Saritha Jayachandran Shenoy, Neenu Kuruvilla, Kummannoor Parameshwaran Venugopal, Geethadevi Madhavikutty, Sameena B
BACKGROUND According to American Thoracic Society criteria FEV1% is the gold standard test in the diagnosis of COPD. The prospect of detecting lung disease, at an early stage has led to widespread measurement of FEF 25-75%. This study will provide an alternative to FEV1% in the diagnosis of COPD, so that the difficulties faced by the patients and the technicians in the measurement of FVC and FEV1% can be minimised. MATERIALS AND METHODS The study was conducted on 304 patients (194 COPD patients and 110 normal individuals) in the Pulmonary Function Test (PFT) Laboratory of Govt. Medical College; Kottayam. The instrument used was ‘Compact Vitalograph’. The results obtained were analysed using SPSS software and the sensitivity and specificity of FEF 25-75% was calculated using 2x2 tables. The positive predictive value (PPV) and negative predictive value (NPV) was also calculated. RESULTS Out of the total 304 subjects, 221 (72.70%) are males and 83 (27.30%) are females. 273 subjects (89.8%) came under ‘COPD’ category and 31 subjects (10.2%) came under ‘normal’ category based on FEF 25 -75. As per our study, FEF 25-75% had a sensitivity of 100%, specificity 28.20% PPV 71.06% and NPV 100%. CONCLUSION As per our study, we found that FEF 25-75% has a high sensitivity and low specificity. 71.06% of subjects who test positive will have COPD and 100% of subjects who test negative do not have the disease, hence its validity in COPD diagnosis is very less compared to FEV1%.
