_{QuickStats: Age-Adjusted Percentage of Adults Aged ≥18 Years with Hypertension, by Sex and Race and Ethnicity — United States, August 2021–August 2023. MMWR Morb Mortal Wkly Rep 2024;73:1110. DOI:\ http://dx.doi.org/10.15585/mmwr.mm7348a5.}

Note: I chose to calculate average blood pressure values per patient because the number of recorded encounters varied significantly across individuals. Some patients had many encounters, while others had only a few. This inconsistency could bias the analysis, as populations with more frequent visits would contribute disproportionately to the overall blood pressure statistics. By aggregating values at the patient level, I aimed to ensure a fairer and more balanced comparison across groups.

Research Question

Do different racial groups show significant differences in systolic and diastolic blood pressure?

Code for the Average BP by Patient.

# Compute per-patient average SBP and DBP
bp_avg <- bp %>%
  group_by(pat_id, race_desc) %>%
  summarise(avg_sbp = mean(systolic, na.rm = TRUE),
    avg_dbp = mean(diastolic, na.rm = TRUE),
    .groups = 'drop')

Summary Statistics by Race

Systolic / Diastolic

## $`AMERICAN INDIAN`
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   124.4   124.4   124.4   124.4   124.4   124.4 
## 
## $ASIAN
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   106.7   115.3   119.6   125.6   128.0   170.3 
## 
## $BLACK
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##    69.5   123.2   133.7   134.8   144.4   214.0 
## 
## $HISPANIC
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   123.4   126.9   134.8   135.2   143.1   147.7 
## 
## $MULTIRACIAL
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##     144     144     144     144     144     144 
## 
## $OTHER
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   102.8   122.3   130.1   131.3   138.5   175.1 
## 
## $`PREFERENCE NOT INDICATED`
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   105.0   116.0   133.0   129.6   141.3   163.5 
## 
## $`WHITE `
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   87.74  121.98  130.00  130.81  138.88  181.33

## $`AMERICAN INDIAN`
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   81.92   81.92   81.92   81.92   81.92   81.92 
## 
## $ASIAN
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   60.96   66.53   72.00   71.63   74.23   95.50 
## 
## $BLACK
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   46.00   70.12   76.96   78.35   86.27  142.00 
## 
## $HISPANIC
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   69.14   69.65   74.39   78.94   83.69   97.85 
## 
## $MULTIRACIAL
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   90.67   90.67   90.67   90.67   90.67   90.67 
## 
## $OTHER
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   54.76   68.00   74.94   75.04   78.59  103.86 
## 
## $`PREFERENCE NOT INDICATED`
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   56.00   64.00   74.00   73.33   78.00   99.00 
## 
## $`WHITE `
##    Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
##   47.35   67.67   73.25   73.61   79.50  113.00

Race Code	Race Desc	No. Patients	Avg Systolic	Avg Diastolic
6	Multiracial	1	144	91
5	Hispanic	4	135	79
4	Black	163	135	78
8	Other	85	132	75
11	White	675	131	74
9	Pref Not Indicated	13	130	74
3	Asian	21	126	72
2	American Indian	1	124	82

Boxplots of Average BP by Race

Histograms of Average BP by Race

T-test results comparing patient-level average blood pressure between racial groups:

Comparison	Systolic p-value	Diastolic p-value	Significance
Black vs Hispanic	0.034	0.00098	Significant
Black vs White	0.009	< 0.001	Highly significant
Hispanic vs White	0.198	0.239	Not significant
Black vs Other	0.953	0.936	Not significant

Conclusion

Black patients had higher average systolic (SBP) and diastolic (DBP) blood pressure than White and other races. While Asian and American Indian patients showed lower average blood pressure in some measures, the sample size for the Asian, HIspanic and American Indians group were too small to draw reliable conclusions.
Boxplots and histograms were used to visualize these trends, and t-tests confirmed that the observed differences—particularly between Black and White patients—were statistically significant.
Although the White patient group was substantially larger than other racial groups, the average blood pressure for Black patients remained consistently higher than all others. Notably, the Multiracial category was underrepresented, with only one patient, limiting any meaningful interpretation for that group.