Underdiagnosis of childhood asthma: A comparison of survey estimates to clinical evaluation

Association of sleep disorders with asthma: a meta-analysis

BACKGROUND

Animal experiments and clinical trials have revealed a potential relationship between sleep disorders and asthma. However, the associations between these factors remain unclear.

MATERIAL AND METHODS

We searched PubMed, Embase, Web of Science and Cochrane Library databases for eligible studies published before 30 December 2022. Studies investigating the association between sleep disorders (insomnia, poor sleep quality and insufficient sleep time) and asthma were selected. Sleep disorders were assessed using questionnaires, interviews, or medical records. Asthma was diagnosed based on medical history and drug use. The Newcastle-Ottawa Scale and the Agency for Healthcare Research and Quality checklist were employed for quality assessment. We used OR with 95% CI as the effect measures and forest plots to display the results. Heterogeneity was evaluated using I2 statistics and subgroup analyses were performed for bias analysis. Publication bias was evaluated using the funnel plots and Egger's test.

RESULTS

Twenty-three studies were included in the primary analysis, which suggested a positive association between sleep disorders and asthma (OR: 1.38, 95% CI 1.10 to 1.74). Subgroup analyses were conducted according to the study design, age, family history of asthma and type of sleep disorders. We did not find any association between sleep disorders and asthma in children aged ˂12 years (OR: 1.13, 95% CI 0.97 to 1.32). The association was insignificant in studies where the family history of asthma was adjusted for (OR: 1.16, 95% CI 0.94 to 1.42). Funnel plot and Egger's test indicated a significant publication bias.

CONCLUSION

Sleep disorders are associated with an increased prevalence and incidence of asthma. However, the quality of the evidence was low because of potential biases.

PROSPERO REGISTRATION NUMBER

CRD42023391989.

Screening Accuracy of FeNO Measurement for Childhood Asthma in a Community Setting

(1) Background: The exhaled fractional nitric oxide is a well-recognized biomarker used in clinical settings for controlling and managing asthma. Less is known about the value of Fractional Exhaled Nitric Oxide (FeNO) measurement in epidemiological studies on childhood asthma, although available evidence suggests that an increased FeNO is associated with an increased risk of asthma. (2) Aim: The aim of the study was to assess FeNO accuracy in the identification of children with asthma, participants in a population-based respiratory survey. (3) Material and methods: The cross-sectional study included 449 children, 224 (49.9%) boys and 225 (50.1%) girls aged 6−10 years. The FeNO was measured in 449 children; Spirometry tests were completed with 441 children, but technically acceptable spirometry was done in 350. All participants fulfilled the questionnaire (ISAAC) for assessment of the status of their respiratory system on which diagnosis was based on. FeNO and Spirometry were performed according to ERS/ATS recommendations. (4) Results: The FeNO was significantly higher in asthmatic children (n = 22): 27.3 ± 21.3 ppb; with allergic rhinitis (n = 106): 9.9 ± 21.6 ppb, with atopic dermatitis (n = 67) 20.8 ± 25.0 ppb, with an asthmatic tendency (n = 27): 19.8 ± 16.0 ppb in comparison to children without any respiratory/atopy symptoms. The highest diagnostic odds ratio and area under the curve were found in any treated asthma or asthma without any atopic symptoms in relation to FeNO cutoff > 35 ppb; DOR 4.85 and 8.37; AUC 0.615 and 0.795, respectively. The adjustment for spirometry parameters did not improve the diagnostic accuracy of FeNO. In each FeNO cutoff, there were more false positive than true positive subjects. (5) Conclusions. The best diagnostic accuracy of FeNO was for isolated asthma without any atopy against children without any coexisting respiratory or allergic disease. The sensitivity and specificity did not reach the required values for a good screening tool; therefore, it should not be used in epidemiological settings.

Maternal Exposure to Polychlorinated Biphenyls and Asthma, Allergic Rhinitis and Atopic Dermatitis in the Offspring: The Environmental Health Fund Birth Cohort

Background: Polychlorinated biphenyls (PCBs) are persistent organic pollutants banned for use worldwide. Due to their biodegradation resistance, they accumulate along the food chain and in the environment. Maternal exposure to PCBs may affect the fetus and the infant. PCBs are immunotoxic and may damage the developing immune system. PCBs are associated with elevated IgE antibodies in cord blood and are considered to be predictive of atopic reactions. Several studies on the association between prenatal exposure to PCBs and atopic reactions were previously published, albeit with conflicting results. Objectives: To examine the association between maternal PCBs levels and atopic reactions in their offspring. Methods: During the years 2013-2015, a prospective birth cohort was recruited at the delivery rooms of Shamir Medical Center (Assaf Harofeh) and "Dana Dwek" Children's Hospital. Four PCBs congeners were investigated: PCBs 118, 138, 153, and 180. In 2019, when children reached the age of 4-6 years, mothers were interviewed using the ISAAC questionnaire to assess symptoms of atopic reactions, including asthma, allergic rhinitis, and atopic dermatitis. Results: One hundred and fifty mother-child dyads were analyzed. No significant differences were found in the median serum PCBs concentrations of each studied congener or total PCBs for asthma, allergic rhinitis, atopic dermatitis diagnosis, or parent-reported symptoms. No association was found between exposure to total PCBs and the risk for asthma symptoms or diagnosis, adjusted to maternal age and family member with atopic condition: aOR = 0.94, 95%CI: (0.88; 0.99). No association was observed between each studied PCB congener and asthma symptoms or diagnosis. The same results were found also for other studied outcomes-allergic rhinitis and atopic dermatitis. Conclusion: Our study joins a series of previous studies that attempt to shed light on environmental exposures in utero as influencing factors for atopic conditions in children. Our results reflect the complexity of the pathophysiology of these phenomena. No relationship between maternal serum PCBs levels was demonstrated for asthma, allergic rhinitis, or atopic dermatitis. However, additional multi-participant studies, with longer, spanning into later pediatric age follow up are needed.

Community-based asthma assessment in young children: adaptations for a multicentre longitudinal study in South Asia

Background:

Systematic assessment of childhood asthma is challenging in low- and middle-income country (LMIC) settings due to the lack of standardised and validated methodologies. We describe the contextual challenges and adaptation strategies in the implementation of a community-based asthma assessment in four resource-constrained settings in Bangladesh, India, and Pakistan.

Method:

We followed a group of children of age 6–8 years for 12 months to record their respiratory health outcomes. The study participants were enrolled at four study sites of the ‘Aetiology of Neonatal Infection in South Asia (ANISA)’ study. We standardised the research methods for the sites, trained field staff for uniform data collection and provided a ‘Child Card’ to the caregiver to record the illness history of the participants. We visited the children on three different occasions to collect data on respiratory-related illnesses. The lung function of the children was assessed in the outreach clinics using portable spirometers before and after 6-minute exercise, and capillary blood was examined under light microscopes to determine eosinophil levels.

Results:

We enrolled 1512 children, 95.5% (1476/1512) of them completed the follow-up, and 81.5% (1232/1512) participants attended the lung function assessment tests. Pre- and post-exercise spirometry was performed successfully in 88.6% (1091/1232) and 85.7% (1056/1232) of children who attempted these tests. Limited access to health care services, shortage of skilled human resources, and cultural diversity were the main challenges in adopting uniform procedures across all sites. Designing the study implementation plan based on the local contexts and providing extensive training of the healthcare workers helped us to overcome these challenges.

Conclusion:

This study can be seen as a large-scale feasibility assessment of applying spirometry and exercise challenge tests in community settings of LMICs and provides confidence to build capacity to evaluate children’s respiratory outcomes in future translational research studies.

Children with under-diagnosed asthma presenting to a pediatric emergency department

BACKGROUND

Undiagnosed asthma in children presenting to the emergency department (ED) for respiratory illnesses might be associated with subsequent asthma morbidity and repeat ED visits.

OBJECTIVE

To examine the prevalence of undiagnosed asthma among children presenting for ED care, and explore associations with sociodemographic and clinical characteristics.

METHODS

We surveyed parents of children ages 2-17 years seeking ED care for respiratory symptoms (including asthma) regarding sociodemographic characteristics, asthma symptoms, prior asthma care and morbidity, and prior asthma diagnosis. Undiagnosed asthma was defined as a positive screening for asthma and no prior diagnosis. We compared sociodemographic and clinical factors of those with diagnosed versus undiagnosed asthma using chi-square, t-tests and multivariable logistic regression model.

RESULTS

Of 362 children, 36% had undiagnosed asthma. Undiagnosed children were younger, had younger parents, and had parents less likely to speak English versus diagnosed children (all p < 0.05). Among undiagnosed children, 42% had moderate or severe asthma and 66% reported ≥1 exacerbation in the prior 12 months. Parent-reported controller medication use was higher among diagnosed versus undiagnosed children (60% vs. 21%, p=.001). In a multivariable logistic regression (adjusting for insurance, education, income and preferred language), no controller usage (aOR 4.26), no asthma exacerbations in the prior year (aOR 2.41) and younger age (aOR 0.76) were significantly associated with undiagnosed asthma.

CONCLUSION

Children presenting to the ED with undiagnosed asthma commonly experience significant prior asthma morbidity. Strategies to improve asthma diagnosis and messaging to their parents may reduce future morbidity.

Spirometry and FeNO testing for asthma in children in UK primary care: a prospective observational cohort study of feasibility and acceptability

BACKGROUND

The National Institute for Health and Care Excellence recommends the use of spirometry and measuring the fraction of exhaled nitric oxide (FeNO) as part of the diagnostic work-up for children with suspected asthma, and spirometry for asthma monitoring, across all care settings. However, the feasibility and acceptability of these tests within primary care are not known.

AIM

To investigate the feasibility, acceptability, training, and capacity requirements of performing spirometry and FeNO testing in children managed for asthma in UK primary care.

DESIGN AND SETTING

Prospective observational study involving 10 general practices in the East Midlands, UK, and 612 children between 2016 and 2017.

METHOD

Training and support to perform spirometry and FeNO in children aged 5 to 16 years were provided to participating practices. Children on the practice's asthma registers, and those with suspected asthma, were invited for a routine asthma review. Time for general practice staff to achieve competencies in performing and/or interpreting both tests, time to perform the tests, number of children able to perform the tests, and feedback on acceptability were recorded.

RESULTS

A total of 27 general practice staff were trained in a mean time of 10.3 (standard deviation 2.7) hours. Usable spirometry and FeNO results were obtained in 575 (94%) and 472 (77%) children respectively. Spirometry is achievable in the majority of children aged ≥5 years, and FeNO in children aged ≥7 years. All of the staff and 97% of families surveyed provided positive feedback for the tests.

CONCLUSION

After training, general practice staff obtained quality spirometry and FeNO data from most children tested. Testing was acceptable to staff and families. The majority of general practice staff reported that spirometry helped them to manage children's asthma better.

The burden of exacerbations in mild asthma: a systematic review

Background

Although most patients with asthma have mild disease, data on how mild asthma is defined, and how frequently exacerbations occur in this patient population are scarce, so we aimed to redress this.

Methods

We searched Medline and Medline In-Process (PubMed), and Embase in OVID for English-language publications containing “mild asthma” plus at least one relevant therapy and outcome/keyword, limited to randomised controlled trials (RCTs) and observational studies published between January 1990 and February 2019. Publications were filtered to ensure appropriate data extraction. The main outcomes were the definitions of mild asthma and exacerbations, baseline exacerbation rates and exacerbation data for placebo recipients in prospective studies. Meta-analysis of exacerbation rates was planned.

Findings

Of 4064 articles identified, 64 were included in our review (49 743 subjects); 54 RCTs and 10 observational/other studies. Six main types of definitions of mild asthma were identified. While care was taken to ensure inclusion only of patients with mild asthma, marked heterogeneity was revealed in the definitions of mild asthma and hence the study populations. Reporting of exacerbations also varied widely between studies, precluding meta-analysis. Between 0–22% of patients were hospitalised for asthma or had a severe exacerbation in the previous year, according to baseline data from prospective studies. In RCTs, severe exacerbation rates in placebo recipients taking only short-acting β₂-agonist therapy ranged from 0.20–2.88 per year.

Conclusions

These data provide new evidence of the burden of exacerbations in mild asthma and highlight the need for standardised definitions of mild asthma and of exacerbations to progress further research.

This comprehensive literature review highlights the risk of exacerbations for patients with mild asthmahttps://bit.ly/3cauSb3

Onset of asthma-like symptoms in children with lower respiratory tract infections

Background

Asthma‐like symptoms (ALS) often occur among children with lower respiratory tract infections (LRTIs). We aimed to determine the potential risk factors for ALS onset in LRTIs children.

Methods

A total of 102 LRTIs with ALS and 474 without ALS were enrolled. The relative risk (RR) was used to test the influence of the clinical factors on the ALS risk. We compared the differences of birth data, wheezing history, disease severity, inflammatory markers, infectious pathogens, allergic markers, cardiac, liver, and kidney injury markers between LRTIs with and without ALS onset. Receiver operating curve (ROC) analysis was applied to determine the predictive value of various markers in the ALS risk in LRTIs. Multivariate logistic regression analysis was performed to evaluate the association between various clinical and laboratory parameters and ALS onset in LRTIs.

Results

The RRs of boys/girls ratio and wheezing history for ALS compared with non‐ALS was 1.263 and 2.850, respectively (P = .026, <10⁻⁴). There were significant differences of age, WBC, PLT, EOS, and CK between LRTIs with and without ALS onset (P = .004, .041, .006, .049, and .035). ROC analysis showed that significant associations between the parameters of age, WBC, and PLT and ALS risk among LRTIs were observed. Multivariate logistic regression analysis showed that the clinical and laboratory parameters were not independently associated with the risk of ALS onset among LRTIs.

Conclusions

Lower age, male, inflammation, and allergic state were risk factors for ALS onset in LRTIs. Comprehensive monitoring and evaluation of these factors may be helpful for ALS prevention.

Prevalence of and factors associated with underdiagnosis of pediatric asthma in Batumi, Georgia

BACKGROUND AND OBJECTIVE

A recent survey in Batumi, Georgia showed a low prevalence of asthma in children (1.8%). A potential explanation is underdiagnosis of asthma. To investigate this, we conducted a follow up to the survey with the objective of estimating the level of childhood asthma underdiagnosis and to describe factors related to it.

METHODS

Subjects included 437 survey participants who had a history of asthma-like symptoms and no diagnosis of asthma. All children underwent clinical examination (spirometry, skin prick tests, FeNO measurement) to identify new cases of asthma. The distribution of host and environmental factors was compared between the group with newly identified asthma and a group of 59 children with previously known asthma (diagnosed asthma).

RESULTS

Clinical investigation identified 107 cases of undiagnosed asthma. The corrected asthma prevalence estimate was 5.1% (95%CI: 4.4%-5.9%) suggesting that 65% of asthma cases were undiagnosed. Compared to children with diagnosed asthma, children with undiagnosed asthma were younger (8.2±1.6 vs. 9.3±2.1; p=0.0005), had less frequent history of allergic disorders (38.3% vs. 64.4%; p=0.001), and a lower prevalence of parental asthma (1.8% vs. 8.4%; p=0.04). The groups did not differ in terms of environmental characteristics except for more exposure to passive smoking in the undiagnosed asthma group (p=0.01). Multivariate analysis confirmed results of simple analyses.

CONCLUSION

In Batumi, 65% of children with asthma remain undiagnosed. Older age of a child, coexisting allergic disorders, and parental asthma seem to facilitate diagnosis. Implementation of current diagnostic guidelines should improve diagnostic accuracy of pediatric asthma in Batumi.

Systematic Approach to Asthma of Varying Severity

Asthma is a serious global health issue and asthma guidelines recommend a stepwise approach to management with goals to achieve control and minimize future risk. Prior to escalation of pharmacotherapy, steps to confirm accurate diagnosis as well as address comorbidities and triggers are critical to effective asthma management. This article provides readers with a structured approach to evaluation and management of asthma of varying severity.

Prevalence of bronchial asthma and its associated risk factors in school-going adolescents in Tier-III North Indian City

BACKGROUND

Asthma is one of the most common chronic diseases of childhood and a major health problem not only in India but globally. Despite multifold increase in prevalence, there is paucity of data on bronchial asthma from non-metro cities. The objectives were to find prevalence of bronchial asthma and various risk factors that are associated in this age group and determine the extent of under diagnosis.

MATERIALS AND METHODS

A cross-sectional study involving 927 students from four government and three private schools was conducted using International Study of Asthma and Allergies in Childhood questionnaire.

RESULTS

Prevalence of bronchial asthma in adolescents was 13.1% (n = 121) of which 10.3% had episodes in the past 1 year. Prevalence was higher among males (8.77%) compared to females (4.33%). About 77.7% of total asthmatics were newly diagnosed cases. Prevalence was significantly higher among those having pets at home (P < 0.001), belonging to higher socioeconomic status (P = 0.021), using smoke-producing fuel at home (firewood/cow dung/kerosene; P = 0.032), and with history of smoking among family members (P = 0.035). Among current asthmatics, 72.3% reported cold/rhinitis (54.6% in March-May duration), 63.6% nocturnal dry cough, 50.5% sleep disturbances, and 38.9% speech disturbances in the past 1 year.

CONCLUSION

The study shows higher prevalence of bronchial asthma in school-going population (11-16 years) compared to other parts of Northern India possibly attributable to rapid industrialization and post harvesting season when the study was carried out. Preventive interventions need to be taken to reduce disease burden at community level.

Treatment perceptions in patients with asthma: Synthesis of factors influencing adherence

BACKGROUND

Non-adherence to asthma treatment is a contributing factor for poorly controlled asthma.

AIM

The aim of this systematic review is to explore patients' perceptions of their inhaled asthma treatment, and how these relate to adherence, using both qualitative and quantitative data.

METHODS

Pre-determined search terms and inclusion criteria were used to search electronic databases (The Cochrane Library, MEDLINE, EMBASE and PsycINFO). Two researchers screened titles and abstracts using the Rayyan web app and data were extracted in relation to psychological components (beliefs about, and attitudes towards, medicines) and adherence.

RESULTS

Of 1638 papers, 36 met the inclusion criteria. Key themes were: Perceived need for treatment - all 12 studies using the BMQ to measure patients' perceived need for treatment found that patients' beliefs about their necessity for treatment were associated with adherence-; Concerns about treatment - immediate and long-term side effects (58%), worries about safety (19%), and potential addiction to asthma medication (31%)-; and Perceived social stigma - 22% of studies reported that embarrassment contributed to poor adherence.

CONCLUSIONS

Acknowledging and addressing patient treatment beliefs and perceptual barriers to adherence is integral to designing adherence interventions for asthma patients. Further research is needed to better our understanding of the relationship between treatment perceptions and adherence.

An international comparison of risk factors between two regions with distinct differences in asthma prevalence

BACKGROUND AND PURPOSE

Investigation of the geographic variation in asthma prevalence can improve our understanding of asthma etiology and management. The purpose of our investigation was to compare the prevalence of asthma and wheeze among adolescents living in two distinct international regions and to investigate reasons for observed differences.

METHODS

A cross-sectional survey of 13-14 year olds was completed in Saskatoon, Canada (n=1200) and Skopje, Republic of Macedonia (n=3026), as part of the International Study of Asthma and Allergies in Childhood (ISAAC) Phase 3 study. Surveys were self-completed by students following the ISAAC protocol. Multiple logistic regression models were used to investigate associations with reports of asthma and current wheeze. A mediation analysis was then completed.

RESULTS

Asthma prevalence was much higher in Saskatoon than Skopje (21.3% vs. 1.7%) as was the prevalence of current wheeze (28.2% vs. 8.8%). Higher paracetamol (acetaminophen) use was a consistent risk factor for asthma and wheeze in both locations and showed dose-response relationships. In both countries, paracetamol use and physical activity mediated some of the association for both asthma and wheeze. In Saskatoon, among those with current wheeze, 42.6% reported ever having a diagnosis of asthma compared to 10.2% among Skopje adolescents.

CONCLUSIONS

The results suggest that the variation in risk factors between the two locations may explain some of the differences in the prevalence of asthma and wheeze between these two study sites. However, diagnostic labeling patterns should not be ruled out as another potential explanatory factor.

Incidence of asthma in young adults from Castellon, Spain: A prospective cohort study

BACKGROUND

The objective was to estimate the incidence of asthma in young adults from 13-15 years old to 23-25 years old, and associated factors.

METHODS

In 2012, a population-based prospective cohort study was carried out in Castellon from the cohort who had participated in the International Study of Asthma and Allergy in Childhood in 1994 and 2002. A telephone survey was undertaken using the same questionnaires. A new case of asthma was defined as a participant free of the disease in 2002 who suffered asthma, was diagnosed with asthma, or took medications against asthma based on self-report from 2002 to 2012.

RESULTS

The mean age of participants was 24.9±0.6 with a follow-up of 79.1%. Asthma cumulative incidence was 3.4%: 44 new cases occurred among 1280 participants. The incidence was higher in females than males with relative risk (RR)=2.02 (95% confidence interval [CI] 1.1-3.8). A significant decrease of asthma incidence density was observed (8.2 cases to 3.5 cases per 1000 person/year). Factors associated with the incidence of asthma were allergic rhinitis (RR=4.05; 95% CI 1.7-9.6), bronchitis (RR=2.13; 95% CI 1.0-4.5), mother's age at time of birth (RR=0.87; 95% CI 0.8-0.9) and a pet other than a dog or cat (RR=0.42; 95% CI 0.2-0.9). For gender, some variations in the risk factors were observed.

CONCLUSIONS

A significant decrease in the incidence of asthma was observed. Several risk and protective factors were found.

An international comparison of asthma, wheeze, and breathing medication use among children

BACKGROUND

There is variation in childhood asthma between countries with typically higher prevalence in "Westernized" nations. We compared asthma, respiratory symptoms, and medication prevalence in Eastern and Central European regions and Canada.

METHODS

We conducted a cross-sectional survey study of children (5-15 years) from one urban centre in each of Canada, Belarus, Poland, Republic of Georgia (Adjara), Republic of Macedonia, and Ukraine. Surveys were distributed through randomly selected schools to parents (2013-2015).

RESULTS

The prevalence of asthma differed by country from 20.6% in Canada to 1.5% in Ukraine (p < 0.001). This association remained after confounder adjustment. Except for Canada (58.7%) and Poland (42.5%), less than 10% of children with a history of wheeze had a diagnosis of asthma. Regardless of country, more than 50% of children with a diagnosis of asthma used breathing medications in the past year. Finally, except for Georgia (12.1%), all countries had a prevalence of ever wheeze above 20% (23.8% in Poland to 30.9% in Macedonia).

CONCLUSIONS

Despite large differences in asthma prevalence, respiratory morbidity was more comparable suggesting asthma prevalence may be underestimated. Further validation of asthma diagnosis is needed. It is important to promote best diagnostic practices among first contact physicians.

Asthma referrals: a key component of asthma management that needs to be addressed

Heterogeneity of asthma and difficulty in achieving optimal control are the major challenges in the management of asthma. To help attain the best possible clinical outcomes in patients with asthma, several guidelines provide recommendations for patients who will require a referral to a specialist. Such referrals can help in clearing the uncertainty from the initial diagnosis, provide tailored treatment options to patients with persistent symptoms and offer the patients access to health care providers with expertise in the management of the asthma; thus, specialist referrals have a substantial impact on disease prognosis and the patient's health status. Hurdles in implementing these recommendations include lack of their dissemination among health care providers and nonadherence to these guidelines; these hurdles considerably limit the implementation of specialist referrals, eventually affecting the rate of referrals. In this review, recommendations for specialist referrals from several key international and national asthma guidelines and other relevant published literature are evaluated. Furthermore, we highlight why referrals are not happening, how this can be improved, and ultimately, what should be done in the specialist setting, based on existing evidence in published literature.

Childhood asthma in Batumi, Georgia: Prevalence and environmental correlates

OBJECTIVE

A relative lack of data for Eastern Europe and unknown epidemiology of childhood asthma in Batumi (Georgia) justified a study aimed at determining the prevalence of physician-diagnosed asthma and related respiratory conditions, a comparison of the prevalence of these conditions between urban and rural children, and identification of their environmental correlates.

METHODS

Subjects of the cross-sectional population-based study were 3238 urban and 2081 rural children aged 5-17 years whose respiratory status was assessed using the ISAAC questionnaire.

RESULTS

The overall prevalence of asthma was larger in rural children than in urban children (2.8% vs. 1.8%, respectively; p = 0.01). Spastic bronchitis occurred with similar frequency in urban (7.8%) and rural children (6.5%). Compared with urban children, rural subjects had dry cough at night (13.1 vs 8.2%, p < 0.001) and attacks of dyspnea (4.7 vs 2.4%, p < 0.001) more often. The prevalence of other symptoms did not differ significantly between urban and rural subjects. Results of multivariate analyses showed that both asthma and spastic bronchitis were associated (p < 0.05) with parental history of asthma, dampness in the house, and poor financial standing of the family. In addition, asthma was related to coal/wood-based heating whereas spastic bronchitis was associated with passive smoking and lower parental education.

CONCLUSIONS

The findings show a low prevalence of ever-diagnosed asthma in the examined population. Nosological tradition and similar correlates of asthma and spastic bronchitis suggest that some cases of asthma might be included in the diagnostic category of spastic bronchitis.

Rural Dwelling and Temporal Trends in Relation to Childhood Asthma and Related Conditions in Belarus: A Repeated Cross-sectional Survey

There is a lack of asthma research in Belarus, with no investigation of temporal trends. The purpose of the study was to determine the prevalence of asthma and related conditions comparing urban and rural children while investigating temporal changes in the region of Grodno, Belarus. A repeated cross-sectional survey design was used. Parents completed surveys on behalf of the child. Data collection was based on the International Study of Asthma and Allergies in Children (ISAAC) survey and included 5020 urban and rural children aged 7-15 years in 2009-2010 and 4953 children in 2014 from the Grodno Region. Asthma prevalence in 2009 was 1.4% compared with 1.8% in 2014, whereas spastic bronchitis prevalence was higher (2009: 6.8%; 2014: 8.5%). After adjustment for confounders, rural dwelling showed a statistically significant inverse association with each of the allergic conditions or symptoms. However, asthma (odds ratio [OR] = 1.01, 95% confidence interval [CI] = 0.69-1.50) was not associated with rural dwelling. A diagnosis of asthma was more likely in 2014 compared with 2009 (OR = 1.57, 95% CI = 1.05-2.33), as was spastic bronchitis (OR = 1.26, 95% CI = 1.06-1.51). Maternal smoking was associated with the presence of respiratory symptoms. The data showed that the prevalence of diagnosed asthma was comparable between urban and rural areas but lower than other regions, there was generally an increase in the prevalence of asthma and related conditions, and that temporal changes did not vary by urban-rural status. The prevalence of spastic bronchitis was over 3 times higher than that of asthma. These findings also suggest that the presence of undiagnosed asthma in children is occurring in the Grodno Region.

Childhood asthma prevalence and risk factors in three Eastern European countries--the Belarus, Ukraine, Poland Asthma Study (BUPAS): an international prevalence study

Background

The prevalence of asthma and other allergic diseases among children living in Eastern is not well described. Our objective was to estimate and compare the prevalence of asthma, respiratory symptoms and allergic diseases in children in Belarus, Ukraine, and Poland as well as to identify risk factors for these conditions. We also sought to profile and compare children with asthma between locations.

Methods

Data were collected as a part of an international, multicenter, cross-sectional study of childhood asthma: The Belarus Ukraine Poland Asthma Study (BUPAS). Subjects were children aged 7–13 years attending primary and secondary schools in the urban and surrounding rural area of Grodno (Belarus), Ternopil (Ukraine) and Silesia Region (Poland). Physician-diagnosed respiratory diseases and symptoms as well as allergic diseases were ascertained using the ISAAC questionnaire completed by the parents.

Results

In total there were 4019 children from Belarus (rural: 2018, urban: 2001), 4493 from Ukraine (1972; 2521), and 4036 from Poland (2002, 2034). The overall response rate was 76.7 %. Groups were similar in case of gender and age (p > 0.05). Almost all analyzed respiratory and allergic conditions differed significantly between countries including asthma [Poland (rural, urban): 3.5 %, 4.1 %; Ukraine: 1.4 %, 2.1 %; Belarus: 1.4 %, 1.5 %], spastic bronchitis (Poland: 2.7 %, 3.2 %; Ukraine: 7.5 %, 6.5 %; Belarus: 6.4 %, 7.9 %), and chest wheeze in the last year (Poland: 4.8 %, 5.2 %; Ukraine: 11.5 %, 13.0 %; Belarus: 10.7 %, 10.0 %). These differences remained after adjustment for potential confounders. Risk factor associations were generally similar between outcomes. Symptom characteristics of children with asthma between countries were not consistent. The ratio of current wheeze:diagnosis of asthma differed by country: (Rural areas: Belarus: 10.9:1, Ukraine: 17.3:1, Poland: 2.4:1; Urban areas: Belarus: 8.1:1, Ukraine: 7.3:1 Poland: 1.9:1).

Conclusions

The findings show large between-country differences and relatively low prevalence of asthma and allergic diseases in children of Western Belarus and Ukraine. There is evidence for underdiagnosis of asthma in these regions.