BACKGROUND: Different spirometric criteria in diagnosing COPD have been advocated by different groups, debilitating adequate diagnosis and treatment of COPD. We reviewed the clinical relevance of fixed ratio and lower limit of normal (LLN) in diagnosing COPD and explored if modifying factors may affect their clinical relevance. METHODS: Two reviewers independently searched PubMed and Embase for papers that compared both criteria on any clinically relevant outcome, published before June 1st, 2012, without any language restriction. Two reviewers independently extracted the study characteristics, including study design, population characteristics and diagnostic criteria used, and summarized the results of clinical relevance. Study quality was assessed by scoring forms for bias and level of evidence. RESULTS: Of 394 studies retrieved, 11 studies were included, with a median of 1,258 participants. Although both criteria appeared related with various clinically relevant outcomes, we were unable to prefer one criterion over the other, with various performances of the criteria for different outcomes. Should the criteria disagree on diagnosis, an alternative diagnosis should be suspected, in particular in those (elderly) with less severe airflow limitation for whom the LLN appears a better criterion. The fixed ratio appears to perform better in subjects with more severe airflow limitation. CONCLUSION: In diagnosing COPD, severity of airflow limitation appears an important factor for choosing whether the fixed ratio or LLN. Disagreement between the criteria is suggestive for an alternative diagnosis. Future studies on clinical relevance should further reveal the criterion of choice, in order to improve adequate diagnosis and consequent treatments.
BACKGROUND: Different spirometric criteria in diagnosing COPD have been advocated by different groups, debilitating adequate diagnosis and treatment of COPD. We reviewed the clinical relevance of fixed ratio and lower limit of normal (LLN) in diagnosing COPD and explored if modifying factors may affect their clinical relevance. METHODS: Two reviewers independently searched PubMed and Embase for papers that compared both criteria on any clinically relevant outcome, published before June 1st, 2012, without any language restriction. Two reviewers independently extracted the study characteristics, including study design, population characteristics and diagnostic criteria used, and summarized the results of clinical relevance. Study quality was assessed by scoring forms for bias and level of evidence. RESULTS: Of 394 studies retrieved, 11 studies were included, with a median of 1,258 participants. Although both criteria appeared related with various clinically relevant outcomes, we were unable to prefer one criterion over the other, with various performances of the criteria for different outcomes. Should the criteria disagree on diagnosis, an alternative diagnosis should be suspected, in particular in those (elderly) with less severe airflow limitation for whom the LLN appears a better criterion. The fixed ratio appears to perform better in subjects with more severe airflow limitation. CONCLUSION: In diagnosing COPD, severity of airflow limitation appears an important factor for choosing whether the fixed ratio or LLN. Disagreement between the criteria is suggestive for an alternative diagnosis. Future studies on clinical relevance should further reveal the criterion of choice, in order to improve adequate diagnosis and consequent treatments.
Authors: Wouter van Dijk; Wan Tan; Pei Li; Best Guo; Summer Li; Andrea Benedetti; Jean Bourbeau Journal: Ann Fam Med Date: 2015 Jan-Feb Impact factor: 5.166
Authors: Andreas Horner; Joan B Soriano; Milo A Puhan; Michael Studnicka; Bernhard Kaiser; Lowie E G W Vanfleteren; Louisa Gnatiuc; Peter Burney; Marc Miravitlles; Francisco García-Rio; Julio Ancochea; Ana M Menezes; Rogelio Perez-Padilla; Maria Montes de Oca; Carlos A Torres-Duque; Andres Caballero; Mauricio González-García; Sonia Buist; Maria Flamm; Bernd Lamprecht Journal: Respir Res Date: 2017-08-23