#2449 Prevalence and determinants of chronic kidney disease among older community-dwelling adults in Ireland
Authors: Stack Austin , Tandan Meera , Browne Leonard , Rowan Colm , Moriarty Frank 
Published: May 2024

Abstract

Background and Aims
Chronic Kidney Disease (CKD) is a major global health challenge with substantial morbidity and mortality. In Ireland, a comprehensive understanding of the determinants of CKD is lacking, with limited data on the combined impact of socioeconomic and traditional risk factors. While the Irish Longitudinal Study on Ageing (TILDA) has offered insights into CKD burden, a detailed examination of its determinants remains unexplored. The goal of this study was to explore the prevalence and determinants of CKD at the community level within the Irish population.

Method
This is a retrospective cohort study that utilised cross sectional data from the first wave of TILDA conducted between 2009 and 2011. Participants aged 50 years and older who had health assessment and kidney function tests performed were included. The 2012 and 2021 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations were employed to calculate estimated glomerular filtration rates (eGFR) based on cystatin C and creatinine levels. CKD was classified as eGFR &lt; 60 ml/min/1.73 m². We determined the weighted prevalence of CKD using sample weights. Stepwise multivariable logistic regression models were used to identify correlates of CKD and models’ performance were assessed using AUC-ROC curves and the Akaike Information Criterion (AIC). Associations were expressed using adjusted odds ratios (AOR) with 95% confidence intervals (CIs).

Results
Among the 5 386 participants tested for cystatin C and serum creatinine, the weighted CKD prevalence was 11.3% based on the 2021 CKD-EPI definition (excluding race) and 13.9% using the 2012 definition. Prevalence was significantly higher in women than men, and increased with age, reaching about 45% in women over 71 years versus 29% in men. Burden of comorbid conditions in CKD individuals varied from 11% (for cancer) to 89% (for hypertension) and were significantly higher than non-CKD individuals (P&lt; 0.001). Adjusting for age, sex, education, and employment, the adjusted odds of CKD were significantly higher for individuals with hypertension AOR 2.15 (95% CI: 1.58–2.96), diabetes AOR 2.00 (95% CI: 1.50–2.66), cardiovascular disease AOR 1.72 (95% CI: 1.43–2.21), cancer AOR 1.64 (95% CI: 1.16–2.30), and obesity AOR 2.18 (95% CI: 1.61–2.96). The likelihood of CKD was also higher for patients with a hospital admission in the previous year AOR = 1.50 (95% CI: 1.14–1.96), possession of a medical card AOR 1.41 (95% CI: 1.06–1.89), and unemployed individuals AOR 1.61, (95% CI: 1.06–2.50), while the likelihood was significantly lower for individuals with a tertiary education (versus primary) AOR 0.73 (95% CI: 0.54–0.98). With further adjustment for medications, the magnitude of these associations was greatly attenuated with increasing odds of CKD for those receiving higher medication burden: 2-3 drugs AOR 2.02, (95% CI: 1.29–3.29), 3-4 drugs AOR 2.52 (95% CI: 1. 59–4.11), and &gt; 5 drugs AOR 4.49 (95% CI: 2.81–7.39) (see Fig. 1). The AUC score ranged from 0.84 to 0.88, indicating strong model performance.

Conclusion
This study brings renewed attention to observed variation in national estimates of CKD prevalence (11.3% vs 13.9%) that are derived from current prediction equations with important implications for the strategic planning and resourcing of CKD care. This study emphasises the impact of socioeconomic factors, such as health coverage and financial barriers to heath care, education attainment, and employment, on CKD beyond traditional risk factors. Furthermore, the attenuation of known risk factors with increasing medication use highlights the influence of these treatments on CKD dynamics. These findings provide valuable insights for targeted public health strategies and awareness programs in Irish communities to address the increasing burden of CKD.