title: Reliability and utility of a visual analog scale for the assessment of acute mountain sickness.
abstract: Acute mountain sickness (AMS) is a common condition that affects people that ascend too rapidly to high altitude. It is typically assessed with the Lake Louise AMS Self-report Score (LLSelf) that uses a categorical numeric rating scale to answer five questions addressing AMS-related symptoms, such as headache. A 100-mm visual analog scale (VAS) is commonly used to assess subjective phenomena such as pain, but this scale has never been used for the self-assessment of AMS. The purpose of this study was to compare a VAS score to the total LLSelf and to evaluate the test-retest and interrater reliability of the VAS when used as an assessment of AMS. Participants (N = 356) completed both the LLSelf and the VAS on the summit of Mt. Whitney (4419 m). There was a significant relationship (r = 0.65, p < 0.01) between the LLSelf (2.8 +/- 2.0, mean +/- SD) and the VAS (14.4 +/- 14.1 mm). Fifty-seven participants were randomly selected for reliability testing of the VAS. Both test-retest reliability (ICC = 0.996, 95% CI = 0.992 to 0.998) and interrater reliability (ICC = 1.000, 95% CI = 0.999 to 1.000) were high. The mean difference in the VAS score between tests was <1 mm, as was the difference between raters. These results demonstrate excellent reliability for the VAS as an assessment of AMS.
authors: Department of Health, Physical Education, and Recreation, Utah State University, Logan, Utah 84322-7000, USA. dale.wagner@usu.edu
authors: Dale R
authors: DR
authors: Wagner
authors: Kevin
authors: K
authors: Tatsugawa
authors: Daryl
authors: D
authors: Parker
authors: Troy A
authors: TA
authors: Young
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000532:Altitude Sickness / Q000145:classification / Q000175:diagnosis*; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009051:Mountaineering; D010147:Pain Measurement; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires / Q000592:standards