Influence of smoking and alcohol consumption on admissions and duration of hospitalization.

BACKGROUND Previous studies have linked smoking and alcohol consumption to a considerable disease burden and large healthcare expenditures. However, findings from studies based on individual level data are sparse and inconclusive. Our objective was to assess the association between alcohol consumption, smoking and patterns of hospitalization, defined as admission and duration of hospitalization. METHODS The study was based on 12 698 men and women, aged 20 years or more, enrolled in the Copenhagen City Heart Study. We related smoking and alcohol to hospital admission from any cause, smoking- and alcohol-related diseases and duration of hospitalization in a two-part random effects model. RESULTS Smoking status was strongly associated with admission and duration of hospitalization. For smoking-related admissions, odds ratios (OR) of 2.77 (95% CI 2.13-3.59) in men and 6.30 (95% CI 4.80-8.26) in women were observed among smokers of >20 g/day compared to never-smokers. For any admission (excl. smoking-related causes), corresponding ORs were 1.32 (95% CI 1.15-1.51) and 1.80 (95% CI 1.58-2.06), respectively. In men, a U-shaped association between alcohol consumption and risk of admission was found, both regarding any admission and admissions due to alcohol-related diseases. Alcohol was associated with alcohol-related admissions in women but not with duration of hospitalization. CONCLUSIONS Smoking was associated with increased risk of hospital admission and duration of hospitalization. A U-shaped relation was observed for alcohol consumption and risk of hospitalization in men, but no effect on duration was observed. In women, however, alcohol consumption was only vaguely associated with admission and duration of hospitalization.