In the early 1850s while Florence Nightingale was experiencing difficulties with her family over her choice of career as a nurse, she was eager to obtain all available statistical information on hospitals and public health. Her biographer, Woodham-Smith, remarked upon the positively reviving effect which reading statistics had on Florence Nightingale, they were at times the only point of contact with the world which interested her most, and even before the Crimean War she had trained her mind to envisage the harsh realities which lay behind the tables of hospital statistics.

At the same time, when Florence Nightingale was in her early thirties, she was sketching out her religious ideas which were later privately printed as Suggestions for Thought. She interwove with her theology ideas taken from the Belgian statistician Adolphe Quetelet on probability and social behaviour. Florence Nightingale believed that the patterns of behaviour identified by Quetelet were expressions of the ‘Laws of God,’ left by the Creator in order to be discovered and acted upon. An understanding of society through statistics was just the start. The challenge that fell to Florence Nightingale was to use statistics to improve society.

In the Crimean War (1854-56), as in every war fought before this century, there were more deaths from disease than as a result of battle. While working at Scutari Hospital as the Superintendent of Nurses, Florence Nightingale could see plainly that disease was the main enemy, and she made some shocking observations. At Scutari the monthly rate of mortality in the first winter reached 40% and if it had continued at that rate the British army would have been wiped out by disease within a year. The fact that eighteen months later, by improving hygiene, she was able to reduce the rate of mortality to 2% proved to her that much of the suffering of the army was unnecessary.

After the war, with the support of Queen Victoria, a group of doctors and soldiers, and backing from the public as a whole, Florence Nightingale pressed the government to accept the need for Army reform. She fought with Lord Panmure, the Minister for War, over the need for a Royal Commission to inquire into the mortality of the army in peace and in war.

To a great extent the Royal Commission which the government introduced in 1858 was driven by Florence Nightingale’s own enthusiasm and hard work. The epitome of Florence Nightingale’s contribution was the polar area chart traditionally (but wrongly) referred to as her coxcombs. It should not be forgotten that Florence Nightingale was ably supported by Dr William Farr, the pre-eminent medical statistician of the day, who helped her to refine the series of charts on which her reputation as a statistician is mainly built. One of the many benefits of the Royal Commission was the reorganisation of Army statistics which were recognised as among the best in Europe.

Over the next 20 years Florence Nightingale went on to apply statistical methods to civilian hospitals, midwifery, Indian public health and colonial schools.

In 1858 Florence Nightingale was elected the first female member of the Statistical Society and she also became an honorary member of the American Statistical Association.

From as early as 1872 she had taken an interest in making a lasting contribution to education in statistics. She discussed the possibility with her friend Benjamin Jowett, Master of Balliol College, Oxford, of endowing a Professorship of Statistics which would be mainly concerned with the application of statistics to social problems. In 1891 she approached Francis Galton, the eminent mathematician for help with her scheme. The scheme foundered and Florence Nightingale revoked her bequest of £2000 towards the Professorship on the grounds (somewhat tongue in cheek) that she would only "end in endowing some bacillus or microbe, and I do not wish that". In the 1920s, the great statistician Karl Pearson reviewed Florence Nightingale’s correspondence on statistics and commented that a particular memorandum to Galton was still remarkably relevant and one of the finest Florence Nightingale ever wrote.

Florence Nightingale is still relevant to statistics today. She is often quoted with regard to "healthcare auditing" and "quality management". She is regarded as a pioneer of epidemiological methods for her use of public health statistics. Although she was enthusiastic about the far reaching application of statistics she was well aware of how data could be manipulated. All this is a far cry from the romantic image of the "Lady with the Lamp" which people continue to associate with Florence Nightingale.