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 adaptable to other jurisdictions, the proportion of birth admissions in Illinois hospitals in which mothers were not screened for hepatitis B surface antigen prior to delivery. It also identified factors associated with lack of screening. Methods. Based on a cluster sampling design, 1372 birth records were sampled, and data were abstracted by local personnel at 56 hospitals. Selected data elements were reabstracted on a subsample to evaluate recording errors. Results. Reabstracted data demonstrated 95% agreement among reviewers. Hepatitis B surface antigen screening was documented for 90.7% of mothers; 11% of responding hospitals accounted for 45% of nonscreened mothers. Risk factors for not being screened included no prenatal care, Medicaid or no insurance, and delivery at a hospital lacking a written hepatitis B surface antigen policy. Conclusions. In Illinois, prenatal hepatitis B surface antigen screening rates were high and similar to those in other states. Births without screening or transferred information clustered in a few hospitals. The methods used here can economically identify under-screened populations by sampling a large number of hospitals within designated areas.