Rationale, Aims and Objectives Six years ago, the Supreme Court judgement in Montgomery v Lanarkshire changed medical law. It introduced a new patient‐based standard of care for the communication of treatment risks and alternatives, rejecting the doctor‐based standard that had long governed all aspects of medical negligence. This is the first systematic review to analyse the literature on Montgomery. Our aim is to appraise and synthesize the literature on Montgomery's impact on medicine and the law and to identify areas for further academic enquiry and implications for professional guidance and training. Methods Searches were run in Medline, Embase, PsycINFO, Web of Science, Scopus, Westlaw UK, HeinOnline, and LexisNexis. Two reviewers screened papers. Extracted data was analysed and discussed by an interdisciplinary team. PRISMA guidelines were followed. Results Of the 1134 papers identified, 100 met the inclusion criteria. These papers revealed significant disagreement on four core sets of issues, focusing on Montgomery's impact on: (1) legal and professional duties; (2) medical practice; (3) the patient experience; and (4) litigation. The first set addresses whether the case actually changed doctors' legal and professional duties, the relationship between GMC guidance and medical law, and the boundaries of Montgomery. The second explores whether the decision has incentivized defensive medicine, its resource implications, and doctors' knowledge of it. The third concerns whether and how the decision has promoted patient autonomy and involvement in their own care. The fourth focuses on whether the case has caused an increase in litigation. Conclusions Despite the abundance of legal and medical literature on Montgomery, many issues remain unresolved. Empirical research is required for many of the questions. Doctrinal analysis informed by medical knowledge is also required to assess whether Montgomery may have unrecognized ramifications—for example, whether it will require the disclosure of risks associated with diagnostic uncertainty, where doctors advise patients without performing procedures.

Diagnosis lies at the heart of the medical encounter, yet it has received much less attention than treatment. It is widely assumed that negligent diagnosis claims should be governed by the Bolam test, but we demonstrate that this is not always the case. First, we disaggregate the diagnostic process into three different acts: forming the diagnosis, communicating it to the patient, and recording it. Second, we consider alternatives to Bolam for defining negligence, including less deferential profession-led standards, patient-led standards, and even a reasonable person standard. Third, bringing together these distinctions—within the diagnostic process, and between standards of care—we reveal the unappreciated complexity of negligent diagnosis. Analysing the standard of care that might apply to the three different acts in the diagnostic process, we identify reasons to think that Montgomery should apply to the communication of a diagnosis. We also argue that even in areas where the law is well-established, such as the application of Bolam to the formation of a diagnosis, challenging questions arise that require further attention. Throughout, the framework and analysis that we develop have significant implications for a set of negligence cases, as well as for medical education, clinical guidelines, and patient care.

While errors in medical diagnosis are common and often litigated, the different dimensions of diagnosis—formation, communication, recording—have received much less legal attention. When the process of diagnosis is differentiated in this way, new and contentious legal questions emerge that challenge the appropriateness of the Bolam/Bolitho standard. To explore these challenges, we interviewed 31 solicitors and barristers and asked them: (i) whether Montgomery should apply to information about alternative diagnoses; and (ii) whether the Bolam/Bolitho standard should be rejected in ‘pure diagnosis’ cases. Our qualitative analysis of the interviews sheds light not only on the two questions posed, but also on three cross-cutting themes. First, Bolam/Bolitho is criticised on two grounds that are often conflated: its paternalism for patients and its deference to medical professionals. Second, adopting different standards for different aspects of treatment and diagnosis may be justified in principle, but it can sometimes be difficult or not make sense in practice. Third, new conceptions of patients, doctors, and courts are being articulated in terms of rights or responsibilities over risks. In mapping these issues at the frontiers of medical negligence, this empirical study identifies potential pressure points for future legal developments.