congenital malformation incidence/prevalence measurement anorectal malformation incidence/prevalence measurement 2017-07-20T13:04:46Z ARM incidence/prevalence measurement Any measurement in which the number of individuals in a study population that display anorectal malformation at a point in time or develop anorectal malformation within a determined period of time are compared to the total number of individuals in the study population. Often expressed as a percentage but could be expressed as a ratio. Anorectal malformations (ARMs) represent a spectrum of congenital anomalies characterized by the obstruction of the anal opening. CMO:0002753 clinical_measurement_ontology jesmith