Article Text

Prognostic utility of serum CRP levels in combination with CURB-65 in patients with clinically suspected sepsis: a decision curve analysis
  1. Shungo Yamamoto1,
  2. Shin Yamazaki1,
  3. Tsunehiro Shimizu2,
  4. Taro Takeshima1,3,
  5. Shingo Fukuma1,5,
  6. Yosuke Yamamoto1,
  7. Kentaro Tochitani2,
  8. Yasuhiro Tsuchido2,
  9. Koh Shinohara4,
  10. Shunichi Fukuhara1,5
  1. 1Department of Healthcare Epidemiology, School of Public Health in the Graduate School of Medicine, Kyoto University, Kyoto, Japan
  2. 2Department of Infectious Diseases, Kyoto City Hospital, Kyoto, Japan
  3. 3Division of Community and Family Medicine, Center for Community Medicine, Jichi Medical University, Tochigi, Japan
  4. 4Disease Control and Prevention Center, National Center for Global Health and Medicine, Tokyo, Japan
  5. 5Center for Innovative Research for Communities and Clinical Excellence (CIRC2LE), Fukushima Medical University, Fukushima, Japan
  1. Correspondence to Professor Shunichi Fukuhara; fukuhara.shunichi.6m{at}


Objectives The prognostic utility of serum C reactive protein (CRP) alone in sepsis is controversial. We used decision curve analysis (DCA) to evaluate the clinical usefulness of combining serum CRP levels with the CUBR-65 score in patients with suspected sepsis.

Design Retrospective cohort study.

Setting Emergency department (ED) of an urban teaching hospital in Japan.

Participants Consecutive ED patients over 15 years of age who were admitted to the hospital after having a blood culture taken in the ED between 1 January 2010 and 31 December 2012.

Main outcome measures 30-day in-hospital mortality.

Results Data from 1262 patients were analysed for score evaluation. The 30-day in-hospital mortality was 8.4%. Multivariable analysis showed that serum CRP ≥150 mg/L was an independent predictor of death (adjusted OR 2.0; 95% CI 1.3 to 3.1). We compared the predictive performance of CURB-65 with the performance of a modified CURB-65 with that included CRP (≥150 mg/L) to quantify the clinical usefulness of combining serum CRP with CURB-65. The areas under the receiver operating characteristics curves of CURB-65 and a modified CURB-65 were 0.76 (95% CI 0.72 to 0.80) and 0.77 (95% CI 0.72 to 0.81), respectively. Both models had good calibration for mortality and were useful among threshold probabilities from 0% to 30%. However, while incorporating CRP into CURB-65 yielded a significant category-free net reclassification improvement of 0.387 (95% CI 0.193 to 0.582) and integrated discrimination improvement of 0.015 (95% CI 0.004 to 0.027), DCA showed that CURB-65 and the modified CURB-65 score had comparable net benefits for prediction of mortality.

Conclusions Measurement of serum CRP added limited clinical usefulness to CURB-65 in predicting mortality in patients with clinically suspected sepsis, regardless of the source.


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