Article Text

Download PDFPDF

Performance curves of medical researchers during their career: analysis of scientific production from a retrospective cohort
  1. Antoine Duclos1,2,
  2. Eléonore Herquelot1,
  3. Stéphanie Polazzi1,
  4. Muriel Malbezin3,
  5. Olivier Claris4
  1. 1Pôle Information Médicale Évaluation Recherche, Hospices Civils de Lyon, Lyon, France
  2. 2Health Services and Performance Research Lab (EA 7425 HESPER), Université Claude Bernard Lyon 1, Lyon, France
  3. 3Direction de la Recherche Clinique et de l'Innovation, Hospices Civils de Lyon, Lyon, France
  4. 4Department of Neonatal Intensive Care Unit, Hospices Civils de Lyon, Hôpital Femme Mère Enfant, Bron, France
  1. Correspondence to Dr Antoine Duclos; antoineduclos{at}


Objectives To establish the pattern of change in individual scientific production over the career of medical researchers.

Design Retrospective cohort based on prospectively collected data in a hospital information system.

Setting Multicentre university hospital in France.

Participants Two distinct populations of 1835 researchers (full professors vs non-academic physicians) having produced 44 723 publications between 1995 and 2014.

Main outcome measures Annual number of publications referenced in Medline/PubMed with a sensitivity analysis based on publications as first/last author and in high impact journals. The individual volume of publications was modelled by age using generalised estimating equations adjusted for birth cohort, biomedical discipline and academic position of researchers.

Results Averaged over the whole career, the annual number of publications was 5.28 (95% CI 4.90 to 5.69) among professors compared to 0.82 (95% CI 0.76 to 0.89) among non-academic physicians (p<0.0001). The performance curve of professors evolved in three successive phases, including an initiation phase with a sharp increase in scientific production between 25 and 35 years (adjusted incidence rate ratio 102.20, 95% CI 60.99 to 171.30), a maturation phase with a slower increase from 35 to 50 years (2.10, 95% CI 1.75 to 2.51) until a stabilisation phase with constant production followed by a potential decline at the end of career (0.90, 95% CI 0.77 to 1.06). The non-academic physicians experienced a slower pace of learning curve at the beginning of their careers (42.38, 95% CI 25.37 to 70.81) followed by a smaller increase in the annual number of publications (1.29, 95% CI 1.11 to 1.51).

Conclusions Compared to full professors, non-academic physicians had a poor capacity to publish, indicating a low productivity when medical doctors have limited time or little interest in undertaking research. This finding highlights the potential for rethinking the missions of medical doctors towards an enlargement of scientific prerogatives in favour of progress in global knowledge.

  • medical researcher
  • scientific production
  • individual performance

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • ▸ Additional material is available. To view please visit the journal online (

  • Contributors AD identified the research question, interpreted the results and wrote the manuscript. EH analysed the data and provided a first draft of the manuscript. SP produced the dataset to be analysed and provided a critical revision of the manuscript. MM and OC highlighted some new insights on the results and provided a critical revision of the article. All authors gave a final approval to the article. AD is the guarantor of this work.

  • Competing interests None declared.

  • Ethics approval The study was supported by the medical commission and research department of the host institution. Anonymous access and retrospective analysis of personal data was authorised by the national data protection commission (Commission Nationale de l'Informatique et des Libertés, CNIL; number 15-076), in accordance with the French legislation.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data access, responsibility, and analysis Authors had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. AD and EH are responsible for the data analysis.

  • Transparency declaration AD affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.

  • Data sharing statement Statistical codes are available from the corresponding author at No additional data are available.