Flaws in spirometry may mean GPs miss COPD cases
GPs may be failing to diagnose cases of chronic obstructive pulmonary disease because of wild inaccuracies in spirometery readings, researchers suggest.
A US study in Chest found poorly calibrated spirometers can be inaccurate by more than 100 per cent, leading to underdiagnosis and suboptimal treatment.
Researchers collected data from anomalous spirograms during quality assurance reviews and found FVC could be between 44 and 104 per cent higher than predicted.
FVC and FEV1 were more than 20 per cent higher than predicted in 40 per cent of a group of 121 middle-aged men.
The problems – identified in flow-type spirometers – included human errors such as inaccurate zeroing of the flow sensor, as well as condensation, mucus deposition and unstable calibration.
Dr Tony Crockett, a member of the General Practice Airways Group and a GP in Shrivenham, Wiltshire, said: 'We won't stop using spirometers just because they're a bit inaccurate.' He said spirometers were only useful in the context of symptoms.