Abstract: Background: Diagnostic uncertainty (DU) in primary care is ubiquitous, yet no review has specifically examined its communication, or the associated ethical issues.

Aims: To identify what is known about the communication of DU in primary care and the associated ethical issues.

Design: Systematic review, critical interpretive synthesis and ethical analysis of primary research published worldwide.

Method: Medline, Embase, Web of Science and SCOPUS were searched for papers from 1988-2020 relating to primary care AND diagnostic uncertainty AND [ethics OR behaviours OR communication]. Critical interpretive synthesis and ethical analysis were applied to data extracted.

Results: Sixteen papers met inclusion criteria. Although DU is inherent in primary care, its communication is often limited. Evidence on the effects of communicating DU to patients is mixed; research on patient perspectives of DU is lacking. The empirical literature is significantly limited by inconsistencies in how DU is defined and measured. No primary ethical analysis was identified; secondary analysis of the included papers identified ethical issues relating to maintaining patient autonomy in the face of clinical uncertainty, a gap in considering the direct effects of (not) communicating DU on patients, and considerations regarding over-investigation and justice.

Conclusions: This review highlights significant gaps in the literature: there is a need for explicit ethical and patient-centred empirical analyses on the effects of communicating DU, and research directly examining patient preferences for this communication. Consensus on how DU should be defined, and greater research into tools for its measurement, would help to strengthen the empirical evidence base.