The prevalence of asthma has reached a plateau

Parental questionnaires provided reliable data on childhood asthma compared with national registers

BACKGROUND

Much of our knowledge of childhood asthma comes from questionnaire-based studies. Our main aim was to assess the agreement between parental-reported data at 12 years of age and data from two national Swedish registers.

METHODS

Data were obtained from the prospective, longitudinal, population-based Children of Western Sweden cohort, which focused on children born in 2003. The parents answered questionnaires at six months and one, four, eight and 12 years of age. Personal identity numbers linked 3634 children to the Swedish Prescribed Drug Register (SPDR) and the National Patient Register (NPR).

RESULTS

At 12 years of age, there was substantial overall agreement between the asthma medication reported by the parents in the questionnaire and the SPDR for any asthma medication (94.8%, kappa 0.71) and maintenance treatment (95.3%, kappa 0.68). In contrast, the agreement between the outpatient asthma diagnoses in the NPR and the questionnaire-based asthma was 30.5% and it was 32.8% between the NPR and the dispensed asthma medication in the SPDR. Hospitalization was rare for obstructive diseases after early childhood, and 38.2% of the 12-year-old children only received a short-acting beta agonist, with no maintenance treatment.

CONCLUSION

There was good agreement between the questionnaire-based data on asthma medication and the national drug register, but the National Patient Register provided incomplete information on asthma diagnoses, probably because it did not include primary care diagnoses. The results show that well-constructed parental questionnaires can provide reliable data on childhood asthma.

Maternal Vitamin D Levels during Late Pregnancy and Risk of Allergic Diseases and Sensitization during the First Year of Life-A Birth Cohort Study

Allergic diseases are the most common chronic illness in childhood. Findings from developed countries have reported associations between Vitamin D levels during pregnancy and offspring allergy risk. This prospective cohort study aimed to determine the associations between maternal Vitamin D levels during late pregnancy and allergic diseases in Malaysian infants during the first year of life. Serum 25(OH)D concentrations of 380 pregnant women in the third trimester were measured using a chemiluminescent immunoassay. Children's allergic outcomes were assessed at 3, 6, and 12 months based on parental reports. Specific IgE antibodies against food and inhalant allergens were measured in infants at 12 months of age. A total of 43.2% pregnant women were Vitamin D deficient (<30 nmol/L) and 56.8% were nondeficient (≥30 nmol/L). A total of 27.6% of the infants had eczema, 6.1% had wheeze, 27.4% had food sensitization, 10.8% had inhalant allergen sensitization, and 3.8% had IgE-mediated food allergy during the first year of life. Compared with the nondeficient group, maternal Vitamin D deficiency in late pregnancy was not associated with any allergic outcomes after adjustment for potential confounding factors. In conclusion, the present study does not support an association between maternal Vitamin D levels in late pregnancy and allergic outcomes during the first year of life.

30-year trends in asthma and the trends in relation to hospitalization and mortality

INTRODUCTION

The present study examines how trends in the prevalence of asthma during the past three decades associate with hospitalization and mortality during the same period.

METHODS

Altogether 54 320 subjects aged 25-74 years were examined in seven independent cross-sectional population surveys repeated every five years between 1982 and 2012 in Finland. The study protocol included a standardized questionnaire on self-reported asthma, smoking habits and other risk factors, and clinical measurements at the study site. Data on hospitalizations were obtained from the Care Register for Health Care, and data on mortality from the National Causes of Death register.

RESULTS

During the study, the prevalence of asthma increased - especially in women. In asthmatic compared with non-asthmatic subjects, hospitalization was significantly higher for all causes, respiratory causes, cardiovascular causes and lung cancer. In addition, particularly in asthmatic subjects, mean yearly hospital days in the 5-year periods after each survey diminished. In asthmatic subjects, the decrease in yearly all-cause hospital days was from 4.45 (between 1982 and 1987) to 1.11 (between 2012 and 2015) and in subjects without asthma the corresponding decrease was from 1.77 to 0.60 (p < 0.001). Similarly between 1982 and 2015, COPD hospitalization decreased more in asthmatic than in non-asthmatic subjects. Generally in the present study, all-cause mortality decreased between 1982 and 2015, though mortality in asthmatic subjects compared with non-asthmatics was higher from all causes, respiratory causes and lung cancer.

CONCLUSION

There was an increasing trend in the prevalence of asthma and a declining trend in hospitalization, especially in asthmatic subjects.

Prevalence, associated factors, and control level of asthma symptoms among adolescents in Northern Jordan

Objective To investigate the prevalence, associated factors, and control level of asthma in Jordanian high school students. Methods A descriptive, comparative, cross sectional design was used and a cluster sample of 2691 students (mean age = 14.5 years, 51.0% girls), drawn from eight randomly selected public high schools in Northern Jordan, participated in the study. Each student had the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire completed in the classroom between February and May, 2015. Results The prevalence of recent wheezing in the last 12 months was 11.7% whereas the prevalence of diagnosed asthma was 6.2%. About 49% of students experienced cough all the time, and 33.5% experienced waking up at night due to wheezing some of the time. About 30.9% of students reported moderate to big exercise-induced asthma. The mean total Asthma Control Test (ACT) score was 5.85 (SD = 3.56) with all of students reporting uncontrolled asthma during the last month. Higher rates of asthma symptoms were reported by females, 10th graders, and students with negative family history. Importantly, students with diagnosed asthma or recent wheezing reported higher rates of ever smoking tobacco vs. non-asthmatics (p < 0.000); dual (18.6% vs. 9.8%), cigarettes only (11.2% vs. 7.3%), and waterpipe only (18.0% vs. 14.7%). Conclusion Overall, students with asthma or wheezing had increased rates of tobacco smoking. Policies need to be set and enforced to provide a better environment for these youth, especially making all schools smoke-free zones. A multifaceted, comprehensive awareness and management program is required in schools to control and manage asthma symptoms.

Inhaled corticosteroids and bone mineral density at school age: a follow-up study after early childhood wheezing

OBJECTIVE

The aim of the study was to evaluate the association between previous use of ICS and bone mineral density (BMD) at school age in a cohort followed after early childhood wheezing.

METHODS

As part of a prospective follow-up study after hospitalization for wheezing at <24 months of age, BMD was measured in 89 children at 12.3 (median) years of age. Data on ICS use were collected by interviewing the parents, and this was supplemented with data from patient records. Cumulative doses and the duration of ICS use were calculated. Areal BMD (BMDareal , g/cm(2) ) was measured by dual energy X-ray absorptiometry (DXA), and apparent volumetric BMD (aBMDvol , g/cm(3) ) was calculated, for the lumbar spine and femoral neck. Weight, height and pubertal stage were recorded.

FINDINGS

Age, sex, and pubertal stage were significantly associated with BMDareal and aBMDvol of the lumbar spine and BMDareal of the femoral neck. The regular use of ICS for >6 months at age <6 years was associated with a lower BMD of the lumbar spine. A lower BMDareal and aBMDvol of the femoral neck were associated with higher cumulative doses of ICS at age 0-12.3 (median) years. The results were robust to adjustment for age, sex, pubertal stage, height, weight, and use of systemic steroids.

CONCLUSION

ICS use during childhood may be related to a decrease in BMD at late school age. It is important to use the lowest possible ICS dose that maintains adequate asthma control.

Trends in the prevalence of asthma

The asthma epidemic of the last few decades may have peaked; studies suggest that the incidence and prevalence of asthma has decreased in some countries in the last few years, although other studies suggest continuing small increases in prevalence. Increasing awareness and changing diagnostic habits make precise evaluation of epidemiologic trends difficult in the absence of a gold-standard test for asthma, and on a global basis uncertainty persists. Trends in prevalence in some populations (eg, immigrants, farming communities) suggest both adverse and beneficial effects of specific environmental factors. Although the effects of indoor allergens, dampness, and mold and of outdoor air pollutants, especially traffic related, have traditionally dominated risk-factor research, more recent epidemiologic and clinical studies have focused on metabolic and nutritional factors, including maternal obesity and vitamin D levels, mode of delivery and its effect on the infant microbiome, fetal and infant growth, the psychosocial environment, and medication use by mother and infant. It is likely that changes in incidence and prevalence are due to multiple factors, each contributing a relatively small effect. Longitudinal studies from pregnancy through childhood to adulthood will yield greater insights into the complex pathways leading to asthma.

Validation of asthma and eczema in population-based Swedish drug and patient registers

PURPOSE

Validated measures of asthma and eczema at the population level remain a challenge. Our aim was to ascertain if register-based information on asthma/eczema medication can function as a proxy for an asthma/eczema diagnosis and to validate register-based asthma diagnoses.

METHODS

Information was requested on all 0-45-year-old individuals with reported asthma/eczema medication and/or diagnoses in the Swedish Prescribed Drug Register and National Patient Register, between July 2005 and December 2009 (N = 250 691). Medical records for 1952 randomly selected individuals were reviewed to estimate the proportion of individuals with the following: (1) asthma/eczema medication that fulfilled predefined criteria of asthma/eczema (positive predictive value (PPV)) and (2) a register-based asthma diagnosis verified as asthma by predefined criteria.

RESULTS

Positive predictive value for asthma by predefined criteria ranged between 0.75 (95%CI: 0.70-0.78) to 0.94 (95%CI: 0.91-0.96), depending on age group. In pre-school children, PPV for asthma in combination with obstructive bronchitis was 0.87 (95%CI: 0.83-0.90), and PPV for eczema was estimated to 0.45 (95%CI: 0.38-0.51). Eighty percent of children 0-4.5 years and 99% of children >4.5-17 years with a register-based diagnosis of asthma were verified as asthmatics.

CONCLUSION

Asthma medication is a suitable proxy for asthma in older children and adults; the same approach is insufficient for eczema. This validation study of two Swedish registers opens for future large nation-wide register-based studies on asthma.