CRP and kidney disorder: 28-day mortality subgroup analysis of those with a Stage 3a-5 kidney disease found that: first wave patients; aged 85–94, female sex; never and current smoker; CRP ≥ 40 mg/dL; no hypertension; no diabetes; coronary artery disease; and CFS 4 were associated with increased mortality (Additional file 1: Fig. 2).