I read with interest the recent publication by Tabor-Grey, Vasilopoulos and Plowman in Dysphagia [1]. The authors compared volitional peak cough flow measurements obtained with a handheld digital peak flow meter (PF100, Microlife) against measurements obtained with a laboratory system with Lilly type pneumotachograph (MLT1000L, ADInstruments). The purpose was to examine concordance between the measurements, based on the hypothesis that the more convenient and inexpensive handheld device could substitute the laboratory pneumotachograph system. Data from 109 participants with amyotrophic lateral sclerosis (ALS) were analysed using paired t-test (showing no significant difference in group means), Pearson's correlation coefficient (r=0.826, p<0.001), and Lin's concordance correlation coefficient (p c =0.824). The authors' interpretation of these statistics is that these demonstrate 'high reproducibility and agreement between devices' and support the use of the handheld flow meter in individuals with ALS [1].