WASHINGTON, D.C. -- The percentage of Americans who report being sick with the flu on any given day in the first half of October averaged 2.2%, similar to the rates found in October 2011 and October 2012. The prevalence of flu is up from 1.5% in September, representing a typical increase for this time of year.
The start of the flu season inconveniently coincided with the partial government shutdown that began on Oct. 1. As a result, the Centers for Disease Control and Prevention has not posted a weekly update on the scope and severity of flu activity in the U.S. since Sept. 27, a report that analyzed data for the week ending Sept. 21. After the federal government reopened Thursday, the CDC announced that it will release an abbreviated report today for its most recent week of data, but will not delve into data from prior to and during the shutdown until a later date.
The Gallup-Healthways Well-Being Index ask 500 Americans each day whether they had a cold or the flu "yesterday." It is possible that this measure of daily cold and flu prevalence underestimates the true rate, because those who were sick the day before may be less likely to respond to a phone survey than those who were not sick. Still, year-over-year comparisons provide useful information about the relative prevalence of flu in the U.S. population.
Flu and colds in the U.S. usually follows a seasonal pattern, with Americans' self-reports of the illnesses rising in the fall months, peaking in the winter months, and declining in the spring and summer months. The only major exception to this pattern was when flu reports peaked in October 2009, amid the outbreak of the H1N1 flu virus.
As is the norm, more Americans currently report having a cold than the flu. An average of 6.7% of adults report having a cold on any given day so far in October, up from 5.7% in September. This rate of colds in the first half of the month is on par with levels from Octobers of past years, with the exception of a slightly higher rate in October 2009. More generally, about three adults report having a cold "yesterday" for every adult who reports having the flu.
There are key demographic and regional differences in daily reports of the flu and colds so far in October.
- Those in the East and West were slightly more likely than those in the Midwest and South to report having the flu or a cold.
- Younger adults were generally more likely than those who are older to report having the flu or a cold. Americans aged 45-64 were slightly more likely than those aged 30-44 to have a cold.
- Hispanics were the most likely racial or ethnic group to report having either the flu and a cold.
- Lower-income Americans are more likely than higher-income Americans to report having both illnesses.
- Men and women were equally as likely to report having the flu, but men were more likely to report having a cold.
- Smokers and those with asthma were at least slightly more likely than their counterparts to report having the flu or a cold.
- Hispanics, lower-income adults, those living in the West, and asthmatics were the most likely of all population subgroups in the U.S. to report having the flu on the prior day. Higher-income adults, whites, and those living in the South were the least likely.
- Asthmatics, Hispanics, and smokers were the most likely to say they had a cold the prior day so far in October. Seniors, higher-income Americans, and those living in the South were the least likely.
These patterns by group are consistent with what Gallup and Healthways have found in previous years.
Results are based on telephone interviews conducted as part of the Gallup-Healthways Well-Being Index survey Oct. 1-14, 2013, with a random sample of 7,151 adults, aged 18 and older, living in all 50 U.S. states and the District of Columbia.
For results based on the total sample of national adults, one can say with 95% confidence that the margin of sampling error is ±1 percentage point.
Interviews are conducted with respondents on landline telephones and cellular phones, with interviews conducted in Spanish for respondents who are primarily Spanish-speaking. Each sample of national adults includes a minimum quota of 50% cellphone respondents and 50% landline respondents, with additional minimum quotas by region. Landline and cellphone numbers are selected using random-digit-dial methods. Landline respondents are chosen at random within each household on the basis of which member had the most recent birthday.
Samples are weighted to correct for unequal selection probability, nonresponse, and double coverage of landline and cell users in the two sampling frames. They are also weighted to match the national demographics of gender, age, race, Hispanic ethnicity, education, region, population density, and phone status (cellphone only/landline only/both, and cellphone mostly). Demographic weighting targets are based on the March 2012 Current Population Survey figures for the aged 18 and older U.S. population. Phone status targets are based on the July-December 2011 National Health Interview Survey. Population density targets are based on the 2010 census. All reported margins of sampling error include the computed design effects for weighting.
In addition to sampling error, question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of public opinion polls.
For more details on Gallup's polling methodology, visit www.gallup.com.