Determinants of health care costs in the senior elderly: age, comorbidity, impairment, or proximity to death?

Ageing is assumed to be accompanied by greater
health care expenditures but the association is also viewed
as a ‘red herring’. This study aimed to evaluate whether
age is associated with health care costs in the senior
elderly, using electronic health records for 98,220 participants
aged 80 years and over registered with the UK
Clinical Practice Research Datalink and linked Hospital
Episode Statistics (2010–2014). Annual costs of health
care utilization were estimated from a two-part model;
multiple fractional polynomial models were employed to
evaluate the non-linear association of age with predicted
health care costs while also controlling for comorbidities,
impairments, and death proximity. Annual health care
costs increased from 80 years (£2972 in men, £2603 in
women) to 97 (men; £4721) or 98 years (women; £3963),
before declining. Costs were significantly elevated in the
last year of life but this effect declined with age, from
£10,027 in younger octogenarians to £7021 in centenarians.
This decline was steeper in participants with comorbidities
or impairments; £14,500 for 80–84-year-olds and £6752
for centenarians with 7? impairments. At other times,
comorbidity and impairments, not age, were main drivers
of costs. We conclude that comorbidities, impairments, and
proximity to death are key mediators of age-related
increases in health care costs. While the costs of comorbidity
among survivors are not generally associated with
age, additional costs in the last year of life decline with
age.