Validity and reliability of the braden scale and the influence of other risk factors: a multi-centre prospective study

The Braden scale is one of the most intensively studied risk assessment scales used in identifying the risk of developing pressure sores. However, not all studies show that the sensitivity and specificity of this scale is sufficient. This study, therefore, investigated whether adding new risk factors can enhance the sensitivity and specificity of the Braden scale. The Braden scale was tested in a prospective multi-centre design. The nurses of 11 wards filled in the Braden scale every 5 days for each patient who was admitted without pressure sores and who had a probable stay of at least 10 days. Based on a literature study and in-depth interviews with experts, the Braden scale was extended by the risk factor blood circulation. In addition, other risk factors, which are more or less stable patient characteristics, were measured during the admission of the patient. Independent research assistants measured the presence of pressure sores twice a week. As the external criterion for the risk of developing pressure sores, the presence of pressure sores and/or the use of preventive activities was used. Results showed that the original Braden scale was a reliable instrument and that the sensitivity and specificity was sufficient. However, reformulating the factors moisture and nutrition, and adding the risk factor age could enhance the sensitivity and specificity. Furthermore, results showed that the factors sensory perception, and friction and shear were especially important risk factors for the Braden scale. In fact, using only the factors sensory perception, friction and shear, moisture (a reformulated factor) and age give the highest explained variance of the risk of developing pressure sores. The added risk factor blood circulation, did not enhance the sensitivity and specificity of the original Braden scale. Suggestions are given on how to use risk assessment scales in practice.