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MONITORING PEAK EXPIRATORY FLOW RATE
Letters to the editor MONITORING PEAK EXPIRATORY FLOW RATE To the Editor: Dr. Boggs asks that peak expiratory flow rate meter recordings be viewed in a new manner.1 He states that studies are under way to establish the benefit from peak expiratory flow rate control charts. This approach is dependent upon the accuracy of each recording. Peak expiratory flow rate recordings are subject to many vagaries. Patients will inflate results, inaccurately record the time or date, and even fabricate performance. Education of the patients is necessary but not sufficient.2 Controlling for such variables is very important. Uncontrolled or unverified variables associated with peak expiratory flow rate measurements may include the following: 1. Is it being done? 2. Is someone else doing it? 3. Is the technique correct? 4. Is it being done at the intended time and date? 5. Is the best of three attempts recorded accurately? 6. What time relationship is there between performing peak expiratory flow rate and using bronchodilator medication? I strongly encourage the use of electronic expiratory peak flow rate meters that record the time, date, and all results. This does not eliminate all experimental design problems, but when used in a program of proper education, reinforcement and repetitive documentation of proficiency can result in more meaningful studies.3 Presently, the reliability of such studies is open to question.2 The documented failure of compliance with aerosol usage in the treatment of asthma under stringent observation leaves little room for optimism with uncontrolled peak expiratory flow rate monitoring.2,4 –5 Peak expiratory flow rate monitoring is a hard case to sell to many patients especially on a chronic basis. Interpretation of control charts is very sensitive to variance of each point. New study designs should take these concerns into consideration before anticipating any breakthrough.
FRANK CHMELIK, MD Rockford, Illinois
REFERENCES 1. 2. 3. 4.
5.
Boggs PB. Peak expiratory flow rate control chart: a breakthrough in asthma care. Ann Allergy Asthma Immunol 1996;77:429 –32. Chmelik F, Doughty A. Objective measurements of compliance in asthma treatment. Ann Allergy 1994;73:527–32. Chmelik F, Kao N. Compliance with asthma therapy—measurement and implications. Clin Immunotherapy 1996;5:193–204. Spector SL, Kinsman R, Mawhinney H, et al. Compliance of patients with an experimental aerosolized medication: implications for controlled clinical trials. J Allergy Clin Immunol 1986;77:65–70. Mawhinney H, Spector SL, Kinsman RA, et al. Com-
VOLUME 78, APRIL, 1997
pliance in clinical trials of two non-bronchodilator antiasthma medications. Ann Allergy 1991;66:294–9.
Response: I am in agreement with the concept of having accurate data, and am, as are most allergists, fully cognizant of the limitations of peak expiratory flow rate, and other lung function data. I also am fascinated with the potential of electronic devices to provide information regarding date, time, the selection of “best” effort, and for providing information regarding the time interval between before and after bronchodilator PEFR measurements. We have employed such a device (Air Watch) in a large segment of our clinical research of SPC charting throughout the past year. It should also be noted that electronic instrumentation is not a panacea and brings with it additional methodologic problems that further complicate the issues the letter writer raised. It also brings opportunity for improvement in the quality of information available to our patients and ourselves. SPC theory and charting was developed for the purpose of understanding variation in the outcome of processes. So doing, makes possible the identification of opportunities for improvement (OFIs) in the process otherwise not apparent. Any process producing serial data can potentially benefit from the application of SPC theory and charting, hence, the examination of PEFR data in asthma. Once this variation and its sources are understood and appropriate actions are taken to improve the process, it should function optimally. Attention is on the entire process, not just a single aspect. Improvement in this context requires a care perspective beyond when and what medication to take. It also requires a perspective that includes the concept that within every process there is variation in outcome, and that once special causes of variation are identified and removed and common cause variation is optimized, the variation remaining is normal for that process. Any further improvement will require a change in the process per se. We began our evaluation of this theory and tool with PEFR for all the reasons one might logically imagine. SPC charting and theory, however, can be applied to any outcome that is serially quantitated: symptom scores, medication scores, FEV1, FEF50%, etc. Our research has focused on the answer to this question: What about the at-home monitoring of PEFR is currently impossible, that if possible, would fundamentally change the process of at-home monitoring of PEFR? The insights forthcoming to the care of patients with asthma from SPC charting of lung function (PEFR) which are not possible via traditional charting include: 1. Rules for the detection of special causes of variation that make the ongoing identification of causal and trigger agents a reality.
2. The ability to identify special causes of variation makes the concept of continuous quality improvement in the process of asthma care a reality. 3. The ability to “see” the natural limits of the process of care is of immense importance in the identification of the patient at-risk for severe asthma. 4. Knowledge of the above permits improvement in the quality of communication between patients and physicians beyond that available via traditional charting. 5. Because of all of the above, patients become better participants in their own care. They chart the flows, recognize the signals of special cause variation, identify the causal and/or trigger agents or circumstances responsible for the signals, take appropriate action on these signals. In so doing they develop a keener understanding of the process of care in which they are participating, its limitations, and the changes that will be required to make the process clinically optimal. 6. Physicians broaden their focus to improvement in the total process of care. It is my opinion that PEFR monitoring is “a hard case to sell,” not because of the limitations of PEFR monitoring per se, but because of the burden we have placed upon it, specifically the traditional package in which we “sell” it: a charting methodology of limited usefulness whose emphasis is focused on pharmacologic intervention rather than continuous improvement. It is in the traditional context of using PEFR monitoring primarily as an action guide to pharmacologic intervention that physicians and patients do not “buy” PEFR monitoring. To make matters worse, when “buy-in” is not forthcoming, most critics succumb to the temptation to fault the PEFR test itself, rather than the context in which we “sell” it, ie shoot the messenger! Even with all of the limitations inherent in the execution of at-home monitoring of PEFR, the application of SPC theory and charting is exceedingly useful and a far more informative context in which to examine the asthma care process than is traditional charting. It is time for those of us in asthma care to listen to the voice of the customer and accept that patients and physicians want and need more from at-home PEFR monitoring than the traditional method—not the PEFR test—is capable of providing. Needed is a tool that invites and assists the continuous improvement in the quality of care they receive and provide. SPC theory and its charting tool together with PEFR monitoring can provide the latter and, in this context, constitute a major breakthrough in asthma care.
PETER B. BOGGS, MD Shreveport, LA
425
FRANK CHMELIK, MD Rockford, Illinois
REFERENCES 1. 2. 3. 4.
5.
Boggs PB. Peak expiratory flow rate control chart: a breakthrough in asthma care. Ann Allergy Asthma Immunol 1996;77:429 –32. Chmelik F, Doughty A. Objective measurements of compliance in asthma treatment. Ann Allergy 1994;73:527–32. Chmelik F, Kao N. Compliance with asthma therapy—measurement and implications. Clin Immunotherapy 1996;5:193–204. Spector SL, Kinsman R, Mawhinney H, et al. Compliance of patients with an experimental aerosolized medication: implications for controlled clinical trials. J Allergy Clin Immunol 1986;77:65–70. Mawhinney H, Spector SL, Kinsman RA, et al. Com-
VOLUME 78, APRIL, 1997
pliance in clinical trials of two non-bronchodilator antiasthma medications. Ann Allergy 1991;66:294–9.
Response: I am in agreement with the concept of having accurate data, and am, as are most allergists, fully cognizant of the limitations of peak expiratory flow rate, and other lung function data. I also am fascinated with the potential of electronic devices to provide information regarding date, time, the selection of “best” effort, and for providing information regarding the time interval between before and after bronchodilator PEFR measurements. We have employed such a device (Air Watch) in a large segment of our clinical research of SPC charting throughout the past year. It should also be noted that electronic instrumentation is not a panacea and brings with it additional methodologic problems that further complicate the issues the letter writer raised. It also brings opportunity for improvement in the quality of information available to our patients and ourselves. SPC theory and charting was developed for the purpose of understanding variation in the outcome of processes. So doing, makes possible the identification of opportunities for improvement (OFIs) in the process otherwise not apparent. Any process producing serial data can potentially benefit from the application of SPC theory and charting, hence, the examination of PEFR data in asthma. Once this variation and its sources are understood and appropriate actions are taken to improve the process, it should function optimally. Attention is on the entire process, not just a single aspect. Improvement in this context requires a care perspective beyond when and what medication to take. It also requires a perspective that includes the concept that within every process there is variation in outcome, and that once special causes of variation are identified and removed and common cause variation is optimized, the variation remaining is normal for that process. Any further improvement will require a change in the process per se. We began our evaluation of this theory and tool with PEFR for all the reasons one might logically imagine. SPC charting and theory, however, can be applied to any outcome that is serially quantitated: symptom scores, medication scores, FEV1, FEF50%, etc. Our research has focused on the answer to this question: What about the at-home monitoring of PEFR is currently impossible, that if possible, would fundamentally change the process of at-home monitoring of PEFR? The insights forthcoming to the care of patients with asthma from SPC charting of lung function (PEFR) which are not possible via traditional charting include: 1. Rules for the detection of special causes of variation that make the ongoing identification of causal and trigger agents a reality.
2. The ability to identify special causes of variation makes the concept of continuous quality improvement in the process of asthma care a reality. 3. The ability to “see” the natural limits of the process of care is of immense importance in the identification of the patient at-risk for severe asthma. 4. Knowledge of the above permits improvement in the quality of communication between patients and physicians beyond that available via traditional charting. 5. Because of all of the above, patients become better participants in their own care. They chart the flows, recognize the signals of special cause variation, identify the causal and/or trigger agents or circumstances responsible for the signals, take appropriate action on these signals. In so doing they develop a keener understanding of the process of care in which they are participating, its limitations, and the changes that will be required to make the process clinically optimal. 6. Physicians broaden their focus to improvement in the total process of care. It is my opinion that PEFR monitoring is “a hard case to sell,” not because of the limitations of PEFR monitoring per se, but because of the burden we have placed upon it, specifically the traditional package in which we “sell” it: a charting methodology of limited usefulness whose emphasis is focused on pharmacologic intervention rather than continuous improvement. It is in the traditional context of using PEFR monitoring primarily as an action guide to pharmacologic intervention that physicians and patients do not “buy” PEFR monitoring. To make matters worse, when “buy-in” is not forthcoming, most critics succumb to the temptation to fault the PEFR test itself, rather than the context in which we “sell” it, ie shoot the messenger! Even with all of the limitations inherent in the execution of at-home monitoring of PEFR, the application of SPC theory and charting is exceedingly useful and a far more informative context in which to examine the asthma care process than is traditional charting. It is time for those of us in asthma care to listen to the voice of the customer and accept that patients and physicians want and need more from at-home PEFR monitoring than the traditional method—not the PEFR test—is capable of providing. Needed is a tool that invites and assists the continuous improvement in the quality of care they receive and provide. SPC theory and its charting tool together with PEFR monitoring can provide the latter and, in this context, constitute a major breakthrough in asthma care.
PETER B. BOGGS, MD Shreveport, LA
425