Do you think the peak flow record is asthmatic?

The Opinion of this website

Strictly speaking it is the patient rather than the peak flow record who is asthmatic. The peak flow record supports a diagnosis of asthma, in so far as the diurnal variation (expressed as percent predicted) is at the upper 95% confidence limit for a normal person exposed to a dusty environment. The record is taken while on substantial treatment, which is likely to reduce diurnal variation. There is substantial overlap between the diurnal variation of asthmatic and normal people. If the diurnal variation is expressed as percent maximum or mean, diurnal variation will be increased in those with lower mean values, such as patients with COPD. Using the predicted value as denominator reduces this confounding factor.

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