CCSCase–control study
CCHControlled cohort study
CHCohort study
COMComparative study
CRCase report
CSCase series
CSSCross-sectional study
CSNRControlled trial without randomisation
DBPDouble blind parallel trial
DBRPDouble blind randomised placebo controlled trial
EEEconomic evaluation
EVEvaluation
GLGuidelines
HTAHealth Technology Assessment
ISNRInterventional study not randomised
ISSInterventional study with groups sequentially allocated
LSLongitudinal study
MEModel evaluation
NCCNested case–control
OBObservational study
OPCOpen pilot cohort study
PHLSReport from PHLS AIDS Diagnostic Working Group
QRQuasi-randomised study
RDBCRandomised double blind crossover trial
RECReview by expert committee
RCSSReview of cross-sectional studies
RCTRandomised controlled trial
RVReview
SASecondary analysis of RCT data
SRSystematic review
SSWGuideline report from PHLS Syphilis Serology Working Group
SVSurveillance
TESTest evaluation survey
TESCTest evaluation survey on crossover
ELEvidence level

From: Evidence tables

Cover of Antenatal Care
Antenatal Care: Routine Care for the Healthy Pregnant Woman.
NICE Clinical Guidelines, No. 62.
National Collaborating Centre for Women's and Children's Health (UK).
London: RCOG Press; 2008 Mar.
Copyright © 2008, National Collaborating Centre for Women’s and Children’s Health.

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