When expressed as percentage of predicted values, PEF and FEV1 values are not equivalent. We recommend that guidelines be modified to state that across the spectrum of the severity of airflow obstruction there is considerable variability between measurements of FEV1 and PEF when expressed as % predicted such that the FEV1 may be as much as 35% lower or up to 15% higher than the PEF for patients with obstructive lung diseases.

Patients on police and medical orders differ considerably, but the impact of these differences on ED workload is small.