Age, aging and physiological dysregulation in safety–critical work: a retrospective longitudinal study of helicopter emergency medical services pilots

  • Hans BauerEmail author
  • Dennis Nowak
  • Britta Herbig
Original Article



Concurrent progressive physiological dysregulation in different organ systems may be a driver of phenotypical frailty and is associated with morbidity and performance declines. In aging societies, health and performance of older workers are given increased scrutiny. However, there are few studies researching the effect of age on physiological dysregulation specifically in the working population and none for high-risk occupations with close medical supervision. Here, we aim to investigate this association cross-sectionally and longitudinally in a healthy sample of European helicopter emergency medical services pilots.


Using a retrospective cohort design, we constructed indices of (a) physiological dysregulation state (N = 52 participants) and (b) pace of change (N = 41 participants, average follow-up 7.9 years) based on measurements of 18 health risk-associated biomarkers, as documented in the participating pilots’ aeromedical examination records. The relationship of these two indices with average age (range 27.9–60.6 years) and average baseline age (29.3–57.2 years), respectively, was modeled by weighted least squares regression, adjusting for region of origin, smoking, and medication.


Longitudinally, dysregulation significantly increased over the follow-up period, but the pace of change did not increase with baseline age. Cross-sectionally, we observed a significant negative quadratic effect of age on physiological dysregulation state, with maximum estimated physiological dysregulation at ages 45–50.


As hypothesized, progression of dysregulation over approximately 8 years is observable in a healthy occupational sample but it does not accelerate (i.e., does not increase with baseline age). Increases in dysregulation are counteracted by what appears to be a strong healthy worker survivor effect. The study shows that the development of physiological dysregulation in high-risk occupations differs from that in the general population and that physiological dysregulation indices may be helpful in reconciling safety concerns and fair treatment of aging workers in safety–critical jobs.


Functional decline Biological age Age 60 Rule Workforce aging Occupational safety 


Author contributions

HB assisted with the study design and had primary responsibility for data collection, data management & quality control, data analysis, and drafting of the manuscript. DN obtained research funding and conceived/designed the study. BH obtained research funding, conceived/designed the study, and assisted with data collection and data analysis. All authors contributed substantially to the paper’s finalization.


This paper reports findings of a study on age and flight safety in helicopter emergency medical services (HEMS) pilots funded via an unrestricted educational grant from the European HEMS & Air Ambulance Committee e.V. (EHAC).

Compliance with ethical standards

Conflict of interest

EHAC represents European air rescue organizations who favor a liberalization of certain current European regulations on maximum professional pilot age. Freedom from interference in any stage of the research process was laid down contractually between EHAC and the research project team, represented by the manuscript authors. EHAC had no role in the formulation of the study design, the collection, analysis and interpretation of the data, the writing of the report, and the decision to submit the paper for publication.

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from all individual participants included in the study.

Supplementary material

420_2019_1482_MOESM1_ESM.pdf (247 kb)
Supplementary material 1 (PDF 246 kb)
420_2019_1482_MOESM2_ESM.pdf (440 kb)
Supplementary material 2 (PDF 439 kb)


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Institute and Clinic for Occupational, Social, and Environmental MedicineUniversity Hospital of LMU MunichMunichGermany

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