Both home-based handheld and in-clinic spirometry demonstrated comparable treatment effects to placebo in patients with persistent asthma, according to study results published in Respiratory Medicine.
In a 6-week phase 3 study of beclomethasone dipropionate (BDP) via breath-actuated inhaler (BAI) vs placebo in patients with persistent asthma, forced expiratory volume in 1 second (FEV1) was assessed by both office-based and handheld spirometry. Office-based measurements were recorded at weeks 2, 4, and 6, while daily measurements were taken using the home-based handheld spirometer. The effect of drug treatment on FEV1 for each spirometry method was compared between groups.
Of the 713 patients enrolled, 425 were randomly assigned to treatment: 108 patients in the BDP BAI 320 μg group; 105 patients in the BDP BAI 640 μg group; 105 patients in the BDP metered-dose inhaler 320 μg group; and 107 patients in the combined placebo group. FEV1 improvements based on drug treatment groups were previously reported.
The study focused on the effect-size agreement between home-based and clinical spirometry. The correlation between values of FEV1 measured using the handheld devices and the values recorded at the clinic was high. Nearly all patients achieved home FEV1 values close to clinic FEV1 values, with very few patients demonstrating excessively high or low home values well off the line of identity with clinic FEV1.
“The high correlation (correlation coefficient, 0.8393) between the values of FEV1 measured using a handheld device every morning at home and the values recorded at the clinic using standard techniques suggest that handheld spirometry is able to provide consistent and reliable results in the home setting,” the researchers wrote. “[B]ecause at-home measurements can realistically be taken with greater frequency, they provide more comprehensive data than could be achieved from in-clinic measurements only.”
Kerwin E, Hickey L, Small C, et al. Relationship between handheld and clinic-based spirometry measurements in asthma patients receiving beclomethasone [published online March 20, 2019]. Respir Med. doi:10.1016/j.rmed.2019.03.010