#1241 Healthcare resource utilisation in adults with chronic kidney disease by KDIGO categorisation in England: 2010-2019
Authors: Cockwell Paul , Farmer Ruth , Popoola Remi , Muttram Louise , Shay Christina 
Published: May 2024

Abstract

Background and Aims
Chronic kidney disease (CKD) is associated with high clinical burden for patients and substantial economic costs for healthcare systems. Detailed estimates of healthcare resource utilization (HCRU) for patients with CKD in the UK are limited, particularly by stage of CKD. This study assessed outpatient and non-elective inpatient HCRU by stage of CKD in England.

Method
This non-interventional study utilised data from primary care electronic health records from Clinical Practice Research Datalink (CPRD) AURUM and Hospital Episode Statistics (HES) admitted patient care (APC). Patients aged ≥18 years registered in CPRD with eligible linkage to HES between January 1, 2010 and December 31, 2019 with 2+ eGFR measurement during the period were identified. CKD was defined by eGFR &lt;60 ml/min/1.73 m2 and/or presence of a uACR measurement ≥3 mg/mmol, both confirmed by a second measurement 90-365 days later. Start of follow-up (index) was set to the earliest date during the study period that CKD was confirmed. Follow-up for HCRU ended at earliest of death, administrative censoring, or 31st December 2019. Patients with end-stage kidney disease (eGFR &lt;9 ml/min/1.73 m2) at index were excluded. Number of HCRU events for each HCRU category was estimated as rates per 1,000 person years (PY) for each calendar year based on cumulative number of events. Event rates were calculated as number of outcomes/total time at risk. Confidence intervals (95%) were calculated assuming a Poisson distribution. Age- and sex-adjusted rates were calculated to compare rates across CKD stages.

Results
Of 6.1 million adult patients meeting study inclusion criteria, 743,945 adults (12.2%) with CKD were identified. Mean age (SD) was 76.1 (11.5) years, 55.2% were female, and 89.8% White, contributing a total of 3,055,600 years of follow-up. Most (60.9%) patients had stage 3a CKD (eGFR 45-&lt;59 ml/min/1.73 m2). Among patients with uACR measurements (44.4%), 48.0% were A1 (&lt;3 mg/mmol), 44.4% A2 (3-30 mg/mmol), and 7.6% A3 (&gt;30 mg/mmol). Overall, per 1000 PY, there were 24,763 primary care visits, 475 non-elective all-cause hospitalisations, 4,950 attended (722 unattended) outpatient visits, including 308 (43 unattended) outpatient nephrology visits and 368.1 attended (61.2 unattended) cardiology visits. For all HCRU categories, greater KDIGO risk category at index was associated with higher HCRU. For example, after age and sex adjustment, patients with CKD stage 3b had a mean of 0.53/PY non-elective all-cause hospitalisations compared to 0.77/PY for patients with CKD stage 4. Additionally, a mean of 5.18 outpatient visits per PY was observed for patients with CKD stage 3b, of which 0.91 were nephrology outpatient visits compared to 8.39 outpatient visits per PY for stage 4, of which 2.65 were nephrology outpatient visits. Generally, both lower eGFR and higher uACR were individually associated with higher HCRU.

Conclusion
This study demonstrates high HCRU for patients with CKD, with increasing rates of HCRU with lower kidney function and greater kidney damage. Patients with more advanced CKD contribute at a disproportionally higher rate of outpatient healthcare encounters and non-elective hospitalisations. Efforts to prevent the development and progression of CKD and improving clinical outcomes will reduce frequency and cost of HCRU.