Year: 2015
Type: review
Study design: Systematic Review
Abstract: BACKGROUND: Quasi-randomization might expedite recruitment into trials in emergency care settings but may also introduce selection bias. METHODS: We searched the Cochrane Library and other databases for systematic reviews of interventions in emergency medicine or urgent care settings. We assessed selection bias (baseline imbalances) in prognostic indicators between treatment groups in trials using true randomization versus trials using quasi-randomization. RESULTS: Seven reviews contained 16 trials that used true randomization and 11 that used quasi-randomization. Baseline group imbalance was identified in four trials using true randomization (25%) and in two quasi-randomized trials (18%). Of the four truly randomized trials with imbalance, three concealed treatment allocation adequately. Clinical heterogeneity and poor reporting limited the assessment of trial recruitment outcomes. CONCLUSIONS: We did not find strong or consistent evidence that quasi-randomization is associated with selection bias more often than true randomization. High risk of bias judgements for quasi-randomized emergency studies should therefore not be assumed in systematic reviews. Clinical heterogeneity across trials within reviews, coupled with limited availability of relevant trial accrual data, meant it was not possible to adequately explore the possibility that true randomization might result in slower trial recruitment rates, or the recruitment of less representative populations.
Source: Research Synthesis Methods
DOI: 10.1002/jrsm.1163
Institution: University of York
Language: English
Subfield: Statistics, Probability and Uncertainty
Field: Decision Sciences
Domain: Social Sciences
Open Access status: hybrid
Estimated APC paid: $3,020
OpenAlex ID: W1903511252