Metric properties of the Spanish version of the Lake Louise Acute Mountain Sickness Questionnaire

Abstract

Objectives To assess the metric properties of the Lake Louise Acute Mountain Sickness (LLAMSQ) five-item questionnaire. Methods At the end of the course “Neuroscience in pre-Columbian Andean cultures” (Peru, 2009), the participants answered the self-reported version of the LLAMSQ. The following psychometric attributes were explored: acceptability (observed versus possible scores; floor and ceiling effects), scaling assumptions (item-total correlation >0.30), internal consistency (Cronbach¿s alpha), precision (standard error of measurement), and convergent and discriminative validity. Differences in mean score of LLAMSQ between symptomatic acute mountain sickness subjects and asymptomatic ones were calculated. Results The participants stayed for days at Cuzco (3,400 meters above sea level, MASL), Sacred valley (2,850 MASL) and Machu Picchu (2,450 MASL). Seventy people (60% males; mean age 50±8 years; 88.6% neurologists) were included in the study. LLAMSQ mean score was 3.36±2.02 (median 3; skewness 0.61). Ceiling and floor effects were 7.3% and 1.4%, respectively. Cronbach¿s alpha was 0.61, and standard error of measurement 1.26. LLAMSQ mean score significantly correlated (r=0.41, P=.002) with physical items (ataxia, dyspnoea, tremor, mental symptoms). LLAMSQ mean scores were significantly higher (worse) in those subjects who presented with acute sickness mountain (5.8 vs 3.0; Mann-Whitney, P<.0001). Conclusions Metric properties of the LLASMQ Spanish version are adequate. This questionnaire seems to be useful in the early detection of high-altitude illness.