Objective measurement of spectacle wear with a temperature sensor data logger

PurposeThis study seeks to establish the utility of the SmartButton Data Logger () to monitor spectacle wear for research and clinical applications. MethodsFifty adults wore a thermosensor on their spectacles for 2weeks for each of two mount types while keeping wear-time logs. Temperatures during reported spectacle wear (ON) were compared to temperatures during non-wear (OFF) with repeated measures analysis of variance (ANOVA). In addition, two strategies to approximate spectacle wear from temperature data were evaluated: (1) Filtering data based on temperature ranges to identify spectacle wear (either group mean ON temperature, or an individual's mean ON temperature), and (2) Separate examiners inspecting temperature against time plots to identify spectacle wear. The success of these methods to approximate wear time was evaluated by per cent error with respect to subject reported wear time. ResultsGroup mean ON (31.8 [0.6]degrees Celsius [degrees C]) and OFF (24.7 [1.5]degrees C) temperatures differed significantly (F-1,F-47=471.2, p<0.001), but there was no difference in temperature between mounts (F-1,F-47=1.9, p=0.18). Median per cent error and first and third quartiles (Q1, Q3) of each technique used to approximate wear time were: group mean filtering=8% (Q1 3%, Q3 18%), individual mean filtering=7% (Q1 4%, Q3 19%), Examiner 1=6% (Q1 2%, Q3 14%), Examiner 2=7% (Q1 3%, Q3 12%). ConclusionsThe SmartButton can monitor spectacle compliance in patients with all approximation methods evaluated providing less than 10% median per cent error in wear time.