In Spain, hospital admissions for asthma associated with bronchiectasis nearly doubled from 2001 to 2015, a new study reveals.
Although bronchiectasis was not associated with higher mortality, having both conditions correlated with longer hospital stays and higher costs.
The study, “Trend from 2001 to 2015 in the prevalence of bronchiectasis among patients hospitalized for asthma and effect of bronchiectasis on in-hospital mortality,” was published in the Journal of Asthma.
Bronchiectasis is the third most common chronic airway disease after asthma and chronic obstructive pulmonary disease (COPD). Scientific evidence suggests a strong association between COPD and bronchiectasis and the presence of both conditions leads to more exacerbations and worst outcomes.
Yet, the association between asthma and bronchiectasis is less clear. Previous studies concluded that only a small fraction of bronchiectasis cases are linked to bronchial asthma; estimates show that only 1.4 to 5.4% of bronchiectasis cases are caused by asthma.
The prevalence of bronchiectasis in patients with asthma is very variable, ranging from 2% up to 80% depending on methods used. Bronchiectasis is linked to a greater asthma severity, but its impact on asthma progression is unknown.
Using the Spanish National Hospital Discharge database, researchers analyzed the presence of bronchiectasis in patients hospitalized due to asthma to identify factors associated with worse outcomes.
The study included 342,644 patients diagnosed with asthma in Spain from 2001 until 2015. Overall, 10,377 asthma patients also had bronchiectasis (3.02%). The majority (77.06%) were women.
Compared to people without bronchiectasis, asthma patients with bronchiectasis were older – mean age 68 vs. 47 – and had more comorbidities, or other conditions (9.45% vs. 6.58%).
Regarding respiratory infections, Pseudomonas aeruginosa bacteria were found more frequently in patients with asthma and bronchiectasis (8%) than in patients with asthma alone (0.66%). Similar results were observed for infections caused by the Aspergillus species, a type of fungus.
The use of non-invasive mechanical ventilation was more frequent in people with bronchiectasis (2.43%) compared to patients without this condition (1.56%). However, the opposite was observed for invasive ventilation, with 0.81% in bronchiectasis patients compared to 1.03% in people with asthma alone.
Patients with bronchiectasis had longer mean hospital stays, 9.39 days vs. 6.17 days in people without bronchiectasis. In addition, both the rate of readmission and hospital costs were higher in people with both asthma and bronchiectasis.
In-hospital mortality rate again was higher in patients with bronchiectasis (2.07%) compared to people without the disease (1.2%). However, after accounting for age, gender and comorbidities (conditions occurring simultaneously), this difference was no longer significant.
Significantly, the prevalence of bronchiectasis in asthma patients increased from 2.16% in 2001 to 4.47% in 2015.
The increase in bronchiectasis frequency was accompanied by increases in mean age, number of patients with comorbidities, percentage of smokers and infections by Pseudomonas aeruginosa. Non-invasive ventilation, oxygen therapy, aerosol therapy and mean hospital costs also increased significantly during this period in both men and women.
Meanwhile, the need for invasive mechanical ventilation decreased gradually, but only in women.
Further analysis suggested that factors affecting in-hospital mortality rate for patients with asthma with and without bronchiectasis were very similar and included older age, having more comorbidities, infections by Pseudomonas aeruginosa, hospital readmissions, and need for mechanical ventilation.
Still, for the asthma with bronchiectasis group, being a man and having Pseudomonas aeruginosa significantly increased the risk of death.
Overall, the results “are in favor of the presence of bronchiectasis being related to the existence of poorly controlled asthma, either as a risk factor or as a consequence of this fact. More studies are needed to corroborate and deepen the characteristics of this relationship” the study’s scientists wrote.