Objective: The goal of this case control study was to evaluate the relationship between smoking and female urinary incontinence.
Study design: The study included 606 women whose smoking histories were known; 322 were incontinent and 284 were continent. The condition(s) causing each subject's incontinence was determined by urodynamic testing; 40% of the continent subjects had the same testing.
Results: There were highly significant overall differences (p = 0.000009) in the distribution of current, former, and never smokers between incontinent (35%, 16%, 49%) and continent (24%, 8%, 68%) groups. The odds ratio for genuine stress incontinence was 2.20 for former (95% confidence interval 1.18 to 4.11) and 2.48 for current smokers (95% confidence interval 1.60 to 3.84); for motor incontinence it was 2.92 for former (95% confidence interval 1.58 to 5.39) and 1.89 (95% confidence interval 1.19 to 3.02) for current smokers. Increasing daily and lifetime cigarette consumption was associated with an increasing odds ratio for genuine stress incontinence but not for motor incontinence. The increased risk for incontinence was not due to differences in age, parity, weight, or hypoestrogenic status.
Conclusion: The data establish a strong statistical relationship between current and former cigarette smoking and both stress and motor urinary incontinence in women.