J. R. T. Colley

Influence of family factors on the incidence of lower respiratory illness during the first year of life.

In a study of a cohort of over 2000 children born between 1963 and 1965, the incidence of bronchitis and pneumonia during their first year of life was found to be associated with several family factors. The most important determinant of respiratory illness in these infants was an attack of bronchitis or pneumonia in a sibling. The age of these siblings, and their number, also contributed to this incidence. Parental respiratory symptoms, including persistent cough and phlegm, and asthma or wheezing, as well as parental smoking habits, had lesser but nevertheless important effects. Parental smoking, however, stands out from all other factors as the one most amenable to change in seeking to prevent bronchitis and pneumonia in infants.

Respiratory effects of lowering tar and nicotine levels of cigarettes smoked by young male middle tar smokers. I. Design of a randomised controlled trial.

STUDY OBJECTIVE--The aim was to investigate the effect on respiratory health of male middle tar smokers changing the tar and nicotine levels of the cigarettes they smoke for a six month period. DESIGN--This was a randomised controlled trial. Middle tar smokers were randomly allocated to smoke one of three different types of cigarette (low tar, middle nicotine; middle tar, middle nicotine; and low tar, low nicotine) in place of their usual cigarette for a six month period. Main outcome measures were assessment of respiratory health by documenting respiratory symptoms and peak expiratory flow rates, and of nicotine inhalation by measuring the urinary excretion of nicotine metabolites. SETTING--21 local authority districts of England. SUBJECTS--Participants were male middle tar smokers aged 18-44 years. MAIN RESULTS--Postal questionnaires were sent to 265,016 individuals selected from the electoral registers of 21 local authority districts of England; 64% of questionnaires were returned revealing 7736 men aged 18-44 years who smoked only middle tar cigarettes. Of these, 7029 (90%) were sent a health warning and 707 (10%) were not; the latter acted as a control group to assess the effect of the health warning. Of the 7029 men who had received a health warning and were visited at the recruitment stage, 2666 agreed and were eligible to participate in the trial although only 1541 (58% of those who agreed and were eligible) actually started smoking the study cigarettes; 643 men (24% of those willing to participate at the beginning of the trial and 42% of those who actually started smoking the study cigarettes) completed the trial smoking the study cigarettes. Of these, 213 were in the low tar middle nicotine group, 220 were in the middle tar middle nicotine group, and 210 were in the low tar low nicotine group. CONCLUSIONS--This study shows the feasibility of identifying and recruiting sufficient numbers of male middle tar smokers, with adequate numbers completing the trial, to detect any changes in respiratory health over a six month period.

Respiratory symptoms and ventilatory function: a family study.

The family study described in this paper was designed primarily to assess the influence of familial, social, and environmental factors upon the development of respiratory disease in children in the first five years of life. The purpose of this paper is to describe the effect of age, sex, smoking habit, area of residence, social class, and domestic environment on respiratory symptoms and ventilatory function in the parents and siblings. It should be emphasized that this group of parents essentially consists of young people; this is in contrast with most other studies of respiratory disease that have concentrated upon middle-aged adults in specific occupational groups. Preliminary observations of this study were reported by Colley and Holland (1967).