When discussing evidence based practices for hearing aid fitting, what is meant by the term levels of evidence?
It really comes down to your ability to systematically evaluate the strength of the evidence your are reviewing. This is a fairly complicated question, and I will try and give you some practical insights that might be useful. An excellent resource to begin learning about evidence based practice is the July/August 2005 special issue of the Journal of the American Academy of Audiology. The special issue features guest editor Robyn Cox, whose article, Evidence-Based Practice in Provision of Amplification, describes a level of evidence hierarchy. This hierarchy helps us size up the strength of the clinical evidence in a systematic manner. Coxs article describes 6 levels of evidence. I have included a chart below that has these 6 levels in order from the highest level of evidence (1a) to the lowest level of evidence (Level 4). The numbering here will differ slightly from Cox (2005) since I have used 1a, 1b, 2a, 2b where she uses 1,2,3,4 respectively, for the first 4 levels. When audiologist
