Undiagnosed Asthma-COPD overlap among patients diagnosed as Asthma and COPD in a referral hospital, India.

Patients who have features of both Asthma & COPD are now known as Asthma COPD overlap (ACO). Prevalence of ACO based on the Global Initiative for Asthma (GINA) and Global initiative for obstructive lung disease (GOLD) Syndromic Approach is scarce. In this cross-sectional observational study, we recruited physician-diagnosed-pAsthma, pCOPD & pACO by simple random sampling. Clinical features, spirometry, 6-min walk test, Serum Immunoglobulin E, % blood eosinophils and chest x-rays were reviewed. Syndromic approach was applied, and the diagnosis was reclassified accordingly. In all, 877 patients were included (Male = 445, Female = 432). Physician diagnosis for these were: pAsthma-713, pCOPD-157 and pACO-7. They were reclassified using the Syndromic approach as: sAsthma, sCOPD and sACO. The 713 pAsthmatics were reclassified as follows: sAsthma-684 (95.94%), sCOPD-12 (1.68%) and sACO-17 (2.38%). Of the 157 pCOPD patients, 91 (57.96%) were reclassified as sCOPD, 23 (14.6%) as sACO, and 17 (927.38%) as sAsthma. Of the 7 previously diagnosed pACO patients, only 1 (14.28%) was reclassified as sACO, 5 (71.42%) as sAsthma and 1 (14.28%) as sCOPD. sCOPD patients had more exacerbations (52.88% vs 46.34%, p = 0.479), critical care admissions (16.35% vs 7.32%, p = 0.157) and intubations (17.31% vs 9.76%, p = 0.255) compared to sACO patients, the latter had more events than sAsthma patients: exacerbations 46.34% vs 10.11% (p < 0.001), critical care admissions 7.32% vs 1.64% (p = 0.010) and intubations 9.76% vs 1.5% (p < 0.001). The syndromic approach helped us to identify ACO and also more appropriately classified COPD & Asthma. There was a significant difference between physician diagnosis and diagnosis using Syndromic Approach. It revealed considerable misclassification of several Asthmatic and ACO subjects, who could have been denied inhaled corticosteroids, as they were wrongly categorised as COPD by physician diagnosis.