TABLE 3.

Results of Adherence Intervention Net Cost Sensitivity and Scenario Analyses

	Change from Base-Case Value, %a	Cost of Adherence Intervention, $	HIV Infections Averted	Treatment Cost Savings, $	Treatment Savings/ Intervention Cost
Base-case results	–	16,811	0.134	49,702	2.96
Pharmacist compensation
$64.11 per hourb	−23.20	13,643	0.134	49,702	3.64
$104.77 per hourb	+25.10	20,191	0.134	49,702	2.46
Receptionist compensation
$13.01 per hourc	−30.20	16,693	0.134	49,702	2.98
$27.13 per hourc	+45.50	16,988	0.134	49,702	2.93
Clinic overhead rate
15%	−40.00	15,863	0.134	49,702	3.13
35%	+40.00	18,112	0.134	49,702	2.74
Value of patients’ time
$0	−100.00	15,341	0.134	49,702	3.13
$33.19/hourd	+343.00	21,847	0.134	49,702	2.74
Patients’ round-trip travel costs
$7.72e	−51.80	15,983	0.134	49,702	3.15
$24.74e	+54.50	18,112	0.134	49,702	2.69
Reduction in HIV transmission rate for patients with undetectable virus
96%f	+6.67	16,811	0.134	49,791	2.96
84%f	−6.67	16,811	0.123	45,570	2.71
Lifetime HIV treatment costs
$373,916g	+0.63	16,811	0.134	50,015	3.27
$368,510g	−0.83	16,811	0.134	49,292	2.93
Most favorable combinationh	–	10,376	0.123	45,194	5.06
Least favorable combinationh	–	29,457	0.145	54,352	1.53

^aBase-case parameter values: pharmacist compensation=$83.78/hour (includes inflation-adjusted median hourly wage for pharmacists of $58.22,³³ plus benefits calculated at the average fringe benefit rate³⁴); 43.9% is the average fringe benefit rate for health care and social assistance workers in the United States³⁴; receptionist compensation=$18.65/hour (includes inflation-adjusted median hourly wage for receptionists of $12.96, plus benefits³⁵); clinic overhead rate= 25%; value of patients’ time =$7.50/hour³⁶; median round-trip travel cost (includes mileage cost and patient’s time cost) =$16.01, which corresponds to an 18-mile, 45-minute trip; annual HIV transmission rate without antiretroviral therapy= 0.03716; HIV transmission rate reduction for patients with undetectable viral load= 90%; adnd HIV-related treatment costs averted by preventing an HIV infection =$371,578.²⁶

^bInflation-adjusted 10th and 90th percentile hourly wages for pharmacists in the United States,³³ plus U.S. average fringe benefit rate.³⁴

^cInflation-adjusted 10th and 90th percentile hourly wages for receptionists in the United States,³⁵ plus U.S. average fringe benefit rate.³⁴

^dMedian hourly compensation (wage plus fringe benefits) for civilian workers in the United States.³⁴

^e25th and 75th percentile round-trip travel costs for study participants who completed the intervention.

^fThe upper bound estimate (96%) is the reduction in the likelihood of HIV transmission for patients on ART with suppressed (undetectable) virus in the HTPN 052 study³; the lower bound estimate (84%) was selected so that the base-case estimate (90%) was the mean of the lower and upper bounds.

^g5th and 95th percentile estimates of HIV-related treatment costs averted by preventing an HIV infection.²⁶

^hThe combination of parameters that is the most favorable to the intervention consists of the top parameter of each parameter pair.

ART= antiretroviral therapy; HIV= human immunodeficiency virus.