Outcomes of Basic Versus Advanced Life Support for Out-of-Hospital Medical Emergencies
Authors: Stephen B. Soumerai
Journal: Annals of Internal Medicine (2016)

Letters5 July 2016Outcomes of Basic Versus Advanced Life Support for Out-of-Hospital Medical EmergenciesStephen B. Soumerai, ScDStephen B. Soumerai, ScDFrom Harvard Medical School, Boston, Massachusetts.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/L15-0627 SectionsAboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail TO THE EDITOR:The recent article by Sanghavi and colleagues reports interesting Medicare claims data on the reduced survival of patients receiving advanced life support (ALS) versus basic life support (BLS) ambulances (1). Unsurprisingly, as with all research, this study raises important questions about bias and confounding.First, the authors used a cross-sectional design with no estimate of pre–post change and no adequate counterfactual (control). Although conducting a randomized, control trial (RCT) is difficult, a hierarchy of quasi-experimental (non-RCT) designs produce differing levels of validity of causal inferences (2). The cross-sectional design, with or without propensity score adjustments or instrumental ...References1. Sanghavi P, Jena AB, Newhouse JP, Zaslavsky AM. Outcomes of basic versus advanced life support for out-of-hospital medical emergencies. Ann Intern Med. 2015;163:681-90. [PMID: 26457627]. doi:10.7326/M15-0557 LinkGoogle Scholar2. Soumerai SB, Starr D, Majumdar SR. How do you know which health care effectiveness research you can trust? A guide to study design for the perplexed. Prev Chronic Dis. 2015;12:E101. [PMID: 26111157] doi:10.5888/pcd12.150187 CrossrefMedlineGoogle Scholar3. Effective Practice and Organisation of Care (EPOC). What study designs should be included in an EPOC review? EPOC Resources for review authors. Oslo: Norwegian Knowledge Centre for the Health Services; 2013. Accessed at http://epoc.cochrane.org/epoc-specific-resources-review-authors on 18 March 2016. Google Scholar4. Garabedian LF, Chu P, Toh S, Zaslavsky AM, Soumerai SB. Potential bias of instrumental variable analyses for observational comparative effectiveness research. Ann Intern Med. 2014;161:131-8. [PMID: 25023252]. doi:10.7326/M13-1887 LinkGoogle Scholar Author, Article, and Disclosure InformationAffiliations: From Harvard Medical School, Boston, Massachusetts.Disclosures: Author has disclosed no conflicts of interest. Form can be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=L15-0627. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetailsSee AlsoOutcomes of Basic Versus Advanced Life Support for Out-of-Hospital Medical Emergencies Prachi Sanghavi , Anupam B. Jena , Joseph P. Newhouse , and Alan M. Zaslavsky Outcomes of Basic Versus Advanced Life Support for Out-of-Hospital Medical Emergencies Prachi Sanghavi , Anupam B. Jena , Joseph P. Newhouse , and Alan M. Zaslavsky Outcomes of Basic Versus Advanced Life Support for Out-of-Hospital Medical Emergencies Yusuke Tsutsumi , Yasushi Tsujimoto , Yuki Kataoka , and Tatsuyoshi Ikenoue Metrics Cited byInstrumental variables: The power of wishful thinking vs the confounded reality of comparative effectiveness researchPrehospital Resuscitation 5 July 2016Volume 165, Issue 1Page: 68-69KeywordsAmbulancesComplex systemsConflicts of interestDeath ratesDisclosureMedicareResearch designSystematic reviewsTriage ePublished: 5 July 2016 Issue Published: 5 July 2016 Copyright & PermissionsCopyright © 2016 by American College of Physicians. All Rights Reserved.PDF downloadLoading ...