title: Predictive validity of Waterlow Scale for pressure ulcer development risk in hospitalized patients.
abstract: OBJECTIVE
  We sought to evaluate the predictive validity of the Waterlow Scale in hospitalized patients.
  
  
  METHODS
  The study was conducted at a general private hospital with 220 beds and a mean time of hospitalization of 7.4 days and a mean occupation rate of approximately 80%. Adult patients with a Braden Scale score of 18 or less and a Waterlow Scale score of 16 or more were studied. The sample consisted of 98 patients with a mean age of 71.1 + or - 15.5 years.
  
  
  METHODS
  Skin assessment and scoring by using the Waterlow and Braden scales were completed on alternate days. Patients were examined at least 3 times to be considered for analysis. The data were submitted to sensitivity and specificity analysis by using receiver operating characteristic (ROC) curves and positive (+LR) and negative (-LR) likelihood ratios.
  
  
  RESULTS
  The cutoff scores were 17, 20, and 20 in the first, second, and third assessment, respectively. Sensitivity was 71.4%, 85.7%, and 85.7% and specificity was 67.0%, 40.7%, and 32.9%, respectively. Analysis of the area under the ROC curve revealed good accuracy (0.64, 95% confidence interval [CI]: 0.35-0.93) only for the cutoff score 17 in the first assessment. The results also showed probabilities of 14%, 10%, and 9% for the development of pressure ulcer when the test results were positive (+LR) and of 3% (-LR) when the test results were negative for the cutoff scores in the first, second, and third assessment, respectively.
  
  
  CONCLUSIONS
  The Waterlow Scale achieved good predictive validity in predicting pressure ulcer in hospitalized patients when a cutoff score of 17 was used in the first assessment.
authors.affiliation: Health Professionals Education Coordinator, Oswaldo Cruz German Hospital, São Paulo, Brazil.
authors.forename: Letícia Faria
authors.initials: LF
authors.lastname: Serpa
authors.forename: Vera Lúcia Conceição
authors.initials: VL
authors.lastname: de Gouveia Santos
authors.forename: Gustavo
authors.initials: G
authors.lastname: Gomboski
authors.forename: Sandra Marina
authors.initials: SM
authors.lastname: Rosado
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D016001:Confidence Intervals; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006760:Hospitalization / Q000706:statistics & numerical data*; D006769:Hospitals, General; D006801:Humans; D015994:Incidence; D007902:Length of Stay; D008875:Middle Aged; D009730:Nursing Assessment / Q000379:methods*; D015403:Nursing Evaluation Research; D011237:Predictive Value of Tests; D003668:Pressure Ulcer / Q000175:diagnosis* / Q000453:epidemiology* / Q000451:nursing; D011336:Probability; D012372:ROC Curve; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D014945:Wound Healing / Q000502:physiology