IDEAS home Printed from https://ideas.repec.org/a/eee/intell/v110y2025ics0160289625000236.html
   My bibliography  Save this article

Joint modeling of cognitive aging and survival: Evaluation of birth cohort differences

Author

Listed:
  • Thorvaldsson, Valgeir
  • Skoog, Ingmar
  • Johansson, Boo

Abstract

We examined generational differences in the associations between cognitive functioning (i.e., level and rate of change) and survival after age 70. Data were drawn from two population-based cohorts born in 1901–1907 (n = 1106) and 1930 (n = 896), each systematically sampled from the same city population and assessed on the same cognitive battery at ages 70, 75, 79, 85, 88, 90, 92, 95, 97, 99, and 100. Cognitive performance was indexed using a composite score derived from tests of spatial ability, perceptual-motor speed, and reasoning. Mortality data, obtained from the Swedish national population register, were complete for >99 % of the 1901–07 cohort and 39 % of the 1930 cohort (last update: April 2023). We fitted joint models for longitudinal cognitive change and survival, controlling for sex and education. Across both cohorts, a one SD lower cognitive level was associated with a 1.43-fold higher mortality hazard, 95 % HDI [1.34, 1.53]. Models including cohort interactions revealed stronger effects of cognitive level in the 1901–07 cohort (HR = 1.50 [1.39, 1.61]) compared to the 1930 cohort (HR = 1.26 [1.14, 1.40]). Moreover, steeper rates of cognitive decline were associated with increased mortality risk in the 1930 cohort (HR = 1.74 [1.40, 2.17]), but not in the 1901–07 cohort (HR = 1.07 [0.97, 1.77]). These findings suggest that cognitive level is a stronger mortality predictor among earlier-born cohorts, whereas rate of cognitive decline plays a larger role in later-born cohorts, highlighting cohort-specific differences in how cognitive aging informs survival probability.

Suggested Citation

  • Thorvaldsson, Valgeir & Skoog, Ingmar & Johansson, Boo, 2025. "Joint modeling of cognitive aging and survival: Evaluation of birth cohort differences," Intelligence, Elsevier, vol. 110(C).
    • Handle: RePEc:eee:intell:v:110:y:2025:i:c:s0160289625000236
    DOI: 10.1016/j.intell.2025.101920
    as

    Download full text from publisher

    File URL: http://www.sciencedirect.com/science/article/pii/S0160289625000236
    Download Restriction: Full text for ScienceDirect subscribers only
    File URL: https://libkey.io/10.1016/j.intell.2025.101920?utm_source=ideas
    LibKey link: if access is restricted and if your library uses this service, LibKey will redirect you to where you can use your library subscription to access this item
    ---><---

    As the access to this document is restricted, you may want to search for a different version of it.

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:eee:intell:v:110:y:2025:i:c:s0160289625000236. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    We have no bibliographic references for this item. You can help adding them by using this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: Catherine Liu (email available below). General contact details of provider: https://www.journals.elsevier.com/intelligence .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.