Underdiagnosis Of Asthma Research Articles

30-day Spirometry Holter method design and prospective observational study

Asthma underdiagnosis and overdiagnosis remain significant problems for healthcare systems worldwide and indicate considerable pain points with current guidelines and diagnostic methods; therefore, new, targeted approaches seem crucial. This study introduces a novel spirometry-based approach using digital tools for objective asthma diagnosis support. This was a single-centre (Warsaw Medical University, Poland) prospective cohort study. It included adults with suspected asthma per GINA 2020, without confirmed obstruction in ambulatory spirometry. Patients were equipped and trained with a portable spirometer with built-in manoeuvre quality features AioCare® (HealthUp, Poland). The protocol included twice-daily spirometry examinations over four weeks and symptom reporting in the mobile app. The number of obstructions detected, probability of finding obstruction over time, spirometry values’ variability, technical correctness, and reported symptoms were evaluated. 26 patients enrolled (14 females, mean age 37.6 years old, BMI 24.7 kg/m^2), with a primary outcome of observed obstruction in 42% of participants (3.08 per patient, 95%CI: 0.78–5.37). The detection probability of obstruction plateaued at 100% within the first 21 days of monitoring. Diurnal PEF and FEV1 variability were exceeded (≥ 10%) in 73% and 66% of patients, respectively. 88% of participants performed over half of their tests correctly. 85% of patients reported symptoms at least once. The Spirometry Holter is a novel and feasible tool for monitoring airway limitation variability in line with GINA guidelines. It shows promise in objectively supporting asthma diagnoses in treatment-naive patients lacking documented prior obstruction.

Management of Elderly Asthma: Key Questions and Tentative Answers.

The aging lung undergoes structural changes, immunosenescence, and inflammation, rendering the elderly more susceptible to developing obstructive airway disease. Thus, asthma in those of chronological age ≥ 65 years is not rare. Elderly asthma (EA) imposes considerable burdens in terms of mortality and morbidity, and expenditure. However, clinicians lack knowledge of EA and thus often prescribe inappropriate management. In this review, we ask 3 key questions frequently encountered during EA diagnosis and treatment: 1) Is EA different?; 2) How can we appropriately diagnose EA?; 3) Are there management strategies specific to EA? Based on recent studies, we provide tentative answers as follows: 1) late-onset EA differs in clinical features and pathogenetic mechanisms from non-EA, and thus further phenotypic and endotypic characterization of EA is needed; 2) both over- and under-diagnosis of asthma in the elderly can be reduced if the objective diagnostic tests are appropriately performed; 3) cautious prescription of ICS to selected EA patients should be encouraged, and a multifaceted approach which involves increasing medical awareness and inhaler use proficiency and adherence, seeking the assistance of caregivers, and correcting micronutrient deficiencies is required to reduce acute exacerbations in EA patients.

Risk Factors for the Absence of Diagnosis of Asthma Despite Disease Symptoms: Results from the Swedish GA2LEN Study.

BackgroundAsthma is a common chronic disease presenting with airway symptoms such as wheezing, chest tightness and attacks of breathlessness. Underdiagnosis of asthma is common and correlates to negative outcomes such as a lower quality of life and reduced work capacity.PurposeThis study aims to identify factors for not being diagnosed with asthma if presenting with asthma symptoms.Patients and MethodsA questionnaire was sent to 45,000 subjects (age 16–74 years) in Sweden. Subjects who reported both wheeze and breathlessness and wheeze when not having a cold were defined as having asthma-related symptoms. Data on demographics, educational level, smoking, physical activity, comorbidities, symptoms and asthma were collected. Logistic regression was used to identify risk factors for not being diagnosed with asthma.ResultsOf the 25,391 who responded to the survey, 6.2% reported asthma-related symptoms. Of these, 946 had been diagnosed with asthma previously, while 632 had not. Independent risk factors for not being diagnosed with asthma were higher age (OR (95% CI) (2.17 (1.39–3.40))), male sex (1.46 (1.17–1.81)), current smoking (2.92 (2.22–3.84)), low level of education (1.43 (1.01–2.01)), low physical activity (1.36 (1.06–1.74)), and hypertension (1.50 (1.06–2.12)).ConclusionMen, smokers, older subjects, and those with low educational level or low physical activity are less likely to be diagnosed with asthma despite presenting asthma-related symptoms.

Exhaled volatilome analysis as a useful tool to discriminate asthma with other coexisting atopic diseases in women of childbearing age

The prevalence of asthma is considerably high among women of childbearing age. Most asthmatic women also often have other atopic disorders. Therefore, the differentiation between patients with atopic diseases without asthma and asthmatics with coexisting diseases is essential to avoid underdiagnosis of asthma and to design strategies to reduce symptom severity and improve quality of life of patients. Hence, we aimed for the first time to conduct an analysis of volatile organic compounds in exhaled breath of women of childbearing age as a new approach to discriminate between asthmatics with other coexisting atopic diseases and non-asthmatics (with or without atopic diseases), which could be a helpful tool for more accurate asthma detection and monitoring using a noninvasive technique in the near future. In this study, exhaled air samples of 336 women (training set (n = 211) and validation set (n = 125)) were collected and analyzed by thermal desorption coupled with gas chromatography-mass spectrometry. ASCA (ANOVA (analysis of variance) simultaneous component analysis) and LASSO + LS (least absolute shrinkage and selection operator + logistic regression) were employed for data analysis. Fifteen statistically significant models (p-value < 0.05 in permutation tests) that discriminated asthma with other coexisting atopic diseases in women of childbearing age were generated. Acetone, 2-ethyl-1-hexanol and a tetrahydroisoquinoline derivative were selected as discriminants of asthma with other coexisting atopic diseases. In addition, carbon disulfide, a tetrahydroisoquinoline derivative, 2-ethyl-1-hexanol and decane discriminated asthma disease among patients with other atopic disorders. Results of this study indicate that refined metabolomic analysis of exhaled breath allows asthma with other coexisting atopic diseases discrimination in women of reproductive age.

European Respiratory Society clinical practice guidelines for the diagnosis of asthma in children aged 5-16 years.

Diagnosing asthma in children represents an important clinical challenge. There is no single gold-standard test to confirm the diagnosis. Consequently, over- and under-diagnosis of asthma is frequent in children. A task force supported by the European Respiratory Society has developed these evidence-based clinical practice guidelines for the diagnosis of asthma in children aged 5-16 years using nine Population, Intervention, Comparator and Outcome (PICO) questions. The task force conducted systematic literature searches for all PICO questions and screened the outputs from these, including relevant full-text articles. All task force members approved the final decision for inclusion of research papers. The task force assessed the quality of the evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. The task force then developed a diagnostic algorithm based on the critical appraisal of the PICO questions, preferences expressed by lay members and test availability. Proposed cut-offs were determined based on the best available evidence. The task force formulated recommendations using the GRADE Evidence to Decision framework. Based on the critical appraisal of the evidence and the Evidence to Decision framework, the task force recommends spirometry, bronchodilator reversibility testing and exhaled nitric oxide fraction as first-line diagnostic tests in children under investigation for asthma. The task force recommends against diagnosing asthma in children based on clinical history alone or following a single abnormal objective test. Finally, this guideline also proposes a set of research priorities to improve asthma diagnosis in children in the future.

Coexistence of asthmatic and non-respiratory allergic symptoms in children of Batumi Region, Georgia: occurrence and association with known diagnosis of asthma

Our recent studies showed that in children in the Batumi region, Georgia, underdiagnosis of asthma is 65%, and that not all children with known asthma had a history of allergic disorders. So, we decided to assess the association of known diagnosis of paediatric asthma with asthma-like symptoms and non-respiratory allergic symptoms and diseases using questionnaire-derived data provided by respiratory health survey. Subjects of the cross-sectional population-based study were 3,239 urban and 2,113 rural children aged 5-17 years whose respiratory status was assessed using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. For children with a known diagnosis of asthma, the occurrence of respiratory symptoms suggestive of asthmatic tendency and of allergic symptoms and diseases was measured and statistical association of known asthma with the respiratory and allergic symptoms was expressed as odds ratios (OR) and their 95% confidence intervals (95% CI). Respiratory and all allergic symptoms and diseases, except for eczema, were statistically significantly (p < 0.05) more prevalent in children with asthma than in children without asthma. Based on the distribution of asthma vis-à-vis asthmatic tendency without or with allergic symptoms and allergic diseases the following odds ratios expressing likelihood of asthma were obtained: for asthmatic tendency: OR = 18.09 (95% CI: 11.82-27.68), for any allergic symptom: OR = 6.85 (95% CI: 4.69-10.02), for any allergic disease: OR = 10.75 (95% CI: 7.36-15.70), for asthmatic tendency with coexisting any allergic symptom: OR = 18.94 (95% CI: 12.96-27.68), for asthmatic tendency with coexisting any allergic disease: OR = 25.65 (95% CI: 17.47-37.67), and for asthmatic tendency with coexisting any allergic symptom and allergic disease: OR = 27.02 (95% CI: 18.18-40.15). The findings support the view that in epidemiological setting questionnaire-based studies on asthma seems to more readily identify cases in children with more severe clinical presentation of the disease and with coexisting allergic disorders, perhaps reflecting diagnostic practices of consulting paediatricians.

Symptom-based screening tool for asthma syndrome among young children in Uganda

Under-diagnosis of asthma in ‘under-fives’ may be alleviated by improved inquiry into disease history. We assessed a questionnaire-based screening tool for asthma among 614 ‘under-fives’ with severe respiratory illness in Uganda. The questionnaire responses were compared to post hoc consensus diagnoses by three pediatricians who were guided by study definitions that were based on medical history, physical examination findings, laboratory and radiological tests, and response to bronchodilators. Children with asthma or bronchiolitis were categorized as “asthma syndrome”. Using this approach, 253 (41.2%) had asthma syndrome. History of and present breathing difficulties and present cough and wheezing was the best performing combination of four questionnaire items [sensitivity 80.8% (95% CI 77.6–84.0); specificity 84.7% (95% CI 81.8–87.6)]. The screening tool for asthma syndrome in ‘under-fives’ may provide a simple, cheap and quick method of identifying children with possible asthma. The validity and reliability of this tool in primary care settings should be tested.

Asthma in Children Under 5 Years in Rural Kyrgyzstan: A Diagnostic Vacuum? a Qualitative FRESH AIR Study

Background: Worldwide, asthma is the most frequent non-communicable disease in childhood, often starting in infancy. However, asthma is underdiagnosed in children &lt;5 years of age (Under-5s) in low and middle-income countries. Aims: This study explored perceptions of, and reasons for, underdiagnosis of asthma in Under-5s in rural Kyrgyzstan. Methods: Semi-structured qualitative interviews with 22 rural primary care health professionals and 13 caregivers to Under-5s with recurrent lower respiratory tract illnesses. Results: Most health professionals and caregivers perceived asthma as a severe, debilitating, and potentially fatal disease in young children. None of the health professionals had diagnosed any Under-5s with asthma. In the health professionals’ biomedical understanding, asthma occurs predominantly in adolescents and adults, and consists of attacks of respiratory distress, with mandatory heredity and allergy. The health professionals veered away from the asthma diagnosis to avoid scaring parents, and they replaced the diagnostic vacuum with infectious diagnoses. Surprisingly, stigma regarding the population with asthma appeared to be uncommon. Most caregivers were receptive to the idea of treatment with inhaled medication and to the statement that asthma could also be a mild disease. Conclusion: The apparent systemic underdiagnosis of asthma in rural Kyrgyzstan seemed self-perpetuating. The misconceptions and dated diagnostic criteria and tradition had no provision for asthma in Under-5s; therefore, few children were diagnosed with asthma. This reinforced the inappropriate fear and belief in society that asthma is a rare, severe, and debilitating disease. Training of health professionals and providing information to the public should address the current perception of asthma and raise awareness that asthma is often a mild and treatable disease.

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

Background and objectiveA 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. MethodsSubjects 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). ResultsClinical 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. ConclusionIn 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.

Reducing childhood respiratory morbidity and mortality in low and middle income countries: a current challenge

Pneumonia overdiagnosis and asthma underdiagnosis in children should be addressed together in low resource settingshttp://bit.ly/2XPvega

Prevalence, risk factors and underdiagnosis of asthma in the general population aged over 60 years.

IntroductionBronchial asthma is one of the frequent chronic diseases in elderly persons. Global data show that 6.5–17% of the elderly suffer from asthma. However, there are no Polish data available on asthma prevalence in this group.AimThis article is a retrospective analysis of the Polish Multicentre Study of Epidemiology of Allergic Diseases (PMSEAD) results aimed at assessing prevalence and clinical characteristics in the elderly.Material and methodsThe study was conducted in 1998–1999 in 11 research centres in Poland, including the Lodz centre. The study included randomly selected subjects of both sexes. Demographics and prevalence were assessed among adults (aged 16–80 years) based on the nationwide database and the detailed clinical analysis was based on the Lodz centre database.ResultsNationwide data were obtained from 12 970 adults, including 1057 respondents in the Lodz Province; 20.3% of respondents in Poland and 23.6% in the Lodz Province were over 60 years of age. In both groups, elderly participants significantly more frequently suffered from asthma (asthma prevalence in this group was 6.7% for Poland and 12.0% for the Lodz Province). The multivariate analysis demonstrated that age over 60 years (OR = 2.08), residence in the city centre (OR = 3.30), and occurrence of seasonal allergic rhinitis (OR = 3.11) were significant risk factors for asthma occurrence among the residents of the Lodz Province. Among the elderly in Lodz, almost 50% of patients with asthma had not had a proper diagnosis made despite reporting clinical symptoms.ConclusionsIn Poland asthma is a common and frequently underdiagnosed disease in the elderly.

Underdiagnosis and Overdiagnosis of Asthma.

Asthma is diagnosed on the basis of respiratory symptoms of wheeze, cough, chest tightness, and/or dyspnea together with physiologic evidence of variable expiratory airflow limitation. The prevalence of asthma varies widely around the world, ranging from 0.2% to 21.0% in adults and from 2.8% to 37.6% in 6- to 7-year-old children. Population-based studies in children, adults, and the elderly suggest that from 20% to 70% of people with asthma in the community remain undiagnosed and hence untreated. Underdiagnosis of asthma has been found to be associated with underreporting of respiratory symptoms by patients to physicians as well as poor socioeconomic status. On the opposite side of the spectrum, studies of patients with physician-diagnosed asthma suggest that 30-35% of adults and children diagnosed with asthma do not have current asthma, suggesting that asthma is also overdiagnosed in the community. Overdiagnosis of current asthma can occur because of physicians' failure to confirm variable airflow limitation at the time of diagnosis or when sustained clinical remission of disease goes unrecognized. In this review, we define under- and overdiagnosis and explore the prevalence and burden of under- and overdiagnosis of asthma both in patients and within healthcare systems. We further describe potential solutions to prevent under- and overdiagnosis of asthma.

Clinical prediction models to support the diagnosis of asthma in primary care: a systematic review protocol

Substantial over-diagnosis and under-diagnosis of asthma in adults and children has recently been reported. As asthma is mostly diagnosed in non-specialist settings, a clinical prediction model (CPM) to aid the diagnosis of asthma in primary care may help improve diagnostic accuracy. We aim to systematically identify, describe, compare, and synthesise existing CPMs designed to support the diagnosis of asthma in children and adults presenting with symptoms suggestive of the disease, in primary care settings or equivalent populations. We will systematically search Medline, Embase and CINAHL from 1 January 1990 to present. Any CPM derived for use in a primary care population will be included. Equivalent populations in countries without a developed primary care service will also be included. The probability of asthma diagnosis will be the primary outcome. We will include CPMs designed for use in clinical practice to aid the diagnostic decision making of a healthcare professional during the assessment of an individual with symptoms suggestive of asthma. We will include derivation studies, and external model validation studies. Two reviewers will independently screen titles/abstracts and full texts for eligibility and extract data from included papers. The CHARMS checklist (or PROBAST if available) will be used to assess risk of bias within each study. Results will be summarised by narrative synthesis with meta-analyses completed if possible. This systematic review will provide comprehensive information about existing CPMs for the diagnosis of asthma in primary care and will inform the development of a future diagnostic model.

Recurrent lower respiratory illnesses among young children in rural Kyrgyzstan: overuse of antibiotics and possible under-diagnosis of asthma. A qualitative FRESH AIR study

Lower respiratory tract illnesses (LRT-illnesses) in children under 5 years (U5s) are a leading cause of morbidity, hospitalisations and mortality worldwide, particularly in low-income countries. It is pertinent to understand possible inconsistent management. This study explored perceptions and practices among caregivers and health professionals on recurrent LRT-illnesses in U5s. Semi-structured interviews with 13 caregivers to U5s with recurrent LRT-illnesses and with 22 primary care health professional interviews in two rural provinces in Kyrgyzstan were triangulated. Data were thematically analysed. The majority (8/13) of caregivers described their young children as having recurrent coughing, noisy breathing and respiratory distress of whom several had responded positively to acute salbutamol and/or had been repeatedly hospitalised for LRT-illness. Family stress and financial burdens were significant. The health professionals classified young children with recurrent LRT-illnesses primarily with pneumonia and/or a multitude of bronchitis diagnoses. Broad-spectrum antibiotics and supportive medicine were used repeatedly, prescribed by health professionals or purchased un-prescribed by the caregivers at the pharmacy. The health professionals had never applied the asthma diagnosis to U5s nor had they prescribed inhaled steroids, and none of the interviewed caregivers’ U5s were diagnosed with asthma. Health professionals and caregivers shared a common concern for the children’s recurrent respiratory illnesses developing into a severe chronic pulmonary condition, including asthma. In conclusion, the study identified an inconsistent management of LRT-illnesses in U5s, with exorbitant use of antibiotics and an apparently systemic under-diagnosis of asthma/wheeze. When the diagnosis asthma is not used, the illness is not considered as a long-term condition, requiring preventer/controller medication.

Asthma diagnosis among children along an urban-rural gradient

ABSTRACTObjective: Studies have reported lower asthma prevalence in rural compared to urban areas. While environmental factors have mostly been implicated for these differences, the lower asthma prevalence could also be linked to asthma under-diagnosis in rural children. We investigate if rural children experience under-diagnosis of asthma more compared to urban children. Methods: In 2013, we conducted a cross-sectional survey of schoolchildren across an urban-rural gradient in Saskatchewan, Canada. The participants formed sampling frame for future studies. In 2015, we approached those who gave consent in 2013 for further testing, repeated the survey, and conducted clinical testing. Based on survey responses, children were classified into “no asthma,” “at-risk-for-asthma,” and “diagnosed asthma.” We then classified asthma status as either “no asthma” or “probable asthma” based on a validated asthma algorithm. Results: The study population of 335 schoolchildren (aged 7–17 years) comprised of 73.4% from large urban, 13.7% from small urban, and 12.8% from rural areas. Proportion with report of physician-diagnosed asthma was 28.5% (Large urban), 34.8% (Small urban), and 20.9% (Rural). Mean percent predicted FEV1 and FEF25%–75% were lower in rural compared to small urban and large urban children (p < 0.05). Among those not classified as with “diagnosed asthma” by the survey, the algorithm further identified presence of asthma in 5.5% large urban, 8.1% small urban, and 18.8% rural children (p = 0.03). Conclusion: The study revealed evidence of asthma underdiagnosis in rural areas and further supports the use of objective measures in addition to symptoms history when investigating asthma across urban-rural gradients.

Evaluation of clinically and physiologically atypical asthma: If it doesn't wheeze it may still be asthma

ABSTRACTObjective: Children with asthma-like symptoms may not clinically wheeze. The objectives of this study were to evaluate if children, without physician-documented wheeze, wheeze during bronchial-challenge-testing (BCT), and if measurements of O2Sat and respiratory rate during BCT improve the BCT sensitivity? Methods: Seven hundred and twenty-four children, who were referred for suspicion of asthma, performed a BCT. Positive BCT was determined by the provocation concentration (PC) which resulted in a 20% decrease in FEV1 (PC20), (in those who were able to perform spirometry, group B), or (in those unable to perform spirometry, group A) a 50% increase in respiratory rate (PCRR), or a 5% decrease in oxygen-saturation (PCO2-Sat) or appearance of wheezing (PCwheeze). Results: Five hundred and seven BCTs were positive: group A n = 89 age, median (IQR), 3 (2.5–3.7) years (17.6%), were unable to perform spirometry, and group B n = 418 age 10.7 (6.8–15.6) years (82.4%), were able to perform spirometry. Children, without physician-documented wheeze in the total population (groups A plus B), were more likely (65.5%) to have a positive BCT without wheeze compared with those with physician-documented wheeze (41.0%, P < 0.001). In group A, adding PCRR and PCO2-Sat increased BCT sensitivity by 23.6%. Conclusions: Many children in both groups did not wheeze despite reaching BCT endpoints. Children without physician-documented wheeze tended not to wheeze at BCT. This may result in clinical under-diagnosis of asthma if depending on the presence of wheeze. In young children, adding PCRR and PCO2-Sat substantially increases BCT sensitivity and may improve asthma diagnosis.

Underdiagnosis of Asthma in Syrian Shelters in Conflict Zones–Highlighting the Need for a Healthcare Training Program

Underdiagnosis of asthma is an important public health issue, particularly in conflict zones where populations are moved into crowded shelters. A survey of people living in Syrian shelters found a high prevalence of undiagnosed asthma. This is likely due to intense exposure of cooking fumes and tobacco smoke, as well as post-traumatic stress disorder. There is a need for chronic respiratory disease care in these settings.

Socio-demographic factors related to under-diagnosis of childhood asthma in Upper Silesia, Poland.

<b>Introduction.</b> The presented study of 4,535 children aged 7-17 years in the Upper Silesian region of Poland yielded 186 cases of previously known asthma, and 44 children with newly diagnosed asthma. The aim of the presented study was to identify non-medical factors that could explain why children with a newly established diagnosis ('undiagnosed asthma') had not been diagnosed in the past. <b>Materials and method.</b> The study was performed according to a case-control design. Parents of the children answered questionnaires on socio-economic status and family-related factors. Statistical determinants of undiagnosed asthma were explored using raw (OR) and logistic odds ratios with their 95% confidence intervals (logOR, 95%CI). <b>Results.</b> Children with undiagnosed asthma were younger compared to the group with previously known asthma (11.3±2.1 vs. 12.6±2.5 years; p=0.0008). Newly diagnosed cases were more frequent in children who had less parental attention (less than 1 hour/day spent by parent with child - OR=4.36; 95%CI: 1.76-10.81) and who were not registered with specialized health care (OR=2.20; 95%CI: 0.95-5.06). Results of logistic regression analysis suggest that under-diagnosis of asthma is related to age below 12 years - logOR = 3.59 (95%CI: 1.28-10.36), distance to a health centre > 5km - logOR = 3.45 (95%CI: 1.05-11.36), time spent with child < 1 hour/day - logOR = 6.28 (95%CI: 1.98-19.91). <b>Conclusion.</b> Among non-medical determinants of undiagnosed asthma the age of a child plays a major role. Another factors of importance is the large distance between residence and health centre, and low parental attention at home.

Household biomass fuel use, asthma symptoms severity, and asthma underdiagnosis in rural schoolchildren in Nigeria: a cross-sectional observational study

BackgroundIn 2014, the International Study of Asthma and Allergies in Childhood (ISAAC) reported that the highest prevalence of symptoms of severe asthma was found in the low- and middle-income countries (LMICs), including Nigeria. While exposure to biomass fuel use may be an important risk factor in the development of asthma, its association with asthma symptoms severity has not been well-established. The aim of this study is to extend the spectrum of environmental risk factors that may be contributing towards increasing asthma morbidity, especially asthma symptoms severity in rural schoolchildren in Nigeria and to examine possible asthma underdiagnosis among this population.MethodsAuthors conducted a cross-sectional survey in three rural communities in Nigeria. Asthma symptoms were defined according to the ISAAC criteria. Information on the types of household fuel used for cooking was used to determine household cooking fuel status. Asthma symptoms severity was defined based on frequencies of wheeze, day- and night-time symptoms, and speech limitations. Logistic regression analyses were used to explore associations.ResultsA total of 1,690 Nigerian schoolchildren participated in the study. Overall, 37 (2.2%) had diagnosed asthma and 413 (24.4%) had possible asthma (asthma-related symptoms but not diagnosed asthma). Children from biomass fuel households had higher proportion of possible asthma (27.7 vs. 22.2%; p < 0.05) and symptoms of severe asthma (18.2 vs. 7.6%; p = 0.048). In adjusted analyses, biomass fuel use was associated with increased odds of severe symptoms of asthma [odds ratios (OR) = 2.37; 95% CI: 1.16–4.84], but not with possible asthma (OR = 1.22; 95% CI: 0.95–1.56).ConclusionIn rural Nigerian children with asthma symptoms, the use of biomass fuel for cooking is associated with an increased risk of severe asthma symptoms. There is additional evidence that rural children might be underdiagnosed for asthma.

Diagnostic challenges of childhood asthma.

Diagnosis of asthma in childhood is challenging. Both underdiagnosis and overdiagnosis of asthma are important issues. The present review gives information about challenging factors for an accurate diagnosis of childhood asthma. Although underdiagnosis of asthma in childhood has always been the most important diagnostic problem, overdiagnosis of asthma has also been increasingly recognized. This is probably due to diagnosis of asthma based on symptoms and signs alone. Demonstration of variable airflow obstruction by lung function tests is the most common asthma diagnostic tests used in practice and is therefore strongly recommended in children who can cooperate. Recently, an asthma guideline combining the clinical and economic evidences with sensitivity and specificity of diagnostic procedures was developed to improve accuracy of diagnosis and to avoid overdiagnosis. This guideline provided an algorithmic clinical and cost-effective approach and included fractional exhaled nitric oxide measurement as one of the diagnostic tests in addition to lung function. Diagnosis of asthma in children should be made by combining relevant history with at least two confirmatory diagnostic tests whenever possible. Diagnosis based on short-period treatment trials should be limited to young children who are unable to cooperate with these tests.