Limited agreement between written and video asthma symptom questionnaires

Association between environmental factors and current asthma, rhinoconjunctivitis and eczema symptoms in school-aged children from Oropeza Province--Bolivia: a cross-sectional study

BACKGROUND

In recent years, the prevalence of asthma, rhinoconjunctivitis and eczema symptoms in childhood has considerably increased in developing countries including Bolivia, possibly due to changes in lifestyle, environmental and domestic factors. This study aimed to assess the association between environmental factors and asthma, rhinoconjuctivitis and eczema symptoms in school-aged children from Oropeza Province in Chuquisaca, Bolivia.

METHODS

A cross-sectional study was performed in 2340 children attending the fifth grade in 36 randomly selected elementary schools in Oropeza province. The prevalence of symptoms was determined using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Environmental factors were assessed by the ISAAC environmental questionnaire including questions related to exposure to pets, farm animals, indoor and outdoor pollution, presence of disease vectors at home and precarious household conditions. Generalized linear mixed-effects models were adjusted for age, sex and place of living.

RESULTS

Thirty seven percent of children reported that at least one of their parents smoked at home. Wood or coal was used as cooking fuel in 19% of the homes and 29% reported intense truck traffic on the street where they lived. With respect to hygiene conditions, 86% reported exposure to dogs, 59% exposure to cats and 36% regular contact to farm animals. More than one precarious household condition was reported by 8% of children. In the adjusted model exposure to dog (adjusted OR 1.4; CI 95% 1.0-1.9), cat (1.2; 1.0-1.5), farm animals (1.5; 1.2-1.8); intense truck traffic (1.3; 1.0-1.6), parents smoking at home (1.2; 1.0-1.5), presence of disease vectors at home (fourth quartile vs. first quartile: 1.6; 1.2-2.3) and two or more precarious household conditions (1.5; 1.0-2.2) were significantly associated with rhinoconjunctivitis symptoms. The associations were similar for asthma and eczema symptoms; however it did not reach the level of statistical significance for all items.

CONCLUSION

Our results support previous findings reported for poor communities especially in Latin America, showing that lower hygiene conditions did not have protective effect against asthma and rhinoconjunctivitis and eczema symptoms.

Parent-reported ISAAC written questionnaire may underestimate the prevalence of asthma in children aged 10-12 years

OBJECTIVES

The aim of the present study was to compare the validity of the International Study of Asthma and Allergies in Childhood (ISAAC) written (WQ) and audiovisual questionnaires (AVQ 3.0) in two age-groups (10-12 and 13-15 years, respectively).

METHODS

The 13-15 year olds performed the self-completed the WQ and AVQ on the same day. The 10-12 year olds performed the self-completed the AVQ and the parent-completed WQ was completed by their parents. The methacholine challenge test was conducted in 10-12 year olds from one elementary school.

RESULTS

In 10-12 year olds, the AVQ detected a generally higher prevalence of asthma symptoms than WQ. In 13-15 year olds, this was reversed. In 10-12 year olds, poor agreement was found between the parent-completed WQ and the self-reported AVQ. In 13-15 year olds, moderate agreement was found between the self-reported WQ and AVQ. Low sensitivity was found, in predicting bronchial hyper-responsiveness (BHR) for all questions of both WQ and AVQ in 10-12 year olds. However, the AVQ had slightly higher sensitivity than WQ, with the exception of wheeze ever, although it was not statistically significant.

CONCLUSION

The ISAAC AVQ may be another effective instrument for assessing the prevalence of asthma symptoms in children aged 10-12 years, whereas the parent-reported-WQ may underestimate the prevalence of asthma symptoms in this age-group.

The multiple meanings of "wheezing": a questionnaire survey in Portuguese for parents and health professionals

Background

Most epidemiological studies on pediatric asthma rely on the report of "wheezing" in questionnaires. Our aim was to investigate the understanding of this term by parents and health professionals.

Methods

A cross-sectional survey was carried out in hospital and community settings within the south of Portugal. Parents or caregivers self-completed a written questionnaire with information on social characteristics and respiratory history. Multiple choice questions assessed their understanding of "wheezing". Health professionals (physicians, nurses and physiotherapists) were given an adapted version. We used bivariate analysis and multivariate models to study associations between definitions of "wheezing" and participants' characteristics.

Results

Questionnaires from 425 parents and 299 health professionals were included. The term "wheezing" was not recognized by 34% of parents, more frequently those who were younger (OR 0.4 per 10-year increment, 95% CI 0.3-0.7), had lower education (OR 3.3, 95% CI 1.5-7.4), and whose children had no history of respiratory disease (OR 4.6, 95% CI 2.5-8.7) (all ORs adjusted). 31% of parents familiar with "wheezing" either did not identify it as a sound, or did not locate it to the chest, while tactile (40%) and visual (34%) cues to identify "wheezing" were frequently used. Nurses reported using visual stimuli and overall assessments more often than physicians (p < 0.01). The geographical location was independently associated with how parents recognized and described "wheezing".

Conclusions

Different meanings for "wheezing" are recognized in Portuguese language and may be influenced by education, respiratory history and regional terminology. These findings are likely applicable to other non-English languages, and suggest the need for more accurate questionnaires and additional objective measurement instruments to study the epidemiology of wheezing disorders.

A comparison of parent-reported wheezing or shortness of breath among infants as assessed by questionnaire and physician-interview: The Generation R study

PURPOSE

The prevalence of asthma symptoms among preschool children is difficult to determine with accuracy because no gold standard is available for diagnosis. The aim of this study was to compare parent-reported wheezing or shortness of breath among infants as assessed by questionnaire and physician-interview.

METHODS

We studied 1,202 children participating in the Generation R study. Their parents completed a written questionnaire at home when the infant was 12 months old, including items on wheezing or shortness of breath. During the regular free-of-charge youth healthcare visit at age 14 months, the physician interviewed the parents to assess the presence of wheezing or shortness of breath.

RESULTS

The prevalence of wheezing or shortness of breath estimated from questionnaire was significantly higher than from physician-interview (36% vs. 20%; P < 0.001): observed agreement 73% (kappa 0.36). Only 41% of questionnaire-reported symptoms were assessed through the physician-interview, while 73% of physician-interviewed symptoms were reported in the questionnaire. Compared with infants in the subgroup with agreement on the presence of wheezing or shortness of breath, the infants in the subgroups without agreement significantly less often received anti-asthma medication and significantly less often had abnormal respiratory sounds or bronchiolitis or croup, and their mothers were significantly less often working. The proportion of infants receiving anti-asthma medication was higher in interview-data compared with questionnaire-data (22.7% vs. 3.9%; P < 0.001).

CONCLUSIONS

Questionnaire yielded higher prevalence rates for wheezing or shortness of breath than physician-interview. Physician-reported symptoms are associated with a higher proportion of infants receiving anti-asthma medication. Parent-reported asthma symptoms should be confirmed by pediatricians whenever possible.

Meteorologically estimated exposure but not distance predicts asthma symptoms in schoolchildren in the environs of a petrochemical refinery: a cross-sectional study

BACKGROUND

Community concern about asthma prompted an epidemiological study of children living near a petrochemical refinery in Cape Town, South Africa. Because of resource constraints and the complexity of refinery emissions, neither direct environmental measurements nor modelling of airborne pollutants was possible. Instead a meteorologically derived exposure metric was calculated with the refinery as the putative point source. The study aimed to determine whether (1) asthma symptom prevalences were elevated compared to comparable areas in Cape Town and (2) whether there was an association between asthma symptom prevalences and the derived exposure metric.

METHODS

A cross-sectional study was carried out of all consenting school children aged 11 to 14 years attending schools in a defined area, utilizing the International Study of Asthma and Allergy in Childhood (ISAAC) written and video questionnaires. Information was collected on potential confounders, e.g. parental history of atopic disease, active and passive smoking by the participant, birth order, number of children in the home and distance from a major road. The exposure metric combined residential distance of each child from the refinery with a wind vector in the form of wind speed, wind direction and proportion of the year blown.

RESULTS

A total of 2,361 children from 17 schools met the criteria for inclusion. In multivariate analysis, meteorologically estimated exposure (MEE), but not simple distance from the refinery, was positively associated with having to take an inhaler to school [odds ratio per interquartile range (OR) 1.22, 95% confidence interval (CI) 1.06-1.40], and with a number of video elicited asthma symptoms, including recent waking with wheezing (OR 1.33, 95% CI 1.06-1.66) and frequent wheezing at rest (OR 1.27, 95% CI 1.05 - 1.54). Symptom prevalences were higher than in other areas of the city, with frequent waking with wheezing being in great excess (OR 8.92, 95% CI 4.79-16.63).

CONCLUSION

The results support the hypothesis of an increased prevalence of asthma symptoms among children in the area as a result of refinery emissions and provide a substantive basis for community concern. The methodology also provides a low cost means of testing hypotheses about point source pollutant effects on surrounding populations of children.

Point-counterpoint. The triumph of the null hypothesis: epidemiology in an age of change

The recent confusion concerning the relation between hormone replacement therapy and cardiovascular disease has stirred a new wave of debate about the value and future of epidemiology. Opponents of epidemiology suggest an ever-diminishing role in an age of small risks and complex diseases, yet proponents are not in consensus about how to adapt their discipline to the challenges associated with ageing societies and changing disease patterns. While epidemiology is likely to be increasingly called upon to make sense of the risks involved with these changes, wading into this era with a mindset and tools that were derived from epidemiology's 'golden era' of tackling major risk factors, has created more confusion than understanding. Increasingly, we need to downsize epidemiology to what is testable, measurable, and relevant, based on robust methodology and public health rationale. Applying an evolutionary perspective, that views health problems of modernity as a manifestation of the mismatch between our ancient genes and hi-tech lifestyles, can provide guidance for a 21st century research agenda.

Systematic review of worldwide variations of the prevalence of wheezing symptoms in children

BACKGROUND

Considerable variation in the prevalence of childhood asthma and its symptoms (wheezing) has been observed in previous studies and there is evidence that the prevalence has been increasing over time.

METHODS

We have systematically reviewed the reported prevalence and time trends of wheezing symptoms among children, worldwide and within the same country over time. All studies comprising more than 1000 persons and meeting certain other quality criteria published over a 16-year period, between January 1990 and December 2005, are reported and a comparison of ISAAC (International Study of Asthma and Allergies in Childhood) and non-ISAAC studies is made, in part as a way of expanding the power to examine time trends (the older studies tend to be non-ISAAC), but also to examine possible methodological differences between ISAAC and non-ISAAC questions.

RESULTS

A wide range of current prevalence of wheeze was observed between and within countries over time. The UK had the highest recorded prevalence of 32.2% in children aged 13-14 in 1994-5 and Ethiopia had the lowest prevalence, 1.7% in children aged 10-19 in 1996. All studies in Australia and the UK were compared using multiple logistic regression. ISAAC phase I and III studies reported significantly higher prevalence of current wheeze (OR = 1.638) compared with non-ISAAC studies, after adjusting for various other factors (country, survey year, age of child, parental vs child response to the survey). Australia showed a significantly higher prevalence of current wheezing (OR = 1.343) compared with the UK, there was a significant increase in the prevalence odds ratio per survey year (2.5% per year), a significant decrease per age of child (0.7% per year), and a significantly higher response in current wheezing if the response was self-completed by the child (OR = 1.290). These factors, when explored separately for ISAAC and non-ISAAC studies, showed very different results. In ISAAC studies, or non-ISAAC studies using ISAAC questions, there was a significant decrease in current wheezing prevalence over time (2.5% per year). In non-ISAAC studies, which tend to cover an earlier period, there was a significant increase (2.6% per year) in current wheezing prevalence over time. This is very likely to be a result of prevalence of wheezing increasing from the 1970s up to the early 1990s, but decreasing since then.

CONCLUSION

The UK has the highest recorded prevalence of wheezing and Ethiopia the lowest. Prevalence of wheezing in Australia and the UK has increased from the 1970s up to the early 1990s, but decreased since then and ISAAC studies report significantly higher prevalences than non-ISAAC studies.

Allergic disorders in African countries: linking immunology to accurate phenotype

Identification and characterization of risk and protective factors for allergy is important for developing strategies for prevention or treatment. The prevalence of allergy is clearly higher in affluent countries than in developing countries like, e.g. Africa. Especially in urban areas of developing countries, allergy is however on the increase. In Africa, we have the unique opportunity to investigate risk and protective factors and the influence of urbanization and westernization, i.e. almost to take a look at Europe, Australia or the USA as they were before their allergy epidemics. Moreover, migrants from developing to affluent countries experiencing an increased burden of allergy provide new insights into risk and protective factors. Allergen exposure, diet and infections are the major exogenous influences playing a role as risk and protective factors. Depending on the nature, timing, chronicity and level of exposure, each of them can promote or inhibit allergy. Perhaps with the exception of infections, availability of data from Africa on their role in the development of allergy is limited. Detailed epidemiological studies in rural and urban Africa combined with basic immunological research are needed to unravel mechanisms of increase in allergy and of protection. The maturation of the immune system at young age under influence of exogenous factors results in differences in T-cell-skewing (Th1/Th2/Treg) and humoral responses. It is essential to perform studies from a 'non-Eurocentric' angle (e.g. local allergens, locally validated questionnaires and diagnostic procedures). Such studies will provide the affluent countries with new leads to combat the allergy epidemic and more importantly help prevent it in Africa.

Ecological association between childhood asthma and availability of indoor chlorinated swimming pools in Europe

BACKGROUND

It has been hypothesised that the rise in childhood asthma in the developed world could result at least in part from the increasing exposure of children to toxic chlorination products in the air of indoor swimming pools.

OBJECTIVES

Ecological study to evaluate whether this hypothesis can explain the geographical variation in the prevalence of asthma and other atopic diseases in Europe.

METHODS

The relationships between the prevalences of wheezing by written or video questionnaire, of ever asthma, hay fever, rhinitis, and atopic eczema as reported by the International Study of Asthma and Allergies in Childhood (ISAAC), and the number of indoor chlorinated swimming pools per inhabitant in the studied centres were examined. Associations with geoclimatic variables, the gross domestic product (GDP) per capita, and several other lifestyle indicators were also evaluated.

RESULTS

Among children aged 13-14 years, the prevalence of wheezing by written questionnaire, of wheezing by video questionnaire, and of ever asthma across Europe increased respectively by 3.39% (95% CI 1.96 to 4.81), 0.96% (95% CI 0.28 to 1.64), and 2.73% (95% CI 1.94 to 3.52), with an increase of one indoor chlorinated pool per 100 000 inhabitants. Similar increases were found when analysing separately centres in Western or Northern Europe and for ever asthma in Southern Europe. In children aged 6-7 years (33 centres), the prevalence of ever asthma also increased with swimming pool availability (1.47%; 95% CI 0.21 to 2.74). These consistent associations were not found with other atopic diseases and were independent of the influence of altitude, climate, and GDP per capita.

CONCLUSIONS

The prevalence of childhood asthma and availability of indoor swimming pools in Europe are linked through associations that are consistent with the hypothesis implicating pool chlorine in the rise of childhood asthma in industrialised countries.

Agreement between responses to a standardized asthma questionnaire and a questionnaire following a demonstration of asthma symptoms in adults

Asthma epidemiology relies heavily on standardized questionnaires, but little is known about the understanding of asthma symptoms among adults in the community. In 2004, the authors assessed the level of agreement between responses to a standardized questionnaire and responses to a questionnaire completed by participants after viewing a demonstration of asthma symptoms. The study involved 601 young adults from Chile. The field-workers were trained to explain and demonstrate the asthma symptoms to the participants. The symptoms were wheeze, waking at night with breathlessness, breathlessness following exercise, and waking with cough. The kappa statistic did not exceed 0.4, and the recorded prevalence of asthma symptoms following the demonstration was 30-60% lower than that for the standardized questionnaire. Using bronchial responsiveness as the proxy gold standard, the positive likelihood ratios for wheeze and waking short of breath were higher following symptom demonstration. The low agreement between the standardized questionnaire and the postdemonstration questionnaire and the likelihood ratios' closeness to 1 for the standardized questionnaire decreases the authors' confidence in the appropriateness of this tool for estimating the prevalence of asthma in the community. For etiologic studies of asthma, it may contribute to the lack of consistency between different studies analyzing the same etiologic exposures.

School-based asthma surveillance: a comparison of student and parental report

This study addressed the comparability of data obtained from a student-based and parent-based asthma and respiratory health survey. Our goal was to ascertain whether there were meaningful and systematic differences in asthma classification based on symptom and diagnosis reports obtained separately from students and their parents. A brief, written survey, based on the International Study of Asthma and Allergy in Children questionnaire, was administered to 6th through 10th grade students in two schools in Oakland, CA, USA. Students who reported asthma-like indicators for the previous 12-month period were defined as positive and a more extensive questionnaire was mailed home to those parents. A more refined classification of asthma based on parent report of indicators was compared with student report. Forty-four percent of 1298 students were classified as positive for current asthma-like symptoms and 50% of parent surveys were returned. For the positive students with parent surveys, 59% were classified as 'probable' for asthma based on the parent survey. Overall, the agreement between parent and students' classification was 70%, and 83% for students with a parent report of physician diagnosis of asthma. Students who were discordant with parents for physician diagnosis of asthma were more likely to be male, and more likely to have a parent report of unscheduled Emergency Department visit for wheezing or trouble breathing. Findings indicated that with the exception of medication, students reported asthma indicators more frequently that parents, independent of classification. Student report of physician diagnosis with a 12-month report of an asthma symptom was determined to be a good indicator of probable current asthma. Inclusion of or reliance on a parental questionnaire is not likely to improve the reliability of a school-based asthma surveillance program in our population.

Agreement between parental and self-completed questionnaires about asthma in teenagers

In studies of asthma in children, a common method is for the parents to complete questionnaires about their child's asthma symptoms. With longitudinal studies of asthma, children reach an age when they can complete the questionnaire themselves. The aim of this paper was to compare the prevalence of asthma symptoms as well as the agreement between responses to an asthma questionnaire completed by teenagers and their parents. As a part of the Obstructive Lung Disease in Northern Sweden Study (OLIN) pediatric study, where 3345, 13-14-yr-old children completed an asthma questionnaire, 294 (84%) randomly selected parents also completed the questionnaire, which included the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. There were no significant differences in the prevalence of wheeze in the last 12 months, ever asthma, or physician diagnosed asthma as reported by the parents compared with the teenagers. However, the teenagers reported a significantly higher prevalence of wheeze during or after exercise. The absolute agreement was generally very high while the level of agreement (kappa-value) was slightly lower. The highest results in both absolute agreement and kappa-value, were reached by the questions on diagnosis of asthma (98.9% and 0.93), use of asthma medicines (95.5% and 0.78), and whether the child ever had had asthma (97.2% and 0.86), respectively. In conclusion, the agreement between the parents' and the teenagers' responses to the asthma questionnaire was good. The change in methodology from parental to self-completion of the questionnaire did not affect the results in the study.