Statistical analysis of fasting blood sugar level of adult diabetic patients in Jimma university specialized hospital

ABSTRACT Introduction: Diabetes mellitus (DM) is a catabolic multisystem disease with both biochemical and anatomical consequences. It is a chronic disease of carbohydrate, fat and protein metabolism caused by either absolute lack of insulin or insulin resistance or secretors defects. Diabetes mellitus may present with characteristic symptoms such as thirst, polyuria, blurring of vision, and weight loss. Diabetes mellitus is a chronic disease with a high prevalence and a growing concern worldwide. More than 371 million people have diabetes in the world and now a day the burden is increasing particularly in developing countries. In Ethiopia, the number of deaths attributed to diabetes reached over 23,869.00 in 2012. Objectives: To fit an appropriate statistical model and identify associated factors of fasting blood sugar level of adult diabetic patients in Jimma University Specialized hospital. Methods: This study used data obtained from a retrospective cohort follow up study from adult diabetic patients who have been under follow up from 2011-2012 in Jimma University specialized hospital. All patients included in this study were those diabetic patients whose age 18 and above years and who have been followed at least two times. For fasting blood sugar measurement in mg/dL, a linear mixed model (LMM) approach was used to model the relationship of fasting blood sugar level and covariates over time. For the categorized fasting blood sugar level, Generalized Estimating Equation, Generalized Linear Mixed model, and Marginalized Multilevel model were used to assess whether good control of fasting blood sugar changed over time and to identify the associated factors of good control of fasting blood sugar level for diabetic patients. Result and Discussion: From the result of this study, fasting blood sugar level of adult diabetic patients decreased over time. Follow up time, weight, DBP and time interaction with weight are significant factors for fasting blood sugar level. Follow up time, weight, DBP and quadratic time interaction have significant factors for good control fasting blood sugar level of adult diabetic patients. Conclusion: Linear mixed model with quadratic time random effect fits well to the continuous measurement of fasting blood sugar level in mg/dL of adult diabetic patients and generalized models (GEE, GLMM and MMM) with quadratic time effect fits well for the categorized fasting blood sugar level.