Table 1.

Summary of the Probability and Cost Variables Used in the Decision Analysis*

VariableBaseline ValueRange of ValuesReferences
Cost variables
 ELISA test$22$10 –$40 14, Δ
 WB test$54$30 –$7514, Δ
 HIV DNA PCR test$250$100 –$40014, Δ
 Mother's AZT$5646.30$1200 –$700025
 Infant's AZT (per wk)$3.08$1 –$525
 Post-test counseling for HIV-negative mother$14.87$10 –$4021, 23
 Post-test counseling for HIV-positive mother$35.46$30 –$10021, 23
 Lifetime cost for direct health care of perinatally HIV-infected child$171 373.51$65 000 –$250 00012, 15, 21, 22
HIV tests
 ELISA sensitivity1.0.9 –1.028, 29
 ELISA specificity.99.95 –1.028, 29
 WB sensitivity.99.8 –1.024, 28, 29
 WB specificity.99.8 –1.024, 28, 29
 PCR sensitivity.99.95 –1.0
 PCR specificity1.0.9 –1.0
Probability variables
 Prevalence of HIV in pregnant women.0041.0001 –.02227
 Vertical transmission rate without AZT.255.20 –.406
 Vertical transmission rate with maternal and infant AZT.0830 –.136
 Vertical transmission rate with only infant AZT within 48 h of birth.127.127 –.2557
 Acceptance of HIV testing under voluntary screening.927.3 –1.014, 31–37
 Probability of accepting AZT.7.5 –1.052, 53
Other variables
 Average life span of HIV-infected child (y)9.45 –2521, 40
 Average life span of adult in the United States (y)76.155 –8541
 Discount rate.030 –.0818
  • * Baseline case variables, their ranges and references are given in 1997 dollars.

  • No published data on sensitivity. Results based on figures given by Roche, Inc. Specificity for DNA PCR obtained from technical services at Roche Pharmaceutical and is based on inferences from published information for specificity of viral RNA quantitative test.