Data collection
To obtain a significant sample of Albanian asthmatic population, a
number of allergists/pathologists around the country were enrolled to
contribute to the study by providing data about asthmatic subjects (18
years or older) based on their patient register and medical history. The
study was retrospective, and medical records of 400 asthmatic subjects
receiving montelukast (10 mg daily) and 400 asthmatic subjects not
receiving montelukast were evaluated (from January
1st, 2012 to December 31st, 2014).
Asthmatic subjects (International Classification of Diseases (ICD-10
v:2016) code 493) were diagnosed on the basis of GINA (Global Initiative
for Asthma) criteria (https://ginasthma.org) on objective evidence
of variable airflow obstruction. As the number of patients taking
montelukast was the limiting factor of the study, we considered exposed
all patients taking the drug for a period of at least three months,
excluding all subjects with a previous history of MI or IS, as reported
in their medical records (ICD: MI-I21 or IS-I63). These patients were
randomly matched with patients not receiving montelukast as an
anti-asthmatic drug primarily by gender and secondly by age. In order to
identify a predisposition of the monitored patients to an increased CV
risk for MI and IS, information was obtained on drug therapies for major
chronic conditions such as hypertension, diabetes mellitus,
dyslipidemia, cerebrovascular disease, anemia, arrhythmias, epilepsy,
allergies, psychosis, ulcers, cancer, and depression. General
information such as age, gender, patient education level, residence and
income were also recorded, while systemic blood pressure, body mass
index, smoking, obesity or cholesterol were not available for the
majority of the patients and for this reason were not taken into account
in our analysis. According to ICD, the two groups were finally
classified for the presence or absence of MI or IS.