Table 4

Summary of components to consider when evaluating the quality of evidence from research

Study design

Randomized

Allocation concealment

Blinding (if possible)a

Clinically important and objective primary outcome

Beta-errorb

Multi-center

Study conduct

Intention-to-treat analysis

Follow-up or attrition rate

Completion to planned numbers

Study findings

Biological plausibility

Strength of estimate of effect

Precision of estimate of effect

Observed event rate

Study applicability

Consistency across similar studies

Reproducibility

Generalizability


aBlinding may not be possible in device or protocol/process trials. bAdequately powered, appropriate estimate of control event rate and relative or absolute reduction in clinically important primary outcome.

Bellomo and Bagshaw Critical Care 2006 10:232   doi:10.1186/cc5045