Levels of Evidence. Why? What? How?. Time-poor clinician suffering from Information Overload . Evidence-Based Medicine.
(Sackett, D. BMJ 1996;312:71-72).
1. The evidence base, in terms of the number of studies, level of evidence and quality of studies (risk of bias).
2. The consistency of the study results.
3. The potential clinical impact of the proposed recommendation.
4. The generalisability of the body of evidence to the target population for the guideline.
5. The applicability of the body of evidence to the Australian healthcare context.
Checklist for appraising the quality of studies of interventions (Cochrane handbook)
Brain Trauma, F., S. American Association of Neurological, et al. (2007). "Guidelines for the management of severe traumatic brain injury." Journal of Neurotrauma 24 Suppl 1.
Table 1. Applying Classification of Recommendations and Level of Evidence
Morgenstern, L. B., J. C. Hemphill, 3rd, et al. (2010). "Guidelines for the management of spontaneous intracerebral haemorrhage: a guideline for healthcare professionals from the American Heart Association/American Stroke Association." Stroke 41(9): 2108-29.
Surgical RCTs have well-recognized disadvantages:
high costs, administrative complexity, prolonged time to completion, recruitment difficulty, blinding, randomization technique standardization, poor generalizability or external validity, patient compliance, underpowered studies, crossovers and drop outs, multiple surgical options, technological advancement, patient complexity, variability and preference and selection bias ....
It is the well-defined research question that dictates the study design, not that every study should be a RCT because it’s the gold standard”
Fisher, C. G. and K. B. Wood (2007). "Introduction to and techniques of evidence-based medicine." Spine 32(19 Suppl): S66-72.