Recent changes in the prevalence of diseases presenting for health care

Practice-based morbidity surveys inform on the prevalence of diseases presenting for health care. The last major survey in England and Wales was conducted in 1991.

To reveal changes in disease prevalence between 1991 and 2001.

Population-based analysis of persons presenting to GPs. Annual prevalence of diseases reported in the Weekly Returns Service (WRS) of the Royal College of General Practitioners in 2001 was compared with prevalence reported in Morbidity Statistics from General Practice, Fourth National Study (MSGP4).

Thirty-eight general practices contributing to the WRS, monitoring a population of 326,000 in 2001.

Prevalence was determined from Read codes for morbidity entered in the respective survey years. Diseases and disease groups were defined from Read codes mapping to the chapters, major sub-groups and 3-digit codes of the International Classification of Disease version 9 (ICD9). Age-standardised prevalence rates per 10,000 registered persons and 99% confidence intervals (CIs) were calculated using the national census population for 2001 as the standard. Survey differences in prevalence were identified from non-overlapping CIs.

There was a general reduction in the prevalence of disease caused by infection and an increase of degenerative disorders. The prevalence of mental disorders, skin disease and musculoskeletal disorders showed little change. Particular increases were noted for other malignant and benign neoplasms of the skin, hypothyroidism and diabetes. There were marked reductions for disorders of the conjunctiva, ear infections, acute myocardial infarction and heart failure, respiratory infections and injuries.

The role of the GP continues to change. These results confirm the importance of the management of chronic diseases as the dominant (though not the sole) role of the GP. The results demonstrate the use of the WRS as a source of data on disease prevalence.