Fig. 2

Shows the proportion of erythrocytosis in chronic obstructive pulmonary disease (COPD) study participants (n = 45). All participants diagnosed with COPD in the study were screened by a COPD population screener, and after that, spirometry was done to confirm the diagnosis of COPD. The participants had their haemoglobin concentration estimated. All participants with a haemoglobin level of 16.5 g/dL or higher were considered to have erythrocytosis. We found three participants had erythrocytosis out of the 45 participants who had COPD