The correlation between smoking cumulative dose based on Brinkman Index with peak expiratory flow rate

Indonesia is the country with the highest prevalence of smokers above 15 years old according to WHO, with a percentage of 76.2%. Smoking-induced lung damage is characterized by inflammation, leading to the destruction of lung parenchyma and airway obstruction, ultimately worsening lung function parameters. This study aims to find correlation between cumulative dose of smoking based on Brinkman index (BI) with Peak Expiratory Flow Rate (PEFR).

This is a cross-sectional correlative study conducted on January-March 2020. Data were collected through history taking and PEFR measured with a peak flowmeter by taking the average of three peak flowmeter measurements, each separated by a 2-min interval. Inclusion criteria include male active smokers, aged 30 to 40 years, who have had a smoking history for at least 1 year. Exclusion criteria are as follows: uses e-cigarretes for smoking, has a history of chronic lung diseases such as tuberculosis, pneumonia, post-COVID-19 syndrome, asthma, and has not smoked in the last 28 days.

A total of 48 male smokers are included in this study. The mean age of participants was 35.91 years, with a history of smoking of 18.12 years, and 12.5 cigarettes smoked daily. Patients included in this study had BI classified as mild (47.91%), moderate (47.91%), and severe (4.16%). PEFR in patients was classified into green (10.41%), yellow (83.33%), and red (6.25%). Analysis showed significant negative correlation between BI and PEFR (r = -0.721; p < 0.001) suggesting that increasing Brinkman Index may lead to a decrease in PEFR.

Higher BI correlates with a decrease in PEFR. PEFR may prove to be useful in early detection of reduced pulmonary function. Further trials conducted on larger sample sizes and evaluating other lung function parameters are recommended.