Background Laboratory testing is an integral part of day-to-day primary care practice underlying approximately 70% of diagnoses and treatment decisions. Research suggests that a large proportion of requests are avoidable. The aim of this systematic review was to comprehensively search the literature for studies evaluating the effectiveness of interventions for improving general practitioners (GPs) use of laboratory tests.

Methods A search of PubMed, Cochrane Library, Embase and SCOPUS (from inception to 09/02/14) was conducted. Updated searches were performed in November 2014. The following study designs were considered: systematic reviews, randomised controlled trials (RCTs), controlled clinical trials (CCTs), controlled before and after studies (CBAs) and interrupted time series analysis (ITSs). The population of interest were GPs. Interventions were considered if they aimed to improve laboratory testing in General Practice. The outcome of interest was volume of laboratory tests. Quality and risk of bias was assessed using a using a modified version of the EPOC Data Collection Checklist and Quality Criteria for studies with a control group (RCTs, CCTs and CBAs) and for ITSs studies.

Results In total, 6,166 titles and abstracts were reviewed, followed by 87 full texts. Of these, eleven papers were eligible for inclusion in the systematic review. This included four RCTs, six CBAs and one ITS study. The types of interventions examined included education, feedback, guidelines, education with feedback, feedback with guidelines and changing order forms. The quality of included studies varied with seven studies deemed to have a low risk of bias, three with unclear risk of bias and one with high risk of bias. All but one study found significant reductions in the volume of tests following the intervention, with effect sizes ranging from 1.2% to 60%. Due to heterogeneity, results could not be meta-analysed.

Conclusion Feedback and education (including guidelines) based interventions proved most effective for changing GP requesting behaviour. However, the quality of some of the included study designs and the inclusion of various different tests between studies should be considered. Further, the complex health systems of included studies indicate qualitative research is required prior to developing an intervention in the Irish setting.