Posted on May 1, 2013
The CASP International Network (CASPin)  is a non-profit making organisation for people promoting skills in finding, critically appraising and acting on the results of research papers (evidence).
CASPin provide many tools to help you systematically read evidence and this specific tool will help you make sense of any case control study and assess its validity in a quick and easy way.
Appraising a case control study using this tool will take you a little over an hour (depending on how fast you read and how often you check Facebook while reading it). I highly recommend you try this out and here’s a case control study (use of caffeinated substances and risk of crashes in long distance drivers of commercial vehicles: case-control study)  to help you get started.
 CASP International Network [Internet]. CASP; [cited 1 May 2013]. Available from: http://www.casp-uk.net/#!casp-international/c1zsi
 Lisa N Sharwood, Jane Elkington, Lynn Meuleners, Rebecca Ivers, Soufiane Boufous, Mark Stevenson. Use of caffeinated substances and risk of crashes in long distance drivers of commercial vehicles: case-control study [Internet]. BMJ 2013;346:f1140 [cited 1 May 2013]. Available from: http://www.bmj.com/content/346/bmj.f1140
 Anon. Making sense of the evidence about clinical effectiveness [Internet, PDF]. CASP; 14 October 2010 [cited 1 May 2013]. 5 p. Available from: http://media.wix.com/ugd/dded87_63fb65dd4e0548e2bfd0a982295f839e.pdf