Worldwide trends in the burden of asthma symptoms in school-aged children: Global Asthma Network Phase I cross-sectional study.

BACKGROUND: Asthma is the most common chronic disease in children globally. The Global Asthma Network (GAN) Phase I study aimed to determine if the worldwide burden of asthma symptoms is changing. METHODS: This updated cross-sectional study used the same methods as the International study of Asthma and Allergies in Childhood (ISAAC) Phase III. Asthma symptoms were assessed from centres that completed GAN Phase I and ISAAC Phase I (1993-95), ISAAC Phase III (2001-03), or both. We included individuals from two age groups (children aged 6-7 years and adolescents aged 13-14 years) who self-completed written questionnaires at school. We estimated the 10-year rate of change in prevalence of current wheeze, severe asthma symptoms, ever having asthma, exercise wheeze, and night cough (defined by core questions in the questionnaire) for each centre, and we estimated trends across world regions and income levels using mixed-effects linear regression models with region and country income level as confounders. FINDINGS: Overall, 119 795 participants from 27 centres in 14 countries were included: 74 361 adolescents (response rate 90%) and 45 434 children (response rate 79%). About one in ten individuals of both age groups had wheeze in the preceding year, of whom almost half had severe symptoms. Most centres showed a change in prevalence of 2 SE or more between ISAAC Phase III to GAN Phase I. Over the 27-year period (1993-2020), adolescents showed a significant decrease in percentage point prevalence per decade in severe asthma symptoms (-0·37, 95% CI -0·69 to -0·04) and an increase in ever having asthma (1·25, 0·67 to 1·83) and night cough (4·25, 3·06 to 5·44), which was also found in children (3·21, 1·80 to 4·62). The prevalence of current wheeze decreased in low-income countries (-1·37, -2·47 to -0·27], in children and -1·67, -2·70 to -0·64, in adolescents) and increased in lower-middle-income countries (1·99, 0·33 to 3·66, in children and 1·69, 0·13 to 3·25, in adolescents), but it was stable in upper-middle-income and high-income countries. INTERPRETATION: Trends in prevalence and severity of asthma symptoms over the past three decades varied by age group, country income, region, and centre. The high worldwide burden of severe asthma symptoms would be mitigated by enabling access to effective therapies for asthma. FUNDING: International Union Against Tuberculosis and Lung Disease, Boehringer Ingelheim New Zealand, AstraZeneca Educational Grant, National Institute for Health Research, UK Medical Research Council, European Research Council, and Instituto de Salud Carlos III.

The Global Asthma Network rationale and methods for Phase I global surveillance: prevalence, severity, management and risk factors.

The Global Asthma Network (GAN), established in 2012, followed the International Study of Asthma and Allergies in Childhood (ISAAC). ISAAC Phase One involved over 700 000 adolescents and children from 156 centres in 56 countries; it found marked worldwide variation in symptom prevalence of asthma, rhinitis and eczema that was not explained by the current understanding of these diseases; ISAAC Phase Three involved over 1 187 496 adolescents and children (237 centres in 98 countries). It found that asthma symptom prevalence was increasing in many locations especially in low- and middle-income countries where severity was also high, and identified several environmental factors that required further investigation.GAN Phase I, described in this article, builds on the ISAAC findings by collecting further information on asthma, rhinitis and eczema prevalence, severity, diagnoses, asthma emergency room visits, hospital admissions, management and use of asthma essential medicines. The subjects will be the same age groups as ISAAC, and their parents. In this first global monitoring of asthma in children and adults since 2003, further evidence will be obtained to understand asthma, management practices and risk factors, leading to further recognition that asthma is an important non-communicable disease and to reduce its global burden.

The epidemiology, healthcare and societal burden and costs of asthma in the UK and its member nations: analyses of standalone and linked national databases.

BACKGROUND: There are a lack of reliable data on the epidemiology and associated burden and costs of asthma. We sought to provide the first UK-wide estimates of the epidemiology, healthcare utilisation and costs of asthma. METHODS: We obtained and analysed asthma-relevant data from 27 datasets: these comprised national health surveys for 2010-11, and routine administrative, health and social care datasets for 2011-12; 2011-12 costs were estimated in pounds sterling using economic modelling. RESULTS: The prevalence of asthma depended on the definition and data source used. The UK lifetime prevalence of patient-reported symptoms suggestive of asthma was 29.5 % (95 % CI, 27.7-31.3; n = 18.5 million (m) people) and 15.6 % (14.3-16.9, n = 9.8 m) for patient-reported clinician-diagnosed asthma. The annual prevalence of patient-reported clinician-diagnosed-and-treated asthma was 9.6 % (8.9-10.3, n = 6.0 m) and of clinician-reported, diagnosed-and-treated asthma 5.7 % (5.7-5.7; n = 3.6 m). Asthma resulted in at least 6.3 m primary care consultations, 93,000 hospital in-patient episodes, 1800 intensive-care unit episodes and 36,800 disability living allowance claims. The costs of asthma were estimated at least £1.1 billion: 74 % of these costs were for provision of primary care services (60 % prescribing, 14 % consultations), 13 % for disability claims, and 12 % for hospital care. There were 1160 asthma deaths. CONCLUSIONS: Asthma is very common and is responsible for considerable morbidity, healthcare utilisation and financial costs to the UK public sector. Greater policy focus on primary care provision is needed to reduce the risk of asthma exacerbations, hospitalisations and deaths, and reduce costs.

Lifecourse social position and D-dimer; findings from the 1958 British birth cohort.

The aim is to examine the association of lifecourse socioeconomic position (SEP) on circulating levels of D-dimer. Data from the 1958 British birth cohort were used, social class was determined at three stages of respondents' life: at birth, at 23 and at 42 years. A cumulative indicator score of SEP (CIS) was calculated ranging from 0 (always in the highest social class) to 9 (always in the lowest social class). In men and women, associations were observed between CIS and D-dimer (P<0.05). Thus, the respondents in more disadvantaged social classes had elevated levels of D-dimer compared to respondents in less disadvantaged social class. In multivariate analyses, the association of disadvantaged social position with D-dimer was largely explained by fibrinogen, C-reactive protein and von Willebrand Factor in women, and additionally by smoking, alcohol consumption and physical activity in men. Socioeconomic circumstances across the lifecourse at various stages also contribute independently to raised levels of D-dimer in middle age in women only. Risk exposure related to SEP accumulates across life and contributes to raised levels of D-dimer. The association of haemostatic markers and social differences in health may be mediated by inflammatory and other markers.

Does initial breastfeeding lead to lower blood cholesterol in adult life? A quantitative review of the evidence.

BACKGROUND: Earlier studies have suggested that infant feeding may program long-term changes in cholesterol metabolism. OBJECTIVE: We aimed to examine whether breastfeeding is associated with lower blood cholesterol concentrations in adulthood. DESIGN: The study consisted of a systematic review of published observational studies relating initial infant feeding status to blood cholesterol concentrations in adulthood (ie, aged >16 y). Data were available from 17 studies (17 498 subjects; 12 890 breastfed, 4608 formula-fed). Mean differences in total cholesterol concentrations (breastfed minus formula-fed) were pooled by using fixed-effect models. Effects of adjustment (for age at outcome, socioeconomic position, body mass index, and smoking status) and exclusion (of nonexclusive breast feeders) were examined. RESULTS: Mean total blood cholesterol was lower (P = 0.037) among those ever breastfed than among those fed formula milk (mean difference: -0.04 mmol/L; 95% CI: -0.08, 0.00 mmol/L). The difference in cholesterol between infant feeding groups was larger (P = 0.005) and more consistent in 7 studies that analyzed "exclusive" feeding patterns (-0.15 mmol/L; -0.23, -0.06 mmol/L) than in 10 studies that analyzed nonexclusive feeding patterns (-0.01 mmol/L; -0.06, 0.03 mmol/L). Adjustment for potential confounders including socioeconomic position, body mass index, and smoking status in adult life had minimal effect on these estimates. CONCLUSIONS: Initial breastfeeding (particularly when exclusive) may be associated with lower blood cholesterol concentrations in later life. Moves to reduce the cholesterol content of formula feeds below those of breast milk should be treated with caution.

Effects of socioeconomic position on inflammatory and hemostatic markers: a life-course analysis in the 1958 British birth cohort.

The cumulative effects of socioeconomic position (SEP) on cardiovascular disease have been described, but the pathways are unclear. In this study, the authors examined the effects of life-course SEP on inflammatory and hemostatic markers: fibrinogen, C-reactive protein, von Willebrand factor antigen, and tissue plasminogen activator antigen. Data from the 1958 British birth cohort, including data on persons who underwent a biomedical follow-up in 2002-2004, were used. Social class was determined at three stages of respondents' lives: childhood (birth), early adulthood (age 23 years), and midlife (age 42 years). A cumulative indicator score of SEP was calculated that ranged from 0 (always in the highest social class) to 9 (always in the lowest social class). In men and women, associations were observed between cumulative indicator score and fibrinogen (p < 0.001), C-reactive protein (p < 0.001), von Willebrand factor antigen (p < or = 0.05), and tissue plasminogen activator antigen (p < 0.001 only in women). The trends in fibrinogen and C-reactive protein remained after adjustment for body mass index, smoking, and physical activity. However, the trends became nonsignificant for von Willebrand factor antigen and tissue plasminogen activator antigen in women. Risk exposure related to SEP accumulates across the life course and contributes to raised levels of fibrinogen and C-reactive protein, while childhood SEP influences hemostatic markers more than does adult SEP.

Atopic sensitization and the international variation of asthma symptom prevalence in children.

RATIONALE: Atopic sensitization has long been known to be related to asthma in children, but its role in determining asthma prevalence remains to be elucidated further. OBJECTIVES: To investigate the role of atopic sensitization in the large international variation in the prevalence of childhood asthma. METHODS: Cross-sectional studies of random samples of 8- to 12-year-old children (n = 1,000 per center) were performed according to the standardized methodology of Phase Two of the International Study of Asthma and Allergy in Childhood (ISAAC). Thirty study centers in 22 countries worldwide participated and reflect a wide range of living conditions, from rural Africa to urban Europe. Data were collected by parental questionnaires (n = 54,439), skin prick tests (n = 31,759), and measurements of allergen-specific IgE levels in serum (n = 8,951). Economic development was assessed by gross national income per capita (GNI). MEASUREMENTS AND MAIN RESULTS: The prevalence of current wheeze (i.e., during the past year) ranged from 0.8% in Pichincha (Ecuador) to 25.6% in Uruguaiana (Brazil). The fraction of current wheeze attributable to atopic sensitization ranged from 0% in Ankara (Turkey) to 93.8% in Guangzhou (China). There were no correlations between prevalence rates of current wheeze and atopic sensitization, and only weak correlations of both with GNI. However, the fractions and prevalence rates of wheeze attributable to skin test reactivity correlated strongly with GNI (Spearman rank-order coefficient rho = 0.50, P = 0.006, and rho = 0.74, P < 0.0001, respectively). In addition, the strength of the association between current wheeze and skin test reactivity, assessed by odds ratios, increased with GNI (rho = 0.47, P = 0.01). CONCLUSIONS: The link between atopic sensitization and asthma symptoms in children differs strongly between populations and increases with economic development.

Life-course influences on health in British adults: effects of socio-economic position in childhood and adulthood.

BACKGROUND: Little evidence exists on the role of socio-economic position (SEP) in early life on adult disease other than for cardiovascular mortality; data is often retrospective. We assess whether childhood SEP influences disease risk in mid-life, separately from the effect of adult position, and establish how associations vary across multiple measures of disease risk. METHODS: Prospective follow-up to adulthood of all born in England, Scotland and Wales during 1 week in 1958, and with medical data at age 45 years (n = 9377). Outcomes include: blood pressure, body mass index (BMI), glycosylated haemoglobin (HbA1c), total and high density lipoprotein (HDL) cholesterol, triglycerides, fibrinogen, total immunoglobulin E (IgE), one-second forced expiratory volume (FEV1), hearing threshold (4 kHz), visual impairment, symptoms of depression and anxiety, chronic widespread pain. RESULTS: Social class in childhood was associated with blood pressure, BMI, HbA1c, HDL cholesterol, triglycerides, fibrinogen, FEV1, hearing threshold, depressive symptoms and chronic widespread pain, with a general trend of deteriorating health from class I to V. Adult social class was also associated with these measures. Mutually adjusted analyses of child and adult social class suggest that both contribute to disease risk in mid-life: in general, associations for childhood class were as strong as for adult class. Individuals with a manual class at both time-points tended to have the greatest health deficits in adulthood. CONCLUSIONS: Adverse SEP in childhood is associated with a poorer health profile in mid-adulthood, independently of adult social position, and across diverse measures of disease risk and physical and mental functioning.

The predictive value of early life total immunoglobulin E measurement in identifying atopic children in a population-based birth cohort study.

Atopy is common and the prevalence amongst children is rising. Measurements in early childhood that can predict subsequent development of atopy could be clinically useful for targeting preventive measures. We used the Children in Focus (CiF) subgroup of a large population-based birth cohort study (the Avon Longitudinal Study of Parents and Children) to investigate whether total immunoglobulin E (IgE) measured at 12 and 18 months could predict subsequent development of atopy at 5 yr of age. Atopy was determined by positive skin prick test (> or = 3 mm wheal) to one or more of 14 inhalant and food allergens. Prevalence of skin prick positivity to any allergen was 14.5% (104 of 715; 95% CI: 12.0-17.1%). Total IgE levels were significantly higher at 12 months of age (p < 0.0005) but not 18 months of age in those children subsequently atopic. The highest positive predictive value was 41% with an IgE measurement of >51 kU/l, with a sensitivity of 13.5% and a specificity of 95.8%. Although significant differences in early life IgE measurements were seen, the extent of overlap was great, such that the overall performance of IgE at 12 months as a screening test for atopy was poor.

Relationship between travel time to the nearest hospital and survival from ruptured abdominal aortic aneurysms: record linkage study.

BACKGROUND: There is currently a trend in Britain to concentrate specialist services in a smaller number of hospitals in order to improve outcomes. However, for rapidly life-threatening conditions such as ruptured abdominal aortic aneurysms (RAAAs), the resulting increased travel time to hospital might adversely affect survival. This study aimed to evaluate the relationship between travel time to the nearest hospital and survival from RAAAs in West Sussex. METHODS: Information was collected regarding outcome, postcode, age, sex and diagnoses for all West Sussex residents who had a RAAA between January 1996 and September 1999, including admissions and deaths, wherever they occurred. Deprivation scores were calculated based on postcode. Potential travel time to the nearest hospital was calculated using "Microsoft AutoRoute Express" and its effect on outcome was analysed using multiple logistic regression. RESULTS: After adjusting for age, sex, Townsend deprivation score and nearest hospital, the odds ratio for survival associated with a 10 min increase in potential travel time to the nearest hospital was 0.97 (0.88 unadjusted) (95 percent confidence interval for adjusted odds ratio: 0.70 to 1.34; p = 0.86). CONCLUSION: Several previous studies suggested better survival with longer distances travelled. They are likely to be biased by omission of community deaths. This methodologically better study found no such relationship between RAAA survival and travelling time to hospital in West Sussex, although confidence intervals were wide. This is particularly pertinent while there is a push to centralize vascular and other services in the United Kingdom.

Implications of the problem orientated medical record (POMR) for research using electronic GP databases: a comparison of the Doctors Independent Network Database (DIN) and the General Practice Research Database (GPRD).

BACKGROUND: The General Practice Research Database (GPRD) and Doctor's Independent Network Database (DIN), are large electronic primary care databases compiled in the UK during the 1990s. They provide a valuable resource for epidemiological and health services research. GPRD (based on VAMP) presents notes as a series of discrete episodes, whereas DIN is based on a system (MEDITEL) that used a Problem Orientated Medical Record (POMR) which links prescriptions to diagnostic problems. We have examined the implications for research of these different underlying philosophies. METHODS: Records of 40,183 children from 141 practices in DIN and 76,310 from 464 practices in GRPD who were followed to age 5 were used to compare the volume of recording of prescribing and diagnostic codes in the two databases. To assess the importance and additional value of the POMR within DIN, the appropriateness of diagnostic linking to skin emollient prescriptions was investigated. RESULTS: Variation between practices for both the number of days on which prescriptions were issued and diagnoses were recorded was marked in both databases. Mean number of "prescription days" during the first 5 years of life was similar in DIN (19.5) and in GPRD (19.8), but the average number of "diagnostic days" was lower in DIN (15.8) than in GPRD (22.9). Adjustment for linkage increased the average "diagnostic days" to 23.1 in DIN. 32.7% of emollient prescriptions in GPRD appeared with an eczema diagnosis on the same day compared to only 19.4% in DIN; however, 86.4% of prescriptions in DIN were linked to an earlier eczema diagnosis. More specifically 83% of emollient prescriptions appeared under a problem heading of eczema in the 121 practices that were using problem headings satisfactorily. CONCLUSION: Prescribing records in DIN and GPRD are very similar, but the usage of diagnostic codes is more parsimonious in DIN because of its POMR structure. Period prevalence rates will be underestimated in DIN unless this structure is taken into account. The advantage of the POMR is that in 121 of 141 practices using problem headings as intended, most prescriptions can be linked to a problem heading providing a specific reason for their issue.