TREND (Transparent Reporting of Evaluations with Nonrandomized Designs)

The Transparent Reporting of Evaluations with Nonrandomized Designs (TREND) statement grew out of the meta-analysis work on HIV prevention interventions being conducted by the Centers for Disease Control Prevention Research Synthesis (PRS) project in the late 1990s and early 2000s. The objective of the TREND statement was to improve the completeness and reporting of evaluations with nonrandomized designs. The TREND statement emphasizes reporting the theoretical bases of interventions. Clear statement of the theories underlying the interventions, with measurement of the intervening processes, can serve to provide a conceptual basis for assessing the likelihood that the intervention did "cause" the outcome even in the absence of a truly randomized trial. This chapter discusses the development process, evidence of effectiveness of guideline, endorsement and adherence, cautions and limitations or mistakes and/or misconceptions and creators' preferred bits for the TREND statement.