Hospitalization and mortality for acute exacerbation of asthma: an Italian population-based study

Asthma is an ever-increasing disease with a highly variable prevalence among different ethnic groups. Information on hospital admission for acute exacerbation of asthma in adult patients and data regarding short-term prognosis of these patients are limited. We, thus, performed an epidemiological study on hospital admission for asthma acute exacerbation in Italy using hospital discharge database records derived from all Italian hospitals. Patients > 15 years old were identified using clinical Modification (ICD-9-CM) codes. Information on baseline characteristics, vital status at discharge, duration of hospitalization, and up to five secondary discharge diagnoses was collected. Comorbidity was evaluated using the Charlson comorbidity index (CCI). During the observation period (2013-2014), 20,056 patients with asthma acute exacerbation were hospitalized. Median length of hospitalization was 7.9 days (interquartile range 4-10) and mean in-hospital mortality was 0.8%. In-hospital mortality and length of hospitalization varied among different regions (from 0 to 2.9% and from 6.5 to 8.9 days, respectively). Old age, invasive and non-invasive mechanical ventilation, and CCI resulted as significantly associated with higher in-hospital mortality. Our study results, on a large sample of patients, confirm that hospitalization for asthma acute exacerbation is not uncommon among Italian current population. Older age, high CCI, and use of ventilator support were associated with a higher mortality rate. These findings should be analyzed to set up appropriate health care policies on patients with asthma.