Joint Modeling of Longitudinal Systolic and Diastolic Blood Pressure Measurements of Hypertensive Patients Receiving Treatment

Hypertension is a chronic disease that has a major health problem over the centuries due to its signicant contribution to the global health burden. It is also called high blood pressure, described by two numbers Systolic blood pressure (SBP) and diastolic blood pressure (DBP). Hence, joint longitudinal model was used to address how the evolution of SBP is associated with the evolution of DBP. The objective was to investigate the joint evolution and association of SBP and DBP measurements of hypertensive patients and identify the potential risk factors aecting the two end points. In this this study 354 hypertensive patients with age greater than or equal to 18 years, who were on treatment, and who had measured at least three times were included. For a close examination of the separate and joint models, rst, each of the outcomes was analyzed separately using linear mixed model. Then, a joint model was considered to study the joint evolution and identify the potential risk factors aecting the two end points. Fit statistics showed that the joint model resulted in better t to the data than the separate models. Based on the joint model, sex, baseline age, and place of residence were the signicant factors for the progression of blood pressure, while family history and all the interaction term except age by time did not appear signicant. The result from the joint model suggested a strong association between the evolutions and a slowly increasing evolution of the association between SBP and DBP.