Abstract
BACKGROUND: The variability of peak expiratory flow (PEF) is now commonly used in the diagnosis and management of asthma. It is essential for PEF meters to have a linear response in order to obtain an unbiased measurement of PEF variability. As the accuracy and linearity of portable PEF meters have not been rigorously tested in recent years this aspect of their performance has been investigated. METHODS: The response of several portable PEF meters was tested with absolute standards of flow generated by a computer driven, servo controlled pump and their response was compared with that of a pneumotachograph. RESULTS: For each device tested the readings were highly repeatable to within the limits of accuracy with which the pointer position can be assessed by eye. The between instrument variation in reading for six identical devices expressed as a 95% confidence limit was, on average across the range of flows, +/- 8.5 l/min for the Mini-Wright, +/- 7.9 l/min for the Vitalograph, and +/- 6.4 l/min for the Ferraris. PEF meters based on the Wright meter all had similar error profiles with overreading of up to 80 l/min in the mid flow range from 300 to 500 l/min. This overreading was greatest for the Mini-Wright and Ferraris devices, and less so for the original Wright and Vitalograph meters. A Micro-Medical Turbine meter was accurate up to 400 l/min and then began to underread by up to 60 l/min at 720 l/min. For the low range devices the Vitalograph device was accurate to within 10 l/min up to 200 l/min, with the Mini-Wright overreading by up to 30 l/min above 150 l/min. CONCLUSION: Although the Mini-Wright, Ferraris, and Vitalograph meters gave remarkably repeatable results their error profiles for the full range meters will lead to important errors in recording PEF variability. This may lead to incorrect diagnosis and bias in implementing strategies of asthma treatment based on PEF measurement.
Full text
PDF





Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Beasley R., Cushley M., Holgate S. T. A self management plan in the treatment of adult asthma. Thorax. 1989 Mar;44(3):200–204. doi: 10.1136/thx.44.3.200. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brown L. A., Sly R. M. Comparison of Mini-Wright and Standard Wright Peak Flow Meters. Ann Allergy. 1980 Aug;45(2):72–74. [PubMed] [Google Scholar]
- Charlton I., Charlton G., Broomfield J., Mullee M. A. Evaluation of peak flow and symptoms only self management plans for control of asthma in general practice. BMJ. 1990 Dec 15;301(6765):1355–1359. doi: 10.1136/bmj.301.6765.1355. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chiaramonte L. T., Prabhu S. L. Comparative evaluation of five peak flow devices. J Allergy Clin Immunol. 1982 Jun;69(6):509–515. doi: 10.1016/0091-6749(82)90175-0. [DOI] [PubMed] [Google Scholar]
- Eichenhorn M. S., Beauchamp R. K., Harper P. A., Ward J. C. An assessment of three portable peak flow meters. Chest. 1982 Sep;82(3):306–309. doi: 10.1378/chest.82.3.306. [DOI] [PubMed] [Google Scholar]
- FRY D. L., HYATT R. E., MCCALL C. B., MALLOS A. J. Evaluation of three types of respiratory flowmeters. J Appl Physiol. 1957 Mar;10(2):210–214. doi: 10.1152/jappl.1957.10.2.210. [DOI] [PubMed] [Google Scholar]
- Finucane K. E., Egan B. A., Dawson S. V. Linearity and frequency response of pneumotachographs. J Appl Physiol. 1972 Jan;32(1):121–126. doi: 10.1152/jappl.1972.32.1.121. [DOI] [PubMed] [Google Scholar]
- Glindmeyer H. W., 3rd, Anderson S. T., Kern R. G., Hughes J. A portable, adjustable forced vital capacity simulator for routine spirometer calibration. Am Rev Respir Dis. 1980 Mar;121(3):599–603. doi: 10.1164/arrd.1980.121.3.599. [DOI] [PubMed] [Google Scholar]
- Hetzel M. R., Clark T. J. Comparison of normal and asthmatic circadian rhythms in peak expiratory flow rate. Thorax. 1980 Oct;35(10):732–738. doi: 10.1136/thx.35.10.732. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Miller M. R., Pincock A. C. Linearity and temperature control of the Fleisch pneumotachograph. J Appl Physiol (1985) 1986 Feb;60(2):710–715. doi: 10.1152/jappl.1986.60.2.710. [DOI] [PubMed] [Google Scholar]
- Pedersen O. F., Naeraa N., Lyager S., Hilberg C., Larsen L. A device for evaluation of flow recording equipment. Bull Eur Physiopathol Respir. 1983 Sep-Oct;19(5):515–520. [PubMed] [Google Scholar]
- Perks W. H., Tams I. P., Thompson D. A., Prowse K. An evaluation of the mini-Wright peak flow meter. Thorax. 1979 Feb;34(1):79–81. doi: 10.1136/thx.34.1.79. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Perks W. H., Tams I. P., Thompson D. A., Prowse K. An evaluation of the mini-Wright peak flow meter. Thorax. 1979 Feb;34(1):79–81. doi: 10.1136/thx.34.1.79. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pincock A. C., Miller M. R. The effect of temperature on recording spirograms. Am Rev Respir Dis. 1983 Nov;128(5):894–898. doi: 10.1164/arrd.1983.128.5.894. [DOI] [PubMed] [Google Scholar]
- Shapiro S. M., Hendler J. M., Ogirala R. G., Aldrich T. K., Shapiro M. B. An evaluation of the accuracy of Assess and MiniWright peak flowmeters. Chest. 1991 Feb;99(2):358–362. doi: 10.1378/chest.99.2.358. [DOI] [PubMed] [Google Scholar]
- Varène P., Vieillefond H., Saumon G., Lafosse J. E. Etalonnage des pneumotachographes par méthode intégrale. Bull Physiopathol Respir (Nancy) 1974 May-Jun;10(3):349–360. [PubMed] [Google Scholar]
- WRIGHT B. M., McKERROW C. B. Maximum forced expiratory flow rate as a measure of ventilatory capacity: with a description of a new portable instrument for measuring it. Br Med J. 1959 Nov 21;2(5159):1041–1046. doi: 10.1136/bmj.2.5159.1041. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wilson S. H., Cooke N. T., Edwards R. H., Spiro S. G. Predicted normal values for maximal respiratory pressures in caucasian adults and children. Thorax. 1984 Jul;39(7):535–538. doi: 10.1136/thx.39.7.535. [DOI] [PMC free article] [PubMed] [Google Scholar]
