Advisory Committee Chair
Advisory Committee Members
Michael J Hardin
Date of Award
Degree Name by School
Doctor of Philosophy (PhD) School of Health Professions
Benign lipomas are the most common soft tissue tumors. They exhibit great variation in severity and are associated with significant comorbidity. Advanced understanding of genetic and morphological aspects of benign lesions has revealed unexpected similarities to malignant lesions, but little work has addressed variation among benign lesions. There is a need for better understanding of the effects of variation in lipomas on comorbidity, treatment, and outcomes. Improved knowledge of the effects will clarify the extent of the health and economic burden that severe forms of benign lipomas present to patients and society and may add to understanding of malignant lesions. Variation in anatomical location of lipomatous tissue is identified as the primary characteristic associated with variation in outcomes. Data from the 2005 Nationwide Inpatient Sample (NIS) were used for analyses. Lipomas, comorbidity, and treatment were measured with diagnosis and procedure codes and processed using Clinical Classifications Systems (CCS) software to produce clinically meaningful categories. Outcome measures included in-hospital death, adverse medical events, and costs of care. Lipomas were associated significantly with comorbidity and with medical treatment, controlling for comorbidity. Positive correlations occurred with 27 specific health conditions. Additional correlations included odds ratios less than one, but greater than incidence rates in the sample or population. Positive correlations occurred with 11 treatment groups. Patients who died while hospitalized and patients who experienced adverse medical events while hospitalized were less likely to have lipomas than to not have them. However, for both measures, the odds for having lipomas were greater than expected from incidence rates estimated for the general population or the sample. Lipomas were associated with increased odds for costs of care within the upper ranges, when controlling for comorbidity and treatment. Findings indicate that lipomas are associated closely with increased comorbidity and treatment and that the incidence of lipomas is high among those experiencing adverse medical events and those who die during in-patient treatment. In addition, for those with lipomas, costs of care fall disproportionately within the higher ranges. Although many case reports have documented these associations, the relationships had not been analyzed, previously, using nationwide data.
Keel, Theresa L., "Lipomatous Tissue: Variation in Treatment Procedures, Comorbidities, and Outcomes" (2008). All ETDs from UAB. 276.