Hypophosphataemic rickets after ifosfamide treatment in children.

morbidity survey and found that more deaths were assigned to chronic bronchitis and chronic obstructive airways disease than to asthma.28 For every patient with a diagnosis of chronic bronchitis we found another two unlabelled patients with similar symptoms, and for every patient with the diagnosis of asthma we found two or three with wheeze and no diagnosis.This proportion of undiagnosed asthma has also been shown in children.29 30 Moreover, if the threshold for the diagnosis of asthma was lowered to include any patients who had suffered an episode of wheezing in the past 12 months then up to a third of this population would be eligible for the label ofasthma.This large reservoir of patients suggests that sub- stantial shifts in "asthmatic" patients' rates of using hospitals and general practitioners could easily result from changes in diagnostic fashion alone.The apparent lack of criteria on which the diagnosis of chronic bronchitis can be distinguished from asthma in adults together with the shift away from the label of chronic bronchitis suggests that a diagnostic transfer from chronic bronchitis to asthma has occurred.The increasing morbidity and mortality that is attributed to chronic obstructive airways disease also suggests that a new diagnostic fashion is emerging.6Until we have universally agreed clinical and epidemiological diagnoses for asthma, chronic bronchitis, and chronic obstructive airways disease we should be cautious in postulating changes in the epidemiology of respiratory disease only on the basis of trends in drug prescriptions and service utilisation statistics.3'32 We thank Drs Pollock, Forrester, and Terrell for access to their patients and the secretarial staff of the practice for organising the patients' visits.The terbutaline and Nebuhalers were provided by Astra Pharmaceuticals. 1 Anderson HR.Increase in hospitalisation for childhood asthma.Arch Dis Child 1978;53:295-300. 2 Office of Population Censuses and Surveys, Royal College of Gencral Practitioners, Department of Health and Social Securitv.Morbiditv statistics from general practice.Third national study 1981-82.London: HMSO, 1986.(Series MB5 No 1.) 3 Burney PGJ.Asthma mortality in England and Wales: evidence for a further increase, 1974-84.Lancet 1986;ii:323-6. 4 Alderson AM.Trends in morbidity and mortality from asthma.Population Trends 1987;49:18-23. 5 Department of Health and Social Security, Office of Population Censtuses and Surveys.!lospital i'n-patient enquire.London: HMSO,