Skip to main content

# Table 1 Conventional Testing Regime: Private General Practice Clinic Setting – (Funded by Federal Government – Medicare)

Probability of True HIV Positive
(PHIV)
Probability of True HIV Negative
(1 − PHIV)
Outcomes HIV Positive
(EIA+ & WB+)
False HIV Negative
(EIA-)
False HIV Positive
(EIA+ & WB-)
True HIV Negative
(EIA-)
Probability of result (PHIVSenEIASenWB) PHIV (1 − SenEIA) ((1 − PHIV)  (1 − SpecEIA) SpecWB) (1 − PHIV) SpecEIA
Inputs
Visit 1: Initial Screening
Consult time 20 min 20 min 20 min 20 min
Medicate Rebate $71.701$71.701 $71.701$71.701
Staffing GP GP GP GP
Pathology costs
EIA $15.652$15.652 $15.652$15.652
WB confirmatory $29.003$29.003
Visit 2: Test Results
Consult time 40 min 20 min 20 min 20 min
Medicate Rebate $105.554$71.701 $71.701$71.701
Staffing GP GP GP GP
Total Cost of Each Outcome $221.90$159.05 $188.05$159.05
Average cost (AC) per person tested =(PHIVSenEIASenWB) AC per True HIV PositiveEIA + , WB+ + (PHIV (1 − SenEIA)) AC per False HIV NegativeEIA + ((1 − PHIV) SpecEIA) AC per True HIV NegativeEIA + ((1 − PHIV)  (1 − SpecEIA) SpecWB)) AC per False HIV PositiveEIA + , WB
Average number of tests for a positive diagnosis $$=\frac{1}{P_{HIV}\ast Se{n}_{EIA}\ast Se{n}_{WB}}$$
1. Note: AC Average Cost, EIA fourth generation enzyme immunoassay test, GP General Practitioner, P Probability, Sen Sensitivity, Spec Specificity, WB Western Blot Test, + reactive test result, − nonreactive test result
2. 1 = Medicare Rebate Item 36; 2 = Medicare Rebate Item 69,384; 3 = Medicare Rebate Item 69,387; 4 = Medicare Rebate Item 44