Table 3.

Costs and Precision Costs for Cohort, 20% Subcohort, and Case-Cohort Marginal Structural Analyses of Highly Active Antiretroviral Therapy and Incident AIDS or Death Among 950 Men and Women Infected With HIV Type 1, Multicenter AIDS Cohort Study and Women’s Interagency HIV Study, 1996–2007

Analysis and Visit Type	No. of Visits	Cost, dollarsa	Proportional Costs	Precision Costsb	Proportional Precision Costs
Cohort
Full	9,172	14,308,320
Partial	0	0
Total		14,308,320	1c	3.31	1c
Subcohort
Full	1,766	2,754,960
Partial	7,406	7,109,760
Total		9,864,720	0.69	4.30	1.30
Case-cohort
Full	2,891	4,509,960
Partial	6,281	6,029,760
Total		10,539,720	0.74	3.09	0.93

Abbreviations: AIDS, acquired immunodeficiency syndrome; HIV, human immunodeficiency virus.

^aCosts of a full study visit were approximated at $1,560 and costs of a partial study visit at $960 (excluding biomarker determinations).

^bPrecision costs were defined as costs (in millions of dollars) × standard error.

^cProportional costs and precision costs were taken with respect to the full cohort.