PLAB and UK graduates' performance on MRCP(UK) and MRCGP examinations: data linkage study

To assess whether international medical graduates passing the two examinations set by the Professional and Linguistic Assessments Board (PLAB1 and PLAB2) of the General Medical Council (GMC) are equivalent to UK graduates at the end of the first foundation year of medical training (F1), as the GMC requires, and if not, to assess what changes in the PLAB pass marks might produce equivalence.

Data linkage of GMC PLAB performance data with data from the Royal Colleges of Physicians and the Royal College of General Practitioners on performance of PLAB graduates and UK graduates at the MRCP(UK) and MRCGP examinations.

Doctors in training for internal medicine or general practice in the United Kingdom.

7829, 5135, and 4387 PLAB graduates on their first attempt at MRCP(UK) Part 1, Part 2, and PACES assessments from 2001 to 2012 compared with 18,532, 14,094, and 14,376 UK graduates taking the same assessments; 3160 PLAB1 graduates making their first attempt at the MRCGP AKT during 2007-12 compared with 14,235 UK graduates; and 1411 PLAB2 graduates making their first attempt at the MRCGP CSA during 2010-12 compared with 6935 UK graduates.

Performance at MRCP(UK) Part 1, Part 2, and PACES assessments, and MRCGP AKT and CSA assessments in relation to performance on PLAB1 and PLAB2 assessments, as well as to International English Language Testing System (IELTS) scores. MRCP(UK), MRCGP, and PLAB results were analysed as marks relative to the pass mark at the first attempt.

PLAB1 marks were a valid predictor of MRCP(UK) Part 1, MRCP(UK) Part 2, and MRCGP AKT (r=0.521, 0.390, and 0.490; all P<0.001). PLAB2 marks correlated with MRCP(UK) PACES and MRCGP CSA (r=0.274, 0.321; both P<0.001). PLAB graduates had significantly lower MRCP(UK) and MRCGP assessments (Glass's Δ=0.94, 0.91, 1.40, 1.01, and 1.82 for MRCP(UK) Part 1, Part 2, and PACES and MRCGP AKT and CSA), and were more likely to fail assessments and to progress more slowly than UK medical graduates. IELTS scores correlated significantly with later performance, multiple regression showing that the effect of PLAB1 (β=0.496) was much stronger than the effect of IELTS (β=0.086). Changes to PLAB pass marks that would result in international medical graduate and UK medical graduate equivalence were assessed in two ways. Method 1 adjusted PLAB pass marks to equate median performance of PLAB and UK graduates. Method 2 divided PLAB graduates into 12 equally spaced groups according to PLAB performance, and compared these with mean performance of graduates from individual UK medical schools, assessing which PLAB groups were equivalent in MRCP(UK) and MRCGP performance to UK graduates. The two methods produced similar results. To produce equivalent performance on the MRCP and MRGP examinations, the pass mark for PLAB1 would require raising by about 27 marks (13%) and for PLAB2 by about 15-16 marks (20%) above the present standard.

PLAB is a valid assessment of medical knowledge and clinical skills, correlating well with performance at MRCP(UK) and MRCGP. PLAB graduates' knowledge and skills at MRCP(UK) and MRCGP are over one standard deviation below those of UK graduates, although differences in training quality cannot be taken into account. Equivalent performance in MRCGP(UK) and MRCGP would occur if the pass marks of PLAB1 and PLAB2 were raised considerably, but that would also reduce the pass rate, with implications for medical workforce planning. Increasing IELTS requirements would have less impact on equivalence than raising PLAB pass marks.