Results
The incidence of asthma was 10.8 per 1,000 person-years in the constipation group, which was higher than the rate of 5.6 per 1,000 person-years observed in the non-constipation group. After adjustment for age, gender, comorbidities, and medications, constipated patients had a 1.91-fold greater risk of asthma compared to those without constipation (adjusted hazard ratio [aHR]: 1.91 (95% C.I. 1.84-1.99). In subgroup analyses, patients aged 20-39 years had a 2.04-fold highest risk of asthma in the constipation cohort (aHR:2.04, 95% CI, 1.84-2.26). Besides, the severity of constipation is associated with an increased risk of asthma; the aHR was 1.76 (1.69-1.85), 2.15(2.03-2.27), and 2.29(2.10-2.49) for < 3 times, 3-12 times, and ≥12 times of laxatives prescription within one year, respectively. (p<0.001) Moreover, constipated patients had a higher likelihood of asthma, regardless of gender, comorbidities, and medications.