Objectives Clinicians’ fear of legal liability and defensive practice are commonly cited as drivers of low value care. Defensive practice involves ordering tests and procedures, making referrals, and prescribing drugs mainly to reduce perceived legal risks, rather than to advance patient care. Literature on defensive practice dates back to the 1980s but has never been systematically analysed. We conducted the first-ever mapping review of published empirical studies on defensive practice.

Methods We searched SCOPUS, Academic Search Complete (EBSCO), HeinOnline and Ovid MEDLINE with no restrictions. Two authors independently screened and extracted data using EPPI Reviewer software. We extracted data on: year of publication; country of study; study setting (eg, general practice clinic, emergency department); population studied (eg, GPs, surgeons); method of data collection (eg, survey, interview, record audits); and disciplinary affiliation of investigators (eg, medicine, law, economics). We also extracted key findings on the types of defensive practice reported, drivers of this behaviour, and proposed solutions.

Results A total of 67 studies met our inclusion criteria. Most empirical studies on defensive practice have been done in the United States (28 out of 67), by medical researchers using quantitative surveys of clinicians, especially general practitioners, obstetricians and psychiatrists. Research activity on defensive practice intensified markedly from 2011 to present, with an increase in studies outside the US. This timing coincides with the expansion of international campaigns, such as Choosing Wisely, that promote appropriate care. Ordering unnecessary tests was the most commonly reported defensive practice. In addition to fear of legal liability, the culture of medicine and patient expectations were identified as drivers of low value care that can lead to overdiagnosis and overtreatment. Proposed solutions included ameliorating clinicians’ ‘existential anxiety’ about medico-legal risk and reducing ‘blame culture’ through system-level changes.

Conclusions Available empirical data on defensive practice is limited by the predominant focus on the American medico-legal context. Caution is needed in applying these data to other countries with differing healthcare and legal systems. More qualitative research is needed to explore the behavioural drivers of defensive practice and potential solutions to legal fears that contribute to overdiagnosis and overtreatment. Our Australian research is a step toward filling this gap.