Short summary

Background Demographic ageing and advances in medical care have resulted in more Intensive Care Unit (ICU) admissions among older adults, a group often burdened by frailty, comorbidity, and polypharmacy. Long-term health issues usually follow survival after ICU, but the effects on daily life and mortality are still not well understood. Methods This will be a nationwide register-based cohort study of Danish ICU patients aged ≥70 years with stays ≥48 hours and alive at discharge (2013-2023). Each

Rationale

The changes in demography show that, with the growth in the older population and advancements in medical treatment modalities, we are observing an increase in life expectancy [1]. This demographic shift presents a profound challenge to healthcare systems worldwide, as older people typically have increased frailty, polypharmacy, and a higher prevalence of chronic comorbidities. According to the increased risk of illness, an increasing number of older patients will be admitted to the Intensive Care Unit (ICU) [2]. It is known that the physical and psychological impact of an ICU stay on this patient group can be significant and prolonged, and can also exacerbate existing frailty [3, 4]. While survival rates have improved, the ability to regain their function level before admission to the ICU varies. Older patients who survive ICU admissions are at an increased risk of experiencing changes, according to a potential risk for significant long-term healthcare needs and morbidity with both cognitive and physical impairments [3, 5]. Frailty is a clinical condition characterised by increased reliance on and impaired physical functions, which is associated with poorer outcomes when exposed to clinical stressors such as hospitalisation. The use of healthcare services, including home care, is integrated into some validated frailty screening tools, as these provide essential information that helps guide treatment and care decisions [6, 7]. This indicates that a higher utilisation of home care facilities is linked to a greater risk of frailty [8] Co-morbidity refers to the co-occurrence of two or more health conditions within an individual. These conditions can exist independently or as interacting factors, influencing each other's progression. Co-morbidity is associated with an increased risk of poorer health outcomes, higher hospitalization rates and mortality [9, 10] Death and complete recovery represent two opposing outcomes of ICU care. However, survivors often experience sequelae from ICU admission. They cannot be considered fully recovered [11]. These changes frequently lead to a reduced quality of life and an increased use of psychoactive medication [12]. This age group can be particularly vulnerable to significant life changes and exhibits a higher mortality rate [13, 14]. Overall, the growing ageing population presents new challenges for clinical practice and public health [15, 16]. Rationale For this reason, research on life changes after discharge from the Intensive Care Unit (ICU) for patients over 70 years is crucial[17]. It can contribute to knowledge, inform clinical practice on what is essential for this vulnerable patient group, and enhance their quality of life. Hypothesis We hypothesize that older people will have a higher need for home care, an increased risk of changes in residential status, more comorbidities, greater medication use, and higher mortality after treatment in the ICU. However, the heightened risk of adverse health effects will likely diminish over time and may not return to the same level as before ICU treatment due to the disease or the treatment itself. Aim This study aims to investigate changes in life according to home care, comorbidity, residential status and medication use among older patients after discharge from ICU treatment. Additionally, the study seeks to compare mortality between patients who received ICU treatment and a control group matched for age and sex.

Description of the cohort

The study population consisted of older patients aged 70 years and above who had been treated in an ICU in Denmark for at least 48 hours and were discharged alive between 2013 and 2023. The 48-hour threshold was established to focus on patients with severe illnesses, excluding those admitted solely for extended post-operative observation or with less critical conditions. Individuals with ICU stays of less than 48 hours and those who died during ICU treatment were excluded. Each participant in the ICU group was matched with up to ten control individuals based on year of birth, sex, and region of residence to ensure comparability. Ten controls were selected per case to provide sufficient statistical power. The control group consisted of individuals aged 70 years and above who had not been admitted to an ICU during the same period. To reduce potential confounding from prior critical illness, a three-year washout period without ICU admissions was applied to both cases and controls. Both groups were followed up three and twelve months after ICU discharge to assess post-ICU health outcomes.

Data and biological material

Data from DID via RKKP, Statistic Denmark and The Danish Registration of Documentation on Services for the Elderly. Data extracted: Age, sex, civil status, prescription drug use, residential status, receipt of home care services, comorbidity and mortality

Collaborating researchers and departments

Internal medicine research unit, Department of Internal medicine, University Hospital of Southern Denmark, Aabenraa, Denmark

Internal medicine research unit, Department of Internal medicine, University Hospital of Southern Denmark, Aabenraa, Denmark