Agreement between paper and pen visual analogue scales and a wristwatch-based electronic appetite rating system (PRO-Diary), for continuous monitoring of free-living subjective appetite sensations in 7–10 year old children

Electronic capture of free-living subjective appetite data can provide a more reliable alternative to traditional pen and paper visual analogue scales (P&P VAS), whilst reducing researcher workload. Consequently, the aim of this study was to explore the agreement between P&P VAS and a wristwatch-based electronic appetite rating system known as the PRO-Diary© technique, for monitoring free-living appetite sensations in 7–10 year old children. On one occasion, using a within-subject design, the 12 children (n = 6 boys; n = 6 girls) recorded their subjective appetite (hunger, prospective food consumption, and fullness), at two time points before lunch (11:30 and 12:00) and every 60 min thereafter until 21:00. The agreement between the P&P VAS and PRO-Diary© technique was explored using 95% limits of agreement and 95% confidence intervals (95% CI) calculated using the Bland and Altman (1986) technique. For hunger, prospective food consumption and fullness, the 95% limits of agreement were −1 ± 25 mm (95% CI: lower limit −8 mm; upper limit +6 mm), 0 ± 21 mm (95% CI: lower limit −6 mm; upper limit +6 mm) and −6 ± 24 mm (95% CI: lower limit −14 mm; upper limit +1 mm), respectively. Given the advantages associated with electronic data capture (inexpensive; integrated alarm; data easily downloaded), we conclude that the PRO-Diary© technique is an equivalent method to employ when continuously monitoring free-living appetite sensations in 7–10 year old children, but should not be used interchangeably with P&P VAS.