Grading evidence and recommendations: Randomised experimental evaluation of four grading systems

Article type
Authors
Perez G1, Cuello C2, Pacheco K3
1Red Cochrane Iberoamericana, Mexico
2ITESM, Red Cochrane Iberoamericana, Mexico
3ITESM, Mexico
Abstract
Background: More than 60 systems for grading evidence and recommendations have been described, reflecting discrepancies among those creating and synthesizing evidence.

Objectives: To evaluate the effect of presenting a recommendation using different grading systems to determine to what extent the system changes the clinician's eventual response to a particular clinical question.

Methods: Randomised experimental study in clinicians' offices and academic settings. Paediatricians and paediatric residents in private and public practice in Mexico were handed case notes of a child with diarrhoea and a question about clinician preference for using an anti-diarrhoeal medication. The same evidence was provided in a clinical recommendation but with different presentation according to the following grading systems: NICE (National Institute for Health and Clinical Excellence), SIGN (Scottish Intercollegiate Guideline Network), GRADE (Grading of Recommendations Assessment, Development and Evaluation) and CEBM (Centre for Evidence-Based Medicine, Oxford). The main outcome measure was the mean change in direction from baseline response (measured on a 10cm visual scale and a Likert scale) and among groups.

Results: 216 subjects agreed to participate. Most participants changed their decision after reading the clinical recommendations (mean difference (MD) 0.7 cm (95% confidence interval (CI) 0.29 to 1.0; P<0.001)). By groups, mean change (95% CI) from baseline was 0.04 (-0.68 to 0.77) for NICE, 0.31 (-0.41 to 1.05) for SIGN, 2.18 (1.48 to 2.88) for GRADE and 0.08 (-0.52 to 0.69) for CEBM (P = 0.007 between groups). In a final survey, a small difference was noted regarding the clarity of the results presented with the GRADE system.

Conclusions: The clinician's decision to use a therapy was influenced most by the GRADE system. Trial registration number NCT00940290.