Occupational use of high-level disinfectants and asthma incidence in early- to mid-career female nurses: a prospective cohort study.

Abstract

Occupational use of disinfectants among healthcare workers has been associated with asthma. However, most studies are cross-sectional, and longitudinal studies are not entirely consistent. To limit the healthy worker effect, it is important to conduct studies among early- to mid-career workers. We investigated the prospective association between use of disinfectants and asthma incidence in a large cohort of early- to mid-career female nurses. The Nurses' Health Study 3 is an ongoing, prospective, internet-based cohort of female nurses in the USA and Canada (2010-present). Analyses included 17 280 participants without a history of asthma at study entry (mean age: 34 years) and who had completed ≥1 follow-up questionnaire (sent every 6 months). Occupational use of high-level disinfectants (HLDs) was evaluated by questionnaire. We examined the association between HLD use and asthma development, adjusted for age, race, ethnicity, smoking status and body mass index. During 67 392 person-years of follow-up, 391 nurses reported incident clinician-diagnosed asthma. Compared with nurses who reported ≤5 years of HLD use (89%), those with >5 years of HLD use (11%) had increased risk of incident asthma (adjusted HR (95% CI), 1.39 (1.04 to 1.86)). The risk of incident asthma was elevated but not statistically significant in those reporting >5 years of HLD use and current use of ≥2 products (1.72 (0.88 to 3.34)); asthma risk was significantly elevated in women with >5 years of HLD use but no current use (1.46 (1.00 to 2.12)). Occupational use of HLDs was prospectively associated with increased asthma incidence in early- to mid-career nurses.