Incidence and prevalence

The prevalence of a disease is the number of people in a population who have the disease at a particular time. The incidence of the disease is the number of new cases of the disease during a particular time.

The incidence of malaria is	high	in many developing countries.
	low	in developed countries.

The incidence of HIV infection is highest in Africa.

The incidence of HIV infection is lowest in the Caribbean.

Note: You don't say 'The incidence of malaria is common.'

The incidences of a disease in different groups are often compared.

R heumatoid arthritis is more common in females than in males.

Rheumatoid arthritis is less common in males than in females.

Men and women are equally affected by

restless leg syndrome.

Association and causation

Studying the incidence of disease in particular groups of people can lead to the discovery of causation - what makes it occur. For example, the high incidence of lung cancer among cigarette smokers suggests that smoking is a causative factor in the development of lung cancer. However, care must be taken not to assume every association between a disease and a measured variable is causative. To say there is an association between two things simply means that they occur together in a certain situation. For example, several studies have indicated high rates of lung cancer in cooks. Although this could be a consequence of their work (perhaps caused by carcinogens in fumes from frying), it may be simply because professional cooks smoke more than the average. In other words, smoking might confound the association with cooking.

Exercises:

1. Complete the sentences. Look at A and B to help you.

1.The proportion of episodes of illness that end fatally is the …………….rate.

2. The proportion of people who die in a particular period is the ………..rate.

3. The proportion of babies born in a particular period is the ……………rate.

4. The proportion of patients who are still alive five years after treatment is the five-year…………..rate.

5. Ten per cent of the population have rhinitis at any time. This is the ………….

6. Every year, 0.5 – 1.0 % develop the condition. This is the………..

2. Complete the text, using the correct grammatical form of each word. Look at the table and at A, B and C to help you.

Incidence of lung cancer

Country	Incidence (per 100,000)
	Men	Women
China	67.5	26.6
Canada	59.1	30.8
USA	55.7	33.5
UK	51.2	22.0
Japan	44.6	13.3
Sweden	22.0	12.9
India	12.1	3.8

In all countries, lung cancer was (1) …………in men than in women. The (2) …………incidence among men was in China where 67.5 men per 100.000 were diagnosed with lung cancer in the period. In women, however, lung cancer was less (3)…………in China than in the USA and Canada.

The (4)……….incidence in both men and women was in India. Sweden also had a fairly (5)……… incidence in both sexes. Lung cancer is probably (6)…………in India for cultural and economic reasons, whereas in Sweden it is the result of an effective health education campaign.

3. Find prepositions in A, B and C that can be used to make word combinations with the words in the box. Then use the correct forms of the words to complete the sentences.

affected association incidence lead rare

1. Recent surveys showed that the ………..HIV cases had come down in the southern states of India.

2. Epidemiologic data suggest an ………..obesity and depression, but further studies and need.

3. Appropriate preventive measures should………a reduction in the mortality rate.

4. Thalasssaemia is ……….people of Northern European origin.

5. Male and female soldiers are equally………..post-traumatic stress disorder.

Unit 20 Medical ethics

GMC guidelines

Care = protecting and looking after someone

professional competence = level of specialized knowledge and skills

confidential = private, secret

prejudice = have a negative influence on

risk= possibility of something bad happening

fit to practice= in a suitable condition to work

The duties of a doctor registered with the General Medical Council include:

1. Make the care of your patient your first concern.

2. Treat every patient politely and considerately.

3. Give patients information in a way they can understand.

4.Keep your professional knowledge and skills up to date.

5. Recognize the limits of your professional competence.

6. Be honest and trustworthy.

7.Respect and protect confidential information.

8. Make sure that your personal beliefs do not prejudice your parent's care.

9. Act quickly to protect patients from risk if you have good reason to believe that your or your colleague may not be fit to practice.

Note: for a full list of the guidelines, see www.gmc-uk.org

Bioethical issues

Euthanasia

Should the medical profession help the terminally ill to end their lives when they choose?

Genetic engineering

Should we permit an embryo to be cloned – copied exactly – to replace a child who has died?

Should parents be able to select the genetic makeup of their children to produce so-called designer babies?

Human fertility

IVF – in vitro fertilization – has made it possible for infertile women to have children, but should this include women long past the normal age of childbearing?

Embryos can be frozen and implanted in the mother at a later date but should this require the consent or permission of both parents if the marriage has broken down?

What are the rights of a surrogate mother, one who carries a child for a woman who is unable to do so, over that child?

Transplant surgery

Who should give consent for the removal of body parts for transplant surgery?

Assisted dying

A medical student has made some language notes on a journal article.

A 53-year old woman with incurable muscular dystrophy flew to Switzerland to end her life. Assisted dying is legal in Switzerland, but illegal in the UK. Opponents of euthanasia, or “mercy killing”, argue that legalization would lead to abuse and call for doctors who participate to be struck off. What Britain needs, they claim, is better palliative care and more hospices for the terminally ill to allow such patients to die with dignity. This follows a recent US case where the husband of a woman who had been in a persistent vegetative state for 16 years was successful in having artificial feeding withdrawn in spite of opposition from his wife's parents.

struck off = removed from the GMC register and banned from practicing medicine in the UK palliative care = treatment to relieve rather than cure symptoms hospice = facility providing care for terminally ill patients terminally ill = not expected life persistent vegetative state = unable to speak or follow simple commands; does not respond in any psychologically meaningful way palliative – паллиативный, уменьшающий тяжесть симптомов без излечения основного заболевания