| Objective:to compare the validity and efficiency of the Braden Scale and Norton Scale used to assess the risk of pressure ulcer on patients receiving abdominal surgery after general anesthesia, to provide a more efficient tool to reduce the incidence of pressure sore of postoperative patients, to enables nurses to identify the potential risk of pressure ulcer on patients as well as to take targeted precautions for the high-risk patients and to rationally allocate limited health resources.Method:A prospective cohort study and convenience sample was used to investigate120patients with abdominal surgery after general anesthesia by using both scales (Braden and Norton Scales) from two surgery departments of a first grade hospital in Tianjin from June to September in2011. Data was collected by assessing the risk of pressure ulcer, observing changes of skin condition from the day of surgery to the6th day post operation(Do-D6). Data was analyzed by SPSS software V18.0, using Cronbach’s alpha for internal consistency reliability, factor analysis for construct validity and ROC curve for the comparison of predictive validity of the two scales.Results:A total of9patients had suffered from pressure ulcer with the incidence of7.5%. Except the results of Do, the rest6Cronbach’s alpha coefficients of Norton scale lied between0.531～0.698while Braden’s respectively lied between0.555～0.827, which meant the Cronbach’s alpha coefficient of Braden scale was higher than that of Norton scale. The Cronbach’s alpha coefficients of the Braden scale set in0.609-0.784when removing its each item at a time, while the coefficient came to the highest0.784when removing the item’nutritional condition’. The Cronbach’s alpha coefficients of Norton scale lied between0.349-0.565when removing its each item at a time, the coefficient became the highest0.784when removing the item’ consious condition’. Each Pearson correlation coefficient of Braden scale and Norton scale of the D0-D6all showed statistical significance (r=0.469-0.886, P<0.01). The correlation coefficient of Braden scale set between0.479-0.886, comparing that of Norton score lying in0.469～0.866. When Braden scale and Norton scale analyzed by Varimax, the overall cumulative variance contribution rate was respectively92.637%and57.710%(eigenvalues>1). The factor loadings of Norton scale and Braden scale for each item spreaded in0.310～0.960,0.339～0.955. The factors of the two scales were basically the same with the originals. The area under the ROC curve (AUC) of Norton Scale was0.721～0.819from D0-D6, while the area reached the maximum on D3and it was the minimum on Do. Similarly, the AUC of Braden scale ranged from0.608to0.800, in which the area was the maximum on D3and it was the minimum on Do. Each P value of Norton scale on AUC of the7days was below0.05. However, except on Do and D1, P value of Braden scale on AUC of the rest5days was above0.05.,which meant a significant importance on diagnosis of pressure sores postoperatively. The nurses took measures like keeping the bed units clean and dry and helping turning over to reduce the pressure every other2hours for all patients, and4patients were given other measures:2patients using hydrocolloid dressing,1patients with local massage and one using a soft pillow protection.Conclusion:The Cronbach’s alpha of Braden scale for overall internal consistency was higher than that of Norton scale. The ’nutritional condition’ of Braden seal and the ’conscious condition’ of Norton Scale were sugguested to be adjusted given the results. As far as the overall internal consistency, Braden Scale was better than Norton Scale. With the recovery from the surgery, there was an increased correlation between two scales. However, the two scales had their own advangtages and disadvantages on reliability which means there was a lot can be done to improve the reliability of the two scales. The overall cumulative variance contribution rate of factors of Norton Scale was lower than that of Braden after varimax. The factor construct of Braden Scale was nearly the same with the original, which meanhe recommended diagnostic critical values, the sensitivity and specificity of two scales were not as good as what expected. Hence, when applied to different population, the diagnostic critical values should depend on specific circumstances. Given the results of AUC, the diagnostic value of the two scales unable to meet the need to provide precaution in the early stages. As shown above, Braden Scale was better than Norton Scale in discriminant validity and construct validity, while with less ideal predictive validity in patients with abdominal surgery undergoing general anesthesia, which might be affected by better preoperative physical activity, mobilization, nutritional condition of patients receiving selected operation as well as the acute and temperary condition with limited mobility postoperatively. For clinic work, the nurses took precations for pressure ulcer mainly depending on individual experience which brought blindness. |
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