Correlation between respiratory function tests and evolution time in asthmatic patients

A transversal and prospective study was performed to demonstrate a relationship between the evolution time of asthma episodes and alterations observed in the respiratory function tests (RFT) during asymptomatic periods. Asthmatic patients (n = 80) of both sexes, were studied, we investigated the evolution time of the asthmatic episodes and performed RFTs in the patients during their asymptomatic periods. Respiratory patterns were classified as normal, obstructive, or mixed (obstructive-restrictive), and a Spearman correlation test was performed. Twenty nine patients were male and fifty one female. All were between 5 and 49 years of age. Of the total number of patients, 13.7% fell into a normal pattern, 57.5% into an obstructive pattern and 28.7% in a mixed pattern. In the groups showing the shortest evolution time, the obstructive pattern was more common (75% of patients with less than 5 years of evolution time and 53.8% with an evolution time between five and ten years). The mixed pattern was more common in patients with more years suffering asthma (16.6% in the group of patients having 5 or less years of evolution and 50% in the group with more than 20 years). We found a Spearman value of 0.7, and we can conclude that there is more pulmonary damage associated to a longer evolution period of bronchial asthma.