This review then focused only on process indicators backed by high level evidence (Level 1 of the Australian National Health & Medical Research Council's Evidence Hierarchy) [ 16].
At present, there is not high-level evidence (level 1 2) to support implementation of PCT measurements in the ICU, and at the same time, there is not high-level evidence to refrain from implementing this biomarker.
For each outcome, preference was given to higher-level evidence (level 1 and 2), with level 3 evidence also included where level 1 and/or 2 evidence was lacking or conflicting.
Between 2000 and 2010, the overall percentage of high-level evidence (levels I and II) studies more than doubled (12 to 31 %, P < 0.001).
Can or should level I or high level evidence ever come from single center trials?
Level I or high level evidence demands that trials should have a low probability of committing an alpha error.
If we have no empirical proof, why would this finding not be considered as level I or high level evidence, given that blinding of HFOV is not possible?
Therefore, for a trial to be classified as level I or high level evidence, it essentially requires incorporation of these elements into the design.
Is there a magic number of randomized patients or observed events in each arm that makes the probability of committing an alpha error sufficiently unlikely (no matter the condition or population) to justify classifying a study as level I or high level evidence?
Between 2000 and 2010, the overall percentage of high-level evidence studies (levels I and II) increased and low-level evidence studies (levels III, IV, and V) decreased (Table 2) (P < 0.001).
We have demonstrated a trend towards higher level of evidence in hip surgery over a decade, with two journals (the JBJS and Journal of Arthroplasty) showing significant levels of improvement in high-level evidence.
