Session I : Chairman : Sir

Two collaborative studies of acute respiratory disease were organized, one in patients seen in general practice and the other in children admitted to hospital. The main aims were to study the epidemiology and clinical presentation of these diseases and of the viruses associated with them. The field methods used are described and analyses of the consultation rates in general practice and of hospital admissions in children are presented. Both consultations and admissions were most frequent by far in very young children, especially those under theage of 1 year, butthe pattern ofincidence for the various clinical categories differed with age. Lower respiratory illnesses were relatively much more frequent in infants and in adults over 65 than in intermediate age groups. Seasonal variations were slight for most upper respiratory tract conditions but pronounced for lower respiratory illnesses, especially bronchiolitis of infants which was epidemic each winter, and for influenza. Changes in the initial diagnosis in patients seen in general practice did not greatly influence the total morbidity pattern but the final diagnoses showed a substantial proportional increase in the number of cases of lower respiratory illness. The shortcomings of the field methods and clinical records available for use in the study and the reliability of the results are discussed.