Diversity in the pathway from medical student to specialist in the Netherlands: a retrospective cohort study

Background

Medical specialist workforces are not representative of the society they serve, partially due to loss of diversity in the path from student to specialist. We investigated which demographic characteristics of bachelor students of medicine (BSM) are associated with becoming a physician and (particular type of) medical specialist; and whether this suggests 'cloning' (reproduction of sameness) of the existing workforce.

Methods

We used a retrospective cohort design, based on Statistics Netherlands data of all first-year BSM in 2002-2004 in The Netherlands (N = 4503). We used logistic regression to analyze the impact of sex, migration background, urbanity of residence, parental income and assets categories, and having healthcare professional parents, on being registered as physician or medical specialist in 2021. We compared our results to the national pool of physicians (N = 76,845) and medical specialists (N = 49,956) to identify cloning patterns based on Essed's cultural cloning theory.

Findings

Female students had higher odds of becoming a physician (OR 1.87 [1.53-2.28], p < 0.001). Physicians with a migration background other than Turkish, Moroccan, Surinamese, Dutch Caribbean or Indonesian (TMSDI) had lower odds of becoming a specialist (OR 0.55 [0.43-0.71], p < 0.001). This was not significant for TMSDI physicians (OR 0.74 [0.54-1.03], p = 0.073). We found a cloning pattern with regard to sex and migration background. Nationwide, physicians with a Turkish or Moroccan migration background, and female physicians with other migration backgrounds, are least likely to be a medical specialist.

Interpretation

In light of equity in healthcare systems, we recommend that every recruitment body increases the representativeness of their particular specialist workforce.

Funding

ODISSEI.

Risk Prediction of Metachronous Colorectal Cancer from Molecular Features of Adenomas: A Nested Case-Control Study

Current morphologic features defining advanced adenomas (size ≥10 mm, high-grade dysplasia or ≥25% villous component) cannot optimally distinguish individuals at high risk or low risk of metachronous colorectal cancer (me-CRC), which may result in suboptimal surveillance. Certain DNA copy-number alterations (CNAs) are associated with adenoma-to-carcinoma progression. We aimed to evaluate whether these molecular features can better predict an individual's risk of me-CRC than the morphologic advanced adenoma features.In this nested case-control study, 529 individuals with a single adenoma at first colonoscopy were selected from a Norwegian adenoma cohort. DNA copy-number profiles were determined, by low-coverage whole-genome sequencing. Prevalence of CNAs in advanced and non-advanced adenomas and its association (OR) with me-CRC was assessed. For the latter, cases (with me-CRC) were matched to controls (without me-CRC) on follow-up, age and sex.CNAs associated with adenoma-to-carcinoma progression were observed in 85/267 (32%) of advanced adenomas and in 27/262 (10%) of non-advanced adenomas. me-CRC was statistically significantly associated, also after adjustment for other variables, with age at baseline [OR, 1.14; 95% confidence interval CI), 1.03-1.26; P = 0.012], advanced adenomas (OR, 2.46; 95% CI, 1.50-4.01; P < 0.001) and with the presence of ≥3 DNA copy-number losses (OR, 1.90; 95% CI. 1.02-3.54; P = 0.043).Molecularly-defined high-risk adenomas were associated with me-CRC, but the association of advanced adenoma with me-CRC was stronger.

SIGNIFICANCE

Identifying new biomarkers may improve prediction of me-CRC for individuals with adenomas and optimize surveillance intervals to reduce risk of colorectal cancer and reduce oversurveillance of patients with low risk of colorectal cancer. Use of DNA CNAs alone does not improve prediction of me-CRC. Further research to improve risk classification is required.

Inequality of opportunity in selection procedures limits diversity in higher education: An intersectional study of Dutch selective higher education programs

Selection for higher education (HE) programs may hinder equal opportunities for applicants and thereby reduce student diversity and representativeness. However, variables which could play a role in inequality of opportunity are often studied separately from each other. Therefore, this retrospective cohort study conducts an innovative intersectional analysis of the inequality of opportunity in admissions to selective HE programs. Using a combination of multivariable logistic regression analyses and descriptive statistics, we aimed to investigate 1) the representativeness of student populations of selective HE programs, as compared to both the applicant pool and the demographics of the age cohort; 2) the demographic background variables which are associated with an applicant's odds of admission; and 3) the intersectional acceptance rates of applicants with all, some or none of the background characteristics positively associated with odds of admission. The study focused on all selective HE programs (n = 96) in The Netherlands in 2019 and 2020, using Studielink applicant data (N = 85,839) and Statistics Netherlands microdata of ten background characteristics. The results show that student diversity in selective HE programs is limited, partly due to the widespread inequality of opportunity in the selection procedures, and partly due to self-selection. Out of all ten variables, migration background was most often (negatively) associated with the odds of receiving an offer of admission. The intersectional analyses provide detailed insight into how (dis)advantage has different effects for different groups. We therefore recommend the implementation of equitable admissions procedures which take intersectionality into account.

Abstract A004: Molecular adenoma features to predict metachronous colorectal cancer risk: A nested-case control study

Introduction: In colorectal cancer (CRC) surveillance, adenoma characteristics such as size, number of adenomas, dysplasia, and villous components, are used as indicators for risk of developing metachronous cancer and guide the surveillance interval. The current risk groups (e.g., advanced adenomas) cannot optimally distinguish high risk from low risk, which may result in suboptimal surveillance strategies. Specific DNA copy number aberrations are associated with risk of colorectal adenoma-to-carcinoma progression, but these aberrations are present in only a subset of advanced adenomas. Therefore, we hypothesize that specific DNA copy number aberrations may better predict the risk of CRC than advanced adenoma. Aim: To evaluate whether a molecularly-defined high-risk adenoma is a better risk factor for CRC than the presently used advanced adenoma. Materials and methods: DNA copy number profiles were determined, by means of low-coverage whole genome sequencing, on a series of 529 adenomas, selected from a Norwegian adenoma cohort. We retrieved detailed information on adenoma characteristics and whether adenoma patients were subsequently diagnosed with CRC or not. By univariate and multivariate regression analysis we estimated the odds ratio for association between the development of CRC and baseline presence of advanced adenoma versus presence of a molecularly-defined high-risk adenoma, respectively. Results: Molecular high-risk features were observed in 85/267 (32%) of advanced adenomas and in 27/262 (10%) of non-advanced adenomas. The odds ratio for developing metachronous CRC was 3.58 (p=2.84E-8) and 1.90 (p=0.012), when an advanced adenoma or molecular high-risk adenoma was detected at the baseline colonoscopy, respectively. In the multivariate regression analysis only advanced adenoma was as a significant risk factor for CRC. Conclusion: Molecularly-defined high-risk adenomas are associated with an increased risk of CRC. However, the advanced adenoma is a stronger predictor for risk of CRC.

Citation Format: Henriette C. Jodal, Eddymurphy U. Akwiwu, Leticia G. Leon, Margriet Lemmens, Pien Delis-van Diemen, Dagmar Klotz, Meike de Wit, Remond Fijneman, Monique van Leerdam, Evelien Dekker, Manon C. W. Spaander, Gerrit A. Meijer, Michael Bretthauer, Magnus Løberg, Veerle M. H. Coupé, Mette Kalager, Beatriz Carvalho. Molecular adenoma features to predict metachronous colorectal cancer risk: A nested-case control study [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer; 2022 Oct 1-4; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_1):Abstract nr A004.

Selection for health professions education leads to increased inequality of opportunity and decreased student diversity in The Netherlands, but lottery is no solution: A retrospective multi-cohort study

BACKGROUND

Concerns exist about the role of selection in the lack of diversity in health professions education (HPE). In The Netherlands, the gradual transition from weighted lottery to selection allowed for investigating the variables associated with HPE admission, and whether the representativeness of HPE students has changed.

METHOD

We designed a retrospective multi-cohort study using Statistics Netherlands microdata of all 16-year-olds on 1 October 2008, 2012, and 2015 (age cohorts, N > 600,000) and investigated whether they were eligible students for HPE programs (n > 62,000), had applied (n > 14,000), and were HPE students at age 19 (n > 7500). We used multivariable logistic regression to investigate which background variables were associated with becoming an HPE student.

RESULTS

HPE students with ≥1 healthcare professional (HP) parent, ≥1 top-10% income/wealth parent, and women are overrepresented compared to all age cohorts. During hybrid lottery/selection (cohort-2008), applicants with ≥1 top-10% wealth parent and women had higher odds of admission. During 100% selection (cohort-2015) this remained the case. Additionally, applicants with ≥1 HP parent had higher odds, those with a migration background had lower odds.

CONCLUSIONS

Odds of admission are increasingly influenced by applicants' backgrounds. Targeted recruitment and equitable admissions procedures are required to increase matriculation of underrepresented students.

A progressive three-state model to estimate time to cancer: a likelihood-based approach

Background

To optimize colorectal cancer (CRC) screening and surveillance, information regarding the time-dependent risk of advanced adenomas (AA) to develop into CRC is crucial. However, since AA are removed after diagnosis, the time from AA to CRC cannot be observed in an ethically acceptable manner. We propose a statistical method to indirectly infer this time in a progressive three-state disease model using surveillance data.

Methods

Sixteen models were specified, with and without covariates. Parameters of the parametric time-to-event distributions from the adenoma-free state (AF) to AA and from AA to CRC were estimated simultaneously, by maximizing the likelihood function. Model performance was assessed via simulation. The methodology was applied to a random sample of 878 individuals from a Norwegian adenoma cohort.

Results

Estimates of the parameters of the time distributions are consistent and the 95% confidence intervals (CIs) have good coverage. For the Norwegian sample (AF: 78%, AA: 20%, CRC: 2%), a Weibull model for both transition times was selected as the final model based on information criteria. The mean time among those who have made the transition to CRC since AA onset within 50 years was estimated to be 4.80 years (95% CI: 0; 7.61). The 5-year and 10-year cumulative incidence of CRC from AA was 13.8% (95% CI: 7.8%;23.8%) and 15.4% (95% CI: 8.2%;34.0%), respectively.

Conclusions

The time-dependent risk from AA to CRC is crucial to explain differences in the outcomes of microsimulation models used for the optimization of CRC prevention. Our method allows for improving models by the inclusion of data-driven time distributions.

Supplementary Information

The online version contains supplementary material available at (10.1186/s12874-022-01645-2).