PEDIATRICS Vol. 107 No. 3 March 2001, pp. 608-609

Costs and Respiratory Syncytial Virus

To the Editor.

We read with interest the paper by Joffe et al¹ in Pediatrics and agree with the findings they report. However, they make the point in their article that a study by Robbins et al² "suggested prevention of a respiratory syncytial virus (RSV) hospitalization in a high-risk infant might be worth a mean of $5787." In contrast, the analysis by Joffe et al predicted considerably greater costs and that "extreme assumptions about the efficacy of prophylaxis, the direct cost of hospitalization, and the probability of hospitalization were required to reduce the cost per hospitalization averted to <$20 000." Their point was based on findings in Robbins et al that used willingness-to-pay (WTP) estimates from a small sample of providers knowledgeable about RSV.

Because the use of WTP values are still fairly new and not fully accepted by the research community, we think it important to clarify the costs presented in the study by Robbins et al. The number-needed-to-treat analysis consists of 2 cost components to value the averted costs of an RSV hospitalization. The first component is the direct medical care costs of an RSV hospitalization. In our study, we used 3 plausible estimates of the direct costs of an RSV hospitalization for high-risk subgroups. These estimates ranged from a low of $15 000 per hospitalization to a high of $25 000 per hospitalization.

The second cost component is the value the family places on avoiding the RSV hospitalization. This estimate can be considered as the present value of lost productivity, death, etc, weighted by the respective probabilities that such events might occur. We measured the second component as WTP to avoid an RSV hospitalization. These values ranged from $500 to $15 000 with a mean of $5787. Combining the 2 components, we estimated the cost of hospitalization averted to be between $16 325 and $33 700, not the $5787 quoted by Joffe et al.

James M. Robbins
John M. Tilford
Richard J. Jacobs
J. Gary Wheeler
Stephen R. Gillaspy
Gordon E. Schutze
Arkansas Children's Hospital
Department of Pediatrics/CARE
Little Rock, AR 72202-3591

REFERENCES

1. Joffe S, Ray GT, Escobar GJ, Black SB, Lieu TA Cost-effectiveness of respiratory syncytial virus prophylaxis among preterm infants. Pediatrics. 1999; 104:419-427 [Abstract/Free Full Text]
2. Robbins JM, Tilford JM, Jacobs RF, Wheeler JG, Gillaspy SR, Schutze GE A number-needed-to-treat analysis of the use of respiratory syncytial virus immune globulin to prevent hospitalization. Arch Pediatr Adolesc Med. 1998; 152:358-366 [Abstract/Free Full Text]

In Reply.

We thank Dr Robbins and his colleagues for the clarification. Our study and the Robbins study exemplify 2 distinct approaches to economic assessment of health interventions. Our study used cost-effectiveness analysis, in which the future productivity and psychological costs such as pain and suffering are accounted for in the denominator of the cost-effectiveness ratio, which was $ per hospitalization averted. The Robbins study used cost-benefit analysis, in which time costs and psychological costs are assigned an explicit, monetary value. Table 1 summarizes the different types of costs in the studies.

Our study did not explicitly quantify the value of the psychological costs of RSV hospitalization. It would be possible to explicitly quantify the value of preventing morbidity, eg, hospitalization, using the standard metric of quality-adjusted life-years saved.¹ Despite the differences in approaches, both Robbins' study and ours suggest that for most premature infants, the costs of RSV prophylaxis are high relative to its benefits.

Steven Joffe
Pediatric Hematology/Oncology
Dana-Farber Cancer Institute
Boston, MA 02115

Tracy Lieu
Division of Ambulatory Care and Prevention
Harvard Pilgrim Health Care and Harvard Medical School
Boston, MA 02215

REFERENCE

1. Garber AM, Weinstein MC, Torrance GW, Kamlet MS. Theoretical foundations of cost-effectiveness analysis. In: Gold MR, Siegel JE, Russell LB, Weinstein MC, eds. Cost-Effectiveness in Health and Medicine. New York, NY: Oxford University Press; 1996:25-53