CHI-SQUARE ANALYSIS

Behavioral Risk Factor Surveillance System - Chi-Square Analysis

Behavioral Risk Factor Surveillance System - Chi-Square Analysis

Introduction

Centre for Disease Control and Prevention established Behavioral Risk Factor Surveillance System to gather information about the health condition U.S. adults. Main objective of this survey is to determine the impact of random and consequential conditions, including behavior of US adults on preventive health practices, health risk behaviors, and primary health condition that links with numerous health issues, such as obesity, high cholesterol, heart diseases, diabetes, cancer, and injuries.

The data has been taken from the Behavioral Risk Factor Surveillance System (BRFSS) 2005 Cross Panel Data. Three variables have been selected from the entire data set for this research paper. These include “Cholesterol: High cholesterol risk factor” as Dependent Variable, “Phys. Activity Level of Respondents” as independent variable; whereas, “Age of the Respondents” has been taken as controlled variables in the study to examine the simultaneous impact of age on cholesterol level of respondents. Age of the Respondent” is a nominal variable and the “Physical activity level of the respondent” is a categorical variable measuring the engagement of respondent in physical exercises as 'Not at Risk' and 'At Risk'.

Overall, there are 283,338 respondents, who have been covered in the survey. This enhances the accuracy of the results as the error is spread across a large number of respondents included in the study. This research examines the impact of no physical activity on the high cholesterol risk factor of the respondent with respect to change in the age level. Past researches show that the age of an individual is significantly linked with the physical health of the individual (Black, 2009). Age of the respondents is categorized in four segments included in the analysis.

Null and Alternate Hypothesis

Null hypothesis:

Cholesterol risk factor is independent of No Physical Activity Behavior of individual at all ages.

Alternate hypothesis:

There is statistically significant relationship between No Physical Activity Behavior of individual and High Cholesterol Risk Factor at all ages.

These tests have been supported by examining the presence or absence of relation for higher cholesterol level in different race groups. Therefore, demographic variable of Race/ethnicity has been included in the analysis to test the relationship and goodness-of-fit through chi-square test of independence.

Hypothesis Testing

In order to test the relevancy and relationship between the variables, chi-square test for independence has been applied to the data. The purpose of using chi-square test for independence is to compare the means of higher cholesterol risk for independent ethnic groups of age more than 18 years. Race of the respondent is a categorical variable, which is divided in five categories. These include White American, Black American, Multiracial, Hispanic, and Other Mixed Races.

Detailed descriptive statistics of the Chi-square test are presented in the appendix section. This section presents an analysis of test results obtained from test of independence. Test presented below shows the descriptive statistics of the Chi-square test.

 High Cholesterol Risk

 

Age 18 to 24

Age 25 to 44

Age 45 to 64

Age 65 or older

Row Total

Not At Risk

Sample Size

6,213

59,120

69,699

38,923

173,955

Row ...