1. Volume 101, Issue 4, Pages 948-952 (April 1992)
Evaluation of Accuracy and Reproducibility of Peak Flowmeters at 1,400 m 
Reed M. Gardner, Ph.D., Robert O. Crapo, M.D., F.C.C.P., Brian R. Jackson, Robert L. Jensen, Ph.D. 
CHEST 
Volume 101, Issue 4, Pages (April 1992)
DOI: /chest
Copyright © 1992 The American College of Chest Physicians Terms and Conditions

2. Figure 1
Device accuracy and interdevice variability results. Plotted are results from multiple units of each device tested for each of the nine multiples of waveform 24 recommended by the NAEP. Target values from Table 1 are shown on the X-axis and measured values on the Y-axis. To assist in identifying accuracy of devices, line of identity along with ± 10 percent of target value lines are shown. Accuracy of each device type can be seen by reviewing where results fall within the ± 10 percent lines. Interdevice reproducibility can be assessed by observing the scatter of points. Our results show very small scatter for all peak flowmeters, but device D had slightly larger variability than some of other devices.
CHEST  , DOI: ( /chest )
Copyright © 1992 The American College of Chest Physicians Terms and Conditions

3. Figure 2
Summary of accuracy of devices, showing peak flow differences in liters per minute from target values vs target values.
CHEST  , DOI: ( /chest )
Copyright © 1992 The American College of Chest Physicians Terms and Conditions

4. Figure 3
Results of reproducibility testing show reproducibility results for devices A to H for 20 repetitions of three waveform sets—with ±5 percent flow increments. Percent differences from target value ± 1 SD are shown for –5 percent of target value (bottom), target value (middle), and + 5 percent of target value (top of A to H). Results were normalized to measured value of “target” (middle) waveform, since when testing for reproducibility, ability to measure the differences is the key; for example, an asthmatic patient may not get an accurate measured value, but if they then improved their peak flow performance, we wanted to determine if the peak flowmeter would reflect improvement. Solid horizontal lines drawn on 302-L/min and 503-L/min target value plots indicate the NAEP reproducibility range requirement of ± 5 percent. Dashed horizontal lines on the 126-L/min target value plot indicate that ± 5 percent flow difference (6 L/min) is less than the 10-L/min NAEP requirement.
CHEST  , DOI: ( /chest )
Copyright © 1992 The American College of Chest Physicians Terms and Conditions