Abstract
Background: Individuals with respiratory symptoms and preserved pulmonary function increasingly constitute a significant proportion of clinical consultations and may have increased risk of airway disease.
Methods: Using information on 108 246 individuals from a Danish contemporary population-based cohort study, we tested whether respiratory symptoms are strongly associated with subsequent respiratory hospitalisations and death in individuals with preserved pulmonary function. Preserved pulmonary function was defined as a pre-bronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC)≥0.70 and respiratory symptoms included dyspnea, chronic mucus hypersecretion, wheezing, and cough. Individuals with known obstructive lung disease were excluded (n=10 291).
Results: 52 999 had preserved pulmonary function without respiratory symptoms and 30 890 had preserved pulmonary function with respiratory symptoms. During follow-up, we observed 1037 hospitalisations with exacerbation of airway disease, 5743 hospitalisations with pneumonia, and 8750 deaths, of which 463 were due to respiratory diseases. Compared to individuals with preserved pulmonary function without respiratory symptoms, age and sex adjusted hazard ratios for individuals with preserved pulmonary function with respiratory symptoms were 3.34 (95% confidence interval:2.49-4.47) for hospitalisations with exacerbation, 1.59 (1.48-1.71) for hospitalisations with pneumonia, 2.30 (1.78-2.97) for respiratory mortality, and 1.51 (1.44-1.58) for all-cause mortality. Increased risks could already be observed after 2 years follow-up. Results were similar in competing risk analyses with death as competing event where relevant and after adjustment for potential confounders of pulmonary and non-pulmonary diseases.
Conclusions: Respiratory symptoms are strongly associated with subsequent respiratory hospitalisations and death in individuals with preserved pulmonary function.
Methods: Using information on 108 246 individuals from a Danish contemporary population-based cohort study, we tested whether respiratory symptoms are strongly associated with subsequent respiratory hospitalisations and death in individuals with preserved pulmonary function. Preserved pulmonary function was defined as a pre-bronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC)≥0.70 and respiratory symptoms included dyspnea, chronic mucus hypersecretion, wheezing, and cough. Individuals with known obstructive lung disease were excluded (n=10 291).
Results: 52 999 had preserved pulmonary function without respiratory symptoms and 30 890 had preserved pulmonary function with respiratory symptoms. During follow-up, we observed 1037 hospitalisations with exacerbation of airway disease, 5743 hospitalisations with pneumonia, and 8750 deaths, of which 463 were due to respiratory diseases. Compared to individuals with preserved pulmonary function without respiratory symptoms, age and sex adjusted hazard ratios for individuals with preserved pulmonary function with respiratory symptoms were 3.34 (95% confidence interval:2.49-4.47) for hospitalisations with exacerbation, 1.59 (1.48-1.71) for hospitalisations with pneumonia, 2.30 (1.78-2.97) for respiratory mortality, and 1.51 (1.44-1.58) for all-cause mortality. Increased risks could already be observed after 2 years follow-up. Results were similar in competing risk analyses with death as competing event where relevant and after adjustment for potential confounders of pulmonary and non-pulmonary diseases.
Conclusions: Respiratory symptoms are strongly associated with subsequent respiratory hospitalisations and death in individuals with preserved pulmonary function.
| Original language | English |
|---|---|
| Journal | European Respiratory Journal |
| Publication status | Accepted/In press - 11 Jun 2019 |