Poor Neighborhoods Should Be Targeted for Flu Shots to Avoid Hospitalizations, CDC Finds

February 11, 2016
Mary Caffrey

Findings reveal an obvious area for improvement in population health.

The focus on population health—with its charge to take proactive steps to prevent avoidable costs and poor outcomes—is best represented in basics like immunizations. And yet the US health system still racks up plenty of both, as seen in today’s report from CDC on missed opportunities in preventing influenza.

In the Mortality and Morbidity Weekly Report, authors from CDC looked at the relationship between hospitalizations for influenza and poverty, in light of the 4900-27,000 deaths, as well as 114,000 to 624,000 hospitalizations that occur each year from this annual epidemic.

Led by James L. Hadler, MD, the analyze 2 years’ worth of data from 14 states covering 27 million people during the 2010-11 and 2011-12 influenza seasons. Hospitalization rates from the flu in high poverty areas were more than twice that of areas with low poverty, which make it clear that the poor should be targeted for flu shots.

“This relationship was observed in each surveillance site, among children and adults, and across racial and ethnic groups,” the authors found.

What the data show. Age-adjusted incidence of flu-related hospitalizations per 100,000 person years in high-poverty census tracts—where more than 20% of the residents lived below the federal poverty level—was 21.5. The hospitalization rate was only 10.9 per 100,000 person years in census tracts where the poverty rate was less than 5%.

While the data found that poverty by census tract drove hospitalization rates more than racial group, the effect was more pronounced among African Americans; members of this group in the poorest neighborhoods had hospitalization rates above 25%.

The authors suggest that higher hospitalization rates in poor areas could be tied to low vaccination rates, crowding in housing, and higher prevalence of medical conditions that predispose people to influenza.

However, the authors write, differences in vaccinations cannot not fully explain the results; only hospitalized patients age 65 and older had a large enough difference in vaccination rates to fully account for the findings. Overall, they note, vaccination rates among those hospitalized for influenza were inversely associated with area poverty levels, “from a high of 48% in census tracts with the lowest poverty levels to a low of 35% in the census tracts with the highest poverty levels,” with rates among seniors accounting for much of this difference.

Persons over age 65 account for 94% of the influenza hospitalizations in the wealthiest areas and 80% of the hospitalizations in the poorest, the authors found.

Whatever the reasons, vaccinations among the poor must increase, the authors conclude.

“This will require enhanced efforts by public health agencies and healthcare 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 write. “In addition, it will require evaluation of the use of antivirals and efforts to improve them.”

Reference

Hadler JL, Yousey-HIndes K, Perez A, et al. Influenza-related hospitalizations and poverty levels—United States, 2010-2012. MMWR, 2016;65(5)101-105.