Exploratory Data Analysis

National Health Interview Survey (NHIS)

Project Overview:
This exploratory data analysis (EDA) focuses on a subset of 30 variables from the National Health Interview Surveys (NHIS) collected from 2020 to 2023. The analysis examines the correlation between 29 selected variables and the variable MIEV_A, which indicates whether a participant has ever been told they had a heart attack. Note: the variables were renamed and converted to factors to simplify their interpretation.

Data Source (as retrieved in December 2024):
National Health Interview Surveys (NHIS) 2020, 2021, 2022, and 2023 (Sample Adult Interviews)

Data Documentation Link (as of December 2024):
https://www.cdc.gov/nchs/nhis/

Data Structure:

'data.frame':   109842 obs. of  30 variables:
 $ UrbanRuralClassification   : Factor w/ 4 levels "L_Central_Metro",..: 3 4 4 4 4 4 3 3 3 1 ...
 $ SurveyYear                 : Factor w/ 4 levels "2020","2021",..: 4 4 4 4 4 4 4 4 4 4 ...
 $ HouseholdRegion            : Factor w/ 4 levels "Northeast","Midwest",..: 3 3 3 3 3 3 3 3 3 3 ...
 $ InterviewQuarter           : Factor w/ 4 levels "Q1","Q2","Q3",..: 1 1 1 1 1 1 1 1 1 1 ...
 $ InterviewMonth             : Factor w/ 12 levels "January","February",..: 1 1 1 1 1 1 1 1 1 1 ...
 $ SampleAdultSex             : Factor w/ 2 levels "Male","Female": 1 1 1 2 2 2 2 1 2 1 ...
 $ SampleAdultAge             : int  67 73 48 42 50 46 36 44 80 61 ...
 $ RaceEthnicity              : Factor w/ 7 levels "Hispanic","White",..: 3 2 3 2 2 2 2 3 2 3 ...
 $ EducationLevel             : Factor w/ 11 levels "Never_Kindergarten",..: 2 9 6 10 8 9 9 11 9 2 ...
 $ GeneralHealthStatus        : Factor w/ 5 levels "Excellent","Very_Good",..: 5 3 1 1 2 2 1 2 3 3 ...
 $ HypertensionHistory        : Factor w/ 2 levels "Yes","No": 1 1 2 2 2 2 2 2 1 2 ...
 $ HighCholesterolHistory     : Factor w/ 2 levels "Yes","No": 1 2 2 2 2 2 2 2 2 2 ...
 $ CoronaryHeartDiseaseHistory: Factor w/ 2 levels "Yes","No": 2 1 2 2 2 2 2 2 2 2 ...
 $ AnginaHistory              : Factor w/ 2 levels "Yes","No": 2 2 2 2 2 2 2 2 2 2 ...
 $ StrokeHistory              : Factor w/ 2 levels "Yes","No": 1 2 2 2 2 2 2 2 2 2 ...
 $ AsthmaHistory              : Factor w/ 2 levels "Yes","No": 2 1 2 2 2 2 2 2 2 2 ...
 $ CancerHistory              : Factor w/ 2 levels "Yes","No": 2 2 2 2 2 2 2 2 1 2 ...
 $ DiabetesHistory            : Factor w/ 2 levels "Yes","No": 2 1 2 2 2 2 2 2 2 2 ...
 $ ChrObsPulmDisHistory       : Factor w/ 2 levels "Yes","No": 2 2 2 2 2 2 2 2 2 1 ...
 $ ArthritisHistory           : Factor w/ 2 levels "Yes","No": 1 2 2 2 2 1 2 2 1 1 ...
 $ DementiaHistory            : Factor w/ 2 levels "Yes","No": 2 2 2 2 2 2 2 2 2 2 ...
 $ AnxietyDisorderHistory     : Factor w/ 2 levels "Yes","No": 2 2 2 2 2 1 2 2 2 2 ...
 $ DepressionHistory          : Factor w/ 2 levels "Yes","No": 1 2 2 2 2 2 2 2 2 2 ...
 $ BMICategory                : Factor w/ 4 levels "Underweight",..: 3 3 4 3 2 3 2 4 4 3 ...
 $ SmokelessTobaccoUsage      : Factor w/ 2 levels "Yes","No": 1 2 2 2 2 2 2 2 2 2 ...
 $ PipeTobaccoUsage           : Factor w/ 2 levels "Yes","No": 2 2 2 2 2 1 2 2 2 2 ...
 $ CigarUsage                 : Factor w/ 2 levels "Yes","No": 2 2 2 2 2 2 2 2 2 2 ...
 $ ECigaretteUsageStatus      : Factor w/ 3 levels "Current","Former",..: 3 3 3 3 3 3 3 3 3 2 ...
 $ CigaretteSmokingStatus     : Factor w/ 4 levels "Every_Day","Some_Days",..: 4 1 4 3 4 4 4 4 3 1 ...
 $ HeartAttackHistory         : Factor w/ 2 levels "Yes","No": 2 1 2 2 2 2 2 2 2 2 ...

Textual representation of the variable ‘HeartAttackHistory’:

Levels attribute for the variable HeartAttackHistory:

     Level Numeric_Value Frequency
[1,] "Yes" "1"           "3960"   
[2,] "No"  "2"           "105882" 

Visual representation of the variable ‘UrbanRuralClassification’:

Visual representation of the variables ‘UrbanRuralClassification’ and ‘HouseholdRegion’ side-by-side:

Line graph of monthly participant distribution by year using the variables ‘InterviewMonth’ and ‘SurveyYear’:

Line graph of the first quarter by year using the variables ‘InterviewMonth’, ‘SurveyYear’, and ‘InterviewQuarter’:

Line graph of the second quarter by year using the variables ‘InterviewMonth’, ‘SurveyYear’, and ‘InterviewQuarter’:

Line graph of the third quarter by year using the variables ‘InterviewMonth’, ‘SurveyYear’, and ‘InterviewQuarter’:

Line graph of the last quarter by year using the variables ‘InterviewMonth’, ‘SurveyYear’, and ‘InterviewQuarter’:

Side-by-side bar chart of participant distribution by race/ethnicity and gender using the variables ‘RaceEthnicity’ and ‘SampleAdultSex’:

Stacked area graph of education levels across age groups using the variables ‘EducationLevel’ and ‘SampleAdultAge’:

Radial bar chart of the BMI category and the general health status using the variables ‘BMICategory’ and ‘GeneralHealthStatus’:

Stacked bar chart of the 17 variables that contain 2 factors (Yes, No):

Side-by-side frequency tables of the variables ‘ECigaretteUsageStatus’ and ‘CigaretteSmokingStatus’:

Table of P-Values - To be used for determining the statistical relationship or association between the target variable ‘HeartAttackHistory’ and other variables:

      Variable                      P-Values     
 [1,] "UrbanRuralClassification"    "< 2.2e-16"  
 [2,] "SurveyYear"                  "= 0.8319"   
 [3,] "HouseholdRegion"             "< 2.2e-16"  
 [4,] "InterviewQuarter"            "= 0.1108"   
 [5,] "InterviewMonth"              "= 0.173"    
 [6,] "SampleAdultSex"              "< 2.2e-16"  
 [7,] "SampleAdultAge"              "< 2e-16"    
 [8,] "RaceEthnicity"               "< 2.2e-16"  
 [9,] "EducationLevel"              "< 2.2e-16"  
[10,] "GeneralHealthStatus"         "< 2.2e-16"  
[11,] "HypertensionHistory"         "< 2.2e-16"  
[12,] "HighCholesterolHistory"      "< 2.2e-16"  
[13,] "CoronaryHeartDiseaseHistory" "< 2.2e-16"  
[14,] "AnginaHistory"               "< 2.2e-16"  
[15,] "StrokeHistory"               "< 2.2e-16"  
[16,] "AsthmaHistory"               "= 0.0003294"
[17,] "CancerHistory"               "< 2.2e-16"  
[18,] "DiabetesHistory"             "< 2.2e-16"  
[19,] "ChrObsPulmDisHistory"        "< 2.2e-16"  
[20,] "ArthritisHistory"            "< 2.2e-16"  
[21,] "DementiaHistory"             "< 2.2e-16"  
[22,] "AnxietyDisorderHistory"      "= 3.359e-10"
[23,] "DepressionHistory"           "< 2.2e-16"  
[24,] "BMICategory"                 "< 2.2e-16"  
[25,] "SmokelessTobaccoUsage"       "= 6.07e-12" 
[26,] "PipeTobaccoUsage"            "< 2.2e-16"  
[27,] "CigarUsage"                  "< 2.2e-16"  
[28,] "ECigaretteUsageStatus"       "= 6.762e-10"
[29,] "CigaretteSmokingStatus"      "< 2.2e-16"