Smoking has well been established as a major risk factor of cardiovascular disease and is one of the most avoidable causes of cardiovascular mortality. Inhalation of tobacco increases activity of the sympathetic nervous system (fight or flight) that will, in turn, increase heat oxygen consumption that will consequently increase blood pressure and heart. Therefore, hypertension, known as blood pressure, is very closely related to smoking, another major risk factor for cardiovascular disease, and are shown to exhibit a positive correlation. This relationship was explored in the United States using data from the Center of Disease Control as of 2009. This project focused on producing visualizations of the data given in a table format that would exhibit the correlation between smoking and hypertension using a scatter plot and bar charts, any geographical correlation using block histograms, and a visual less data based graphic relating smoking and heart disease.
1. Many Eyes Scatterplot comparing Prevalence of Hypertension and Smoking in the United States in 2009
The scatter plot is widely used in scientific fields to explore correlations between two conditions. This scatter plot compared the prevalence of smoking and prevalence of hypertension by state to see if there was a correlation. As one would expect, this graphic clearly shows states with a higher percentage of population exhibiting hypertension usually had a higher percentage of smoking population.
2. Bar Graph of Smoking and Hypertension Prevalence in the United States as of 2009 (Excel)
The bar graph is also a widely used visualization tool in public health and other scientific fields to make comparisons between several different regions. Therefore, this graph was constructed to compare not only the difference between smoking and hypertension prevalence within a state but to be able to compare these difference between all fifty states. Although there is some correlation visible between states with high smoking prevalence and high hypertension, it is not as clear as a scatter plot. In fact, including an identifying label for all fifty states might actually take away focus from the main trend of positive correlation and make the relationship between smoking and hypertension much less clear. Also, the contrast between blue and red does draw one’s eyes to the comparison between the smoking and hypertension within a state but makes it less likely that one will compare these levels across all states and draw the conclusion that smoking and hypertension are positively correlated. Therefore, this graphical representation does not describe the positive correlation between these two risk factors as well as the scatter plot above.
4. Graphic describing the relationship between Smoking and Hypertension
This last visualization was meant to take the main point of the numbers and data sets and put it into plain language with a very clear and simple picture. The words smoking and disease are in the same color so the viewer will associate the words with each other. Additionally, the figure pictured smoking a cigarette is faceless to make it appeal to both men and women young and old. I chose to make the heart broken rather than blackened or shriveled because it clearly shows that the heart is not functioning the way it used to thus signifying that tobacco has adverse effects on heart functions. Therefore, although this graphic does not explicitly say that smoking and hypertension are directly correlated it shows that people who smoke will suffer from side effects that are detrimental to heart functioning. Additionally, although this diagram is very clear in communicating its message, it does not contain data or “numbers” to corroborate its message. Therefore this graphic would be used to educate people about the relationship between heart disease and smoking that do not have the capacity or time to analyze data in a graphical form.
This project shows that visualizations of data do have a huge effect on what trends are communicated and whether they are effectively communicated. In this case, the Scatter Plot generated by Many Eyesclearly showed that there was a positive correlation between hypertension and smoking. However, to draw this conclusion, one must learn how to read scatter plots and understand the Cartesian coordinate system. For people who lack these skills, the fourth visualization, the diagram, could prove to communicate the same message. The bar graph exhibited the importance of labeling only what contributed to exhibiting the necessary trend rather than providing superfluous information. In other words, identifying each individual state in the bar graph made it much harder to visualize the positive correlation between hypertension and smoking. Finally, constraints of the programs used to generate this visualization can greatly affect their effectiveness. The histogram could have been a much more effective diagram that would not only have highlighted the positive correlation between smoking and hypertension but also any geographical trends that existed within this relationship had color coding been an option along with placing both histograms one on top of each other in the same scale.