What is the diagnostic value of repeated peak expiratory flow measurements to diagnose asthma in primary care?

Clinical Research Results Abstract Research Idea Abstract QuestionWhat is the diagnostic value of repeated peak expiratory flow measurements to diagnose asthma in primary care?BackgroundAsthma is common but often misdiagnosed, especially when relying on clinical assessment alone. Spirometry, bronchodilator reversibility and fractional exhaled nitric oxide testing are objective recommended tests to confirm diagnosis. However, access to these tests is not available in most healthcare settings and spirometry is often normal when the patient’s asthma is stable. Peak expiratory flow rate (PEFR) measurements are inexpensive and widely available but there is currently insufficient evidence to support its use in the asthma diagnostic pathway, except as a 2-week peak flow diary. Methodology To conduct a systematic review to investigate the diagnostic value of repeated PEFR measurements in the asthma diagnostic pathway. We constructed search strategies to conduct a systematic review of the available literature. This produced a library of relevant clinical studies from January 1946 to December 2021 from the MEDLINE, COCHRANE, EMBASE, EMCARE and CINAHL databases. This systematic review will include randomised controlled trials, cohort studies, systematic reviews and meta-analyses which explore the diagnostic accuracy of repeated PEFR measurements in identifying children with asthma. Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) will be used to evaluate the methodological quality of selected studies. A narrative synthesis will be conducted if a meta-analysis is not possible because of heterogeneity. Results Our search strategy yielded 2079 studies from MEDLINE, 878 from COCHRANE, 830 from EMBASE, 151 from EMCARE and 69 from CINAHL. Title and abstract screening has commenced.Questions for discussionWhat practical strategies for using peak flows in clinical practice should we look for in the literature?What pitfalls should we explore? Are peak flow meters available in primary care in low resource settings? Service Development & Evaluation Abstract Declaration of Interest PROSPERO registration number is: CRD42021272922 References and Clinical Trial Registry Information PROSPERO registration number is: CRD42021272922