This large cross-sectional study of doctors attempting the largest high stakes postgraduate clinical examination in the world [24] has demonstrated that female candidates are more likely to pass the examination at first attempt, even when adjusting for the candidates’ ethnicity. Ethnicity has been shown to influence candidates’ performance in examinations [10, 12, 13, 25], and therefore it is important to control for its effect. The size of the sex effect differed between the three groups examined, the largest being in non-UK medical graduates not registered with the GMC, the smallest in UK graduates registered with the GMC, and an intermediate effect size in non-UK medical graduates registered with the GMC.
Comparison with other studies
The finding that female doctors are more likely to pass PACES mirrors the findings of Dewhurst and colleagues [9], who analysed data from the pre-2009 version of PACES in UK graduates only. They found that, after controlling for ethnicity, women had 1.69 the odds of passing (95% CI = 1.42–2.02), a significantly larger order of magnitude to the finding from our logistic regression examining UK graduates only (OR = 1.18; 95% CI = 1.03-1.35).
Sex differences in performance at clinical assessments in the UK in other specialties has also been shown, with women performing better than men at the General Practice specialty examination in both the written Applied Knowledge Test and the practical Clinical Skills Assessment [10, 26]. Women also performed better in the intercollegiate specialty board examinations for surgical training [27]. Indeed, a recent unpublished meta-analysis of UK-based studies has also demonstrated that female doctors perform better than male doctor at postgraduate medical examinations of a clinical nature, although sex differences are generally less pronounced in written examinations [28]. Interestingly the effect of sex is not so clear outside of the UK. In the US, the USMLE Step 3 is the final and clinical component of the medical licensing examination. Two studies have examined the sex difference in performance at this examination in US medical graduates, with one study finding women outperforming men [29], but the other study demonstrated no sex difference [30].
Our finding that female international medical graduates outperform male international medical graduates is also seen in other UK and US postgraduate examinations [26, 31,32,33]. To our knowledge, there are no studies looking at sex differences in the examination performance of international medical graduates with and without registration to practise medicine in the country in which the examination is set.
Limitations of the study
The data were collected for routine administrative purposes, which limited our ability to gather potentially relevant data such as doctor’s age; however this also meant that the data on many variables were complete. The variable that contributed to the majority of the missing data was ethnicity, which was self-declared; however, a comparison of candidates with and without missing data showed no evidence of a difference in terms of passing PACES.
Unanswered questions
It is not clear why candidate demographics relate to PACES outcome. Female doctors may be better at performing the skills tested in clinical assessments [28, 32]. It has been demonstrated that, during one clinical assessment, women ask more relevant history taking items and perform correctly more physical examination manoeuvres [33]. It could be that women are better at retaining and appropriately applying theoretical scientific and medical knowledge to clinical encounters in examinations; although scientific theoretical medical knowledge is formally assessed through written assessments [34] and a recent unpublished meta-analysis showed that sex differences were smaller or not present on written assessments. Further, there was no evidence for a sex difference in the written components of the MRCP (UK) Diploma when examined by Dewhurst and colleagues in 2003/04 [9], although it would be of interest to analyse sex difference on the written MRCP (UK) components during the time of period of the current study.
A popular hypothesis is that sex differences in performance are due to differences in communication styles. A meta-analytic review of medical consultations found that female doctors are more likely to adopt a patient-centred communication style [35]. It has also been demonstrated that women doctors have greater interpersonal skills, which lead to empathic relationships [36,37,38]. These interpersonal skills may encourage the patient to be more forthcoming with regards to salient clinical information, enabling the doctor to correctly diagnose and manage the presenting ailment. However, this hypothesis would not completely explain the sex difference seen in performance at PACES, because there are stations where there is no meaningful verbal interaction with the patient.
A further hypothesis is that male and female doctors differ in values, and that these values lead to different motivations, which in turn influence achievement. Female doctors have been shown to have higher person-related values [37, 39, 40], and one study found that performance in a clinical setting was predicted by person-related values held by the doctor [39]. It could also be that the design of the exam favours female candidates, perhaps examiners of clinical assessments may be unfairly biased towards female candidates or against male candidates. However there is no evidence to suggest a sex bias in clinical examiners in this current format of the PACES examination when assessed between 2009 and 2011 [41].
We did not examine the individual countries from which candidates had obtained their PMQ, but it is possible that the female candidates were more likely to have graduated from English-speaking countries when compared to male international medical graduates. Native English speakers perform better at clinical assessments conducted in English [10], and if women international medical graduates are found to be more likely from a country where English is the dominant language, or where communication skills and cultural values are more similar to the UK when compared to men, this could go toward explaining the sex difference in performance seen in international medical graduates. It may also reflect differences in the selection and training of female doctors in countries around the world [42]. It is also possible that access to PACES and medical education in general may be biased outside of the UK. This may plausibly result in female candidates needing to be higher performers and to be more motivated than their male counterparts, to overcome obstacles that may limit their access to the examination.
Candidates’ age was not examined in this study, but it is likely that non-UK graduates were older and a previous study has demonstrated that older candidates do not perform as well as younger candidates in clinical assessments [33]. The variation between the sex difference in non-UK graduates with and without GMC registration may reflect gendered migration patterns. For example, Lebanese medical graduates practising in the US are significantly less likely to be female than graduates of other countries [43], and a study of Lebanese medical students by the same authors found that female students had less intention of working abroad after graduation than male students [44]. It would be of interest to explore whether the difference in PACES performance has varied year upon year, or whether the sex difference is stable. This study captures just under 3 years worth of data and therefore it is unlikely that any meaningful conclusions will able to be drawn with regards to performance over time.
It is likely that performance in large, high-stakes clinical examinations that have demonstrated good validity reflects performance in actual clinical practice. A study comparing the MRCP (UK) scores of doctors who had and had not had their registration subject to action by the GMC found that those whose license had been acted upon had lower PACES scores [45]. It may be that the factors underlying sex differences in performance in clinical examinations also contribute to female doctors being less subject to medico-legal action [6].