| Verified against primary record | |
| Reporting guideline | CARE, a 13-item checklist for clinical case reports[1] |
|---|---|
| Its stated limit | The sample size is one, and causality determinations are a challenge for case reports[1] |
| Surgical case reports | Routed to a separate guideline, SCARE, not covered by CARE[2] |
| Records read | A reporting guideline, a guideline repository entry, two reviews and a bias reference entry, 9 October 2026 |
| Independently reported | |
| Case selection in this field | The criteria used for selecting cases are seldom stated[3] |
| Bands apply only to the rows beneath them. No complication rate is derived from case series in this entry, because they have no denominator. | |
Case reports and case series are the dominant study designs in medical travel research, and the reason most of what is published cannot support a rate. A 2026 review of complications presenting to the United Kingdom’s health service included 37 studies, of which 35 were case series or case reports.[3] Understanding what these designs can and cannot carry is therefore most of what is needed to read this literature.
The designs, and the guideline that covers one of them
A case report describes one patient. A case series describes a consecutive or selected group, usually assembled retrospectively from records. The reporting guideline for the first is CARE, which resulted in a 13-item checklist, with the stated primary objective of developing, disseminating and implementing systematic reporting guidelines for case reports.[1]
Two scope limits matter and are routinely overlooked. CARE covers case reports and not case series, and the guideline repository that hosts it directs surgical case reports to a separate standard, SCARE.[2] Since most medical travel case reports are surgical, CARE is not in fact the applicable guideline for most of them, and no case-series reporting guideline was located for this entry.
What a case report can and cannot do
The guideline’s developers are direct about both. On the limits, the sample size is one, causality determinations are a challenge for case reports, and their quality is uneven. They also state that case reports written without guidance from reporting standards are insufficiently rigorous to guide clinical practice.[1]
On the value, when systematically aggregated, case reports provide early signals of effectiveness and harms.[1] That is the correct use in this field. A published case of a graft failure after surgery abroad is evidence that such a failure occurred. It is not evidence about how often.
The missing denominator, stated by reviewers
The clearest account of why these designs cannot yield a rate comes from reviewers working on this exact material. They record that the criteria used for selecting cases are seldom stated and that cases may be chosen because they are rare or treatment is novel; that their evidence is limited to cases reported in the literature by researchers who collected data, often from patients who presented as emergencies; and that abstracts and letters lack full details on selection of patients and methods of analysis.[3]
They give a concrete instance. Five case series reporting on bariatric surgery tourism included only emergency, urgent or acute admissions, so they did not include patients presenting with non-urgent complications, patients presenting to general medical teams or breast clinics, or patients presenting to other hospitals. The consequence is stated plainly: case numbers are under-reported, and costs are under-estimated.[3]
And the conclusion they draw is the one this entry exists to record: the overall complication rate for outward medical tourism for elective surgery in the United Kingdom and in Wales is unknown, as is the number of United Kingdom residents choosing to travel abroad for elective surgery.[3] Retrospective case series and case reports are at high risk of bias due to missing information in the records.
How case-series percentages get misread
A worked example shows the trap. A systematic review of complications of aesthetic surgical tourism treated in the United States included 20 studies describing 214 patients, and reported that complications were mainly infectious at 50.9 per cent, with 36.8 per cent hospitalised and 51.8 per cent requiring surgical management, and that 98.1 per cent of patients were female.[4]
Every one of those percentages is a proportion within a population that had already presented with a complication. None is an incidence. There is no denominator of people who travelled, so none of these figures can be converted into a risk, and the sex distribution reflects which patients reached which American clinics rather than who travels. Figures of this shape appear constantly in coverage of this subject described as complication rates. They are not.
Why the unusual case gets published
One further distortion operates on top of selection. The relevant named mechanism is a tendency to submit, accept and publish positive results rather than non-significant or negative results.[5] In a case-report literature the equivalent is that the uneventful recovery is never written up. A clinician who treats a straightforward returning patient has nothing to report; one who treats a rare and severe complication has a publishable case.
The result is a literature weighted toward severity by construction. That is not a criticism of the clinicians who publish it, and the reports are often the only record that a harm occurred at all. It is a reason the collection of them cannot be read as a description of typical experience.
See also
- Complication rates in medical tourism, why a rate needs a denominator
- Selection bias in medical tourism research, how these samples are assembled
- Systematic reviews of medical tourism, what the reviews of this material found
- Medical tourism research methods, the designs that could replace these
References
- Gagnier JJ, Kienle G, Altman DG, Moher D, Sox H, Riley D, and the CARE Group. The CARE guidelines, consensus-based clinical case reporting guideline development. Journal of Medical Case Reports, 2013;7:223, published 10 September 2013; also BMJ Case Reports 2013. Verified against primary record: guideline paper read in full. Retrieved 9 October 2026.
- EQUATOR Network. The CARE reporting guideline for writing clinical case report articles. Verified against primary record: guideline repository entry opened and read, including its direction of surgical case reports to SCARE. Retrieved 9 October 2026.
- England C, Bromham N, Needham-Taylor A, Hounsome J, Gillen E, Ingram BJ, Davies J, Edwards A, Lewis R. Complications and costs to the UK National Health Service due to outward medical tourism for elective surgery, a rapid review. BMJ Open, 2026;16(1):e109050, published 13 January 2026; preprint at medRxiv 10.1101/2025.04.02.25325086. Independently reported: publicly commissioned review, preprint full text read. Retrieved 9 October 2026.
- McAuliffe PB, Muss TEL, Desai AA, Talwar AA, Broach RB, Fischer JP. Complications of aesthetic surgical tourism treated in the USA, a systematic review. Aesthetic Plastic Surgery, 2023;47:455-464. Independently reported: peer-reviewed systematic review. Retrieved 9 October 2026.
- Catalogue of Bias Collaboration, Pluddemann A, Banerjee A, O’Sullivan J. Positive results bias. Catalogue of Biases, 2017. Independently reported: academic reference resource opened and read. Retrieved 9 October 2026.
Sourcing note: the reporting guideline, the repository entry, the two reviews and the bias reference entry were opened and read on 9 October 2026. The percentages from the aesthetic surgery review are reproduced only alongside the statement that they are proportions within a complication-presenting population and not incidence, because they are routinely quoted as rates. No case-series reporting guideline equivalent to CARE was located, and that is reported as a search result rather than as proof that none exists.