Without diluting the clinician’s traditional commitment to the individual patient, the clinical community also has a broader responsibility to the community that provides the resources for health services. The new responsibilities of clinicians in the 21st century are for:

• Productivity
• Efficiency
• Value
• Sustainability
• Equity
• All the patients in the population served with the particular need that is the clinician’s special interest
• Being responsible for more than the referred patients

This last is perhaps the most challenging. The focus of medical services hitherto has been on the patients referred to a service, either self referred or referred by another clinician. The focus of value improvement has to be on the population served by the service, including those people with the disease who are not yet in contact with the service. In England, general practitioners have had responsibility for populations since 1948 but those who work in specialised services, in hospitals or psychiatric services, have not. Of course there are exceptions, for example the excellent book Mental Illness in the Community: the Pathway to Psychiatric Care by David Goldberg and Peter Huxley, published in 1980(1). It shows how at least one mental health service was based on the principles of population psychiatry.

What is population medicine? Imagine you are a rheumatologist in Barchester Royal Infirmary. Last year you saw 346 patients with rheumatoid arthritis, represented by the blue circle, and, as in previous years, worked hard to improve the effectiveness and safety of the service offered, reducing its cost while at the same time struggling to ensure that each of the 346 patients had a good experience. This is evidence-based, patient-centred, and better quality medicine, all necessary and meritorious.

However by reviewing the Barsetshire prevalence literature and the prescribing patterns of the general practitioners of Barsetshire, you estimate that about 1,000 people, represented by the white circle,  have rheumatoid arthritis, not all of them diagnosed, and some wrongly diagnosed. A small survey allows you to estimate that 200 of those not referred, the green circle, would derive great value from your service.

Rather than seek extra resources, you do an audit which suggests that 200 of the 346 patients that you are already seeing could be looked after by generalists with email and telephone support. You build a network of GP’s, pharmacists, physiotherapists, and patients, and agree a clearly defined pathway, expressed through the Map of Medicine and you write an annual report on rheumatoid arthritis in your population. This allows you to compare the population based performance, using nationally agreed outcomes and standards, with that of the 77 other rheumatoid arthritis services in England.

You use the internet to run the network and offer patients unbiased information. You and your team would feel responsible for all the resources both financial, and carbon, used by the population based service, and your job description reflects this.

The skill set for population medicine
Obviously a specialist would need a day a week recognised for this work, and support from an information specialist but to practise population medicine the clinician also needs a new skill set. They need to know how to:

• Develop systems
• Build networks of clinicians and patients
• Design pathways
• Manage knowledge
• Harness the internet’s potential
• Engage patients
• Create and manage programme budgets
• Develop the right culture

The move for services to be accountable to populations as well as to service users is gathering momentum (2), and in the move to maximise value in the words of the title of a great book, “Trying hard is not good enough.” (3) Population medicine is a 21st century necessity and it we need bilingual clinicians, those who can speak the language of their specialty and the language of healthcare for populations that practise it

1. Goldberg D, Huxley P (1980). Mental Illness in the Community: the Pathway to Psychiatric Care. UK: Tavistock Publications Ltd.
2. Mandel KG (2010). Aligning resources with large scale improvement. JAMA 303:663-664.
3. Friedman M (2005) Trying hard is not good enough; how to produce measurable improvements for customers and communities; Trafford

Muir Gray is visiting professor of knowledge management, Nuffield Department of Surgery, University of Oxford.