Introduction: The purpose of this project was to see if Dr. Semmelweis's idea of handwashing helped to reduce the number of sicknesses and deaths per year in the Vienna General Hospital. We will hopefully be able to support his claims by analyzing data in ways that he couldn't at the time.
Background and Context: Dr. Ignaz Semmelweis was a Hungarian physician born in 1818. He worked at the Vienna General Hospital and he wanted to work out and solve a solution for childbed fever. During his time this was a very harmful and deadly disease that could spread and affect thousands of people. It was found to be affecting woman that have just given birth. The woman he was seeing at Vienna General Hospital who had this disease was up to 10% and the woman would often die from it. He knew that there were only two Clinics within the hospital which delivered babies, one staffed by midwives, and one by medical students. He noticed immediately that the rate of deaths in the wing staffed by medical students was much higher than that of the midwives. He didn't know why exactly, but he decided to investigate, coming up with data to prove that handwashing could be the cure, the same data that we analyzed in this project.
Methods: We used RStudio to examine the original data that made Semmelweis realize that something was wrong with the procedures at Vienna General Hospital. We numerically summarized the proportions of deaths before and after the handwashing started, and used several graphs, most importantly a time plot, to examine the effect that handwashing had in the clinic. This graph is able to show us very clearly the impact of hand washing, and how Dr. Semmelweis was actually correct in his assumptions.
1. Meet Dr. Ignaz Semmelweis
We first created a table showing the number of women giving birth at the two clinics at the Vienna General Hospital for the years 1841 to 1846 by loading the Tidyverse package. We were then able to see how dangerous giving birth actually was over the course of five years, for an alarming number of women died as the result of childbirth, most of them from childbed fever.
2. The alarming number of deaths
In the second set of code, we were able to make a table to look at the proportion of deaths out of the number of women giving birth to give us numbers that we could then analyze with visual representation, more specifically by adding a column to yearly.
In the third set of code, we ploted the proportions of deaths at both clinic 1 and clinic 2, where a very defined pattern first emerges. We are visually able to see that there were many more deaths at clinic 1, the clinic being staffed by medical students, than at clinic 2, being staffed by midwives. Semmelweis saw this same pattern, and this is where he originally came up with his hand washing theory. He hypothesized that the only difference between the midwives and the medical students was that the midwives were tending only to women giving birth, while the medical students were also spending times in the autopsy room examining corpses. His idea was that the childbed fever was actually being transferred from the corpses to the women because the medical students weren't washing their hands. We now know that he was in fact right, and it was bacteria being transferred, but the idea was not accepted at that point in time. So, Semmelweis desperately decreed that everyone start washing their hands in an attempt to stop the high mortality rates.
4. The handwashing begins
The next set of code shows the data with an additional column showing the monthly proportion of deaths over time from Clinic 1.
5. The effect of handwashing
The fifth set of code we used to create a plot with the proportion of deaths on the y-axis and the date every two years on the x-axis for both of the combined clinics.
6. The effect of handwashing highlighted
In the sixth set of code, we actually plotted the data for each clinic separately, and as you can see pretty clearly, starting in the summer of 1847, there is a drastic decrease in the proportion of deaths directly due to handwashing. This is exactly when Semmelweis made handwashing obligatory in the clinic.
7. More handwashing, fewer deaths?
In this final set of code, we calculated the mean proportion of deaths before and after hand washing. In the end, our data led us to the discovery that Semmelweis was right all along, and had sufficient evidence to prove his theories. According the the data, doctors who didn't wash their hands increased the proportion of deaths by between 6.7 and 10 percentage points, according to a 95% confidence interval. Although Semmelweis's personal story is a sad one, his legacy has gone on to show that handwashing is a simple but highly effective procedure that could save many lives.