BACKGROUND: There has been a recent increase in interest in alternatives to randomisation in the evaluation of public health interventions. We aim to describe specific scenarios in which randomised trials may not be possible and describe, exemplify and assess alternative strategies. METHODS: Non-systematic exploratory review. RESULTS: In many scenarios barriers are surmountable so that randomised trials (including stepped-wedge and crossover trials) are possible. It is possible to rank alternative designs but context will also determine which choices are preferable. Evidence from non-randomised designs is more convincing when confounders are well-understood, measured and controlled; there is evidence for causal pathways linking intervention and outcomes and/or against other pathways explaining outcomes; and effect sizes are large. CONCLUSION: Non-randomised trials might provide adequate evidence to inform decisions when interventions are demonstrably feasible and acceptable, and where evidence suggests there is little potential for harm, but caution that such designs may not provide adequate evidence when intervention feasibility or acceptability is doubtful, and where existing evidence suggests benefits may be marginal and/or harms possible.
BACKGROUND: There has been a recent increase in interest in alternatives to randomisation in the evaluation of public health interventions. We aim to describe specific scenarios in which randomised trials may not be possible and describe, exemplify and assess alternative strategies. METHODS: Non-systematic exploratory review. RESULTS: In many scenarios barriers are surmountable so that randomised trials (including stepped-wedge and crossover trials) are possible. It is possible to rank alternative designs but context will also determine which choices are preferable. Evidence from non-randomised designs is more convincing when confounders are well-understood, measured and controlled; there is evidence for causal pathways linking intervention and outcomes and/or against other pathways explaining outcomes; and effect sizes are large. CONCLUSION: Non-randomised trials might provide adequate evidence to inform decisions when interventions are demonstrably feasible and acceptable, and where evidence suggests there is little potential for harm, but caution that such designs may not provide adequate evidence when intervention feasibility or acceptability is doubtful, and where existing evidence suggests benefits may be marginal and/or harms possible.
Authors: Paul Montgomery; Evan Mayo-Wilson; Sally Hopewell; Geraldine Macdonald; David Moher; Sean Grant Journal: Am J Public Health Date: 2013-08-15 Impact factor: 9.308
Authors: Jennifer Alvidrez; Anna María Nápoles; Guillermo Bernal; Jacqueline Lloyd; Victoria Cargill; Dionne Godette; Lisa Cooper; Maria Yellow Horse Brave Heart; Rina Das; Tilda Farhat Journal: Am J Public Health Date: 2019-01 Impact factor: 9.308
Authors: Marie H T Martin; Maj Britt D Nielsen; Ida E H Madsen; Signe M A Petersen; Theis Lange; Reiner Rugulies Journal: J Occup Rehabil Date: 2013-12