Red Cell Distribution Width as an Independent Predictor of Long-Term Mortality in Hip Fracture Patients: A Prospective Cohort Study

Abstract

Red blood cell distribution width (RDW) has been found to be a significant prognostic factor of mortality in many cardiovascular diseases. However, a link between RDW at admission with long-term mortality in the hip fracture population has not been well established. Therefore, we sought to evaluate the long-term prognostic value of RDW in a well-defined hip fracture cohort, and to compare the effect of RDW in patients with and without anemia. A prospective cohort study was performed on 1479 hip fracture patients admitted at the General Hospital of Chinese PLA between January 2000 and October 2011 with a follow-up study over a 2-year period. A total of 1479 patients were used for the evaluation of 2-year all-cause mortality, while 804 patients with more than 4 years of follow-up were extracted for further evaluation of 4-year all-cause mortality. Cox proportional regression was used to evaluate the association between admission RDW and long-term mortality, adjusting for potential confounding variables. Higher RDW values were strongly associated with increased all-cause mortality. After adjusting for age, mean corpuscular volume, admission hemoglobin, comorbidities, and complications, RDW had a significant independent association with both 2-year mortality with a hazard ratio (HR) of 1.183 (95% confidence interval [CI], 1.017 to 1.376) and 4-year mortality with an HR of 1.244 (95% CI, 1.052 to 1.471). In stratified analysis, the effect of RDW was even more pronounced, with 2-year mortality HR of 1.341 (95% CI, 1.095 to 1.643) and 4-year mortality HR of 1.345 (95% CI, 1.071 to 1.688) in non-anemic patients. In non-anemic patients, elevated RDW values are significantly associated with increased odds of all-cause mortality, implying that RDW may be a possible laboratory biomarker for risk stratification in non-anemic hip fracture patients. Further studies are needed to confirm the current finding in different and larger hip fracture cohorts.

Red Cell Distribution Width Is a Risk Factor for Hip Fracture in Elderly Men Without Anemia

“…Previous studies have recently reported that higher RDW values are related to poor health outcomes for several aging‐related diseases in the elderly population, particularly cardiovascular disease, stroke, and mortality . Few studies have also provided the associations between RDW values and conditions related to musculoskeletal diseases: Higher RDW values were related to poor postoperative outcomes of patients with hip fractures, and people with prevalent morphometric vertebral fractures have higher RDW levels compared with those without such fractures . Together with previous other studies, our findings support that RDW could have clinical meaningful values in the associations with aging‐related conditions, beyond its hematologic usages.…”

Combination of measures of handgrip strength and red cell distribution width can predict in-hospital complications better than the ASA grade after hip fracture surgery in the elderly

“…The results of our report are substantially supported by recent studies. Previous reports regarding the clinical significance of RDW and grip strength as a surrogate indicator of complications support the claims of the current study [ 4 , 25 , 26 ]. The ability to forecast long-term complication after hip fracture only by RDW have proved effective in one prospective cohort study [ 25 ].…”

Prognostic Value of Red Blood Cell Distribution Width in Non-Cardiovascular Critically or Acutely Patients: A Systematic Review

“…Ten studies provided data on AUC [14–20, 37–39, 41], and its value between 0.61 and 0.82. Finally, four studies reported RDW as a categorical variable [13, 17, 22, 42]. We also found the RDW levels were significantly associated with morality with a rank correlation.…”

“…Among the 32 included studies, 6 studies belonged to the group A [1, 2, 9–11, 38], 9 studies belonged to the group B [23–25, 27–29, 31–33], and 17 studies belonged to the group C [13–22, 36, 37, 39–43]. As for the effect size, RDW was reported as a continuous variable (per 1% increase) in 16 studies [1, 9–11, 16, 17, 21–23, 29, 31, 32, 36, 37, 40, 43], as a binary variable in 8 studies [14, 16, 18, 19, 26, 33, 36, 40], and as a categorical variable in 8 studies [2, 13, 17, 22, 25, 27, 29, 42]. The AUC of RDW for mortality prediction was reported in 25 studies.…”