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Biomedical subjects

D Strachan

Publications and source records attributed to D Strachan.

At least 55 records · Page 3Linked to original sources
PubMed1996

Study of the aetiology of wheezing illness at age 16 in two national British birth cohorts.

BACKGROUND: Data from two national British birth cohorts were used to measure the increase in prevalence of wheezing illness at age 16 between 1974 and 1986, and to investigate the role of several potential risk factors in the increase. METHODS: The occurrence of self-reported asthma or wheezy bronchitis within the past year, and the frequency of attacks of wheezing illness at age 16, were compared in 11,262 and 9266 children born in one week of 1958 and 1970, respectively. The effects of several putative risk factors for asthma--including birth weight, maternal age, birth order, breast feeding, maternal smoking in pregnancy, child's personal smoking, and father's social class--on the change in occurrence of wheezing illness at age 16 were assessed by multiple logistic regression. RESULTS: The annual period prevalence of asthma or wheezy bronchitis at age 16 increased from 3.8% in 1974 to 6.5% in 1986 (prevalence ratio (PR) = 1.71, 95% CI 1.52 to 1.93). The proportion of children experiencing attacks more than once a week increased from 0.2% to 0.7% (PR = 3.77, 95% CI 2.28 to 6.23). The prevalence of self-reported eczema and hayfever within the past year doubled between 1974 and 1986, suggesting that the increase in asthma was part of a general increase in the prevalence of atopic disease. However, in the complete dataset, after adjustment for the effects of the risk factors studied, the prevalence odds ratio for asthma or wheezy bronchitis in 1986 compared with 1974 was virtually unchanged from the unadjusted value at 1.77 (95% CI 1.46 to 2.15). CONCLUSION: The prevalence of wheezing illness in British teenagers increased by approximately 70% between 1974 and 1986. This increase appears to have occurred in the context of a general increase in atopic disease and was largely unexplained by changes in the distribution of maternal age, birth order, birth weight, infant feeding, maternal smoking, active smoking by the child, or father's social class.

Adolescent↗
PubMed1996

Long-term outcome of early childhood wheezing: population data.

The adult prognosis of early childhood wheezing is reviewed using data from three studies (in Melbourne, Tasmania and Britain) which have followed population-based samples of 7 year old children with a history of asthma or wheezing illness into their early thirties. About one quarter of these wheezy children, recruited in the 1960s, reported recent wheeze as adults, but there was considerable variation in the severity of adult wheezing in the three studies. A pattern of remissions and relapses was common over approximately 25 yrs of follow-up. Thus, teenagers who appeared to have outgrown an earlier wheezing tendency remained at risk of future wheezing, particularly if they took up cigarette smoking. Adults who have outgrown their childhood wheezing tendency have ventilatory function similar to healthy controls, suggesting that the abnormalities of neonatal airway function which precede transient wheezing in early childhood do not predict adult obstructive lung disease. In contrast, asthmatic children who continue to wheeze as adults have poorer baseline spirometry than healthy controls, even after inhaled salbutamol. The degree of reduction correlates with the duration and persistence of wheezing. Bronchial hyperresponsiveness and reduced levels of ventilatory function in childhood predict both persistence of wheeze and level of bronchial responsiveness in adult life. These may simply be markers of disease severity, but there is evidence of progressive deterioration of ventilatory function through adolescence in children with persistent symptoms. These progressive changes may underlie the observed association between chest illness in childhood and later adult life.

Adult↗
PubMed1995

Chlamydia pneumoniae: risk factors for seropositivity and association with coronary heart disease.

BACKGROUND: Two studies have suggested that seropositivity for Chlamydia pneumoniae (C. pneumoniae) is a risk factor for coronary heart disease (CHD) but the association remains tenuous. Further data is required in other populations to consolidate this observation. AIMS: Initially to determine descriptive risk factors for C. pneumoniae seropositivity in a general population sample and subsequently to examine the relation of seropositivity for this organism to CHD for the first time in a British population. SETTING: A single general practice health screening clinic and a cardiology clinic involving patients predominantly residing in south London and Surrey. SUBJECTS: 210 consecutive caucasian men (62%) and women (38%) aged 18-79 including 67 men aged 45-65. This latter group acting as controls were then also compared with 103 consecutive males aged 45-65 with angiographically confirmed coronary heart disease. METHODS: A questionnaire was administered by a research nurse and serum was analysed for IgG and IgA against C. pneumoniae and other Chlamydiae by a microimmunofluorescence test. Serum was said to be low positive at a specific IgG antibody titre of 16-32, and high positive if 64 or greater. RESULTS: Amongst the general practice health screening clinic population 14 subjects (7%) were excluded due to possible cross-reactivity with other Chlamydia species (predominantly C. trachomatis). Of the remaining 196 subjects, 13 (6%) had high positive C. pneumoniae IgG titres, 68 (35%) had low titres and 125 had no detectable antibody. After adjustment for sex, age, smoking history, social class and family size only one risk factor for high positive titres in this group was identified, which was the number of children currently living in the home (OR 2.29 (1.09-4.80), P = 0.03). No factors were significantly related to low titres. 22/100 (22%) cases with coronary heart disease and 3/64 (4.7%) of controls had high positive IgG titres for C. pneumoniae. Similarly 21% of cases and 9.4% of controls had positive C. pneumoniae specific IgA serology. 45% of cases and 44% of controls had low C. pneumoniae IgG titres. The association of CHD with a C. pneumoniae IgG titre of 64 or above was independent of all risk factors (OR 7.4 (1.7-33.1), P < 0.01). CONCLUSION: Serological evidence of C. pneumoniae infection is common amongst healthy British subjects. Smoking and social class are not important confounding variables in this study. Reinfection from contact with infected children in the home may be important in inducing higher titres in some subjects. These higher titres are more prevalent in subjects with coronary heart disease in the U.K. as reported in Finland and the U.S.A., and provide further evidence that C. pneumoniae may be important in the pathogenesis of this condition in these populations.

Adolescent↗
PubMed1995

How we do it: use of a venous cannulation needle for endoscopic Teflon injection to the vocal folds.

Since its introduction in the 1960's the injection of Teflon into a paralysed vocal fold has become a standard treatment in laryngology. Although in recent years alternative treatments have been suggested, such as the injection of collagen or autogenous fat (Mikaelian et al., 1991), re-innervation procedures and thyroplasty (Crumley, 1990), the use of Teflon is still widespread (Rontal and Rontal, 1991; Dedo, 1992). Various instruments have been developed for the application of Teflon paste and these take the form of a gun-like syringe with a ratchet mechanism. For a number of years we have injected Teflon using a needle marketed for internal jugular vein cannulation along with a plastic 1 ml syringe thus making substantial savings to our department in terms of both time and cost.

Catheterization, Central Venous↗
PubMed1995

Adult height and mortality in London: early life, socioeconomic confounding, or shrinkage?

STUDY OBJECTIVE: To examine in detail the cause specific associations between height and mortality. DESIGN: A prospective cohort study with an 18 year mortality follow up. SETTING AND PARTICIPANTS: The Whitehall study of 18,403 men in the civil service in London examined between 1967 and 1969 aged 40-64 and followed up for mortality until the end of January 1987. MAIN RESULTS: There was considerable variation in the strength of height-mortality association by cause. Respiratory disease showed the strongest inverse association, cardiovascular disease a moderate effect, and all neoplasms virtually no effect. Adjustment for age and civil service grade reduced the strength of these associations slightly, but had no impact on the heterogeneous pattern by cause (chi 2 3df p < 0.001). The height-mortality association declined with the length of follow up. By 15+ years, the only appreciable height affect was for respiratory disease mortality. CONCLUSIONS: The attenuation of the height-mortality association with length of follow up might be explained by differential height reduction before entry that was greatest for people who were already ill, and hence at greatest risk of dying. The cause specific variation in the height-mortality association lends little support to the contention that impaired growth in childhood is a marker of general susceptibility to disease in adulthood.

Adult↗
PubMed1994

The U.K. Working Party's Diagnostic Criteria for Atopic Dermatitis. II. Observer variation of clinical diagnosis and signs of atopic dermatitis.

The level of agreement between 14 physicians as to what constitutes a case of atopic dermatitis was tested on 15 selected patients with a range of diagnoses. Between-observer agreement was good, with a mean pair agreement index (P0) of 0.94, and a chance corrected index (kappa) of 0.78. Between-observer agreement in the recording of 18 separate physical signs of atopic dermatitis was then tested by asking the 14 physicians to note the presence or absence of each sign in a different group of patients to those seen in the first part of the exercise. Substantial between-observer agreement (kappa > 0.61) was only present for truncal dermatitis. Most signs showed only fair to moderate agreement (kappa 0.21-0.60), and some signs, such as keratosis pilaris, xerosis, orbital pigmentation, fine hair, and extensor dermatitis, showed poor agreement (kappa 0.01-0.20). The findings were similar when the responses of two independent observers from the national study outlined in Paper I were compared for each sign. Within-observer variation for the recording of physical signs was substantially better than between-observer variation. Physicians interested in atopic dermatitis agree reasonably well on what constitutes a typical case of atopic dermatitis. Between-observer variation with regard to some physical signs of atopic dermatitis is of a magnitude which argues against their continued use in clinical and epidemiological studies.

Dermatitis, Atopic↗
PubMed1994

Relation of Helicobacter pylori infection and coronary heart disease.

BACKGROUND: There is evidence suggesting that early life experience may influence adult risk of coronary heart disease (CHD). Chronic bacterial infections have been associated with CHD. OBJECTIVE: To determine whether Helicobacter pylori, a childhood acquired chronic bacterial infection, is associated with an increased risk of coronary heart disease in later life. DESIGN: Case-control study controlling for potential confounding variables with an opportunistically recruited control group. SUBJECTS: 111 consecutive cases with documented CHD were recruited from a cardiology clinic and 74 controls from a general practice health screening clinic. All were white men aged 45-65. METHODS: Serum was analysed for the presence of H pylori specific IgG antibodies by ELISA (98% sensitive and 94% specific for the presence of infection). RESULTS: 59% of the cases and 39% of the controls were seropositive for H pylori (odds ratio 2.28, chi 2 7.35, p = 0.007). After adjustment by multiple logistic regression for age, cardiovascular risk factors, and current social class, the effect of H pylori was little altered (odds ratio 2.15, p = 0.03). Further adjustment for various features of the childhood environment known to be risk factors for H pylori infection only slightly weakened the association (odds ratio 1.9). H pylori seropositivity was not related to the level of risk factors in the control population. CONCLUSION: In this pilot study the association of adult coronary heart disease with H pylori seropositivity suggests that the early childhood environment may be important in determining the risk of CHD in adult life. The association needs confirmation in other better designed studies. If H pylori itself is responsible for the association, then this is of great potential importance as the infection is treatable.

Aged↗
PubMed1993

The descriptive epidemiology of warts in British schoolchildren.

This study set out to determine the prevalence and predictors of warts in British schoolchildren by analysing medical examination data from a national birth cohort study of 9263 British children born 3-9 March 1958. The prevalence of visible warts, according to a medical officer, at the age of 11 was 3.9% (95% confidence intervals 3.5-4.3) and 4.9% (95% confidence intervals 4.5-5.4) at 16. Of the 364 children noted to have warts at the age of 11,337 (93%) no longer had warts at 16. Residence in the south of Britain, having a father with a non-manual occupation, being an only child, and belonging to an ethnic group other than white European were all associated with a decreased risk of visible warts. Region of residence was the strongest predictor of wart prevalence. There were no sex differences in wart prevalence. Warts represent a common source of morbidity in British schoolchildren. Future studies should take into account age, regional factors, social class, family size and ethnic group when comparing wart sufferers with other subjects.

Adolescent↗
PubMed1993

Self-reported prevalence of asthma symptoms in children in Australia, England, Germany and New Zealand: an international comparison using the ISAAC protocol.

There is a need for a standardized approach to international and regional comparisons of the prevalence and severity of asthma, and for the monitoring of asthma morbidity over time. In 1991, standardized written and video questionnaires were developed and administered in surveys of schoolchildren, aged 12-15 yrs, in five regions in four countries: Adelaide, Australia (n = 1,428); Sydney, Australia (n = 1519); West Sussex, England (n = 2,097); Bochum, Germany (n = 1928); and Wellington, New Zealand (n = 1863). The self-reported prevalence of wheezing during the previous 12 months was similar in West Sussex (29% using the written questionnaire and 30% using the video questionnaire), Wellington (28 and 36%), Adelaide (29 and 37%), and Sydney (30 and 40%), but was lower in Bochum (20 and 27%). The one year prevalence of severe wheezing limiting speech was greater in Wellington (11%), Adelaide (10%) and Sydney (13%), than in West Sussex (7%) and Bochum (6%). The self-reported one year prevalences of frequent attacks, frequent nocturnal wheezing, and doctor diagnosed asthma, were also higher in the Australasian centres than in the European centres. We conclude, that an international comparison of asthma symptom prevalence in childhood, using simple standardized instruments, is feasible. Possible explanations for the differences in reported asthma severity between the Australasian and European centres include differences in exposure to risk factors and differences in the management of asthma.

Adolescent↗
PubMed1993

Are viral warts seen more commonly in children with eczema?

BACKGROUND AND DESIGN: We sought to test the hypothesis that warts are seen more commonly in individuals with eczema by analyzing skin examination data from a national birth cohort study of 9263 British children born between March 3 and 9, 1958. RESULTS: Warts were seen less frequently in those with visible eczema at ages 11 and 16 years (relative risk, 0.60; 95% confidence intervals, 0.37 to 0.95; P = .03). This inverse association persisted after adjustment for potential confounders and was consistent within each age and sex group for children with a history of eczema who did not have visible eczema at the time of examination and for children with asthma/wheezy bronchitis regardless of eczema status. Visible acne or psoriasis was not associated with a decreased prevalence of warts. CONCLUSIONS: These findings contradict previous suggestions of an increased risk of viral warts in atopic eczema and raise new questions regarding the role of cell-mediated immunity in atopic subjects.

Acne Vulgaris↗
PubMed1992

Childhood living conditions and Helicobacter pylori seropositivity in adult life.

Infection with Helicobacter pylori increases an individual's risk of peptic ulceration and gastric cancer. In the developed world, prevalence of infection rises with age and varies with social class. We used a cross-sectional study design to test the hypothesis that H pylori infection would be more closely associated with childhood living conditions than with current socioeconomic status. Prevalence of IgG antibodies against H pylori was determined with an enzyme-linked immunosorbent assay in 215 subjects (median age 46 years, range 18-82) attending a health-screening clinic in London. Seropositivity varied from 9% (age less than 30) to 67% (greater than or equal to 70). Subjects were asked about their living conditions at present and when they were aged 8 years. Absence of a fixed hot-water supply (p = 0.0005) and domestic crowding (p = 0.0005) in childhood were powerful independent risk factors for current infection with H pylori. Among current living conditions, only the number of children living in the household was independently associated with H pylori infection (p = 0.004). Most British adults infected with H pylori probably became infected by household contact in childhood.

Adult↗
PubMed1992

Surgical experience with juvenile nasopharyngeal angiofibroma.

A retrospective analysis was made of 24 cases of nasopharyngeal angiofibroma treated by the ENT Department of the Hospital de Clínicas de Porto Alegre between 1975 and 1989. All the patients were male with an average age of 16. All were treated by surgery alone, with an average peri-operative blood loss of 1,784 ml; pre-operative embolization made no significant difference to the blood loss. No other operative complications were encountered. Five patients (21%) had a recurrence, one of which was intracranial and required further surgery to effect a cure. The average length of follow-up was 19 months. We believe that surgical excision must be the treatment of choice for nasopharyngeal angiofibroma.

Adolescent↗
PubMed1991

Strategies of prevention revisited: effects of imprecise measurement of risk factors on the evaluation of "high-risk" and "population-based" approaches to prevention of cardiovascular disease.

Imprecise measurement of risk factors causes misclassification of individuals, limits sensitivity to detect those with high true levels, and dilutes associations between risk factors and disease. The implications of these effects for two particular examples were explored using data from a large prospective study relating plasma cholesterol to coronary heart disease (CHD) mortality and diastolic blood pressure (DBP) to fatal stroke. The absolute and relative effectiveness of three "high-risk" strategies of screening and treatment and a "population-based" shift in the risk factor distribution were compared, assuming different degrees of measurement error. The absolute benefits of each strategy were greater than suggested by unadjusted estimates from survey data. For cholesterol and CHD (a linear relationship in this cohort), uncorrected estimates tended to exaggerate the effectiveness of "high-risk" strategies relative to the "population-based" approach. For DBP and stroke (an exponential relationship), the relative effectiveness of screening and treatment was underestimated if no allowance was made for measurement error. These findings are strictly applicable only to the middle-aged men from whom they were derived, but the effects of misclassification and regression dilution need to be considered in any assessment of preventive strategies.

Adult↗
PubMed1989

Respiratory symptoms as predictors of 27 year mortality in a representative sample of British adults.

OBJECTIVE: To examine associations between reported respiratory symptoms (as elicited by questionnaire) and subsequent mortality. DESIGN: Prospective cohort study. SETTING: 92 General practices in Great Britain. PARTICIPANTS: A nationally representative sample of 1532 British men and women aged between 40 and 64. MAIN OUTCOME MEASURES: Mortality from all causes, cardiovascular disease, lung cancer, and chronic bronchitis. RESULTS: Subjects were interviewed in 1958 regarding various respiratory symptoms (including cough, phlegm, breathlessness, and wheeze) by using a questionnaire which formed the basis of the Medical Research Council's questionnaire on respiratory symptoms. By the end of 1985, 889 deaths had been reported, including 51 in men due to chronic bronchitis. After adjustment for differences in age and smoking habits death rates from chronic bronchitis in men who reported symptoms were greater than those in men who did not for each of the symptoms examined. The adjusted mortality ratios were 3.4 (95% confidence interval 1.8 to 6.5) for morning cough, 3.7 (2.0 to 6.9) for morning phlegm, 6.4 (3.0 to 13.8) for breathlessness when walking on the level, and 10.5 (4.4 to 24.6) for wheeze most days or nights. Mortality ratios were also significantly raised for four episodic symptoms not usually included in more recent respiratory symptom questionnaires--namely, occasional wheeze (mortality ratio 6.0; 95% confidence interval, 2.4 to 15.1), weather affects chest (5.7; 3.1 to 10.3), breathing different in summer (4.9; 2.8 to 8.6), and cold usually goes to chest (3.7; 2.0 to 6.8). The excess mortality associated with these symptoms remained significant after further adjustment for breathlessness or phlegm. Ratios for all cause mortality in men and women were also significantly raised for most respiratory symptoms, death rates being some 20-50% higher in people reporting symptoms after adjustment for age, sex, and smoking. Breathlessness was the only symptom significantly associated with excess mortality from cardiovascular disease (mortality ratio 1.4 (95% confidence interval 1.0 to 1.9) for breathlessness when walking on the level). Ratios were generally around unity and not significant for mortality due to lung cancer. CONCLUSIONS: The results suggest that episodic symptoms, which often do not appear in standard respiratory questionnaires, predict subsequent mortality from chronic obstructive airways disease. This supports the hypothesis that reversible airflow obstruction may be a precursor of progressive and irreversible decline in ventilatory function.

Adult↗