D- OPTIMAL DESIGN IN APPLICATION TO ANTI-HYPERTENSIVE DRUG TREATMENT REGIMEN

Abstract

Statistics is a unique discipline that is relevant to all the field of study because of the tools that it has which can help in solving problems. This research work was on the application of one of the tools in statistics to clinical trials especially in the area of drug dosage. The research work was meant to develop a D-optimal design for combination of anti-hypertensive drug while the objectives were to determine the D-optimal design for linear regression model using D-criterion and the relative efficiencies of other designs to the optimal design. The data employed for the research work were secondary data and were collected from the case notes of some sampled patients with diagnosed hypertension. In this research, there were two (2) design variables each with (having) the following levels: 𝑋1 with 4 dose levels where X1= Aldomet and level 1 =500𝑚𝑔; level 2 =750𝑚𝑔; level 3 =1000𝑚𝑔; level 4 =1500𝑚𝑔 𝑋2 with 2 dose levels where X2= Lisinopril and level 1 =10𝑚𝑔, level 2 =20𝑚𝑔 Due to resource limitations, only n=12 data points were collected. Due to ethical constraints, 7 design points were generated instead of 8 design points because the supposed design points 8 would have adverse effects on the patient. Twenty one (21) designs were created out of which the alphabetic optimality criterion (D- optimality) was used in determining the optimal design where the optimal design was the design with the largest determinant of the information matrix. Another twenty one (21) designs were created that allowed for pair wise comparison of treatment. The result showed that the optimal design was the design that had equal weights for the least design point (-1) and the largest design point (1). The information gained from the research work shows that a patient administered with Aldomet 250mg twice daily (bd), Lisinopril 10mg daily will give positive response to treatment. Also, Aldomet 500mg twice daily (bd) and Lisinopril 20mg daily will reduce the hypertension of a patient that has been diagnosed of high blood pressure