A comparison of peak expiratory flow rates obtained with the Morgan Spirocheck and a Mini Peak Flow Meter

To examine whether the normal Indian standards of Peak Expiratory Flow Rate (PEF) established with the peak flow meter were applicable to PEF values obtained with the Morgan Spirocheck, a comparison was made of PEF(S) measured with the Spirocheck with PEF (M) obtained with a Mini Peak Flow Meter. Data were obtained in 92 subjects (53 males between 20 and 84 years of age and 39 females between 21 and 75 years), comprising staff of the institute, patients undergoing treatment for chronic arthritis, and the accompanying relatives. There was a highly significant correlation between the two values. The values were identical in 14 subjects; the differences between the values were within 10% in 54 subjects, and in excess of 10% in only 20 subjects. In the whole group, the mean and standard error were 363.5 +/- 14.7 and 384 +/- 15.2 lit/min for PEF (S) and PEF (M) respectively. The regression equation PEF (M) = 0.961 x PEF (S) + 34.9 will enable estimation of expected value of PEF (M) corresponding to the observed value of PEF (S) when a standard obtained with a Peak Flow Meter in used assess abnormality in a patient.