Evidence Based Health Care (EBHC) does not imply that all patient decisions are made solely on the basis of evidence.
Evidence forms only one part of the entire paradigm.
The triad comprises of Best Research Evidence, Patient Values, and Clinical Expertise.
Only when the best research evidence is combined with clinical expertise and patient values does one provide EBHC.
Evidence is worthwhile only when it has been generated using scientifically sound principles and techniques.
Unfortunately, many clinicians lack the skills to correctly assess scientific papers, and succumb to marketing by Medical Representatives, funding agencies, opinion builders, leading experts, etc.
Sometimes the issue is complicated by the presence of conflicting findings reported by different studies.
Clinicians might then fall back on expert opinion since it is convenient and comforting.
EBHC is, therefore, no magic bullet. It is deeply influenced by a number of factors, the most important being the quality of evidence.