Mila Pak

Date of Award

January 2015

Document Type


Degree Name

Doctor of Philosophy (PhD)



First Advisor

Glenda N. Lindseth


Background and Purpose: Gallstones affect up to 15% of the U.S. adult population. Women are at greater risk for cholelithiasis, especially if they are overweight, over forty years of age, or have had children. The Veterans Health Administration (VHA) performed 114,653 cholecystectomy surgeries with 107,975 patients diagnosed with cholelithiasis from 2008 to 2013. Female veterans may be at even greater risk for cholelithiasis. However, research with this vulnerable population is sparse. Therefore, the purpose of this study was to examine physiological and environmental risk factors that may be associated with cholelithiasis among female veterans.

Study Design and Theoretical Framework: This retrospective case-control study examined the VHA electronic medical data for possible risk factors associated with cholelithiasis among female veterans. Wittenburg and Lammert’s model, describing factors contributing to cholesterol susceptibility, guided this study examining multifactorial influences that may precipitate cholelithiasis in a population of female veterans.

Sample Selection: Data representing samples of ethnically-diverse female veterans over 40 years of age were retrospectively randomly selected from the VHA data between January, 2008 and December, 2013. Study data were retrieved through the Veterans Affairs Informatics and Computing Infrastructure (VINCI) system from 242 patients assigned to each of the study groups based on presence of absence of cholelithiasis diagnosis.

Methods: Demographic, military service, comorbidity, and laboratory test data were analyzed for differences between the cholelithiasis and control groups. Data were further analyzed using multiple regressions to explore the relationship of risk factors to cholelithiasis occurrence.

Results: Tobacco use was significantly (p< .01) higher in female veterans with cholelithiasis than those without cholelithiasis. Also higher serum cholesterol (p < .01) and hemoglobin A1c (p< .01) levels were positively associated with female veterans experiencing cholelithiasis while lower High-Density Lipoprotein (HDL) blood levels were significantly related (p < .01) to cholelithiasis occurrence for the women. The women also had higher frequencies (p < .01) of hypertension and hepatitis C than those women without cholelithiasis. Results of multiple regression analysis indicated that serum cholesterol, hemoglobin A1c, and HDL levels accounted for 26 % of the variance for risk in female veterans developing cholelithiasis. Also, the women with a history of hypertension and hepatitis C had 2.5 times the risk of developing cholelithiasis than those without hypertension and hepatitis C.

Conclusions and Implications: Tobacco use, higher cholesterol and hemoglobin A1c levels, lower HDL levels, and a history of hypertension and hepatitis C were associated with increased risk for cholelithiasis occurrence in female military veterans. Understanding risk factors associated with cholelithiasis in military female veterans may promote patient-centered care and build preventive strategies in this rising but understudied population.