Anaemia in elderly patients. Incidence and causes of low haemoglobin concentration in a city general practice.

Haemoglobin concentration was determined in all patients (530) over 70 years of age in a general practice in Oslo during an eight month period. 72 had anaemia and were investigated further. Iron deficiency was found in 13 patients and was most often caused by gastrointestinal blood loss. Chronic diseases, particularly chronic infections and rheumatoid arthritis, were responsible for anaemia in 34 patients. Renal failure caused anaemia in 14 patients. In 10 patients we found no explanation for the anaemia. Nine patients with a previously undiscovered disease were found, six of whom could be offered some kind of treatment. We conclude that anaemia in elderly patients in general practice is often caused by chronic diseases. The main cause of iron deficiency is blood loss, and routine prescription of iron is not justified in this age group. The therapeutic benefit from routine measurement of haemoglobin concentration is small and the test should be used selectively.