Table 1. Summary of interventions and outcomes assessed in studies included in existing systematic reviews
Interventions prioritisingefficiencyInterventions prioritising thoroughness
Review Test-ordering outcome(s) Process changes (including computer systems) Guidelines and/or protocols Education Audit and feedback Financial incentives
Solomon et al 199814 Reduction in test-ordering volumeReduction in test expenditurexxxxx
Main et al 201015 Changes in test-ordering volume‘Appropriateness’ of testingx    
Smellie 201216 Reduction in test-ordering volumeReduction in test expenditure‘Appropriateness’ of testingxxxxx
Cadogan et al 201517 Reduction in test-ordering volumexxxx 
Kobewka et al 201518 Reduction in test-ordering volumex xxx
Thomas et al 201519 Reduction in test-ordering volumexx x 
Thomas et al 201620 Change in test-ordering volumex xx 
Zhelev et al 201621 Reduction in test-ordering volumeChanges in test expenditure‘Appropriateness’ of testingChanges in testing patternsxxxxx
Delvaux et al 201722 ‘Appropriateness’ of testingChanges in test expenditureClinical outcomesx    
Maillet et al 201823 Changes in test ordering‘Appropriateness’ of testingWorkloadx