Economic Consequences of Cytomegalovirus Disease Among Stem Cell Transplant Recipients

Background

Cytomegalovirus (CMV), a common opportunistic infection among stem cell transplant recipients, is associated with substantial morbidity and mortality. Limited information is available regarding the economic consequences of CMV disease among these patients. The current study evaluated the incremental healthcare costs associated with CMV disease among stem cell transplant recipients.

Methods

Adults with stem cell transplant were identified in the Truven Health MarketScan® database (Q1 2002-Q4 2011). Patients were required to have ≥ 2 years of continuous enrollment following the transplantation. They were classified into the CMV cohort if they had ≥ 1 observed CMV diagnosis within the 2-year period after transplantation (study period), or the No CMV cohort if they did not have any CMV diagnosis during the entire observation period in the database. Patients in the CMV cohort were matched 1:1 to patients in the No CMV cohort in two steps. The first step was exact matching based on age strata, gender, relevant comorbidities, year of transplantation, type of stem cell transplant, and donor type. The second step was a propensity score match based on region of residence, health plan type, relevant comorbidities, and baseline healthcare resource utilization and costs. The costs in the study period were compared between the two matched cohorts using Wilcoxon signed-rank tests.

Results

Among 189 stem cell transplant recipients with CMV and 2,539 recipients without CMV, a total of 113 matched pairs were identified. The baseline characteristics were comparable between the matched CMV and No CMV cohorts. During the 2-year study period, the CMV cohort was associated with significantly higher costs across all cost categories. The total costs were $586,416 in the CMV cohort vs. $305,462 in the No CMV cohort (incremental cost of $280,954, p < 0.0001). The majority of the differences were attributable to the incremental medical costs, accounting for ~95% of the total incremental costs (Table).

Conclusions

Stem cell transplant recipients with CMV disease incurred significantly higher healthcare costs, including costs for CMV lab tests and antiviral drugs, than those without CMV disease.

Table. Healthcare Costs during the 2-Year Study Period: CMV and No CMV Cohorts

Costs categories (2013 USD)	CMV cohort (N=113)	No CMV cohort (N = 113)	Cost difference	P-value
Total costs	586,416.0	305,462.1	280,953.9	<.0001
Medical costs	543,813.1	276,593.3	267,219.7	<.0001
Inpatient services costs	343,691.6	157,995.6	185,696.0	<.0001
Emergency room services costs	4,555.3	5,404.2	-848.9	0.2860
Outpatient services costs	195,566.2	113,193.6	82,372.6	<.0001
Drug costs	42,602.9	28,868.7	13,734.2	0.0079
Subcategories of total costs
Antiviral drug costs	6,920.6	449.7	6,470.9	<.0001
CMV laboratory test costs	3,357.1	1,473.3	1,883.7	0.0002