WASHINGTON, D.C. — Americans’ self-reports of the flu are rising at the expected rate and are tracking at nearly identical levels of last year. An average of 2.1% of Americans in October reported having the flu the day before the survey, similar to the levels found in October of last year and in 2008, but slightly lower than the 2.7% in 2009.
The Gallup-Healthways Well-Being Index asks 1,000 Americans each day whether they had a cold or the flu “yesterday.” In general, the percentage of Americans who report they had a cold on any given day is roughly three times greater than the percentage who report they had the flu.
The 2009-2010 cold and flu season is associated with the H1N1 pandemic. Gallup data reveal unusually high rates of reported cold and flu incidences through October of that season, before dropping to below-typical rates thereafter.
The measurement of colds versus the flu in a survey research environment is complex because of the overlapping symptoms of the two disease conditions and many Americans’ misunderstanding of which symptoms constitute “the flu” versus “a cold.”
It is also possible that the estimate of daily cold and flu prevalence is underestimated, as would-be respondents who were sick the day before may be less likely to respond to a phone survey than those who were not sick. Still, Gallup’s measurement approach — asking the same question in the same survey day after day — holds these factors constant, thus providing valuable trends for evaluating changes from month to month and year to year.
