[MUSIC] Welcome back everybody, the term preventable harm was first used during the Crimean War in the mid 1800s. A nurse by the name of Florence Nightingale found poor care for wounded soldiers. In addition to being a nurse, Nightingale was well known for her mathematics, statistics and graphical presentation of statistical data. Upon seeing the poor care of soldiers, Nightingale set about collecting data on the causes of mortality of the soldiers in the Crimean War. In the Crimean War, the French and British declared war on Russia in March of 1854. In November of that year, Nightingale and her staff of 38 women volunteer nurses that she had trained arrived in Scutari, which is now in Istanbul. Nightingale and her team found medication shortages, poor hygiene in the hospitals, and widespread infections among the soldiers. In fact, during that winter, over 4,000 soldiers died. Of these, approximately 10 times more died from typhus, typhoid, cholera and dysentery than from battle wounds. This particular diagram is one of the first known graphical presentations of what we now know as hospital acquired infections, or preventable harm in healthcare. Titled, The Diagram of the Causes of Mortality in the Army in the East, presented here what is known as a polar area diagram, also known as the Nightingale Rose Diagram, which is equivalent to a modern circular histogram. It was often used to plot cyclic phenomenon, like the counts of death by month. For example, if the counts of deaths in each month for a year are to be plotted, then there will be 12 sectors, one for each month all with the same angle of 30 degrees each. The radius of each sector would be proportional to the square root of the death count for that month. So the area of the sector represents the number of deaths in a given month. If the death count in each month is subdivided by the causes of death, it's then possible to make multiple comparisons on one diagram. In this polar diagram representing April 1854 to March 1855, the areas of the blue, red and black wedges are each measured from the center. The blue wedges measured from the center of the circle represent area for area, the deaths from preventable or mitigable zymotic disease, also known as preventable or mitigable infectious diseases. The red wedges measured from the center represent the deaths from wounds, and the black wedges measured from the center are the deaths from all other causes. You can see, in January 1855 was the worst month for soldiers' deaths from preventable or zymotic diseases. In March of 1855, Nightingale had already begun to implement some evidence based practices, like hand washing, to reduce these infections. And you can see the impact by the decrease in areas represented by the blue wedges in February and March of 1855. Due to Nightingale's requests for further interventions, the Sanitary Commission arrived in March of 1855 and implemented more interventions to eliminate these preventable deaths. Interventions included flushing out the sewer systems and improving ventilation. And as you can see in the polar diagram on your left, representing April 1855 to March of 1856, both the total number represented by the area of the wedges and the proportion of death due to preventable harm, compared to all other types of harm, had decreased. It was believed that Nightingale was able to reduce the death rate from 42% to 2% among Crimean War soldiers with these evidence-based intervention she led, or through calling on the Sanitary Commission. Nightingale is described as a true pioneer in the graphical representation of statistics. For this work and other contributions in 1859, Nightingale was elected the first female member of the Royal Statistical Society. This work is some of the earliest evidence of the concept of preventable harm in healthcare and of evidence based quality improvement.
