Flu Shots, Work Absences and Hospitalizations: Is an Ounce of Prevention Worth a Pound of Cure?
University of Toronto
November 11, 2008
Available at SSRN.
In this study, I evaluate the health and economic consequences of a broad-based flu vaccination program. The Ontario Influenza Immunization Campaign was introduced in 2001 and delivers free flu shots to healthy children and adults. This program was novel; historically the flu shot had been recommended only for the elderly or infirm and policy expansion outside these groups continues to be controversial. The Ontario campaign offers a useful policy experiment to address this controversy by evaluating the impact of vaccinating children and younger adults against flu. Given that a simple before and after comparison of Ontario and other provinces may incorrectly attribute all changes in outcomes to the flu shot campaign, I instead develop a triple difference identification strategy that exploits variation in the match of the flu shot to the flu. I find that when the flu shot was a good match against circulating strains of flu, Ontario had substantially greater decreases in illness and lost work-time than other provinces after the introduction of the flu shot campaign. Further, based on the results for hospitalizations alone, an ounce of prevention saves a pound of cure; the program expansion costs approximately $33 million per year while, in an average match season, the program saves $102 million in respiratory hospitalization costs and $64 million in work absence costs. While the results are strongest for children and younger adults, hospitalization rates for those older than 65 fell significantly even though this group experienced no relative change in vaccination. This suggests that increased vaccination of the young has positive externality effects for the elderly.