An appraisal of the efficacy and cost effectiveness of antenatal screening for hepatitis B

In this review published data are used to determine the benefits and costs of antenatal screening for hepatitis B carriers to prevent the later occurrence of hepatoma and chronic liver disease in their offspring. In Britain, babies born to carrier mothers have a 25% risk of perinatal infection and of becoming carriers themselves (the risk is 82% if their mothers are positive for the e antigen and 10% if negative). The carrier state increases the risk of hepatoma an estimated 86 times and the risk of chronic liver disease 20 times. Life table analysis showed that there is an 11% lifetime risk in carriers in Britain of dying from hepatoma (which results in seven years of life lost on average) and a 7% risk of chronic liver disease (14 years of life lost). Neonatal vaccination reduces the risk of the infant becoming a carrier by about 90%. Perinatal transmission occurs in 38 of every 100,000 neonates in Britain. Antenatal screening of all women and vaccinating babies of carrier mothers would prevent perinatal transmission in 34 of the 38 children (90%), or 255 per year in Britain. Of these 34, 8.4 children would be Chinese in ethnic origin, 4.2 African, 11.5 South Asian (from the Indian subcontinent), 2.0 Caribbean, and 7.3 would be white. Six deaths in the 34 from hepatoma or chronic liver disease caused by hepatitis B would then be prevented. The direct cost in Britain of screening all women, irrespective of ethnicity, at their first pregnancy only, would be 1300 pounds for each year of life saved (undiscounted) or 2500 pounds if screening at every pregnancy. Screening just Chinese, Africans, and South Asians, at first pregnancy only, would cost 330 pounds for each year of life saved but would prevent only 64% of these deaths. Vaccinating the infants of carrier mothers is likely also to prevent horizontal transmission of hepatitis B in early childhood and prevent the carrier state developing in an estimated three extra children for each child protected from vertical transmission. When this is taken into account the number of deaths prevented increases fourfold, reducing the cost for each year of life saved by 75%. Screening all women at first pregnancy only is an acceptably cost effective policy in Britain (1300 pounds for each year of life saved), actually preventing 45 deaths a year from hepatoma and chronic liver disease (or about 180 deaths if those horizontally infected are included), at a total cost of 540,000 pounds a year. It has the advantage of being comprehensive, equitable, and easier to implement than a policy based on screening of high risk ethnic groups.