Application of Shewhart Control Chart to Analyze the Effect of Income on Body Mass Index and Blood Pressure

Abstract

This study investigates whether the level of income influences body mass index and blood pressure and we also determine whether there is a positive or negative correlation between the study variables (income, body mass index, and blood pressure). The Shewhart control chart procedure was applied to determine the effect of income on body mass index and blood pressure on subgroup categories. The Pearson correlation procedure was used to determine the relationship between the study variables. The findings showed that the percentage of high income earners is higher with respect to normal body mass index (normal weight) than middle and low-income earners, respectively. The result also revealed that the percentage of low-income earners with normal blood pressure is higher compared to middle and high-income earners. The analysis indicates that the percentage of elevated blood pressure and hypertension is higher for middle and high-income earners than low-income earners. The result showed a weak negative correlation (r =-0.33) between income and BMI and a very strong positive correlation (r = 0.88) between income and blood pressure. This study concludes that the level of income influences body mass index and blood pressure based on working-class categories and lifestyle.