The visual analogue scale (VAS) is an established, validated, self-report measure usually consisting of a 10 cm line on paper with verbal anchors labeling the ends. Palmtop computers (PTCs also known as personal digital appliances) have incorporated VAS entry by use of a touch screen. However, the validity and psychophysical properties of the electronic VAS have never been formally compared with the conventional paper VAS. The aim of this study is to determine the agreement between the electronic (eVAS) and paper (pVAS) modes. Twenty-four healthy volunteers were recruited for this study. Each study participant provided input using both measurement methods by marking the eVAS and pVAS in response to two kinds of stimuli, cognitive and sensory. A verbal rating scale of seven descriptors of intensity represented the cognitive stimuli. Participants were asked to mark the location that best corresponded to the pain intensity described by each word on scales from 'no pain' to 'worst possible pain'. The sensory stimuli used were a set of test weights consisting of plastic containers ranging from 7 to 129 g. The VAS for sensory stimuli ranged from 0 (no weight) to 'reference weight' (the heaviest weight outside the range of test weights). There were two types of input stimuli and two modes for recording responses for a total of four experimental conditions. Two evaluators independently measured and recorded all the pVAS forms to the nearest millimeter. A total of 2016 stimuli were rated. The overall correlation for ratings of both sensory and cognitive stimuli on eVAS and pVAS was r = 0.91. For paired verbal stimuli the correlation was r = 0.97. For paired sensory stimuli the correlation was r = 0.86. The correlation between group eVAS and pVAS ratings to common verbal stimuli was r = 0.99. For common sensory stimuli the group correlation was r = 0.99. The median of correlations comparing eVAS and pVAS ratings was 0.99 for verbal stimuli and 0.98 for sensory stimuli. Multivariate analyses showed equivalent stimuli to be rated much the same whether entered on paper VAS or PTC touch screen VAS (P < 0.0001). Support was found for the validity of the computer version of the VAS scale.
EEG sleep recordings were obtained on consecutive nights from six hospitalized depressed patients before, during, and after treatment with amitriptyline for a total of 370 nights of data, about 85% of all nights of the study. Amitriptyline significantly reduced time spent in rapid eye movement (REM) sleep and prolonged the REM latency throughout the treatment period. Three patients who improved during treatment showed a REM rebound when amitriptyline was discontinued, whereas three patients who did not improve showed no REM rebound.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.