Cost-effectiveness Analysis and Vaccine Policy

Lisa A. Prosser, Ph.D.University of Michigan

May 2, 2011

Overview

• Role of cost-effectiveness evidence in current Advisory Committee on Immunization Practices (ACIP) process

• Limitations in current health valuation approaches

• Lessons from newborn screening• Future directions & global implications

Evidence Reviewed by ACIP

Source: Smith, 2010

Cost-effectiveness in practice

• Inadequacy of the cost-effectiveness framework to capture important values

• Identifying a threshold for determining cost-effectiveness

• Challenge of communicating results to decision makers

Valuation of health benefits

• Limitations of QALYs, DALYs, other established measures– Risk profile– Priorities by age

• Conjoint analysis and other approaches provide complementary information

QALY Losses

Event (in 1 year old) QALY Loss (Disutility)

H1N1 Influenza Illness Episode 0.0001

Vaccination-Related Adverse Event:Guillain-Barré Syndrome

0.0039

Source: Lavelle et al., 2010

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Time trade-off amounts by patient age

Source: Prosser et al., 2010

Thresholds

• Implied threshold from ACIP recommendations

• WTP per QALY – no “one size fits all”– A QALY is a QALY is a QALY (or is it?)– Prevention vs. treatment– Characteristics of the condition, patient

population

• WHO thresholds

Lessons from newborn screening

• Advisory Committee for Heritable Disorders in Newborns and Children (ACHDNC)

• Evidence Evaluation Methods Working Group• Decision modeling to project outcomes– Short and long-term health outcomes– …but not QALYs– “false positives” vs. identified cases

Newborn Screening – Projected Outcomes

Clinical Ident. Screening ∆

Population 100,000 100,000 -

Children w/MCADD 5.88 (0.01) 8.4 (0.01) 2.52

FP screen N/A 20 (0.02) 20

Costs (lifetime) $630,710 $1,629,482 $998,778

QALYs 2,976,780.08 2,976,827.03 36.42

C/E ratio $27,423 (670)

Source: Prosser et al., Pediatrics, 2010

Newborn Screening – Projected Outcomes

Clinical Ident. Screening ∆

Population 100,000 100,000 -

Children w/MCADD 5.88 (0.01) 8.4 (0.01) 2.52

FP screen N/A 20 (0.02) 20

Costs (lifetime) $630,710 $1,629,482 $998,778

QALYs 2,976,780.08 2,976,827.03 36.42

C/E ratio $27,423 (670)

Source: Prosser et al., Pediatrics, 2010

QALYs gained via screening 46.95

QALYs lost from FPs -0.01

QALYs lost from treatment -10.52

Total QALYs 36.42

Conjoint Analysis

• Conjoint analysis, originally developed for marketing and transportation analysis, allows for:– Estimation of the relative importance of different aspects

of a health service– Trade-offs between these aspects– Total satisfaction or utility respondents derive from health

services

• Relatively new in health applications

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Conjoint Analysis - Applications

• Preferences for health services and barriers to utilization of health care in sub-Saharan Africa

• Measuring WTP per QALY– Population-based– Condition-specific

• Valuation of QALYs– Scoring algorithm for EQ-5D– Time trade-off amounts

Marginal WTPAttribute mWTP 95% CI

Each injection avoided $7.68* $5.75 -$9.60

Immunization coverage, 80% v. 90%

$65.42* $52.30 - $78.54

Extra dose Hepatitis B $9.13 -$4.82 - $23.08

Lower risk of fever (over 6 mos), 10% v. 30%

$124.70* $105.90 - $143.60

*P-value <0.001

Source: Gidengil et al., forthcoming.

Implications for Global Vaccine Policy

• Increased need to understand public values for health and health care beyond QALYs, DALYs, or other summary measures

• Research on measuring preferences in resource-limited settings

• Can inform valuation of health benefits and prioritization more broadly

Summary

• Future research directions in cost-effectiveness research need to include new approaches for valuing health benefits– How preferences vary by condition, potential

harms, patient population, etc.– How best to evaluate? Incorporated into or

considered separately from the cost-effectiveness ratio?

Thank You