Date of Award

January 2015

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)


School of Public Health

First Advisor

Robert Heimer


INTRODUCTION: Globally, influenza is responsible for 3-5 million cases of severe illness annually. In the United States alone, it is estimated that flu-associated infections account for 3.1 million hospitalized days per year. While the overall impact of flu is relatively well-studied, severe influenza is not well-characterized among the substance abuser and smoker populations.

OBJECTIVES: This study characterizes the risks for and complications associated with serious influenza infection among the substance abuser and smoking populations within Connecticut.

METHODS: Data were obtained via retrospective medical chart review. Cases were individuals within New Haven and Middlesex counties hospitalized with a positive influenza test during the 2011-2012, 2012-2013, and 2013-2014 flu seasons. Smoking and substance use status were analyzed for associations with variables along three main categories: demographics, illness severity measures (e.g. ICU admission, death), and co-morbid conditions. Odds ratios were obtained for statistically significant associations. Logistic regression was used to model risks of smoking.

RESULTS: Of the 961 cases, 61 (6.3%) were substance abusers and 257 (26.7%) were current smokers. On average, substance abusers were 8 years younger upon admission, 1.72 (95% CI 1.03 – 2.94) times more likely to be male than female, 3.86 (95% CI 2.12 – 7.01) times more likely to be black than non-Hispanic white, and faced the highest burden of flu in January. Substance abusers had greater odds of being admitted to the ICU (OR=1.93) and requiring mechanical ventilation (OR=2.65). Smoking status was not significantly associated with increases in illness severity but smokers were at increased risk for COPD (OR=4.34), liver disease (OR=2.42), and HIV (OR=3.70). Overall, substance abusers have 3.53 (95% CI 2.78 – 4.51) times the risk of being hospitalized with an influenza infection than non-drug users, twice the risk of influenza-associated hospitalization for smokers (RR=1.72).

CONCLUSIONS: Influenza hospitalizations are mildly to moderately more severe among substance users. Future directions could include targeted flu vaccine interventions for this population, through programs such as syringe exchange and substance abuse treatment.


This is an Open Access Thesis.