Marker or mechanism? Medical imaging utilisation and population life expectancy in 38 OECD countries, 2000 to 2024 year.
- 1College of Medical Sciences Warsaw
Abstract
BackgroundMedical imaging is central to modern diagnosis and treatment, yet its contribution to population-level survival has rarely been quantified, and the few existing estimates have been interpreted as evidence that imaging directly extends life. Whether national imaging utilisation reflects a distinct clinical mechanism or a broader process of health-system development has not been formally tested.
MethodsLongitudinal ecological panel study of 38 OECD countries, 2000-2024 (950 possible country-years). CT and MRI availability and utilisation were linked to life expectancy at birth, treatable and preventable mortality, and seven cause-specific mortality outcomes. Two-way fixed-effects models with country and year fixed effects and country-clustered standard errors were adjusted sequentially for log GDP per capita, log health expenditure per capita, population aged [≥]65 years, physician density and smoking prevalence. Three falsification families were specified: lead-exposure (placebo) models regressing current life expectancy on future imaging utilisation; negative control exposures with no diagnostic-imaging pathway to survival; and wild cluster bootstrap inference.
ResultsIn the principal adjusted model, CT utilisation at a three-year lag was associated with higher life expectancy ({beta} = 0.85 years per 100 additional examinations per 1,000 inhabitants, 95% CI 0.16 to 1.54; cluster-robust p = 0.015; bootstrap p = 0.034; n = 339, 29 countries). Scanner availability showed weaker, generally non-significant associations. All three falsification analyses failed to support a modality-specific effect. Future CT utilisation predicted current life expectancy as strongly as past utilisation (three-year lead {beta} = 0.86, 95% CI 0.15 to 1.57, p = 0.017), consistent with high within-country autocorrelation of the exposure (r = 0.64 at three years). Radiotherapy equipment density, a therapeutic rather than diagnostic technology, showed an equal and more precise association ({beta} = 0.85 per 10 units per million, 95% CI 0.32 to 1.38, p = 0.0017), as did PET scanner density and health expenditure, whereas physician density showed none. Associations were stronger for preventable ({beta} = -43.3 per 100,000, p = 0.0002) than treatable mortality ({beta} = -13.5, p = 0.19), and all were attenuated to the null under country-specific linear trends.
ConclusionsNational CT utilisation is a robust ecological correlate of life expectancy but does not behave as a causal determinant under falsification. It is best understood as a marker of health-system capital development. Claims that imaging adds years of life are not supportable on ecological evidence of this kind.
Related
- Does population aging promote embeddedness in the regional medical device trade network? Evidence from RCEP member countries
- International trends in clozapine utilisation prevalence in adults, adolescents and older people: An observational study in 42 countries between 2015 and 2024
- Balancing CO₂ emissions, energy consumption, health expenditure: implications for life expectancy in GCC countries.
- Optimizing threat expectancy change during exposure therapy for anxiety disorders: Study protocol for a mechanism-focused two-arm parallel group randomized controlled superiority trial with sequential Bayes factor design
- A Tale of Two Countries: Challenges in the Adoption of Artificial Intelligence in Medical Imaging in India and Singapore.
BibTeX
@misc{obuchowicz2026marker,
title = {{Marker or mechanism? Medical imaging utilisation and population life expectancy in 38 OECD countries, 2000 to 2024 year.}},
author = {R. Obuchowicz},
howpublished = {medRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.02.26362082},
url = {https://www.medrxiv.org/content/10.64898/2026.09.02.26362082v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Marker or mechanism? Medical imaging utilisation and population life expectancy in 38 OECD countries, 2000 to 2024 year.
AU - R. Obuchowicz
PY - 2026
DA - 2026/09/02
PB - medRxiv
DO - 10.64898/2026.09.02.26362082
UR - https://www.medrxiv.org/content/10.64898/2026.09.02.26362082v1
AB - BackgroundMedical imaging is central to modern diagnosis and treatment, yet its contribution to population-level survival has rarely been quantified, and the few existing estimates have been interpreted as evidence that imaging directly extends life. Whether national imaging utilisation reflects a distinct clinical mechanism or a broader process of health-system development has not been formally tested. MethodsLongitudinal ecological panel study of 38 OECD countries, 2000-2024 (950 possible country-years). CT and MRI availability and utilisation were linked to life expectancy at birth, treatable and preventable mortality, and seven cause-specific mortality outcomes. Two-way fixed-effects models with country and year fixed effects and country-clustered standard errors were adjusted sequentially for log GDP per capita, log health expenditure per capita, population aged [≥]65 years, physician density and smoking prevalence. Three falsification families were specified: lead-exposure (placebo) models regressing current life expectancy on future imaging utilisation; negative control exposures with no diagnostic-imaging pathway to survival; and wild cluster bootstrap inference. ResultsIn the principal adjusted model, CT utilisation at a three-year lag was associated with higher life expectancy ({beta} = 0.85 years per 100 additional examinations per 1,000 inhabitants, 95% CI 0.16 to 1.54; cluster-robust p = 0.015; bootstrap p = 0.034; n = 339, 29 countries). Scanner availability showed weaker, generally non-significant associations. All three falsification analyses failed to support a modality-specific effect. Future CT utilisation predicted current life expectancy as strongly as past utilisation (three-year lead {beta} = 0.86, 95% CI 0.15 to 1.57, p = 0.017), consistent with high within-country autocorrelation of the exposure (r = 0.64 at three years). Radiotherapy equipment density, a therapeutic rather than diagnostic technology, showed an equal and more precise association ({beta} = 0.85 per 10 units per million, 95% CI 0.32 to 1.38, p = 0.0017), as did PET scanner density and health expenditure, whereas physician density showed none. Associations were stronger for preventable ({beta} = -43.3 per 100,000, p = 0.0002) than treatable mortality ({beta} = -13.5, p = 0.19), and all were attenuated to the null under country-specific linear trends. ConclusionsNational CT utilisation is a robust ecological correlate of life expectancy but does not behave as a causal determinant under falsification. It is best understood as a marker of health-system capital development. Claims that imaging adds years of life are not supportable on ecological evidence of this kind.
ER -