An intraindividual comparison of standard and mini-Wright scores

The relationship between peak expiratory flow rate scores recorded with the standard Wright meter and those recorded with the mini-Wright meter was determined by correlating these scores on an intraindividual basis. These correlations were compared with correlations between pairs of standard scores. The latter were computed so as to provide an estimate of peak expiratory flow rate variability unrelated to recording apparatus. The results showed that pairs of standard Wright scores were more highly related to one another than were pairs of standard and mini-Wright scores. From these observations it was concluded that standard and mini-Wright scores are not equivalent and therefore may not confidently be interchanged.