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Background and Methods

Background:

The mean systolic blood pressure (in mm-Hg) was gathered from either gender for 189 countries from 1989-2008 (Gapminder). Previous studies have tested blood pressure with hemodynamic factors that account for hypertension, there were no differences in office blood pressure, heart rate and body mass index between genders. This knowledge was then used to tailor therapeutic approaches and improve blood pressure control (Ferrario). In another study on hypertension done by the CDC, their reported differences were tested using a t statistic at the p < 0.05 significance level. They found that hypertension was higher in males as well as it increased in age (CDC). In another study done by the ACSH (American Council on Science and Health), hypertension was more prevalent and occurred earlier in women than men. Researchers adjusted for other factors such as smoking, diabetes, cholesterol, and BMI, but the effect was still the same afterward with a slight accentuation. Different physiology accounted for these differences in this particular study (Dinerstein). In our study, we plan on looking at genders across the nation within a 20 year span, and comparing blood pressures between them rather than getting into the more medical aspect of higher blood pressure such as hypertension. It will be interesting to see the comparisons to these past studies and our data that we are analyzing to determine differences in gender, country, and year. Our research question is “Is there any difference in the mean systolic blood pressure of men and women around the globe”?

CDC. “Products - Data Briefs - Number 364 - April 2020.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 24 Apr. 2020, www.cdc.gov/nchs/products/databriefs/db364.htm .

Carlos M. Ferrario. (2013). Hemodynamic and hormonal patterns of untreated essential hypertension in men and women [pdf]. Retrieved from https://journals.sagepub.com/doi/pdf/10.1177/1753944713513221

Dinerstein, Chuck. “High Blood Pressure Differs In Women From Men.” American Council on Science and Health, 23 Jan. 2020, www.acsh.org/news/2020/01/21/high-blood-pressure-differs-women-men-14519 .

Gapminder. (2008). Blood pressure, men, SBP, mmHg. [data file]. Retrieved from https://www.gapminder.org/data/

Gapminder. (2008). Blood pressure, women, SBP, mmHg. [data file]. Retrieved from https://www.gapminder.org/data/

Methods:

Data Collection:

The data was collected on systolic blood pressure on men and women in 189 different countries. The mean systolic pressure for each country and gender is recorded in the data spreadsheet for each year 1989 through 2008. The number of individuals sampled is not disclosed but it was of statistical significance to be representative mean values for entire countries. The source we used (Gapminder) combines data from multiple sources. Each documentation page has a version number and links to the previous versions. Whenever they update or make changes to the data, they make a new version. The data on blood pressure is calculated as if each country has the same age composition as the rest of the world.

Carlos M. Ferrario. (2013). Hemodynamic and hormonal patterns of untreated essential hypertension in men and women [pdf]. Retrieved from https://journals.sagepub.com/doi/pdf/10.1177/1753944713513221

Harvard Dataverse. (2020). Blood Pressure Data. [data file]. Retrieved from https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/EA1SAP

Gapminder. (2008). Blood pressure, men, SBP, mmHg. [data file]. Retrieved from https://www.gapminder.org/data/

Gapminder. (2008). Blood pressure, women, SBP, mmHg. [data file]. Retrieved from https://www.gapminder.org/data/

Variables:

1.) Country of origin: categorical/explanatory

2.) Gender (men or female): categorical/explanatory

3.) Systolic Blood Pressure (mmHg): quantitative/response

4.) Time (years): quantitative/explanatory

Statistical Methods:

a.) In order to analyze the data, we will compare both the mean systolic blood pressure for the populations of both men and females of each country until we hopefully identify a trend. We believe that the best approach to visually representing the data would be to use a dot plot and even a histogram to better view comparison. In using a dot plot, we would label the x-axis with the country of origin and the y-axis with the systolic blood pressure (in mmHg). There would then be a legend explaining how different colored dots represent different genders. In using a histogram, the x-axis, y-axis, and legend would be labeled the same but with a different format, comparing each bar side-to-side.

b.) The population mean, represented by μ, will be substantial in generalizing results and determining an accurate average. Finding a p-value from the data set will also yield important information as to whether there is evidence against the null hypothesis. By using these visual representations, we will be able to see any trends and correlation between gender and systolic blood pressure.

c.) HA: There is a difference in the systolic blood pressures of women and men

d.) Our confidence interval will estimate the average difference in the systolic blood pressure means between men and women

e.) We are going to be using a theory-based approach because we are using already existing data to draw our own conclusions based on our hypothesis.