[An evaluation of three commercially available peak flowmeters]

The accuracy, reproducibility and interdevice variability of three models of portable peak flowmeters (standard and low range) were evaluated by using a computerized standard flow generator. Standard range; The mini-Wright peak flow meter generally overestimated peak flow from 120 L/min to 540 L/min and the Assess peak flowmeter underestimated peak flow at full range. The Pulmo-Graph peak flowmeter showed a similar pattern to the mini-Wright but with more accuracy. The Assess showed the best linearity. The reproducibilities of the three models deteriorated over 20 L/min at high flow rates. The interdevice variability of the mini-Wright was better than those of the Assess or the Pulmo-Graph. Low range: The accuracy and interdevice variability of the Pulmo-Graph were better than those of the Assess or the mini-Wright. The reproducibility of Assess seemed to be inferior to the other's. The measured flow from the low ranges was not the same as that of the standard ranges. The three peak flowmeter models have different spring mechanisms for their readings, and the measured flows by one model should not be compared with other models.