(120) Living alone and prognosis in elderly patients with chronic kidney disease: a nationwide study from Denmark

Background: Patient care is increasingly relying upon involvement of patient relatives, including for patients with chronic kidney disease (CKD). However, patients living alone may be disadvantaged due to a lack of support.

Objectives: We aimed to assess the difference in prognosis after incident CKD in elderly patients between patients living alone versus living with others in a nationwide cohort study.

Methods: We identified all patients aged 65 years or older with incident CKD from January 1, 2016, to December 31, 2020, with follow-up until December 31, 2021. We used data from national registries to identify CKD from out-patient creatinine measurements and linked these data to hospital treatment procedures and information from the Civil Person Registration system by the universal and unique personal identification number assigned to all Danish residents.
We defined incident CKD as having two or more estimated glomerular filtration rate (eGFR) values below 60 ml/min/1.73 m2 registered at least 90 days apart. We categorized eGFR according to “Kidney Disease: Improving Global Outcomes” (KDIGO) CKD stages into 45-59 ml/min/1.73 m2 (mildly/moderately decreased), 30-44 ml/min/1.73 m2 (moderately/severely decreased), 15-29 ml/min/1.73 m2 (severely decreased), < 15 ml/min/1.73 m2 (kidney failure).
We assessed cohabitation (living alone, or living with others), also in national registry data. We described the population by age group, sex and stage of CKD. Analyzing mortality, we followed patients from date of CKD to death or end of follow-up, whichever came first. We calculated the median time to death, using age as the time scale and reported these by cohabitation status with 95% confidence intervals (CIs).
In further analyses, we will estimate the cumulated proportion who experienced a rapid decline in kidney function, as a measure of prognosis, and model the association between cohabitation and prognosis/mortality in regression models.

Results: We identified 204,662 elderly patients with CKD from 2016 to 2020, with 55% women and 38% 80 years or older. For severity, 84 % had mildly/moderately decreased kidney function, 13% had moderately/severely decreased kidney function, 2 % had severely decreased kidney function and only less than 1% (457 patients) presented with kidney failure.
At index, 55% lived with others and 45% lived alone. Overall, 53,715 died during follow-up, and median age at death was 82 (95% CI: 82;82) for CKD patients living together with someone, but 78 (95% CI: 77;78) for those living alone.

Conclusions: The results are preliminary, and further analyses, including age adjustment, mortality estimates and information on adult children, will be available for presentation at the ISPE conference 2024.