Risk factors for ARDS in the United States - Analysis of the 1993 National Mortality Followback Study

Objective: To identify specific comorbid factors that are present in US decedents with ARDS. Design: We searched the 1993 National Mortality Followback Study for all decedents who had a code for ARDS mentioned on their death certificate. We also searched for comorbid conditions both on the death certificates (sepsis, medical or surgical misadventures, cirrhosis) and in the study database (current or former smoking, use of alcohol at least 3 d/wk, race, gender, and age). We calculated proportional mortality ratios (PMRs) for these risk factors. Results: Of the 19,003 decedents for whom data were available, 252 decedents, representing an estimated 19,460 US decedents, had ARDS listed on their death certificate. PMRs among decedents with ARDS were significantly increased for medical or surgical misadventures (PMR, 11.8; 95% confidence interval [CI], 3.8 to 36.7), sepsis (PMR, 5.6; 95% CI, 2.0 to 16.0), nonwhite race (PMR, 2.6; 95% CI, 1.4 to 5.0), and cirrhosis (PMR, 2.2; 95% CI, 1.1 to 4.6). PMRs were increased but not statistically significant for current smokers (PMR, 1.2; 95% CI, 0.5 to 3.0) or former smokers (PMR, 1.8; 95% CI, 0.7 to 4.3) compared to never smokers, and drinking alcohol on greater than or equal to 3 d/wk in the year prior to death, when compared to drinking alcohol less than < 3 d/wk (PMR, 1.8; 95% CI, 0.6 to 4.9). Conclusions: The results of this study confirm the positive associations between ARDS mortality and the presence of sepsis and cirrhosis, and suggest possible new relationships between ARDS mortality and nonwhite individuals and patients with medical or surgical misadventures.