title: Visual analogue self-assessment of acute mountain sickness in adolescents: experience from two Himalayan expeditions.
abstract: OBJECTIVE
  Recent studies have investigated visual analogue scales (VAS) as an alternative to the Lake Louise AMS Self-Report Score (LLS) for the self-assessment of acute mountain sickness (AMS). We investigated their use in adolescents.
  
  
  METHODS
  The study was conducted during the 2009 and 2010 British Schools Exploring Society 35-day expeditions to Ladakh. Comparable ascent profiles were followed, reaching a maximum altitude of 6000 m. LLS and VAS AMS scores were recorded each morning. VAS comprised 100 mm lines for each LLS symptom; VAS scores were summed to give a composite daily total (VAS(c), expressed as a percentage). In 2010, an additional line was used to score overall "altitude sickness' (VAS(o)).
  
  
  RESULTS
  42 individuals participated in 2009 (83% compliance; mean age 17.4 years); 28 in 2010 (82% compliance; 17.5 years). 759 data points were recorded in 2009; 529 in 2010. There was a significant correlation between LLS and VAS(c) on both expeditions (rho=0.80, p<0.001 in 2009; rho=0.65, p<0.001 in 2010). These significant correlations remained when cases of AMS were analyzed separately. However, in all cases, the relationship between LLS and VAS was distorted, with a tendency for VAS to underscore symptoms of AMS when LLS<5. A VAS(c) value of 5.5% had an 82% specificity and sensitivity for all cases of AMS; VAS(c) of 9.5% had a 90% specificity and sensitivity for moderate and severe AMS.
  
  
  CONCLUSIONS
  Whilst adolescents are capable of self-monitoring for AMS using VAS, the relationship with LLS is distorted. The LLS, despite its limitations, therefore remains the preferred method for the self-assessment of AMS in adolescents.
authors.affiliation: Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom. maryslingo@doctors.org.uk
authors.forename: Mary E
authors.initials: ME
authors.lastname: Slingo
authors.forename: Fionna S J
authors.initials: FS
authors.lastname: Lowe
authors.forename: Andrew R P
authors.initials: AR
authors.lastname: Pieri
authors.forename: Chris H E
authors.initials: CH
authors.lastname: Imray
mesh_terms: D000293:Adolescent; D000328:Adult; D000531:Altitude; D000532:Altitude Sickness / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D019540:Area Under Curve; D059026:Diagnostic Self Evaluation; D004244:Dizziness / Q000209:etiology; D005101:Expeditions; D005221:Fatigue / Q000209:etiology; D005260:Female; D006261:Headache / Q000209:etiology; D006801:Humans; D007194:India; D008297:Male; D009051:Mountaineering; D009325:Nausea / Q000209:etiology; D010147:Pain Measurement; D012372:ROC Curve; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D014839:Vomiting / Q000209:etiology; D055815:Young Adult