Economic Evaluations of Immunoprophylaxis
in Infants at High Risk for Respiratory Syncytial Virus
Shedding Light or Creating Confusion?
Terry
P. Klassen, MD, MSc, FRCPC

GREAT ADVANCES in pediatrics have arisen from the
discovery of new drugs designed to treat diseases that may cause death or
severe morbidity in children. These discoveries most often arise from basic
research and are brought to market by pharmaceutical companies at an
estimated cost of $500 million per drug.
1
No one can dispute that much benefit to patients has emerged from these
developments.
Increasing emphasis is being placed on the need for decisions in health
care to be evidence based. With the recognition that health care resources
are limited, it has become equally important for new interventions to
undergo economic evaluations. Without such examinations of the efficiency of
new interventions, the costs of health care will escalate at an ever-faster
rate. In many countries, costs for pharmaceutical agents are becoming the
fastest-growing component in their health care budgets.
Bronchiolitis is a disease that has frustrated pediatricians for many
years because of its huge impact on the resources of our children's
hospitals. However, few interventions have proven both safe and effective.
In high-risk infants, bronchiolitis has a disproportional impact. Hence, it
is even more critical to identify effective and efficient interventions.
In light of this, strategies that can lessen the impact of this disease
have great appeal. Three randomized controlled trials (RCTs), involving 2261
infants, have examined the effectiveness of immunoprophylaxis in high-risk
infants; 2 of these trials involved respiratory syncytial virus
immunoglobulin intravenous (RSV-IGIV),2,
3 and 1 trial involved palivizumab.4
The primary observed benefit has been the reduction of hospitalization
burden. No significant benefit has been observed in reducing mortality. In
this context, an economic evaluation may be useful in helping clinicians and
health administrators decide whether to adopt a passive immunization
strategy.
Economic evaluations ask the basic question of whether a new intervention
is worth adopting, based on estimates of costs and benefits. In a
cost-minimization study, the benefits are assumed to be the same for all
interventions; hence, only the costs are compared. For other types of
analyses, the costs of the alternatives are identified, and the benefits are
valued in natural units (cost-effectiveness analysis), quality of life
(cost-utility analysis), or dollar amounts (cost-benefit analysis).
Guidelines for economic evaluations have been established and published.5
Yet evidence exists that many economic evaluations of drugs fail to meet a
minimum standard of quality. Hill et al6
examined 326 pharmacoeconomic analyses that had been submitted to the
Australian Pharmaceutical Benefits Scheme. Of these analyses, 218 (67%) had
significant problems, including comparative clinical efficacy, comparator
issues, modeling issues, and calculation errors.6
Evans7 has argued that
such guidelines may give the false illusion of scientific rigor, clothing
such evaluations in an outward appearance of respectability, while the
influence of the funding organization may still distort conclusions and
recommendations. His premise is based on the fact that there are too many
levels of subjectivity and choice with regard to methods in an economic
evaluation.
The influence of funding support on study conclusions has been shown in
other areas of medicine. Stelfox et al8
found a strong relationship between authors' published positions on the
safety of calcium-channel antagonists and their financial relationships with
pharmaceutical manufacturers. Editors of the major medical journals have
recognized the potential of financial interest to distort the results and
conclusions of studies. In a joint editorial, editors called on
investigators to state full disclosure and to create university-industry
agreements that would ensure scientific independence and integrity.1
Governments and health care organizations require some process by which
to make decisions regarding the adoption of new therapeutic agents.
Therefore, the question remains, can such distortion be avoided when
performing an economic evaluation?
The study by Kamal-Bahl et al9
in the October 2002 issue of the ARCHIVES illustrates this challenge. The
authors performed a systematic review of 12 economic evaluations examining
the use of both RSV-IGIV and palivizumab. The results had estimates that
ranged from cost savings to considerable incremental costs per
hospitalization that were avoided with the use of either agent. Studies
comparing the 2 agents reported mixed results about their relative
cost-effectiveness. How would a decision maker come to a firm conclusion
about the adoption of either agent with such conflicting evidence?
Even more disturbing in their systematic review was that when they
stratified the studies according to whether there was some form of funding
from the manufacturer, 4 of the 4 studies with pharmaceutical support
reported the possibility of cost-effectiveness or cost-savings with
prophylaxis in the entire high-risk infant population, either in their point
estimate or in their sensitivity analysis, vs 0 of the 8 studies without
such funding (P = .002). It is somewhat astounding that from 3 RCTs,
12 economic evaluations have been spawned. In the area of new oncology
drugs, Friedberg et al10
have previously demonstrated that pharmaceutical-sponsored economic
evaluations were significantly less likely to report unfavorable results
than those without such sponsorship.
If economic evaluations are to play a key role in health care decision
making, greater clarity is required. Rigorous RCTs designed with sufficient
power to detect clinically important differences in clinically relevant
outcomes must remain a cornerstone of such evaluations. The debate about
RSV-IGIV and palivizumab would have significantly been clarified had even
larger RCTs been conducted using mortality or markers of severe morbidity,
outcomes other than health services utilizations. Economic evaluations must
be methodologically sound and conducted by individuals with sufficient
training and expertise to understand the nuances and complexities of
economics. At the same time, there must be sufficient transparency for
others to read, understand, and potentially replicate the study. At the very
minimum, disclosure of sponsorship should be mandatory, but it is probably
not fully sufficient to guard against bias. The systematic review of
economic evaluations of palivizumab and RSV-IGIV by Kamal-Bahl et al would
suggest that pharmaceutical sponsorship per se would severely undermine any
conclusions reached. As Lewis has stated, "Some bargains are Faustian and
some horses are Trojan. Dance carefully with the porcupine, and know in
advance the price of intimacy."11(p785)
Author/Article Information

Terry P. Klassen, MD, MSc, FRCPC
Department of Pediatrics
University of Alberta
Canada
2C3.67 Walter C. Mackenzie Center
Edmonton, Alberta T6G 2R
(e-mail: terry.klassen@ualberta.ca)
REFERENCES

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