The effects of CRP-to-prealbumin and CRP-to-albumin ratios and other laboratory-derived indices on clinical outcomes in the oldest-old patients in a geriatric ward: A retrospective observational study

Abstract

This study explores the prognostic value of several inflammation-based indices—C-reactive protein (CRP)-to-albumin ratio (CAR), CRP-to-prealbumin ratio (CPR), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio, monocyte-to-lymphocyte ratio, and mean platelet volume-to-lymphocyte ratio (MPVLR)—in hospitalized patients aged 80 years and older. A total of 133 patients were retrospectively analyzed. The in-hospital mortality rate was 11.3%, and the median length of hospital stay was 15 days. Patients who died were significantly older and had higher CAR, CPR, NLR, and MPVLR levels compared to survivors (p < 0.05 for all). In multivariate Cox regression analysis, CAR (HR = 1.671, p = 0.021), NLR (HR = 1.175, p = 0.006), and MPVLR (HR = 1.169, p = 0.007) emerged as independent predictors of in-hospital mortality. Receiver operating characteristic curve analysis demonstrated moderate discriminative ability for these indices: NLR (area under the curve (AUC) = 0.777, cutoff >3.12, p < 0.001), CAR (AUC = 0.721, cutoff >0.99, p < 0.001), MPVLR (AUC = 0.689, cutoff >9.82, p = 0.006), and CPR (AUC = 0.676, cutoff >187.8, p = 0.009). These findings suggest that inflammatory indices—particularly NLR, CAR, and MPVLR—may serve as accessible and clinically relevant prognostic tools in very old-hospitalized patients.