Major components of the direct medical costs of alpha1-antitrypsin deficiency.
OBJECTIVE
To examine the sources of the direct medical costs of alpha(1)-antitrypsin (AAT) deficiency based on survey data from affected individuals.


BACKGROUND
Prior research has reported the total cost of AAT deficiency but has not examined the specific components of the direct medical costs of affected individuals.


METHODS
In order to detail the sources of the direct medical costs, we sent surveys to 688 respondents of a previous survey. We estimated the costs in three ways, which differed in the method of managing missing values. With method 1, the group mean value of cost per unit of utilization, multiplied by the occurrences of utilization, was used to replace the missing value. Two sensitivity analyses (ie, methods 2 and 3) were conducted to test the robustness of our estimate. With method 2, values of zero were entered for all missing values. With method 3, the missing values were replaced by the group mean value. The Wilcoxon test was used to test the cost differences between patients of different phenotypes. All cost data were expressed in 1998 US dollars.


CONCLUSIONS
Two hundred ninety-two individuals responded to the survey. The annual total health-care costs were high (mean range, $36,471 to $46,114 US dollars; median range, $12,485 to $37,100 US dollars [according to the method for managing missing data]) for AAT deficiency. The total costs for individuals with the PI*ZZ phenotype exceeded those for individuals with a non-PI*ZZ phenotype. The use of IV augmentation therapy accounted for more than half of all direct medical costs for the respondents. Besides the costs for therapy with alpha(1)-proteinase inhibitor (Prolastin; Bayer; West Haven, CT), other major cost sources were prescription drugs other than alpha(1)-proteinase inhibitor, hospitalization, health insurance, and physician visits.
Mullins
C Daniel
CD
University of Maryland School of Pharmacy, Center on Drugs and Public Policy, 2nd Floor, 515 W. Lombard Street, Baltimore, MD 21201, USA. dmullins@rx.umaryland.edu
Wang
Junling
J
Stoller
James K
JK
D000328:Adult; D000368:Aged; D003365:Costs and Cost Analysis / Q000706:statistics & numerical data; D004180:Direct Service Costs / Q000706:statistics & numerical data*; D005260:Female; D017048:Health Care Costs / Q000706:statistics & numerical data; D006306:Health Surveys; D006801:Humans; D007348:Insurance, Health / Q000191:economics; D008297:Male; D008432:Mathematical Computing; D008875:Middle Aged; D010348:Patient Care Team / Q000191:economics / Q000706:statistics & numerical data; D010641:Phenotype; D018709:Statistics, Nonparametric; D014481:United States; D019896:alpha 1-Antitrypsin Deficiency / Q000191:economics* / Q000235:genetics