Parental smoking and post-infancy wheezing in children: a prospective cohort study.

The contribution of parental smoking to wheezing in children was studied in a subset of all British births between April 5 and 11, 1970 (N = 9,670). Children of smoking mothers had an 18.0 per cent cumulative incidence of post-infancy wheezing through 10 years of age, compared with 16.2 per cent among children of nonsmoking mothers (risk ratio 1.11, 95% CI: 1.02, 1.21). This difference was confined to wheezing attributed to wheezy bronchitis, of which children of smokers had 7.4 per cent, and those of nonsmokers had 5.2 per cent (risk ratio 1.44, 95% CI: 1.24, 1.68). The incidence of wheezy bronchitis increased as mothers smoked more cigarettes. After multiple logistic regression analysis was used to control for paternal smoking, social status, sex, family allergy, crowding, breast-feeding, gas cooking and heating, and bedroom dampness, the association of maternal smoking with childhood wheezy bronchitis persisted. Some of this effect was explained by maternal respiratory symptoms and maternal depression, but not by neonatal problems, the child's allergic symptoms, or paternal respiratory symptoms. There was a 14 per cent increase in childhood wheezy bronchitis when mothers smoked over four cigarettes per day, and a 49 per cent increase when mothers smoked over 14 cigarettes daily.

Prevalence of asthma among teenagers attending school in Tahiti.

The prevalence of asthma was studied in 6731 adolescents (average age 13.5 years, 48.6% boys) attending school in three towns of the isle of Tahiti, according to the ethnic origin of both parents. The pupils completed a self-administered questionnaire in class; 14.3% gave an affirmative answer to the question "Have you ever had attacks of asthma?" (cumulative prevalence). That prevalence was 11.4% in the Europeans, 13.7% in the Chinese, 13.8% in the Polynesians, 15.3% in those whose parents were "halves" (half-bred from Polynesians and Europeans), and 16.0% in the miscellaneous group (= other origins) (P less than 0.02). Asthma was significantly more frequent in boys only among the Europeans and those with one European parent. The results of this study confirm the high prevalence of asthma in French Polynesia found in a previous study. They give no evidence of a racial difference in prevalence but suggest an influence of environment.

Asthma and wheezy bronchitis in adolescents: biosocial correlates.

This study examined the epidemiological aspects of asthma and wheezy bronchitis at 16 years of age in children of a large British National cohort previously studied at the time of birth and when they were 7 and 11. It confirmed, for age 16, the steady decline in numbers of children suffering from asthma or wheezy bronchitis previously seen between ages 7 and 11. Significantly more boys than girls continued to report having these ailments. At age 16, children with asthma were more likely than those without to suffer from such allergy-related conditions as eczema and to come from homes where the principal wage-earner has a nonmanual job and where both mother and child smoke.

Factors affecting estimates of the prevalence of asthma and wheezing in childhood.

Nine recent studies of the prevalence of asthma and wheezing in childhood are reviewed. Sample prevalences are found to range from 5 to 31% and possible reasons for this are considered; it is shown that the prevalence of asthma found is highly dependent on the criteria used for diagnosis. Some clinical and research implications are discussed.

Intraoperative respiratory complications in patients with upper respiratory tract infections.

A retrospective survey of 3,585 patients aged newborn to 20 years was performed to investigate the prevalence of intraoperative respiratory complications in patients with symptoms of upper respiratory tract infections (URIs). There were no significant differences in complication rates between asymptomatic patients (1.61 per 100) and those with symptoms (1.64 per 100); however, patients who were asymptomatic but had a recent history of an URI had a significantly higher complication rate (5.31 per 100; p less than 0.05) than the asymptomatic patients. There were no significant differences in intraoperative complications between patients managed with and without tracheal intubation, nor was there any association between the type of anaesthetic agent used and the development of intraoperative respiratory complications. Results from the study suggest no increased risk of respiratory complications for patients presenting with uncomplicated URIs. However, patients who were asymptomatic but had a recent history of an URI showed a significantly increased risk for the development of intraoperative complications.

Asthma and wheezy bronchitis in a British national sample.

The relationship between biosocial factors and childhood asthma and wheezy bronchitis in a British national sample was examined. At age 11, 3 1/2% of the children in this sample were reported to have suffered from either asthma or asthma-wheezy bronchitis; an additional 8.8% reported wheezy bronchitis without asthma. Significantly more boys than girls had asthma at this age. The presence of asthma and wheezy bronchitis was found to associate with parental occupation, household amenities, and noncrowding in the home, as well as to vary by geographic region. Discriminant analysis showed that it was possible to differentiate between the three groups comprising asthma and wheezy bronchitis, wheezy bronchitis only, and nonsufferers, due mainly to allergy-related factors such as eczema.

The significance of recurrent childhood respiratory disorders in flight training applicants.

A random sample of 1700 18-year-old applicants for flight training, who had been free from respiratory symptoms for 1 year or more, was screened for respiratory symptoms in the past. Those who denied such a history had a questionnaire sent to their parents for further verification. Altogether 70 subjects with a past history of "wheezing," "asthma," or "spastic bronchitis" were thus identified. Abnormalities in either FEV1/FVC, Vmax50 or Vmax75 were found in 40% of the subjects with a history of childhood "wheezing," "asthma," or "spastic bronchitis," but only in 8% of controls without such a history. A history of wheezing had no effect on the RV/TLC ratio. The age at which the last bout had occurred had no apparent effect on the degree of flow abnormalities. The most sensitive index for a flow abnormality was Vmax50, which was less than 74% of the predicted values in 2/(30%) of the 70 subjects tested. It is concluded that, in subjects with a history of "wheezing," "asthma," or "spastic bronchitis," flow abnormalities may persist even after prolonged remissions.

A longitudinal study of children exposed to sulfur oxides.

This study is a longitudinal comparison of the health of children exposed to markedly different concentrations of sulfur dioxide (SO2) and moderately different concentrations of particulate sulfate (SO4=). The four groups of subjects lived in two areas of one smelter town and in two other towns, one of which was also a smelter town. In the area of highest pollution, children were intermittently exposed to high SO2 levels (peak three-hour average concentration exceeded 2,500 micrograms/m3) and moderate particulate SO4= levels (average concentration was 10.1 micrograms/m3). When the children were grouped by the four gradients of pollution observed, the prevalence of cough (measured by questionnaire) correlated significantly with pollution levels (trend chi-square = 5.6, p = 0.02). No significant differences in the incidence of cough or other symptoms occurred among the groups of subjects over three years, and pulmonary function and lung function growth over the study were roughly equal among all the groups. These results suggest that intermittent elevations in SO2 concentration, in the presence of moderate particulate SO4= concentration, produced evidence of bronchial irritation in the subjects, but no chronic effect on lung function or lung function growth was detected.

Snoring in adults: some epidemiologic aspects.

Although snoring is a common problem it has received little attention in the medical literature. Therefore, a study was undertaken to determine the prevalence and epidemiologic aspects of snoring. The results showed that it is much more common than previously thought--86% of the married men and 57% of the married women were reported to snore. Overall, snoring was found to be more frequent in adult men than women, and its prevalence in adults was not related to age. It was found that 15% of the husbands and 52% of the wives were bothered by their spouse's snoring. Physicians must be made more aware of this problem and its potential effects on patients.

Wheezing bronchitis in children on a South Pacific Island.

Retrospective and prospective studies were done on children with wheezing bronchitis on the small Pacific island of Niue. Wheezing bronchitis was found to be a common cause of morbidity, but not mortality in these children. Episodes of the disease were most common in children under the age of 4 years and tended to disappear as they became older. A case-control study indicated smoking by the mother (P less than 0.0001), positive stool examination for parasites (P less than 0.001), mother with a history of wheezing bronchitis (P less than 0.01) and father smoking (P less than 0.05) were all correlated with wheezing bronchitis. Skin testing and serologic results indicated that hypersensitivity to house dust mite (Dermatophagoides pteronyssinus) and plantain (Plantago lanceolata) antigens were also associated with having wheezing bronchitis. This study demonstrates the multifactorial etiology of wheezing bronchitis on a Pacific island.

Asthma prevalence in Tokelauan children in two environments.

The prevalence of asthma has been studied in Tokelauan children aged 0--14 years in two environments--Tokelau and New Zealand. Only 11.0% of the 706 children examined in Tokelau were classified as asthmatic, whereas 25.3% of the 1,160 children seen in New Zealand were asthmatic. For those children examined in New Zealand there was no significant difference in the prevalence of asthma between those children who were born in New Zealand and those who were born in Tolelau.

Asthma and wheeze in New Zealand adolescents.

Two epidemiological surveys of New Zealand adolescents are reported. The prevalence of asthma was 7.5 percent in Rotorua and 7.9 percent in Wairoa. Additional questions asked in Wairoa identified 18.2 percent of subjects who had experienced wheeze but had not been labelled "asthma". The association of active asthma with nasal obstruction was confirmed. Wheeze which had not been labelled asthma was associated with the combination of subject's own and maternal cigarette smoking. The use of asthma medication was associated with easier geographic and socio-economic access to medical care, as well as with asthma activity.