Protocol - Peak Expiratory Flow Rate (PEFR)

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A patient is instructed to inhale deeply and blow into a peak expiratory flow monitor three times. Peak expiratory flow rate (PEFR) can be measured as part of spirometry testing (see Spirometry measure) or as a separate measurement. The highest PEFR value is typically used for analysis.

Specific Instructions

A minimum of three acceptable blows is necessary. The maneuver can be performed in either the sitting or standing position, but one of these options should be used in a standardized manner within a particular study.




Test Procedure

Peak Expiratory Flow Rate (PEFR) is dependent on effort and lung volume, with subject cooperation being essential. PEFR must be achieved as rapidly as possible and at as high a lung volume as possible, in order to obtain the maximum value. The subject must be encouraged to blow as vigorously as possible. The neck should be in a neutral position, not flexed or extended, and the subject must not cough. A nose clip is not necessary.

After the point of full lung inflation, the subject must deliver the blow without any delay. Hesitating for as little as 2s [seconds] or flexing the neck allows the tracheal visco-elastic properties to relax and PEFR to drop by as much as 10%. Tonguing, spitting or coughing at the start of the blow may falsely raise the recorded PEFR in some devices.

The subject must perform a minimum of three PEFR maneuvers. When PEFR is a self-administered recording used to monitor disease status, it is important that the subject has been adequately taught how to perform the test, when to perform it, and what action to take depending on the resulting value obtained.

Within-maneuver evaluation

The subject must be observed to ensure a good seal at the mouth, no hesitation occurred, and there was no abnormal start to the maneuver.

Between-maneuver evaluation

The PEFR values and their order must be recorded so that maneuver-induced bronchospasm can be detected. If the largest two out of three acceptable blows are not reproducible within 0.67 L s-1 (40 L min-1), up to two additional blows can be performed. Ninety-five percent of untrained healthy subjects and patients can reproduce PEFR to within 0.67 L s-1 (40 L min-1), and ninety percent to within 0.5 L s-1 (30 L min-1). If satisfactory repeatability has not been achieved in five attempts, more are not likely to be helpful.

Test result selection

The largest value from at least three acceptable blows is recorded.

Personnel and Training Required

A technician who is trained on how to use a peak flow meter or spirometer is required.

Equipment Needs

Peak expiratory flow rate (PEFR) requires an instrument that meets American Thoracic Society/European Respiratory Society (ATS/ERS) standards, which require a flat frequency response (+-5%) up to 15 Hz. PEFR can be measured using a spirometer; alternatively, simpler peak flow meters, which only measure PEFR, can be used.

Requirement CategoryRequired
Major equipment No
Specialized training Yes
Specialized requirements for biospecimen collection No
Average time of greater than 15 minutes in an unaffected individual No
Mode of Administration

Physical Measurement


Child, Adolescent, Adult, Senior


Adults and children age 6 and older

Selection Rationale

This is a simple method of measuring airway obstruction, and it will detect moderate or severe disease. The simplicity of the method is its main advantage.


Chinese, English

Logical Observation Identifiers Names and Codes (LOINC) Resp peak expiratory flow rate proto 62623-4 LOINC
Human Phenotype Ontology Reduced maximal expiratory pressure HP:0012497 HPO
caDSR Form PhenX PX090801 - Peak Expiratory Flow Rate Pefr 5969406 caDSR Form
Derived Variables


Process and Review

Expert Review Panel #6 (ERP 6) reviewed the measures in the Respiratory domain.

Guidance from ERP 6 includes:

• No significant changes to measure

Back-compatible: no changes to Data Dictionary

Protocol Name from Source

Miller, M. R., et al, Standardization of spirometry. Series “ATS/ERS task force: Standardization of lung function testing.”, EUR RESPIR J, 2005


Miller, M. R., Hankinson, J., Brusasco, V., Burgos, F., Casaburi, R., Coates, A., ... Wanger, J. (2005). Standardisation of spirometry. Series “ATS/ERS task force: Standardisation of lung function testing.” European Respiratory Journal, 26(2), 330-331.

General References

Shirley, D. K., Kaner, R. J., & Glesby, M. J. (2015). Screening for chronic obstructive pulmonary disease (COPD) in an urban HIV clinic: A pilot study. AIDS Patient Care STDS, 29(5), 232-239.

Protocol ID


Export Variables
Variable Name Variable IDVariable DescriptiondbGaP Mapping
PX090801040000 Maximum Peak Expiratory Flow Rate Variable Mapping
PX090801040100 Maximum Peak Expiratory Flow Rate units N/A
PX090801010000 Peak Expiratory Flow Rate 1 Variable Mapping
PX090801010100 Peak Expiratory Flow Rate 1 units N/A
PX090801020000 Peak Expiratory Flow Rate 2 Variable Mapping
PX090801020100 Peak Expiratory Flow Rate 2 units N/A
PX090801030000 Peak Expiratory Flow Rate 3 Variable Mapping
PX090801030100 Peak Expiratory Flow Rate 3 units N/A
Measure Name

Peak Expiratory Flow Rate (PEFR)

Release Date

January 29, 2010


The peak expiratory flow rate measures airflow (maximum speed of expiration) and the presence and degree of obstruction in the airways.


This test is commonly used to diagnose and monitor lung diseases such as asthma; less commonly, it is used in chronic obstructive pulmonary disease (COPD).


Respiratory, PEFR, spirometry, chronic obstructive pulmonary disease, COPD, asthma

Measure Protocols
Protocol ID Protocol Name
90801 Peak Expiratory Flow Rate (PEFR)

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