Assessing prenatal hepatitis B screening in Illinois with an inexpensive study design adaptable to other jurisdictions

Objectives. This study estimated, using an economical survey design adaptab le to other jurisdictions, the proportion of birth admissions in Illinois h ospitals in which mothers were not screened for hepatitis B surface antigen prior to delivery. It also identified factors associated with lack of scre ening. Methods. Based on a cluster sampling design, 1372 birth records were sample d, and data were abstracted by local personnel at 56 hospitals. Selected da ta elements were reabstracted on a subsample to evaluate recording errors. Results. Reabstracted data demonstrated 95% agreement among reviewers. Hepa titis B surface antigen screening was documented for 90.7% of mothers; 11% of responding hospitals accounted for 45% of nonscreened mothers. Risk fact ors for not being screened included no prenatal care, Medicaid or no insura nce, and delivery at a hospital lacking a written hepatitis B surface antig en policy. Conclusions. In Illinois, prenatal hepatitis B surface antigen screening ra tes were high and similar to those in other states. Births without screenin g or transferred information clustered in a few hospitals. The methods used here can economically identify under-screened populations by sampling a la rge number of hospitals within designated areas.