Medical school accreditation tiers track national exam scores, not university grades

The retrospective analysis, published in BMC Medical Education, examined Comprehensive Basic Science Examination (CBSE) results from 2019 to 2021 and grouped 23 medical schools by the duration of their national accreditation: long-term, mid-term, or short-term.

The study included 25,757 individuals across the 23 institutions. Researchers documented three outcomes for each student: CBSE scores, grade point average (GPA) in university courses, and repeat examination results. They then compared performance across accreditation categories and between genders.

The headline finding concerns the mismatch between the two assessment systems. Students at long-term accredited universities scored significantly higher on the CBSE than peers at mid-term and short-term accredited institutions, with the difference reaching statistical significance at P < 0.001. Yet GPA moved in the opposite direction: grade point averages were elevated at short-term accredited institutions. According to the authors, this inverse pattern indicates a diminished alignment between internal assessments and standardized performance.

Repeat-examination rates added a third signal. Short-term accredited universities exhibited higher repeat rates, also at P < 0.001, meaning students at those schools were more likely to need a second attempt at the comprehensive exam. Taken together, the authors conclude that accreditation category and years of accreditation are associated with higher CBSE performance and more favorable repeat-testing patterns, while internal grading shows the reverse pattern.

Gender produced a second divergence. Female students outperformed males in university courses, while males scored significantly higher on the CBSE, with both differences significant at P < 0.001. The study explored these gender differences as part of its analysis of whether accreditation categories align with measurable student outcomes, though the abstract does not report effect sizes or explain the mechanisms behind the gender gap.

The background to the study is a practical one. National medical school accreditation is intended to differentiate institutional quality and support improvement, but there is limited country-specific evidence on whether accreditation categories actually align with measurable student outcomes. This study was designed to test that alignment using two independent yardsticks: the grades each university assigns its own students, and a standardized comprehensive examination taken across institutions.

The authors’ interpretation is cautious. They suggest that standardized examination outcomes may align more closely with accreditation tiers than institutional grades do, and they highlight the need to strengthen governance and comparability of internal assessment across institutions. In other words, the accreditation signal shows up clearly in the external, standardized measure but is blurred, or even inverted, in the internal one.

Several limitations should be kept in mind when weighing these results. The study is retrospective and observational, so it documents associations rather than demonstrating that accreditation causes better exam performance. The data cover CBSE results from 2019 to 2021 at 23 medical schools in a single country, and the findings concern basic science examination performance and internal grades, not later clinical competence or career outcomes. The published abstract also does not report the magnitude of the score differences, only their statistical significance.

Even with those caveats, the scale of the dataset gives the finding weight. For accreditation bodies, the implication is that a school’s tier corresponds to how its students fare on the national standardized exam and how often they must retake it, while the grades those schools award internally may not be comparable across institutions. For educators, the inverse GPA pattern raises questions about how internal assessment standards vary with accreditation duration, and the authors argue that governance of internal assessment deserves strengthening if grades are to serve as a reliable, comparable measure of student achievement.

Subject of Research: The association between medical school accreditation duration and students' university grades and comprehensive exam performance

Article Title: Medical school accreditation and educational outcomes: a national equity study of students’ university grades and comprehensive exam scores

Article References: Abed, M., Rashidi, F., Sabet, B., Nojomi, M., & Meysamie, A. (2026). Medical school accreditation and educational outcomes: a national equity study of students’ university grades and comprehensive exam scores. BMC Medical Education. https://doi.org/10.1186/s12909-026-10334-3

Image Credits: AI Generated

DOI: 10.1186/s12909-026-10334-3

Keywords: medical education, accreditation, medical schools, comprehensive basic science examination, grade point average, student assessment, gender differences, retrospective study, Iran, BMC Medical Education, Medical, school