Risk factors of asthma exacerbation based on asthma severity: a nationwide population-based observational study in South Korea

Abstract

ObjectivesAsthma exacerbation, associated with many risks factors, can reflect management failure. However, little is known about how risk factors are associated with exacerbation, according to asthma severity. We aimed to investigate differences in risk factors in patients with different asthma severity and evaluate whether risk factors differed between frequent exacerbators and patients with single exacerbation.DesignNationwide population-based observational study.SettingKorean National Sample Cohort database.ParticipantsWe included 22 130 adults with asthma diagnoses more than twice (ICD-10 (International Classification of Diseases, Tenth revision) codes J45 and J46) and one prescription for asthma medication from 2010 to 2011.Outcome measuresAsthma exacerbation was defined as having a corticosteroid (CS) burst characterised by a prescription of high-dose oral CS for ≥3 days or one systemic CS injection, hospitalisation or emergency department visit.ResultsAmong severities, history of CS bursts was significantly associated with exacerbation. In mild and moderate asthma, exacerbation was significantly associated with age ≥45 years, being female, gastro-oesophageal reflux disease and chronic rhinitis. High medication possession ratio (MPR≥50%), compared with low MPR (<20%) showed adjusted ORs of 0.828 (95% CI 0.707 to 0.971) and 0.362 (0.185 to 0.708) in moderate and severe asthma, respectively. In severe asthma, compared with mild asthma, only allergic rhinitis and history of hospitalisation were strongly associated with exacerbation. When comparing frequent exacerbators to patients with single exacerbation, age ≥45 years, atopic dermatitis, anxiety and history of CS burst were significant risk factors in mild and moderate asthma, whereas no risk factors were significant in severe asthma.ConclusionsDifferent associations between risk factors and asthma exacerbations based on asthma severity suggest that patients with mild asthma require greater attention to their age and comorbidities, whereas those with severe asthma require greater attention to hospitalisation history and drug adherence.

Independent risk factors for death in patients admitted for asthma exacerbation in Taiwan

“…A history of corticosteroid bursts also was a risk factor for future exacerbation among all severities. 26 Here we demonstrated that the indicators of asthma severity, including a history of asthma-associated hospitalization, use of SABA, and a dosage of OCS use >70 mg prednisolone during hospitalized treatment in the preceding year, were independently associated with fatal asthma. These findings indicate that asthma severity is the important determinant associated with near-fatal/fatal asthma and asthma-related mortality after discharge of an asthma admission.…”

“…These studies showed that comorbidity, which existed in older asthma patients, may have contributed to asthma mortality. 11,26,27 Whether the aforementioned factors can be utilized to independently predict the in-hospital mortality in asthma patients who require ED visits and/or hospitalizations for asthma exacerbation has not been assessed.…”

Exacerbation-prone asthma in the context of race and ancestry in Asthma Clinical Research Network trials

“…1,[4][5][6][7][8][9] Recently, we identified a black, exacerbation-prone asthma subgroup from a randomized trial cohort that was best characterized by subjects with an asthma exacerbation in the prior year and lower lung function, factors also associated with exacerbations in other cohorts. [10][11][12][13] Post hoc analyses of National Heart, Lung, and Blood Institute (NHLBI)-sponsored Asthma Clinical Research Network (ACRN) and AsthmaNet clinical trial cohorts have shown that African American subjects have lower lung function, a greater proportion of uncontrolled asthma, and a greater likelihood of treatment failure compared with their white counterparts. 14,15 Race and ethnic designations do not sufficiently capture the ancestral genetic, cultural, geographic, or socioeconomic contexts that underlie differences in asthma severity between racial groups.…”

Factors influencing bronchial asthma exacerbations with special emphasis on inhaler usage

“…6 Kang HR et al, also observed similar finding that exacerbations of bronchial asthma episodes were significantly more among those aged more than 45 years. 7 Smith K et al, also noted in their study that elderly were at more risk of exacerbations of bronchial asthma. 8 Thus, all studies confirm that advanced age is associated more attacks of exacerbations of bronchial asthma.…”

“…9 But again Kang HR et al, found that it was more in females. 7 Anto JM et al, stated that the risk of exacerbations of bronchial asthma was 1.97 times more in females. 11 Thus, there is no coherence between the studies as to whether gender can be a risk factor for exacerbations of bronchial asthma.…”