Abstract
Background and Aims:
Chronic Kidney Disease (CKD) typically co-exists with multiple long-term conditions (LTCs). The impact of CKD combined with multiple LTCs on hospitalisation rates is not known. We hypothesised that hospitalisation rates would be high in people with multiple LTCs, particularly in those with CKD. We also hypothesised that the association between multiple LTCs and hospitalisation would be greatest in subgroups and with certain patterns of LTCs.
Method:
Two cohorts were studied in parallel: UK Biobank (2006-2019) and Secure Anonymised Information Linkage Databank (SAIL: 2011-2018, Wales, UK). UK Biobank is a prospective research cohort. SAIL is a routine care database. Participants were included if their kidney function was measured at baseline. LTCs were obtained from self-report (UK Biobank) and primary care read codes (SAIL). Participants were categorised into zero, one, two, three and four or more LTCs with and without CKD. CKD was defined as estimated glomerular filtration rate less than 60 ml/min/1.73m2 (single blood test for UK Biobank, two blood tests three months apart for SAIL). Hospitalisation events were obtained from linked hospital records.
Results:
Among 469,344 of 502,503 UK Biobank participants, those without CKD had a median age of 58 and a median of 1 LTC. Those with CKD had a median age of 64 and a median of 2 LTCs. Among 1,620,490 of 2,768,862 SAIL participants, those without CKD had a median age of 50 and a median of 1 LTC. Those with CKD had a median age of 79 and a median of 4 LTCs. Participants with four or more LTCs had high event rates (Rate Ratios (RRs) 5.35 (95% CI 5.20-5.51)/3.77 (95% CI 3.71-3.82)) with higher rates in CKD (RRs 8.99 (95% CI 8.47-9.54)/9.92 (95% CI 9.75-10.09)).
Amongst those with CKD, the association between each increase in LTC count and hospitalisation was greatest in those under the age of 50 (RRs 1.93 (95% CI 1.73-2.16)/1.35(95% CI 1.29-1.41)). Event rates were highest in those with eGFR<30ml/min/1.73m2, but the impact of multiple LTCs was weaker in these participants compared to those with higher eGFRs.
Event rates were high in certain patterns of LTCs: cardiometabolic LTCs (RRs 4.45 (95% CI 4.02-4.92)/2.81 (95% CI 2.71-2.91)), complex patterns (RRs 3.60 (95% CI 3.26-3.96)/2.91 (95% CI 2.81-3.01)) and physical/mental LTCs (RRs 3.30 (95% CI 2.86-3.80)/3.18 (95% CI 3.06-3.30)).
Conclusion:
People with multiple LTCs have high rates of hospitalisation and the rates are augmented in those with CKD. The impact of multiple LTCs is greatest in younger patients and in those with certain patterns of LTCs. Strategies should be developed to prevent hospitalisations in these high-risk groups.
Hospitalisation Events by Chronic Kidney Disease (CKD) status and number of Long-term conditions (LTCs) in UK Biobank
Hospitalisation Events by Chronic Kidney Disease (CKD) status and number of Long-term conditions (LTCs) in SAIL
Perspectives from health, social care and policy stakeholders on the value of a single self-report outcome measure across long-term conditions: a qualitative study
