High Heterogeneity in Prenatal Detection of Severe Congenital Heart Defects Among Physicians, Hospitals and Regions...

Prenatal detection rates (PDRs) of severe congenital heart defects (SCHDs) are often presented as regional and national aggregates, which might hide significant heterogeneity in PDRs among physicians, hospitals, and regions. The objective was to quantify the variability in the sensitivity of second-trimester ultrasound examination (U/S) to detect SCHDs, and to identify at which level this variability was the greatest.

This was a retrospective observational cohort of all pregnancy-child dyads with SCHDs in Quebec between 2007 and 2015. We matched the clinical data from the hospitals with the administrative data from the health care system. The variability at each level was estimated using multilevel models by calculating intraclass correlation coefficients.

Of 1274 SCHD, 697 were diagnosed prenatally following a referral for a suspected cardiac anomaly on U/S, yielding a sensitivity of 54.7% (95% confidence interval [CI], 52.0%-57.4%). Significant heterogeneity was observed among physicians, hospitals, and regions with the greatest heterogeneity among physicians. The U/S sensitivities in the lowest quartile for physicians, hospitals, and regions were 27.4%, 29.0%, and 39.8%, and those in the highest quartile were 87.3%, 70.1%, and 62.9%, respectively. The mean difference of sensitivity between the lowest and highest quartiles was 59.9% (95% CI, 51.7-68.1) for physicians, and 41.1% (95% CI, 30.3-51.9) for hospitals. The intraclass correlation coefficients at the physician level indicated the greatest heterogeneity among physicians (intrahospital).

There was considerable heterogeneity in PDRs between physicians and hospitals. The driver of the heterogeneity seemed to be at the physician level, with higher interphysician variability. Any measures of improvement should be directed to the physician level.