FACTFILE ON ASTHMA

by Dr John Fry CBE, MD, FRCS, FRCGP

The changing face of asthma

Several remarkable events have occurred in relation to asthma. Firstly, its prevalence has doubled in the last decade. However, this may be because doctors have changed their diagnostic labelling and are more likely to diagnose asthma rather than wheezy chests or bronchitis. Other major events have been the availability of new more effective bronchodilators and corticosteroids and the introduction of definitive management guidelines.

Prevalence

In patients who consult, the highest prevalences are in children and in adults aged 50 years and above. In a practice of 2,000 patients, it is likely that there are over 200 people who have asthma or have had asthma in the past. Each year, of these 80 consult their general practitioner, two or three will be diagnosed as new asthmatics; and 28 will have acute attacks. (1)

One-half of asthmatics start to suffer in childhood, one-third between the ages of 15 and 44 (adult onset) and the remainder (one-sixth) after the age of 45 (late onset).

The natural course of asthma is better than is generally realised. The outcome of asthma is better, the earlier the age of onset.

Hospitalisation

The number of admissions for asthma increased over three-fold from 1980 to 1991. Asthma is the second most frequent reason for admission, after abortion. An average district general hospital (DGH) (serving a population of 250,000) admitted 776 patients with asthma, with an average stay of four days each, at a cost of £530. This means 15 cases each week per DGH, and six each year per general practitioner.

Deaths

Around 2,000 people are certified as dying from asthma each year. The numbers have not changed much in the past 20 years. Two-thirds of deaths are in those aged over 65; only one in ten who die are aged between 5and 44.

GP Prescriptions

From 1982 to 1992, the number of prescriptions for asthma drugs went up by 10 million, and the cost more than trebled (from £98 million to £322 million). The average cost of a prescription for an asthma drug increased from £2.90 in 1982 to £7.49 in 1992.

Comments

Diagnosis of asthma has increased, but it is uncertain whether this is a true trend or a result of change in disease-labelling, and more confidence among doctors as a consequence of the availability of more effective drugs. The nature and causes of asthma are also uncertain, but in many cases attacks tend to cease spontaneously. The benefits of treatment also are uncertain. Mortality has not increased, there is no evidence of fewer attacks, hospitalisation has trebled, and the volume and costs of prescriptions have doubled. Therefore, it is essential to keep an open mind on this intriguing and challenging condition, and not to become ensnared into creating overly rigid management guidelines.

Sources

Office of Health Economics. Compendium of health statistics. 8th edn. London: OHE, 1992.

Office of Population Censuses and Surveys. Morbidity statistics from general practice 1991-2 (MSGP 4). OPCS Monitor; MB5 94/1. London: OPCS, 1994.

References

1. Neville RG, Clark RC, Hoskins G, Smith B. National asthma attack audit, 1991-2. Br Med J 1993; 306: 559-62.
2. Fry J, Sandler G. Common diseases. 5th edn. London: Kluwer, 1993.