Asthma-related Outcomes In Children Research Articles

The Association Between Urinary Concentrations of Organophosphate Metabolites and Asthma-Related Outcomes Among Schoolchildren From Informal Settlements.

Objectives: There is inconsistent evidence on the relationship between pesticide exposure and childhood respiratory outcomes in non-agricultural settings. This study investigated the association between organophosphate (OP) pesticide exposure and asthma-related outcomes in children residing in four informal settlements. Methods: The study was a longitudinal study of 590 schoolchildren, with a 12months follow-up period. A standardised questionnaire adopted from the International Study of Asthma and Allergies in Childhood was administered to caregivers for child's respiratory symptoms and household characteristics. Spirometry and fractional-exhaled nitric oxide, including a phadiatop test (atopy status) and urinary dialkyl phosphate (DAP) metabolites were measured at baseline and follow-up. DAP metabolites included diethylphosphate (DEP) and dimethyl phosphate (DMP) measured at baseline and follow-up and dimethylthiophosphate (DMTP) measured only at baseline. Results: The mean ages of schoolchildren were 9.9 ± 0.91years and the overal incidence proportions of new doctor diagnosed asthma was 2.2%. No consistent patterns of increased risk of asthma outcomes with increasing DAP concentrations was found in multivariate analysis. Conclusion: Future studies with longer follow-up periods and repeated OP biomonitoring are recommended.

The challenges and facilitators of self-management in pediatric asthma.

Self-management education in asthma can dramatically reduce asthma morbidity, but specific pediatric challenges need to be addressed. The purpose of this review is to discuss the most recent and significant advances regarding self-management interventions in pediatric asthma. Recent evidence supports school-based programs including asthma self-management skills for children to significantly improve asthma control. A defined theoretical intervention framework, parent involvement, child satisfaction, and running the intervention outside the child's own free time are suggested drivers of successful implementation. Real-time telemedically delivered asthma education may also improve asthma-related outcomes in children. Moreover, mobile applications supporting self-management are generally welcomed by children and parents. Current evidence supports the use of models of health behaviors change in mobile application design and content development; self-monitoring alone is ineffective but useful when coupled with decision support for proactive care. School-based and e-health interventions are potential facilitators for the implementation of successful self-management asthma programs, providing access to large numbers of children with asthma. This supports the healthcare practitioners to work together with researchers to promote these interventions, while following current recommendations for the effective transition of children into competent and confident adults to continue to successfully self-manage their asthma.

Tailoring asthma treatment on eosinophilic markers (exhaled nitric oxide or sputum eosinophils): a systematic review and meta-analysis

BackgroundAsthma guidelines guide health practitioners to adjust treatments to the minimum level required for asthma control. As many people with asthma have an eosinophilic endotype, tailoring asthma medications based on...

Ambient Air Pollution and Asthma-Related Outcomes in Children of Color of the USA: a Scoping Review of Literature Published Between 2013 and 2017.

Given racial disparities in ambient air pollution (AAP) exposure and asthma risk, this review offers an overview of the literature investigating the ambient air pollution-asthma relationship in children of color between 2013 and 2017. AAP is likely a key contributor to the excess burden of asthma in children of color due to pervasive exposure before birth, at home, and in school. Recent findings suggest that psychosocial stressors may modify the relationship between AAP and asthma. The effect of AAP on asthma in children of color is likely modulated by multiple unique psychosocial stressors and gene-environment interactions. Although children of color are being included in asthma studies, more research is still needed on impacts of specific criteria pollutants throughout the life course. Additionally, future studies should consider historical factors when analyzing current exposure profiles.

Tailored interventions based on sputum eosinophils versus clinical symptoms for asthma in children and adults.

Asthma severity and control can be measured both subjectively and objectively. Sputum analysis for evaluation of percentage of sputum eosinophilia directly measures airway inflammation, and is one method of objectively monitoring asthma. Using sputum analysis to adjust or tailor asthma medications is potentially superior to traditional methods based on symptoms and spirometry. To evaluate the efficacy of tailoring asthma interventions based on sputum analysis in comparison to traditional methods (usually symptom-based with or without spirometry/peak flow) for asthma-related outcomes in children and adults. We searched the Cochrane Airways Group Specialised Register of Trials, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, trials' registries, and reference lists of articles. The last search was conducted in February 2017. All randomised controlled comparisons of adjustment of asthma therapy based on sputum eosinophils compared to traditional methods (primarily clinical symptoms and spirometry/peak flow). Results of searches were reviewed against pre-determined criteria for inclusion. In this update, two reviewers selected relevant studies, independently assessed trial quality and extracted the data. We contacted authors for further information when relevant. We analysed data as 'treatment received' and performed sensitivity analyses. Three new studies were added in this update, resulting in a total of six included studies (five in adults and one involving children/adolescents). These six studies were clinically and methodologically heterogeneous (use of medications, cut-off for percentage of sputum eosinophils and definition of asthma exacerbation). Of 374 participants randomised, 333 completed the trials. In the meta-analysis, there was a significant reduction in the occurrence of any exacerbations when treatment was based on sputum eosinophil counts, compared to that based on clinical symptoms with or without lung function; pooled odds ratio (OR) was 0.57 (95% confidence interval (CI) 0.38 to 0.86). The risk of having one or more exacerbations over 16 months was 82% in the control arm and 62% (95% CI 49% to 74%) in the sputum strategy arm, resulting in a number needed to treat to benefit (NNTB) of 6 (95% CI 4 to 13).There were also differences between the groups in the rate of exacerbation (any exacerbation per year) and severity of exacerbations defined by requirement for use of oral corticosteroids and hospitalisations: the risk of one or more hospitalisations over 16 months was 24% in controls compared to 8% (95% CI 3% to 21%) in the sputum arm. Data for clinical symptoms, quality of life and spirometry were not significantly different between groups. The mean dose of inhaled corticosteroids per day was also similar in both groups. However sputum induction was not always possible. The included studies did not record any adverse events.One study was not blinded and thus was considered to have a high risk of bias. However, when this study was removed in a sensitivity analysis, the difference between the groups for the primary outcome (exacerbations) remained statistically significant between groups. The GRADE quality of the evidence ranged from moderate (for the outcomes 'Occurrence of any exacerbation' and 'Hospitalisation' ) to low (for the outcome 'Mean dose of inhaled corticosteroids per person per day') due to the inconsistency in defining exacerbations and the small number of hospital admissions. In this updated review, tailoring asthma interventions based on sputum eosinophils is beneficial in reducing the frequency of asthma exacerbations in adults with asthma. Adults with frequent exacerbations and severe asthma may derive the greatest benefit from this additional monitoring test, although we were unable to confirm this through subgroup analysis. There is insufficient data available to assess tailoring asthma medications based on sputum eosinophilia in children.Further robust RCTs need to be undertaken and these should include participants with different underlying asthma severities and endotypes.

Culture-specific programs for children and adults from minority groups who have asthma.

People with asthma who come from minority groups often have poorer asthma outcomes, including more acute asthma-related doctor visits for flare-ups. Various programmes used to educate and empower people with asthma have previously been shown to improve certain asthma outcomes (e.g. adherence outcomes, asthma knowledge scores in children and parents, and cost-effectiveness). Models of care for chronic diseases in minority groups usually include a focus of the cultural context of the individual, and not just the symptoms of the disease. Therefore, questions about whether tailoring asthma education programmes that are culturally specific for people from minority groups are effective at improving asthma-related outcomes, that are feasible and cost-effective need to be answered. To determine whether culture-specific asthma education programmes, in comparison to generic asthma education programmes or usual care, improve asthma-related outcomes in children and adults with asthma who belong to minority groups. We searched the Cochrane Register of Controlled Trials (CENTRAL), the Cochrane Airways Group Specialised Register, MEDLINE, Embase, review articles and reference lists of relevant articles. The latest search fully incorporated into the review was performed in June 2016. Randomised controlled trials (RCTs) comparing the use of culture-specific asthma education programmes with generic asthma education programmes, or usual care, in adults or children from minority groups with asthma. Two review authors independently selected, extracted and assessed the data for inclusion. We contacted study authors for further information if required. In this review update, an additional three studies and 220 participants were added. A total of seven RCTs (two in adults, four in children, one in both children and adults) with 837 participants (aged from one to 63 years) with asthma from ethnic minority groups were eligible for inclusion in this review. The methodological quality of studies ranged from very low to low. For our primary outcome (asthma exacerbations during follow-up), the quality of evidence was low for all outcomes. In adults, use of a culture-specific programme, compared to generic programmes or usual care did not significantly reduce the number of participants from two studies with 294 participants for: exacerbations with one or more exacerbations during follow-up (odds ratio (OR) 0.80, 95% confidence interval (CI) 0.50 to 1.26), hospitalisations over 12 months (OR 0.83, 95% CI 0.31 to 2.22) and exacerbations requiring oral corticosteroids (OR 0.97, 95% CI 0.55 to 1.73). However, use of a culture-specific programme, improved asthma quality of life scores in 280 adults from two studies (mean difference (MD) 0.26, 95% CI 0.17 to 0.36) (although the MD was less then the minimal important difference for the score). In children, use of a culture-specific programme was superior to generic programmes or usual care in reducing severe asthma exacerbations requiring hospitalisation in two studies with 305 children (rate ratio 0.48, 95% CI 0.24 to 0.95), asthma control in one study with 62 children and QoL in three studies with 213 children, but not for the number of exacerbations during follow-up (OR 1.55, 95% CI 0.66 to 3.66) or the number of exacerbations (MD 0.18, 95% CI -0.25 to 0.62) among 100 children from two studies. The available evidence showed that culture-specific education programmes for adults and children from minority groups are likely effective in improving asthma-related outcomes. This review was limited by few studies and evidence of very low to low quality. Not all asthma-related outcomes improved with culture-specific programs for both adults and children. Nevertheless, while modified culture-specific education programs are usually more time intensive, the findings of this review suggest using culture-specific asthma education programmes for children and adults from minority groups. However, more robust RCTs are needed to further strengthen the quality of evidence and determine the cost-effectiveness of culture-specific programs.

Exhaled nitric oxide levels to guide treatment for children with asthma.

Asthma guidelines aim to guide health practitioners to optimise treatment for patients to minimise symptoms, improve or maintain good lung function, and prevent acute exacerbations. The principle of asthma guidelines is based on a step-up or step-down regimen of asthma medications to maximise health using minimum doses. Fractional exhaled nitric oxide (FeNO) is a marker of eosinophilic inflammation and tailoring asthma medications in accordance to airway eosinophilic levels may improve asthma outcomes such as indices of control or reduce exacerbations, or both. To evaluate the efficacy of tailoring asthma interventions based on fractional exhaled nitric oxide (FeNO), in comparison to not using FeNO, that is, management based on clinical symptoms (with or without spirometry/peak flow) or asthma guidelines (or both), for asthma-related outcomes in children. We searched the Cochrane Airways Group Specialised Register of Trials, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and reference lists of articles. The last searches were in June 2016. All randomised controlled trials (RCTs) comparing adjustment of asthma medications based on FeNO levels compared to those not using FeNO, that is, management based on clinical symptoms or asthma guidelines (or both) involving children. We reviewed results of searches against predetermined criteria for inclusion. Two review authors independently selected relevant studies, assessed trial quality and extracted data. We contacted study authors for further information with responses provided from three. The review included nine studies; these studies differed in a variety of ways including definition of asthma exacerbations, FeNO cut-off levels used (12 parts per billion (ppb) to 30 ppb), the way in which FeNO was used to adjust therapy and duration of study (6 to 12 months). Of 1426 children randomised, 1329 completed the studies. The inclusion criteria for the participants in each study varied but all had a diagnosis of asthma. There was a significant difference in the number of children having one or more asthma exacerbations over the study period, they were significantly lower in the FeNO group in comparison to the control group (odds ratio (OR) 0.58, 95% confidence interval (CI) 0.45 to 0.75; 1279 participants; 8 studies). The number needed to treat for an additional beneficial outcome (NNTB) over 52 weeks was 9 (95% CI 6 to 15). There was no difference between the groups when comparing exacerbation rates (mean difference (MD) -0.37, 95% CI -0.8 to 0.06; 736 participants; 4 studies; I2 = 67%). The number of children in the FeNO group requiring oral corticosteroid courses was lower in comparison to the children in the control group (OR 0.63, 95% CI 0.48 to 0.83; 1169 participants; 7 studies; I2 = 0%). There was no statistically significant difference between the groups for exacerbations requiring hospitalisation (OR 0.75, 95% CI 0.41 to 1.36; 1110 participants; 6 studies; I2 = 0%). There were no significant differences between the groups for any of the secondary outcomes (forced expiratory volume in one second (FEV1), FeNO levels, symptom scores or inhaled corticosteroid doses at final visit). The included studies recorded no adverse events.Three studies had inadequate blinding and were thus considered to have a high risk of bias. However, when these studies were removed in subgroup analysis, the difference between the groups for the primary outcome (exacerbations) remained statistically significant. The GRADE quality of the evidence ranged from moderate (for the outcome 'Number of participants who had one or more exacerbations over the study period') to very low (for the outcome 'Exacerbation rates'), based on lack of blinding, statistical heterogeneity and imprecision. In this updated review with five new included studies, tailoring asthma medications based on FeNO levels (in comparison with primarily guideline management) significantly decreased the number of children who had one or more exacerbations over the study period but did not impact on the day-to-day clinical symptoms or inhaled corticosteroid doses. Therefore, the use of FeNO to guide asthma therapy in children may be beneficial in a subset of children, it cannot be universally recommended for all children with asthma.Further RCTs need to be conducted and these should encompass different asthma severities, different settings including primary care and less affluent settings, and consider different FeNO cut-offs.

Vitamin D Supplementation for Childhood Asthma: A Systematic Review and Meta-Analysis.

ImportanceThere is growing evidence that vitamin D plays a role in the pathogenesis of asthma but it is unclear whether supplementation during childhood may improve asthma outcomes.ObjectivesThe objective of this systematic review and meta-analysis was to evaluate the efficacy and safety of vitamin D supplementation as a treatment or adjunct treatment for asthma.Data SourcesWe searched MEDLINE, Embase, CENTRAL, and CINAHL through July 2014.Study SelectionWe included RCTs that evaluated vitamin D supplementation in children versus active control or placebo for asthma.Data Extraction and SynthesisOne reviewer extracted data and one reviewer verified data accuracy. We qualitatively summarized the main results of efficacy and safety and meta-analyzed data on comparable outcomes across studies. We used GRADE for strength of evidence.Main Outcome MeasuresMain planned outcomes measures were ED visits and hospitalizations. As secondary outcomes, we examined measures of asthma control, including frequency of asthma exacerbations, asthma symptom scores, measures of lung function, β2-agonist use and daily steroid use, adverse events and 25-hydroxyvitamin D levels.ResultsEight RCTs (one parallel, one crossover design) comprising 573 children aged 3 to 18 years were included. One study (moderate-quality, n = 100) reported significantly less ED visits for children treated with vitamin D. No other studies examined the primary outcome (ED visits and hospitalizations). There was a reduced risk of asthma exacerbations in children receiving vitamin D (low-quality; RR 0.41, 95% CI 0.27 to 0.63, 3 studies, n = 378). There was no significant effect for asthma symptom scores and lung function. The serum 25(OH)D level was higher in the vitamin D group at the end of the intervention (low-quality; MD 19.66 nmol/L, 95% CI 5.96 nmol/L to 33.37 nmol/L, 5 studies, n = 167).LimitationsWe identified a high degree of clinical diversity (interventions and outcomes) and methodological heterogeneity (sample size and risk of bias) in included trials.Conclusions and RelevanceRandomized controlled trials provide some low-quality evidence to support vitamin D supplementation for the reduction of asthma exacerbations. Evidence on the benefits of vitamin D supplementation for other asthma-related outcomes in children is either limited or inconclusive. We recommend that future trials focus on patient-relevant outcomes that are comparable across studies, including standardized definitions of asthma exacerbations.

Perfluoroalkyl chemicals and asthma among children 12-19 years of age: NHANES (1999-2008).

Background: Perfluoroalkyl chemicals (PFCs) are a family of commonly used industrial chemicals whose persistence and ubiquity in human blood samples has led to concern about possible toxicity. Several animal studies and one recent human study have suggested a link between exposure to PFCs and asthma, although few epidemiologic studies have been conducted.Objectives: We investigated children’s PFC serum concentrations and their associations with asthma-related outcomes.Methods: We evaluated the association between serum concentrations of eight PFCs, including perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS), with self-reported lifetime asthma, recent wheezing, and current asthma using data from participants 12–19 years of age from the 1999–2000 and 2003–2008 National Health and Nutrition Examination Surveys.Results: In multivariable-adjusted models, PFOA was associated with higher odds of ever having received a diagnosis of asthma [odds ratio (OR) = 1.18; 95% CI: 1.01, 1.39 for a doubling in PFOA], whereas for PFOS there were inverse relationships with both asthma and wheezing (OR = 0.88; 95% CI: 0.74, 1.04, and OR = 0.83; 95% CI: 0.67, 1.02, respectively). The associations were attenuated after accounting for sampling weights. No associations were seen between the other PFCs and any outcome.Conclusions: This cross-sectional study provides some evidence for associations between exposure to PFCs and asthma-related outcomes in children. The evidence is inconsistent, however, and prospective studies are needed.Citation: Humblet O, Diaz-Ramirez LG, Balmes JR, Pinney SM, Hiatt RA. 2014. Perfluoroalkyl chemicals and asthma among children 12–19 years of age: NHANES (1999–2008). Environ Health Perspect 122:1129–1133; http://dx.doi.org/10.1289/ehp.1306606

Increased ultrafine particles and carbon monoxide concentrations are associated with asthma exacerbation among urban children

ObjectivesIncreased air pollutant concentrations have been linked to several asthma-related outcomes in children, including respiratory symptoms, medication use, and hospital visits. However, few studies have examined effects of ultrafine particles in a pediatric population. Our primary objective was to examine the effects of ambient concentrations of ultrafine particles on asthma exacerbation among urban children and determine whether consistent treatment with inhaled corticosteroids could attenuate these effects. We also explored the relationship between asthma exacerbation and ambient concentrations of accumulation mode particles, fine particles (≤2.5 micrograms [μm]; PM2.5), carbon monoxide, sulfur dioxide, and ozone. We hypothesized that increased 1–7 day concentrations of ultrafine particles and other pollutants would be associated with increases in the relative odds of an asthma exacerbation, but that this increase in risk would be attenuated among children receiving school-based corticosteroid therapy. MethodsWe conducted a pilot study using data from 3 to 10 year-old children participating in the School-Based Asthma Therapy trial. Using a time-stratified case-crossover design and conditional logistic regression, we estimated the relative odds of a pediatric asthma visit treated with prednisone (n=96 visits among 74 children) associated with increased pollutant concentrations in the previous 7 days. We re-ran these analyses separately for children receiving medications through the school-based intervention and children in a usual care control group. ResultsInterquartile range increases in ultrafine particles and carbon monoxide concentrations in the previous 7 days were associated with increases in the relative odds of a pediatric asthma visit, with the largest increases observed for 4-day mean ultrafine particles (interquartile range=2088p/cm3; OR=1.27; 95% CI=0.90–1.79) and 7-day mean carbon monoxide (interquartile range=0.17ppm; OR=1.63; 95% CI=1.03–2.59). Relative odds estimates were larger among children receiving school-based inhaled corticosteroid treatment. We observed no such associations with accumulation mode particles, black carbon, fine particles (≤2.5μm), or sulfur dioxide. Ozone concentrations were inversely associated with the relative odds of a pediatric asthma visit. ConclusionsThese findings suggest a response to markers of traffic pollution among urban asthmatic children. Effects were strongest among children receiving preventive medications through school, suggesting that this group of children was particularly sensitive to environmental triggers. Medication adherence alone may be insufficient to protect the most vulnerable from environmental asthma triggers. However, further research is necessary to confirm this finding.

Weighing Asthma Risk

Being either underweight or obese correlates with worse lung function and asthma-related outcomes in children.

Tailored interventions based on exhaled nitric oxide versus clinical symptoms for asthma in children and adults

The measurement of severity and control of asthma in both children and adults can be based on subjective or objective measures. It has been advocated that fractional exhaled nitric oxide (FeNO) can be used to monitor airway inflammation as it correlates with some markers of asthma. Interventions for asthma therapies have been traditionally based on symptoms and/or spirometry. To evaluate the efficacy of tailoring asthma interventions based on exhaled nitric oxide in comparison to clinical symptoms (with or without spirometry/peak flow) for asthma related outcomes in children and adults. We searched the Cochrane Airways Group Specialised Register of Trials, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and reference lists of articles. The last search was completed in February 2009. All randomised controlled comparisons of adjustment of asthma therapy based on exhaled nitric oxide compared to traditional methods (primarily clinical symptoms and spirometry/peak flow). Results of searches were reviewed against pre-determined criteria for inclusion. Relevant studies were independently selected in duplicate. Two authors independently assessed trial quality and extracted data. Authors were contacted for further information with response from one. Two studies have been added for this update, which now includes six (2 adults and 4 children/adolescent) studies; these studies differed in a variety of ways including definition of asthma exacerbations, FeNO cut off levels, the way in which FeNO was used to adjust therapy and duration of study. Of 1053 participants randomised, 1010 completed the trials. In the meta-analysis, there was no significant difference between groups for the primary outcome of asthma exacerbations or for other outcomes (clinical symptoms, FeNO level and spirometry). In post-hoc analysis, a significant reduction in mean final daily dose inhaled corticosteroid per adult was found in the group where treatment was based on FeNO in comparison to clinical symptoms, (mean difference -450 mcg; 95% CI -677 to -223 mcg budesonide equivalent/day). However, the total amount of inhaled corticosteroid used in one of the adult studies was 11% greater in the FeNO arm. In contrast, in the paediatric studies, there was a significant increase in inhaled corticosteroid dose in the FeNO strategy arm (mean difference of 140 mcg; 95% CI 29 to 251, mcg budesonide equivalent/day). Tailoring the dose of inhaled corticosteroids based on exhaled nitric oxide in comparison to clinical symptoms was carried out in different ways in the six studies and found only modest benefit at best and potentially higher doses of inhaled corticosteroids in children. The role of utilising exhaled nitric oxide to tailor the dose of inhaled corticosteroids cannot be routinely recommended for clinical practice at this stage and remains uncertain.

Chronic pediatric asthma and chiropractic spinal manipulation: A prospective clinical series and randomized clinical pilot study

Objectives: The first objective was to determine if chiropractic spinal manipulative therapy (SMT) in addition to optimal medical management resulted in clinically important changes in asthma-related outcomes in children. The second objective was to assess the feasibility of conducting a full-scale, randomized clinical trial in terms of recruitment, evaluation, treatment, and ability to deliver a sham SMT procedure. Study Design: Prospective clinical case series combined with an observer-blinded, pilot randomized clinical trial with a 1-year follow-up period. Setting: Primary contact, college outpatient clinic, and a pediatric hospital. Patients: A total of 36 patients aged 6 to 17 years with mild and moderate persistent asthma were admitted to the study. Outcome Measures: Pulmonary function tests; patient- and parent- or guardian-rated asthma-specific quality of life, asthma severity, and improvement; am and pm peak expiratory flow rates; and diary-based day and nighttime symptoms. Interventions: Twenty chiropractic treatment sessions were scheduled during the 3-month intervention phase. Patients were randomly assigned to receive either active SMT or sham SMT in addition to their standardized ongoing medical management. Results: It is possible to blind the participants to the nature of the SMT intervention, and a full-scale trial with the described design is feasible to conduct. At the end of the 12-week intervention phase, objective lung function tests and patient-rated day and nighttime symptoms based on diary recordings showed little or no change. Of the patient-rated measures, a reduction of approximately 20% in β2 bronchodilator use was seen (P =.10). The quality of life scores improved by 10% to 28% (P <.01), with the activity scale showing the most change. Asthma severity ratings showed a reduction of 39% (P <.001), and there was an overall improvement rating corresponding to 50% to 75%. The pulmonologist-rated improvement was small. Similarly, the improvements in parent- or guardian-rated outcomes were mostly small and not statistically significant. The changes in patient-rated severity and the improvement rating remained unchanged at 12-month posttreatment follow-up as assessed by a brief postal questionnaire. Conclusion: After 3 months of combining chiropractic SMT with optimal medical management for pediatric asthma, the children rated their quality of life substantially higher and their asthma severity substantially lower. These improvements were maintained at the 1-year follow-up assessment. There were no important changes in lung function or hyperresponsiveness at any time. The observed improvements are unlikely as a result of the specific effects of chiropractic SMT alone, but other aspects of the clinical encounter that should not be dismissed readily. Further research is needed to assess which components of the chiropractic encounter are responsible for important improvements in patient-oriented outcomes so that they may be incorporated into the care of all patients with asthma. (J Manipulative Physiol Ther 2001;24:369-77)