What makes large epidemiological studies comparable?
- PMID: 20889461
- DOI: 10.1183/09031936.00110310
What makes large epidemiological studies comparable?
Comment on
-
Recent trends in COPD prevalence in Spain: a repeated cross-sectional survey 1997-2007.Eur Respir J. 2010 Oct;36(4):758-65. doi: 10.1183/09031936.00138409. Epub 2009 Dec 8. Eur Respir J. 2010. PMID: 19996189
-
No increase in the prevalence of COPD in two decades.Eur Respir J. 2010 Oct;36(4):766-73. doi: 10.1183/09031936.00178109. Epub 2010 Aug 6. Eur Respir J. 2010. PMID: 20693258