Lc. Immergluck et al., Cost-effectiveness of universal compared with voluntary screening for human immunodeficiency virus among pregnant women in Chicago, PEDIATRICS, 105(4), 2000, pp. E541-E549
Objectives. To determine and compare the cost-effectiveness of implementing
3 screening strategies to detect human immunodeficiency virus (HIV) infect
ion among pregnant women in Chicago, Illinois: no screening, voluntary scre
ening, and universal screening.
Methods. A decision-analysis model was developed, using standard cost-effec
tiveness analysis from a societal perspective. Reference case estimates wer
e derived from a surveillance project conducted by the Illinois Department
of Public Health and studies were published in the medical literature. Cost
s included direct and indirect medical costs associated with identification
of pregnant women infected with HIV and identification, prevention, and tr
eatment of perinatally HIV-infected newborns. Specifically, for each screen
ing option, the cost per pregnant woman screened, the resulting number of p
ediatric HIV infections, and the number of newborn life-years were calculat
ed. All costs were adjusted to the 1997 dollar value and discounted at 3%.
Sensitivity analyses were determined for all variables included in the deci
sion model.
Results. The estimated prevalence of HIV infection among pregnant women in
Chicago is .41%. For every 100 000 pregnant women, it is estimated that 104
.6 children would be infected with HIV if no screening strategy were implem
ented and 44.8 children would be infected if voluntary HIV testing (assumin
g a 92.7% acceptance rate) were available. In comparison, if universal HIV
testing was performed, the number of children infected with HIV would decre
ase to 40 cases. Sensitivity analysis across a maternal HIV prevalence rate
of .01% to 2.2% found that universal screening would be cost-saving in com
munities where the seroprevalence is .21%. In Chicago, it would take an est
imated 5.2 months of screening pregnant women to avert 1 case of pediatric
HIV. Taking into consideration the lifetime costs of treating a child with
HIV infection, universal HIV testing of 100 000 pregnant women would result
in a cost-savings of $3.69 million when compared with no screening, and $2
69 445 when compared with voluntary screening. We estimated that it would c
ost $11.1 million to screen 100 000 pregnant women in Chicago. The cost-sav
ings produced with increased screening are the direct result of reduced cas
es of newborns infected with HIV. A 2-way sensitivity analysis was performe
d to examine how costs vary as a function of the voluntary rates for HIV-po
sitive and HIV-negative women. When screening falls below 50% for HIV-posit
ive mothers, universal screening becomes cheaper than voluntary screening e
ven if no HIV-negative mothers were screened.
Conclusion. Reference case analyses showed that universal HIV screening of
pregnant women in Chicago would both decrease the number of HIV-infected ne
wborns and save money in comparison to voluntary or no testing strategies.
Sensitivity analysis was robust across all variables for the conclusion tha
t universal screening was more effective than voluntary screening. For many
communities that have HIV prevalence rates for mothers of >.21%, universal
screening would also save money in comparison to voluntary screening. For
communities with prevalence rates <.21%, the benefits of universal screenin
g may outweigh the costs for screening as we found that desirable increment
al cost-effectiveness ratios were found for prevalence rates as low as .007
5%.