Asthma after childhood pneumonia. Cumulative prevalence was not best statistic to use.
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Biomedical subjects
Publications and source records attributed to J B Clough.
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In recent years there has been a growing interest in the measurement of pulmonary function in infants for both clinical and research purposes. Such measurements remain limited by the complexity of the equipment as well as by the technical and physiological challenges of testing infants and neonates. Despite these problems, assessment of respiratory function in early life provides exciting information about the post-natal growth and development of lungs in health and disease. The aim of this paper is to discuss the physiological, technical and ethical problems surrounding these procedures, as well as reviewing the current methods of testing pulmonary function in the very young. Consideration is given to the developments needed if infant pulmonary function tests are to realise fully, their potential as research and clinical tools.
Asthma and related allergic disorders in childhood have increased considerably in prevalence over the last few decades. During the same period of increasing morbidity from childhood asthma in the community, there have been dramatic advances in understanding of the basic immunopathologic features of the disease and consequently the development of a far more rational approach to its treatment. The immunopathologic condition of eosinophil-mediated airway inflammation is established very early in the evolution of asthma in childhood. It may even antedate the onset of symptoms. The present state of the art dictates that early intervention with potent therapies cannot be justified on the basis of symptoms alone and may in any case have no influence on the natural history of the condition. This means that current cautious therapeutic guidelines should continue to be followed. However, with the development of more accurate markers predicting ongoing disease, it will be possible to evaluate a whole range of early interventions in the future. Much evidence, though indirect, points to the possibility that the only true prophylaxis that will affect the natural history of asthma will need to be commenced before clinical features are manifest.
Asthma is one of the atopic diseases strongly associated with allergy. High aeroallergen exposure in the immediate postnatal period has been associated with higher risk of sensitization and chronic asthma. It is proposed that following in utero allergen sensitization, postnatal high dose allergen exposure localizes inflammation to the airways. In association with adjuvantizing effects of some virus infections, eosinophils and neutrophils are recruited which contribute to epithelial damage and the initiation of the remodelling process. Eventually, the latter processes lead to sufficient airway narrowing to manifest as the first symptoms of asthma. Thus, the immunopathology of asthma is fully established by the time of first symptoms and future strategies will need to identify those at risk of developing the disease before irreversible changes in the airways are established.
Active smoking is an increasing problem amongst U.K. teenagers. The smoking habits of a cohort of 14-16-year-olds were determined and the association between regular active smoking and domestic and social factors investigated. Current smoking habits of a cohort of 2289 14-16-year-olds were assessed using a simple postal questionnaire. Data concerning potential factors associated with active smoking were collected from questionnaire completed by parents. Nine hundred and sixty-nine (44.8%) children admitted to having smoked at some time, with 562 (30.0%) having smoked in the previous 12 months. Three hundred and six (14.1%) children were regular smokers and 158 (51.6% of regular smokers, 7.3% of total cohort) smoked daily. Age, number of other children in the household, parental smoking, smoking sibling(s) and living in a single parent household were all independently associated with regular smoking. Regular smoking was a significant problem amongst this cohort of teenagers. Living with other smokers, age, household size and living with one parent all predicted a regular smoking habit.
Although the earliest reliable lung function tests in infants were performed as long as 40 years ago, there has only recently been a growth in this area, as simpler methods and better equipment and IT resources have been developed. Exciting information is accumulating about the normal physiology and pathology of the infant lung. Many basic questions are still unanswered and the ability to perform these tests remains confined to a few specialized centres. To co-ordinate the development of ILFT and establish standardization in a number of areas including measurement conditions, equipment specifications, methodology protocols and data analysis, international collaboration is necessary between the teams working in this field (Table 5). Collaborative groups are currently addressing these issues and are also developing recommendations regarding the design of randomized clinical trials, multi-centre studies and research agendas. Infant lung function testing remains primarily a research tool. Our aim should be not only to refine and develop the techniques of physiological measurement but to apply ILFT to the objective study of respiratory illness in infants in the clinical setting so as to aid in the prevention and treatment of these common, debilitating and costly diseases.
The study compared the ability of characteristics defined by an asthma survey (wheeze versus cough and asthma diagnosis versus no diagnosis) to predict later respiratory problems in a cohort of 108 schoolchildren who had reported either recent wheeze or recurrent cough in a 1987 asthma survey. The children recorded daily respiratory symptoms and peak flow from April 1989 until May 1990. The frequency and severity of lower respiratory symptom episodes and peak flow dips were compared in the wheeze and cough groups and in the diagnosed versus nondiagnosed children. The independent effects of initial wheeze, atopy, diagnosis and bronchial hyperresponsiveness (BHR) on the longitudinal outcome measures were assessed using multiple linear regression. Children with initial wheeze had more chronic symptoms and peak flow variability than those with cough alone, but wheeze had only a weak effect on frequency and severity of acute lower respiratory episodes. Children with both wheeze and atopy had more acute symptomatic episodes and more chronic symptoms than did the other children. Children with diagnosed asthma (versus no diagnosis) had significantly more frequent and severe lower respiratory exacerbations, more days symptomatic and greater peak flow variability. The predictive effects of diagnosis were independent of (and stronger than the effects of) wheeze, atopy and BHR, or combinations of these variables. The results suggest that among children who report respiratory symptoms, survey-reported wheeze on its own is a weaker marker of significant respiratory disease than is a doctor's diagnosis of asthma.
Early intervention strategies in infant wheezing will be dependent on the ability to predict persistence of disease. We undertook a prospective longitudinal study to determine which factors might be predictive for the persistence of wheeze. We examined a group of 107 children 3 to 36 mo of age with at least one atopic parent. Children were recruited within 12 wk of first wheeze. Factors assessed included: personal atopy (IgE > 1 SD above age-related normal and/or eczema and/or positive skin tests); parental atopy; number of siblings; age at first wheeze; sex; serum-soluble IL-2R; proliferation of peripheral blood mononuclear cells (PBMC) to beta-lactoglobulin and to D. pteronyssinus; production of IFN-gamma on stimulation of PBMC with beta-lactoglobulin and with D. pteronyssinus. A positive clinical outcome (child requiring prophylactic antiasthma treatment after 1 yr) was observed in 53 (49.5%) children. Predictor variables were assessed by univariate and multivariate logistic regression. Wheeze was more likely to be persistent in older, atopic children with biparental atopy. The model offering best prediction of persistent wheeze with least risk of including asymptomatic subjects was age at presentation + sIL-2R. Trials of early intervention strategies using a logistic regression equation based on this model for patient recruitment can now be designed.
The asthma phenotype can be described using a combination of the following: symptom type, pattern and severity; markers of atopy; and measurement of bronchial responsiveness. Because of the very nature of the disease, symptoms of asthma are variable in both the short-and the long-term, and the natural history of the disease is such that symptoms in an individual may evolve over time through different patterns. Although atopy appears to be a life-long attribute resulting from an early life switching to a TH2 immune response, the surrogate markers of atopy each are subject to their own time-related determinants and patterns of change with age. Bronchial responsiveness in childhood is neither specific nor sensitive for asthma, and although showing good short-term repeatability, can vary widely when measured over a period of months or years. Stimuli for responsiveness testing should be chosen which can be inhaled safely in high doses so as to allow an end point to be reached by as many subjects within a population as possible, and individuals may have to be tested repeatedly over time so as to avoid misclassification.
A cohort of 2,289 children, previously studied at the age of 6-8 yr, were followed up by means of a postal questionnaire when aged 14 -16 yr to examine the association between potential risk factors and the natural history of respiratory symptoms. Children with current symptoms, persistent symptoms, and late-onset symptoms were identified and multivariate analyses were performed to determine the independent association between risk factors and these various symptom-based subgroups. Personal and family history of atopy was significantly associated with all symptom groups and with the presence of doctor-diagnosed asthma. Smoking, either active or passive, was shown to be significantly associated with current, persistent, and late-onset symptoms. Other factors shown to be significantly associated with certain symptom groups were gender (late-onset wheeze), single-parent households (current cough, persistent cough), social class (late-onset wheeze), number of children in the household (persistent wheeze, late-onset cough), number of furry pets in the household (current wheeze), birth weight (late-onset wheeze), and gas cookers (current wheeze, persistent wheeze). In a subgroup of children studied in more detail in 1987, bronchial hyperresponsiveness in 1987 was positively associated with persistent wheeze in 1995, whereas positive skin-prick testing in 1987 was not.
Investigated relations between young people's scores on the Attitudes Toward Guns and Violence Questionnaire (AGVQ; Shapiro, Dorman, Burkey, Welker, & Clough, 1997), demographic variables, and exposure to firearms and violence. 1,164 students, Grades 3 to 12, from an urban, suburban, parochial, and private school system completed anonymous self-report questionnaires in their classrooms. Boys produced higher AGVQ scores than did girls. Scores were similar in Grades 3 and 5, were much higher in Grade 6 than in Grade 5, and were similar in Grades 6 and above. This pattern was found across sex, race, and school system. African Americans obtained higher scores than Caucasians on the AGVQ and on 2 of its 4 factors. Students in the urban public schools produced higher scores than did youth in the other school systems. Both traumatic and nontraumatic exposure to firearms were associated with high AGVQ scores. Sex, grade, and firearm exposure were associated with relatively large differences, while ethnic group and school system were associated with relatively small differences.
BACKGROUND: Tobacco smoking is a major cause of preventable disease and premature death. Physicians should play an active role in the control of smoking by encouraging cessation and helping the smoker to choose the most suitable aid to cessation. AIM: To evaluate a simple, ear acupuncture treatment for the cessation of smoking. METHOD: Randomized, single-blind, placebo-controlled trial of 78 currently smoking volunteers from the general public. Volunteers attended an acupuncture clinic in a general practice setting and were given a single treatment of electroacupuncture using two needles at either an active or a placebo site plus self-retained ear seeds for two weeks. The major outcome measure was biochemically validated total cessation of smoking at six months. RESULTS: A total of 12.5% of the active treatment group compared with 0% of the placebo group ceased smoking at six months (P = 0.055, 95% confidence interval -0.033 to 0.323). CONCLUSION: This simple ear electroacupuncture treatment was significantly more effective in helping volunteers to quit smoking than placebo treatment.
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Administered the Attitudes Toward Guns and Violence Questionnaire (AGVQ) to 1,619 students in Grades 3, 5, 6, 7, 9, 11, and 12 from four demographically diverse school systems. Fifty-two of the 61 items exhibited satisfactory part-whole correlation and correlation with a validity criterion. Factor analysis revealed four main factors: Aggressive Response to Shame, Comfort With Aggression, Excitement, and Power/Safety. The instrument was reduced to 23 items by deleting items with high cross-loadings. Construct validity was similar for the longer and shorter versions. Youth who self-reported owning a gun produced scores 1.5 SD higher than nonowners. Low scores were associated with a 1 in 125 chance of gun ownership, and high scores were associated with a 1 in 3 chance. Congruency coefficients indicated similar factor structure for the present sample and a separate sample of 5th-, 7th- and 9th-grade students. These results indicate that the AGVQ is a reliable and valid measure of violence-related attitudes in young people.
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Inhaled steroids improve pulmonary function and bronchial responsiveness in older asthmatics. Data from studies using subjective outcome measures to determine the effectiveness of inhaled steroids in infants with recurrent wheezing are equivocal. Therefore, this study tested the hypothesis that beclomethasone dipropionate improves pulmonary function, including bronchial responsiveness to histamine, in recurrently wheezy infants. The study was double blind, placebo controlled lasting nine weeks. After the first baseline week, pulmonary function was measured using the rapid thoracoabdominal compression technique and bronchial responsiveness assessed with a histamine challenge test. Infants were then randomly allocated to receive doses of placebo or beclomethasone dipropionate (100 micrograms/puff) from metered aerosols. Two puffs of test aerosol were administered twice daily for eight weeks via a large volume spacer fitted with a facemask. Symptoms were recorded daily and pulmonary function and bronchial responsiveness assessed at the end of the treatment period; 50 infants, median age 12 months (range 5 to 18 months), were recruited. Twenty three in the beclomethasone dipropionate group and 15 in the placebo group completed the study and had pairs of pulmonary function measurements. Three were probable treatment failures (one beclomethasone dipropionate, two placebo), three were possible treatment failures (placebo), and others were non-compliant with study protocol. Baseline variables were not significantly different between those infants who completed the study and those who did not. Beclomethasone dipropionate and placebo groups were similar in all respects at baseline. Lung function and symptoms improved for both groups of infants during the study. Bronchial responsiveness increased significantly in the placebo group but there were not statistically significant differences between groups for any of the other outcome measures. It is concluded that beclomethasone dipropionate (400 microgram daily) via a large volume spacer does not significantly improve lung function or symptoms in recurrently wheezy infants but might hav a beneficial effect on bronchial responsiveness.
Peak expiratory flow (PEF) measurements are increasingly recommended in childhood asthma management. However, few data are available on the temporal relationship between the onset of upper and lower respiratory tract symptoms and significant falls in PEF. We wanted to determine whether falls in PEF constitute a sensitive marker for clinical episodes of respiratory morbidity. We therefore analysed data on daily PEF and respiratory symptom recording from a 12 month longitudinal study in 192 children aged 7 and 8 yrs with current respiratory symptoms. Outcome measures were number of and relationship between: 1) episodes of fall in PEF (defined as a fall in PEF for more than 2 days to < 1.5 SD below individual mean morning PEF); and 2) upper and lower respiratory tract symptom events (defined as a respiratory symptoms score of > 3 units within three consecutive days). One hundred and eight six of the 192 children completed the study. For the group as a whole, the mean number of PEF episodes per subject was 3.5, and the mean number of symptom events 8.9, with 29% of symptom events being temporally associated with a PEF episode, and 40% of PEF episodes not being accompanied by a symptom event. Forty nine percent of PEF episodes were preceded by at least two consecutive days of either upper or lower respiratory symptoms. We conclude that falls in PEF alone were not a sensitive marker for episodes of respiratory morbidity. On almost half of the occasions where PEF did fall, morbidity could have been detected at least 2 days earlier using symptom reporting.(ABSTRACT TRUNCATED AT 250 WORDS)
An important feature of "asthma" in children is the occurrence of repeated episodes of airflow obstruction lasting days or weeks. In this 1-yr longitudinal study, we investigated the nature of these episodes and their relationship to other indices of asthma. A random sample of children aged 7 and 8 yr reporting either cough or wheeze was invited to attend for skin testing. Ninety-six atopic children, half with cough and half with wheeze, and 96 nonatopic children, again half with cough and half with wheeze, were selected to join a longitudinal study. All children recorded twice daily peak expiratory flow (PEF) measurements and a daily 10-point symptom score. One hundred eighty-three children (95.3%) successfully completed the study. Episodes of respiratory morbidity, defined as falls in PEF to less than 1.5 standard deviations (SD) below subject mean lasting for more than 2 days, were identified and the 642 resulting episodes examined. Episodes were more common in autumn and winter (p = 0.003 to 0.017). The mean number of episodes per child was 3.5 (range 0 to 8): 94 (51.4%) children experienced more than three episodes, 54 (30.0%) experiencing five or more. The average duration of episodes was 4.1 days (range 2 to 27 days), with 44 (24%) subjects demonstrating episodes of average duration of 5 days or more and 18 (10%) of greater than 7 days. Episodes were more severe in children with wheeze (p = 0.013) and slightly more frequent in those with cough alone (p < 0.05). Atopy had no effect on episode frequency, duration, or magnitude.