Long-term predictors of severe exacerbations and mortality in a cohort of well-characterised adults with asthma

Abstract Background We aimed to explore long-term predictors of severe exacerbations and mortality in adults with well-characterised asthma. Study design and methods Adults (aged ≥ 15) with an objectively verified diagnosis of asthma were recruited from a Danish respiratory outpatient clinic between 1974 and 1990. All individuals were followed in Danish registries for vital status, hospital admissions for asthma and cause of death until end of 2017. Predictors of exacerbations were obtained from a repeated measures model. Standardised mortality rates (SMR) for all-causes were compared with the Danish background population. Hazard ratios for mortality were obtained from a cox proportional hazards model in a two-step process. Results At baseline, the cohort comprised 1071 patients (mean age 38, SD 16, 61% women), of whom 357 (33%) died during follow-up, with 93 (26%) dying from asthma (primary diagnosis). We found an SMR of 1.24 (95% CI 1.11–1.37, p  twice daily. Being non-atopic, having a positive histamine challenge test and symptoms more than twice a week were also predictors of repeated exacerbations. Conclusions Markers of poor asthma control, including high use of SABA, are predictors of long-term exacerbation rate and mortality over 30 years in patients with well-characterised asthma. Improving asthma control, including lung function and reducing use of reliever medication, is vital for improving the long-term outcome of asthma

Demographic, lifestyle and comorbid risk factors for all-cause mortality in a Danish cohort of middle-aged adults with incident asthma

OBJECTIVE: We aimed to identify factors associated with all-cause mortality in adults with incident asthma. DESIGN AND SETTING: Cross-sectional cohort study, in the metropolitan areas of Copenhagen and Aarhus, Denmark. PARTICIPANTS: Adults aged 50–64 years enrolled in the Danish Diet, Cancer, and Health cohort were followed up from baseline (1993–1997) in the National Patients Registry for first-time admissions for asthma and vital status. We defined incident asthma as at least one first-time hospital admission with asthma as the primary registered diagnosis between baseline and end of follow-up (2013) in participants without previously known asthma. Among the cohort comprising 57 053 individuals, we identified 785 adults (aged 50—64) with incident asthma, of whom 76 died during follow-up. PRIMARY AND SECONDARY OUTCOME MEASURES: Baseline reported socioeconomic and lifestyle traits, and comorbidities associated with all-cause mortality. RESULTS: Self-reported leisure-time physical activity was associated with a substantial reduction in risk with an HR of 0.53 (95% CI 0.33 to 0.85). Being male, single and having a diagnosis of hypertension or diabetes were associated with an increased risk of all-cause mortality with an HR of 1.83 (95% CI 1.14 to 2.38), 2.16 (95% CI 2.06 to 4.40), 2.47 (95% CI 1.54 to 3.95) and of 2.42 (95% CI 0.96 to 6.11), respectively. CONCLUSIONS: This long-term study of adults with hospital contacts for incident asthma revealed that self-reported leisure-time physical activity is associated with an approximately 50% reduction in all-cause mortality. In contrast, both hypertension and diabetes were associated with a higher risk of mortality