AN ESTIMATE OF THE PREVALENCE OF CONGENITAL CARDIOVASCULAR MALFORMATIONS BASED ON MORTALITY RATES

This study presents a unique approach to the problem of estimating prevalence of congenital heart disease. A master file of 10,588 children who received care for congenital heart disease under the California Crippled Children Services in 1957-62 was used as a base population. Death clearance on this population was done for the period 1957 through 1964, and age-specific mortality rates were calculated. Deaths from congenital heart disease of all children who had been born in California between 1957 and 1963 were then used, with an adjustment for those with congenital heart disease who die of other causes, as numerators for rates, using as denominators populations estimated at 3.2, 4.5, or 5.0 per 1,000 live births. The rates which were based on the prevalence of 4.5 per 1,000 live births were found to closely approximate those in the observed population of children under the care of the Crippled Children Services. The Crippled Children Services case load may not be typical of the general population with respect to mortality from congenital heart disease, but the bias, if any, is likely to be in the direction of higher mortality in this group. Therefore, the estimate based on the experience of Crippled Children Services cases is likely to be a conservative one, and it is concluded that the prevalence of congenital heart disease among children born in California is at least 4.5 per 1,000.