Red Cell Distribution Width (RDW) is a predictor of mortality in the general population. The prevalence of increased RDW and its significance in the intensive care unit are unknown. Objective To investigate the association between RDW at the initiation of critical care and all cause mortality Design Multicenter observational study Setting Two tertiary academic hospitals in Boston, Massachusetts Patients 51,413 patients, age ≥ 18 years, who received critical care between 1997 and 2007 Measurements The exposure of interest was RDW and categorized a priori in quintiles as ≤13.3%, 13.3–14.0%, 14.0–14.7%, 14.7–15.8%, and >15.8%. Logistic regression examined death by days 30, 90 and 365 post-critical care initiation, in-hospital mortality and bloodstream infection. Adjusted odds ratios were estimated by multivariable logistic regression models. Adjustment included age, sex, race, Deyo-Charlson index, CABG, MI, CHF, hematocrit, WBC, MCV, BUN, red blood cell transfusion, sepsis and creatinine. Interventions None Key Results RDW was a particularly strong predictor of all cause mortality 30 days following critical care initiation with a significant risk gradient across RDW quintiles following multivariable adjustment: RDW 13.3–14.0% OR 1.19 (95% CI, 1.08–1.30; P<0.001); RDW 14.0–14.7% OR 1.28 (95% CI, 1.16–1.42; P<0.001); RDW 14.7–15.8% OR 1.69 (95% CI, 1.52–1.86; P<0.001); RDW > 15.8% OR 2.61 (95% CI, 2.37–2.86; P<0.001); all relative to patients with RDW ≤13.3%. Similar significant robust associations post multivariable adjustments are seen with death by days 90 and 365 post-critical care initiation as well as in-hospital mortality. In a sub-analysis of patients with blood cultures drawn (n= 18,525), RDW at critical care initiation was associated with the risk of bloodstream infection and remained significant following multivariable adjustment. The adjusted risk of bloodstream infection was 1.40- and 1.44-fold higher in patients with RDW values in the 14.7–15.8% and >15.8% quintiles, respectively, compared with those with RDW ≤13.3%. Estimating the ROC AUC shows that RDW has moderate discriminative power for 30-day mortality (AUC = 0.67). Conclusion RDW is a robust predictor of the risk of all cause patient mortality and bloodstream infection in the critically ill. RDW is commonly measured, inexpensive and widely available and may reflect overall inflammation, oxidative stress, or arterial underfilling in the critically ill.

Objective We hypothesized that deficiency in 25-hydroxy vitamin D (25(OH)D) prior to hospital admission would be associated with all cause mortality in the critically ill. Design Multicenter observational study of patients treated in medical and surgical intensive care units. Setting 209 medical and surgical intensive care beds in two teaching hospitals in Boston, Massachusetts Patients 2,399 patients, age ≥ 18 years, in whom 25(OH)D was measured prior to hospitalization between 1998 and 2009. Measurements Pre-admission 25(OH)D was categorized as deficiency in 25(OH)D (≤15ng/mL), insufficiency (16–29ng/mL) and sufficiency (≥30ng/mL). Logistic regression examined death by days 30, 90 and 365 post-ICU admission, in hospital mortality and blood culture positivity. Adjusted odds ratios were estimated by multivariable logistic regression models. Interventions None Key Results Pre-admission 25(OH)D deficiency is predictive for short term and long term mortality. 30 days following ICU admission, patients with 25(OH)D deficiency have an OR for mortality of 1.69(95%CI, 1.28–2.23;P<.0001) relative to patients with 25(OH)D sufficiency. 25(OH)D deficiency remains a significant predictor of mortality at 30 days following ICU admission following multivariable adjustment (adjusted OR 1.69; 95%CI, 1.26–2.26;P<.0001). 30 days following ICU admission, patients with 25(OH)D insufficiency have an OR of 1.32(95%CI, 1.02–1.72; P=0.036) and an adjusted OR of 1.36(95%CI, 1.03–1.79;P=0.029) relative to patients with 25(OH)D sufficiency. Results were similar at 90 and 365 days following ICU admission and for in hospital mortality. In a subgroup analysis of patients who had blood cultures drawn (n=1,160), 25(OH)D deficiency was associated with increased risk of blood culture positivity. Patients with 25(OH)D insufficiency have an OR for blood culture positivity of 1.64(95%CI, 1.05–2.55;P=0.03) relative to patients with 25(OH)D sufficiency which remains significant following multivariable adjustment: OR 1.58(95%CI, 1.01–2.49;P=0.048). Conclusion Deficiency of 25(OH)D prior to hospital admission is a significant predictor of short and long term all cause patient mortality and blood culture positivity in a critically ill patient population.