Probability of Clostridium difficile Infection in Medicare Beneficiaries in the United States 1991–2007, by Smoking Status and Region of Residence.

Footnotes:aPredicted marginal probabilities from survey-weighted, fully adjusted model. Covariates were year of birth (centered), sex, race, ethnicity, body mass index, alcohol use, marital status, education, total assets, heart disease, chronic lung disease, diabetes mellitus, stroke, end-stage renal disease, depression, Crohn disease, ulcerative colitis, irritable bowel disease, celiac disease, number of medical visits, number of infection-related visits.bDifference in CDI probability compared to never smokers.