Assessing equivalence and noninferiority.
OBJECTIVE
For systematic reviews, no guidance exists for what review methods support valid conclusions of equivalence (EQ) and noninferiority (NI). To provide such guidance, we convened a workgroup of 13 experienced systematic reviewers from seven evidence-based practice centers (EPCs) and the Agency for Healthcare Research and Quality (AHRQ).


METHODS
The Lead EPC first performed two methods projects intended to assist the workgroup in clarifying the context, prioritizing the issues, targeting the scope, and summarizing the state of the art.


RESULTS
Based on expert opinion, we devised guidance in four areas: 1) Unique risk of bias issues for trials self-identifying as EQ-NI trials; 2) Setting the reviewer's minimum important difference; 3) Analytic foundations for concluding EQ or NI; and 4) Language considerations when concluding EQ or NI.


CONCLUSIONS
This article summarizes the main recommendations, and the full guidance chapter appears on the AHRQ Web site.
Evidence-based Practice Center, ECRI Institute, Plymouth Meeting, PA, USA. jtreadwell@ecri.org
Jonathan R
JR
Treadwell
Stacey
S
Uhl
Kelley
K
Tipton
Tatyana
T
Shamliyan
Meera
M
Viswanathan
Nancy D
ND
Berkman
Xin
X
Sun
Craig I
CI
Coleman
Adam G
AG
Elshaug
Sonal
S
Singh
Shi-Yi
SY
Wang
Rema
R
Ramakrishnan
D015982:Bias; D002986:Clinical Trials as Topic / Q000379:methods; D057186:Comparative Effectiveness Research / Q000379:methods* / Q000592:standards; D019317:Evidence-Based Medicine; D017408:Guidelines as Topic; D006801:Humans; D012196:Review Literature as Topic; D009626:Terminology as Topic; D013810:Therapeutic Equivalency; D014481:United States; D016270:United States Agency for Healthcare Research and Quality