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A new predictive indicator for development of pressure ulcers in bedridden patients based on common laboratory tests results
  1. N Hatanaka1,4,
  2. Y Yamamoto1,
  3. K Ichihara2,
  4. S Mastuo1,
  5. Y Nakamura3,
  6. M Watanabe4,
  7. Y Iwatani4
  1. 1
    Department of Clinical Pathology, Tenri Hospital, Nara, Japan
  2. 2
    Faculty of Health Sciences, Yamaguchi University Medical School, Ube, Japan
  3. 3
    Department of Operation, Tenri Hospital, Nara, Japan
  4. 4
    Department of Biomedical Informatics, Division of Health Science, Osaka University Graduate School of Medicine, Osaka, Japan
  1. Ms Noriko Hatanaka, Department of Clinical Pathology, Tenri Hospital, 200 Mishima-cho, Tenri, Nara 632-8552, Japan; hattan7{at}


Background: Various scales have been devised to predict development of pressure ulcers on the basis of clinical and laboratory data, such as the Braden Scale (Braden score), which is used to monitor activity and skin conditions of bedridden patients. However, none of these scales facilitates clinically reliable prediction.

Aims: To develop a clinical laboratory data-based predictive equation for the development of pressure ulcers.

Methods: Subjects were 149 hospitalised patients with respiratory disorders who were monitored for the development of pressure ulcers over a 3-month period. The proportional hazards model (Cox regression) was used to analyse the results of 12 basic laboratory tests on the day of hospitalisation in comparison with Braden score.

Results: Pressure ulcers developed in 38 patients within the study period. A Cox regression model consisting solely of Braden scale items showed that none of these items contributed to significantly predicting pressure ulcers. Rather, a combination of haemoglobin (Hb), C-reactive protein (CRP), albumin (Alb), age, and gender produced the best model for prediction. Using the set of explanatory variables, we created a new indicator based on a multiple logistic regression equation. The new indicator showed high sensitivity (0.73) and specificity (0.70), and its diagnostic power was higher than that of Alb, Hb, CRP, or the Braden score alone.

Conclusions: The new indicator may become a more useful clinical tool for predicting presser ulcers than Braden score. The new indicator warrants verification studies to facilitate its clinical implementation in the future.

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  • Competing interests: None declared.

  • Ethics approval: The study protocol was approved by the ethics committee.

  • Patient consent: Patients provided informed consent for their participation in the study.