Abstract Introduction Atherosclerotic cardiovascular disease (ASCVD) and chronic kidney disease (CKD) are associated with a significant impact on healthcare systems. Elevated C-reactive protein (CRP) levels are a marker of systemic inflammation, which is common in people with ASCVD and CKD. Purpose To assess healthcare costs in UK individuals with ASCVD, CKD stages 3–4 or both by CRP levels. Methods To investigate all-cause mortality of UK individuals with ASCVD or CKD or both by level of systemic inflammation (defined by C-reactive protein CRP). Methods This was an observational study using the Discover database, an electronic health record research dataset covering approximately 95% of individuals living in North West London, UK. Mutually exclusive cohorts consisting of adults (≥ 18 years old) with a record of (i) ASCVD only; (ii) CKD stages 3–4 only; or (iii) both conditions were defined (Figure 1). Individuals entered the cohort when all eligibility criteria were met; index date was the date of the first eligible CRP measurement. A reference cohort of adults aged ≥ 50 years (to account for the high mean age of the clinical cohorts) with neither ASCVD nor CKD stages 3–5 was randomly sampled and the first CRP measurement used as index date (Figure 1). Each cohort was stratified into quartiles based on CRP levels. Per-person per-year (PPPY) direct healthcare costs were assessed annually between 2015 and 2019, with estimates age standardized using the 2013 European Standard Population. Results Cohorts with ASCVD (n=46,774), CKD stages 3–4 (n=16,723) or ASCVD and CKD stages 3–4 (n=15,765), and a reference cohort (n=99,999), were assessed. The proportion of women ranged from 43% (ASCVD cohort) to 64% (CKD stages 3–4); mean age ranged from 62.1 years (reference cohort) to 75.1 years (ASCVD + CKD stages 3–4). Median CRP levels ranged from 2.6 mg/L in the reference cohort to 4.0 mg/L in the ASCVD and CKD stages 3–4 cohort. PPPY healthcare costs were higher in all clinical cohorts than in the reference cohort (£1144 95% confidence interval 1144–1145), and highest in the cohort with ASCVD and CKD stages 3–4 (£6993 6818–7169) (Figure 2). Inpatient admissions were the main driver of costs across all cohorts, except for the reference cohort, for which prescription costs were the biggest contributor. Costs generally increased with CRP quartile from quartile (Q) 1 to Q4 within each cohort (Figure 2); costs were lowest in Q1 of the reference cohort (£769 PPPY 768–770) and highest in Q4 of the ASCVD and CKD stages 3–4 cohort (£8736 PPPY 8510–8962). Conclusion In this UK study, healthcare costs were highest for individuals with ASCVD and CKD stages 3–4 and were greater than the sum of the costs associated with each condition alone. Higher costs were observed for groups with higher CRP levels within each cohort. This highlights the potential utility of CRP for the identification of individuals with a high healthcare burden, beyond clinical characteristics.
Ray et al. (Sat,) studied this question.