Nutrition and Health Sciences, Department of


Date of this Version



A DISSERTATION Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Doctor of Philosophy, Major: Interdepartmental Area of Nutrition. Under the Supervision of Professor Nancy M. Lewis.
Lincoln, Nebraska: July, 2009
Copyright © 2009 Paula K Ritter-Gooder


The purpose of this study was to validate content of the Nutrition Diagnostic Term NC- 3.2 Involuntary Weight Loss using expert raters. This descriptive survey invited all Board Certified Specialists in Gerontological Nutrition (CSG) to participate by mail. An instrument was developed that included the definition, etiologies, and signs and symptoms of the diagnosis with items added from literature review. CSG rated how common or characteristic each item is to the diagnosis using a 5 point Likert scale. A weighted response for each item was used to calculate a Diagnostic Content Validity (DCV) score. DCV scores of 0.80 and above were classified as major characteristics, 0.50 to 0.799 were minor characteristics, and those scoring below 0.50 were unrepresentative of the diagnosis. A mean total DCV score was calculated using the major and minor characteristics. Dietitians were asked to comment on clarity and completeness of the language. Seventy three percent of CSG (n=110) had participated, 43% percent had an MS degree or higher level of education. Reported years of practice in gerontological nutrition were 15±10 years (mean ± SD). The DCV score was 0.80 for the definition, 0.63 for the etiologies, and 0.69 for signs and symptoms. Total DCV score for the diagnostic term was 0.69. Thirty six percent and 40% of the CSG recommended adding language to etiologies and signs and symptoms respectively. Results indicate the majority of items were valid to the diagnostic term but responses for adding items need further investigation in clinical testing, the next phase of validation.
Advisor: Nancy M. Lewis