Odds Ratio of BMI category for patients hospitalized with 2009 pandemic influenza A(H1N1) compared to the U.S. NHANES 2003–2006 population hospitalized for any reason over a 12-month period, by category of body mass index (BMI) and presence of ACIP-recognized chronic medical conditions.

Note: OR, Odds Ratio, CI, confidence interval.
BMI (kg/m2) categories for 2–19 year olds based on age- and sex-specific CDC 2000 growth charts: underweight<5th percentile, normal weight 5–84th percentile, overweight 59–94th percentile, obese ≥95th percentile.
BMI (kg/m2) categories for ≥20 year olds: underweight<18.5, normal weight 18.5–24.9, overweight 25.0–29.9, obese 30.0–39.9, morbidly obese ≥40.
* For this analysis ACIP-recognized chronic medical conditions include cardiovascular disease, pulmonary disease, liver condition, cancer, and diabetes.
** National Health and Nutrition Examination Survey (NHANES) 2003–2006, respondents who report having been admitted to hospital for any reason in the 12 months prior to interview.
† There were no observations in this strata from the NHANES survey.