Purpose: To examine whether young adults with asthma are at higher risk of initiating hypnotic use.
Methods: The study population was participants from the Norwegian youth health surveys, where all 10th grade students (15-17 years old) in five counties were invited. 10,164 participants with no prior use of hypnotics were linked to the Norwegian Prescription Database. Four groups were defined based on survey data about ever having had asthma and prescription data on asthma drugs received in the year prior to start of follow-up: (1) no asthma; (2) not active asthma; (3) active recently developed asthma; and (4) still active asthma. Incidence proportions were estimated as share of participants filling hypnotic prescriptions during 2005-July 2010. Incidence rate ratios (IRR), adjusted for potential confounders (illnesses, lifestyle and sociodemographic factors), were estimated with the number of hypnotic prescriptions filled during 2005-July 2010 as outcome.
Results: The incidence proportion of filling hypnotic prescriptions was 6.1%, ranging from 5.7% in no asthma group to 9.5% in active recently developed asthma group. Crude IRR was 1.35 (95%CI 0.93-1.95) for not active asthma, 4.18 (1.83-9.55) for active recently developed asthma, and 1.63 (0.85-3.14) for still active asthma, with no asthma as reference. Adjusted IRR for active recently developed asthma group changed to 4.72 (2.07-10.75) while the other groups remained statistically not significant.
Conclusions: In this prospective study of young adults without prior use of hypnotics, an increased risk of initiating hypnotic use was present in asthmatics, especially among those who recently had received asthma drugs.
Copyright © 2011 John Wiley & Sons, Ltd.