Florence Nightingale used mathematics to improve health care

May 12 is the 200th anniversary of the birth of Florence Nightingale. Known as "The Lady of the Lamp," Nightingale is best known as the founder of modern nursing. But she was also a trailblazer in the field of epidemiology, using statistics and visual graphs to push for better conditions, saving countless lives.

The Crimean War was a bloody affair with Britain and France joining Turkey's fight against Russia. In 1854, after a newspaper report came out detailing appalling conditions in military hospitals, the Secretary of War, Sidney Herbert, called upon his lifelong friend Nightingale for help. When she and her team of 38 nurses arrived in Turkey, they were horrified. They found overcrowded wards, patients covered in filth, sewage all over the floors, and rotting animals in the courtyard. 

Before becoming a nurse, Nightingale studied and taught mathematics, and she used those skills to help prove the need for a solution. Using statistics, she was able to track the number of deaths, and proved that more soldiers were dying from diseases they picked up in hospitals than they were from battlefield wounds. In other words, hospitals were more deadly than the enemy. 

Once she was able to use this data to convince the military to improve sanitation, she was also able to track the reduction in deaths from hospital disease, where mortality dropped from 40 per cent down to just 2.2 per cent in one year. To illustrate this in a visual way to help convince the people in charge, she used graphs, including what is known as a polar area diagram.

After the war, she continued to push for data to inform medical decisions. In 1860, Nightingale successfully advocated for the uniform collection of hospital statistics at the International Statistical Congress in London. This became the first time that a patient's outcomes could be compared by hospital, region, and country.

From 1857 onwards, Florence Nightingale suffered from chronic illness, which many now believe was brucellosis, a bacterial infection that can cause chronic fatigue, fever and pain, that she may have contracted while nursing in the Crimean War.  But even while bedridden, she worked from home, as many of us do today, publishing hundreds of books, reports and pamphlets advocating for sanitary reform in all military hospitals and establishing reputable nursing colleges.

Florence Nightingale's statistical analysis of disease was instrumental in establishing the science of epidemiology, in which mathematical models are used to track the spread of diseases such as COVID-19. It is the epidemiologists whose mathematics produced the "curve" we are all trying to flatten. They track how the numbers of cases are on the rise or decline, and make predictions about future trends. 

On an recent episode of Quirks & Quarks, an epidemiologist predicted that after we see a decline in COVID-19 cases and re-open businesses, there could be a series of smaller waves of outbreaks in the future that we may have to deal with.   

Epidemiologists are the eyes on disease that enable health care workers, politicians and the public to take appropriate action to stop the spread, and mathematics is their primary tool — as it was for Florence Nightingale.

As we celebrate her 200th birthday, we can thank the Lady of the Lamp for illuminating our view on diseases that appear among us.