RISK OF OVERTREATMENT WITH CURRENT PEAK FLOW CRITERIA IN SELF-MANAGEMENT PLANS

Home peak expiratory flow (PEF) measurements have become the cornersto ne of asthma self-management plans. However, the cut-off values for ch anging treatment have not been formally tested, This study focusses on the possible overtreatment brought about by the different cut-off val ues and denominators currently employed. Data from 133 clinically stab le asthmatic patients from a 2.5 yr follow-up study were analysed, The results showed that strict adherence to current criteria would lead t o severe overtreatment, with up to 30% of clinically stable patients c rossing into the lowest (red) zone at least once a year when personal best is the denominator and when it has not been limited to a defined fine of day or to defined prior bronchodilator use. As expected, the p assage of clinically stable patients into the lower zones became less frequent when cut-off values were sharpened and when time- and treatme nt-specific PEFs were used as the denominators. Strict adherence to co mmonly used peak expiratory flow cut-off values would lead to consider able overtreatment. In order to avoid overtreatment, the morning peak expiratory flow before any (bronchodilator) treatment should be relate d to the personal best peak expiratory flow measured under the same co nditions. The choice of the right cut-off value will also depend on st udies being performed to test the amount of undertreatment with a give n value.