EBH listserv members
Periodically we evaluate the critical appraisal criteria we use for DynaMed. This listserv has helped us in the past (2008) when we added critical appraisal criteria for randomized trials in the case of early trial termination.
We have found critical appraisal criteria for randomized parallel trials are not optimal for analyzing crossover trials. The CONSORT statement has numerous extensions but does not have an extension for crossover trials. The Cochrane
Handbook was updated in 2011 (version 5.1.0) to include a risk of bias assessment criteria for crossover trials.
In consideration of critical appraisal criteria for randomized trials used today and the risk of bias criteria for crossover trials from the Cochrane Handbook we have developed the criteria listed below as a planned revision to our level
of evidence criteria for DynaMed (found at
https://dynamed.ebscohost.com/content/LOE). We welcome your feedback in consideration of refining these criteria before we implement them.
DynaMed criteria
for level 1 (likely reliable) evidence for interventional conclusions from crossover trials – must meet ALL criteria to be considered level 1 evidence
1)
Conducted in patients with condition not expected to change spontaneously during course of trial
2)
Clinical outcome (also called patient-oriented outcomes)
3)
Random allocation method for order of assignment
(i.e. not assigned by date of birth, day of presentation, “every other”)
4)
Washout period between interventions long enough to avoid carryover effects between interventions
5)
Adequate duration of intervention and assessment period to represent outcome being measured
6)
Blinding of all persons (patients, treating clinicians, outcome assessors) if possible
7)
Follow-up (endpoint assessment) of at least 80% of trial participants AND adequate such that losses to follow-up could not materially change
results
8)
Accounting for dropouts (even if not included in analysis)
9)
Analysis of paired data
10)
Analysis not suggesting period effects (i.e. effect resulting for order of intervention), or period effects if present not materially
changing results
11)
Adequate statistical power
12)
No other factors contributing substantial bias, such as subgroup or post hoc analyses
Thank you.
Brian
Brian S. Alper, MD, MSPH, FAAFP
Editor-in-Chief, DynaMed
Medical Director, EBSCO Information Services
[log in to unmask]
10 Estes Street
Ipswich, MA 01938-0231
Phone 800-356-6500 or 978-356-6500 ext. 2749
Cell 978-804-8719
Fax 978-356-7332
dynamed.ebscohost.com
"It only takes a pebble to start an avalanche."
