 77% (95% CI, 70-84%), and 77% (95% CI, 70-84%), respectively. Univariate analysis shows that non-isolated ARM, VACTERL association, and severe CHD were associated with mortality. However, only severe CHD is the independent factor associated with mortality, with a hazard ratio of 4.0 (95% CI, 1.9-8.4).  Conclusion: CHD is common among ARM patients, and one in five ARM patients had a severe cardiac defect, significantly affecting their survival. What is Known: • VACTERL association and congenital heart disease are common in patient with anorectal malformation. • Low birth weight and prematurity are associated with a lower rate of survival. What is New: • Congenital heart disease is common in ARM patients in a middle-income country. • Severe congenital heart disease plays a significant role in the survival of patients with an anorectal malformation in lower- and middle-income countries.