Childhood adversities and adult-onset asthma: a cohort study

OBJECTIVES Childhood adversities may be important determinants of later illnesses and poor health behaviour. However, large-scale prospective studies on the associations between childhood adversities and the onset of asthma in adulthood are lacking. DESIGN Prospective cohort study with 7-year follow-up. SETTING Nationally representative study. Data were collected from the Health and Social Support (HeSSup) survey and national registers. PARTICIPANTS The participants represent the Finnish population from the following age groups: 20-24, 30-34, 40-44, and 50-54 years at baseline in 1998 (24 057 survey participants formed the final cohort of this study). The occurrence of childhood adversities was assessed at baseline with a six-item survey scale. The analyses were adjusted for sociodemographic characteristics, behavioural health risks and common mental disorders. PRIMARY AND SECONDARY OUTCOMES The survey data were linked to data from national health registers on incident asthma during a 7-year follow-up to define new-onset asthma cases with verified diagnoses. RESULTS A total of 12 126 (59%) participants reported that they encountered a childhood adversity. Of them 3677 (18% of all) endured three to six adversities. During a follow-up of 7 years, 593 (2.9%) participants were diagnosed with incident asthma. Those who reported three or more childhood adversities had a 1.6-fold (95% CI 1.31 to 2.01) greater risk of asthma compared to those without childhood adversities. This hazard attenuated but remained statistically significant after adjustment for conventional risk factors (HR 1.33; 95% CI 1.06 to 1.67). CONCLUSIONS Adults who report having encountered adversities in childhood may have an increased risk of developing asthma.