BACKGROUND: Respiratory assessments frequently utilize Peak Expiratory Flow Rate (PEFR) as a fundamental measure of lung function. However, standard reference ranges may not accurately represent variations across different demographic groups. This study aims to address this gap by examining the variability of PEFR among healthy Pakistani adults.

METHODS: This cross-sectional study was conducted over a six-month period at a tertiary care hospital in Wah Cantt, Pakistan, involving 400 consenting participants. A consecutive sampling technique was employed. Anthropometric measurements, including height and weight, were obtained using a stadiometer and calibrated weighing scale, respectively. Each participant performed three PEFR maneuvers using a peak flow meter, and the highest value was recorded. Additional data, including age and gender, were collected using a structured proforma. Data was analyzed using SPSS.

RESULTS: PEFR showed a strong positive correlation with height (0.616 in males 0.767 in females) and a negative correlation with age (-0.418 in males and -0.115 in females). Male participants exhibited significantly higher PEFR values compared to females.

CONCLUSION: The findings indicate that PEFR is influenced by gender, height, and age. Specifically, males tend to have higher PEFR values; PEFR increases with greater height and decreases with advancing age. These results underscore the importance of considering demographic-specific factors when interpreting PEFR values and support the development of localized reference standards for clinical use.

KEYWORDS: Peak Expiratory Flow Rate, Lung Function, Spirometry, Pulmonary Assessment, Demographic Variation