Living in poverty is an independent risk factor for influenza hospitalization, suggesting that poor communities should be specially targeted for vaccine outreach and other efforts to prevent flu and improve outcomes, officials with the CDC said Thursday.
People living in the poorest neighborhoods were nearly twice as likely as those living in more affluent areas to be hospitalized with complications of the flu, in data from the national influenza surveillance network FluSurv-NET published in the CDC's
Since influenza surveillance data typically do not include individual measures of socioeconomic status, the newly published analysis is among the first to examine the impact of living in poverty on flu outcomes.
The analysis included data on flu hospitalizations during the 2010-2011 and 2011-2012 influenza seasons from 78 counties in 14 states. The sample represented approximately 9% of the U.S. population. Census tract data were used to estimate the economic status of patients hospitalized with the flu.
For both seasons combined, the age-adjusted incidence of influenza-related hospitalizations per 100,000 person-years living in high poverty neighborhoods (≥20% of people living below the federal poverty level) was 21.5 (95% CI 20.7-22.4), which was nearly twice the incidence seen in low poverty areas (<5% of people living below the poverty level) (10.9, 95% CI 10.3-11.4), researchers reported.
Greater poverty was associated with a greater risk for hospitalization, and the relationship was seen in all 14 surveillance sites, in all age groups examined, and in different racial/ethnic groups.
Older people (≥65) accounted for 94% of hospitalizations in the lowest poverty census tracts compared to 80% of hospitalizations in the highest.
"The association of higher census tract-level poverty with higher influenza-related hospitalization rates appears to be robust, occurring across counties in 14 states, within pediatric and adult age groups and across racial/ethnic groups," the researchers wrote.
"Possible contributing factors are lower vaccination rates in residents of poorer census tracts, poverty-related crowding with higher rates of influenza transmission and higher prevalence of medical conditions predisposing persons to influenza complications in poorer areas."
The researchers noted that regardless of the cause, greater emphasis on increasing flu vaccination rates and prescribing antivirals in the outpatient setting is needed in poorer communities to reduce the poverty-associated disparity in influenza hospitalizations.
"This will require enhanced efforts by public health agencies and health care providers to address missed opportunities for vaccination and system barriers, as well as a better understanding of personal barriers to influenza vaccination in these neighborhoods," they wrote. "In addition, it will require evaluation of use of antivirals and efforts to improve them."
Primary Source
Morbidity and Mortality Weekly Report
Hadler JL, et al "Influenza-Related Hospitalizations and Poverty Levels -- United States, 2010-2012" MMWR 2016; 65(5): 101-105.