TY - JOUR T1 - High-altitude alpine therapy and lung function in asthma: Systematic review and meta-analysis JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2016.PA4293 VL - 48 IS - suppl 60 SP - PA4293 AU - Denis Vinnikov AU - Abdullah Khafagy AU - Paul Blanc AU - Nurlan Brimkulov AU - Craig Steinmaus Y1 - 2016/09/01 UR - http://erj.ersjournals.com/content/48/suppl_60/PA4293.abstract N2 - Background. High-altitude climate therapy (HACT) is a long-standing environmental intervention in childhood and adult asthma. Nonetheless, objective improvement following HACT has not been subjected to systematic analysis.Aim. To systematically analyze lung function changes following HACT.Methods. We used meta-analysis to analyze the effect of HACT on changes in lung function in asthma. We systematically searched Pubmed, Embase, and www.elibrary.ru, including non-English language reports appearing 1970- mid-2015. We included studies of children or adults with HACT ≤12 weeks at an altitude ≥1500 meters above sea level (MASL). We analyzed changes in forced expiratory volume in one second (FEV1), FEV1/vital capacity, or peak expiratory flow rate following HACT. Because studies reported effect sizes by varying scales, we calculated the reported effect as the standardized mean difference (SMD) so that this could be pooled across studies.Results. We included data for 948 participants (age range 4-58 years) from 22 studies, altogether including 29 substrata based on asthma type or severity. Of these 29 substrata, 93% reported lung function improvement following HACT, with an overall pooled SMD of 0.55 (95% CI 0.45-0.64). The measured effect of HACT was greater in adults (n=14 substrata): SMD=0.75; 95% CI 0.63-0.88 than in children (n=15 substrata): SMD=0.30; 95% CI 0.16-0.44. Studies at altitude above 2000 MASL yielded a similar effect to those at lower altitude.Conclusions. Based on a cut-point of a 0.50 change in SMD to define a meaningful clinical difference, HACT appears to have efficacy as an intervention. This extent of benefit appears to be limited to adults with asthma. ER -