Chest
Original ResearchAsthmaA New Diagnostic Score for Occupational Asthma: The Area Between the Curves (ABC Score) of Peak Expiratory Flow on Days at and Away From Work
Section snippets
Computing the ABC PEF Score by Time of Day
The average 2-h PEF plot is a graph in the Oasys program of the mean rest-day and workday PEF values plotted in 2-h segments according to the time of the day (in relation to the 24-h clock). It plots the mean of all workday readings taken between, for example, 6:30 am and 8:30 am as one data point, then all those taken between 8:30 am and 10:30 am as the next point, and so on in 2-h segments throughout the 24 h of the day. The rest day readings are then plotted in the same way in 2-h segments (
Results
After removal of patients who did not fulfill our inclusion criteria, data set 1 included records from 55 occupational asthma-positive patients and 59 occupational asthma-negative patients. Test set 2 contained records from 54 occupational asthma-positive patients and 58 occupational asthma-negative patients.
Table 1 shows the distribution of the three diagnostic tests that were used as the independent validators for occupational asthma in both data sets 1 and 2. The distribution of tests was
Discussion
This study has developed a new scoring system for occupational asthma based on serial PEF measurements analyzed by Oasys-2 software. using the average 2-h plot of PEF on days on and off work, by clock time, or time from waking up. We found that all scores investigated were significant predictors of occupational asthma. Furthermore, a score based on the area between rest-day and workday curves per hour from waking was the strongest predictor of occupational asthma and explained the largest
Conclusions
The ABC score is a new scoring system based on mean PEF on days on and off work for diagnosing occupational asthma from serial PEF recordings, which can be calculated from shorter records than needed for the current Oasys-2 scoring system. A score of 15 L/min/h between rest days and workdays provides the highest specificity without compromising sensitivity, and 5.6 L/min/h provides an optimal combination of reasonable sensitivity and specificity based on ROC analysis. Even at 10 L/min/h,
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Airway Diseases Related to the Use of Cleaning Agents in Occupational Settings
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2020, ChestCitation Excerpt :Alternatives to laboratory- and office-based PFT may be sought in existing approaches and innovative technologies. Home measurement of peak expiratory flow (PEF) using an inexpensive portable handheld device is already a guideline-recommended option to facilitate patient self-management in asthma and in the diagnosis of occupational asthma, but its role is less well defined in COPD.9,12,26 Many studies have investigated the potential for PEF to be used as a surrogate for PFT in the diagnosis and management of patients with asthma and COPD, but the results have been mixed.
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This project was funded by a PhD fellowship from the COLT Foundation.
Drs. Burge, Vellore, and Robertson have no conflicts of interest to disclose. Dr. Jaakkola has received some travel awards for scientific meetings from GlaxoSmithKline and MSD. Mrs. Moore received COLT fellowship funds for her part-time PhD, of which this research forms a part. The work is presented at international and national meetings and spoken about in smaller groups as part of teaching about the diagnosis of occupational asthma.
Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal.org/misc/reprints.shtml).
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Dr. Burge promotes and disseminates the use of serial measurements of peak expiratory flow for the diagnosis of occupational asthma. His department receives some monies from grants, donations, and legal fees to support the research. He has no personal financial interest. Dr. Pantin has published on the subject of OASYS software to enhance its reputation, and otherwise has no conflict of interest relating to this article.