Ionisers for chronic asthma

No Concentration Decrease of House Dust Mite Allergens With Rising Altitude in Alpine Regions

Purpose

Several studies over the past 4 decades have indicated a significant reduction in house dust mite (HDM) and HDM allergen concentration in areas higher than 1,500 m above sea level. These have served as basis of allergen avoidance therapies for HDM allergy and asthma. However, modern construction techniques used in the insulation, heating, and glazing of buildings as well as global warming have changed the environmental parameters for HDM living conditions. The present study revisits the paradigm of decreasing HDM allergen concentrations with increasing altitude in the alpine region of Germany and Austria.

Methods

A total of 122 dust samples from different abodes (hotels, privates and mountain huts) at different altitudes (400-2,600 m) were taken, and concentrations of HDM allergens were analyzed. Humidity and temperature conditions, and numerous indoor environmental parameters such as fine dust, type of flooring, age of building, and frequency of cleaning were determined.

Results

HDM allergen concentrations did not significantly change with increasing altitude or relative humidity. At the level of indoor parameters, correlations could be found for different flooring types and the concentration of HDM allergens.

Conclusions

In contrast to the widespread view of the relationship between altitude and HDM allergen concentrations, clinically relevant concentrations of HDM allergens could be detected in high-lying alpine regions in Austria and Germany. These results indicate that improvement in conditions of asthmatic patients sensitized against HDMs during a stay at high altitude can no longer be ascribed to decreased levels of HDM allergens, instead, other mechanisms may trigger the beneficial effect.

The method quality of cross-over studies involved in Cochrane Systematic Reviews

BACKGROUND

It is possible that cross-over studies included in current systematic reviews are being inadequately assessed, because the current risk of bias tools do not consider possible biases specific to cross-over design. We performed this study to evaluate whether this was being done in cross-over studies included in Cochrane Systematic Reviews (CSRs).

METHODS

We searched the Cochrane Library (up to 2013 issue 5) for CSRs that included at least one cross-over trial. Two authors independently undertook the study selection and data extraction. A random sample of the CSRs was selected and we evaluated whether the cross-over trials in these CSRs were assessed according to criteria suggested by the Cochrane handbook. In addition we reassessed the risk of bias of these cross-over trials by a checklist developed form the Cochrane handbook.

RESULTS

We identified 688 CSRs that included one or more cross-over studies. We chose a random sample of 60 CSRs and these included 139 cross-over studies. None of these CSRs undertook a risk of bias assessment specific for cross-over studies. In fact items specific for cross-over studies were seldom considered anywhere in quality assessment of these CSRs. When we reassessed the risk of bias, including the 3 items specific to cross-over trials, of these 139 studies, a low risk of bias was judged for appropriate cross-over design in 110(79%), carry-over effects in 48(34%) and for reporting data in all stages of the trial in 114(82%).Assessment of biases in cross-over trials could affect the GRADE assessment of a review's findings.

CONCLUSION

The current Cochrane risk of bias tool is not adequate to assess cross-over studies. Items specific to cross-over trials leading to potential risk of bias are generally neglected in CSRs. A proposed check list for the evaluation of cross-over trials is provided.

Air ions and respiratory function outcomes: a comprehensive review

Background

From a mechanistic or physical perspective there is no basis to suspect that electric charges on clusters of air molecules (air ions) would have beneficial or deleterious effects on respiratory function. Yet, there is a large lay and scientific literature spanning 80 years that asserts exposure to air ions affects the respiratory system and has other biological effects.

Aims

This review evaluates the scientific evidence in published human experimental studies regarding the effects of exposure to air ions on respiratory performance and symptoms.

Methods

We identified 23 studies (published 1933–1993) that met our inclusion criteria. Relevant data pertaining to study population characteristics, study design, experimental methods, statistical techniques, and study results were assessed. Where relevant, random effects meta-analysis models were utilized to quantify similar exposure and outcome groupings.

Results

The included studies examined the therapeutic benefits of exposure to negative air ions on respiratory outcomes, such as ventilatory function and asthmatic symptoms. Study specific sample sizes ranged between 7 and 23, and studies varied considerably by subject characteristics (e.g., infants with asthma, adults with emphysema), experimental method, outcomes measured (e.g., subjective symptoms, sensitivity, clinical pulmonary function), analytical design, and statistical reporting.

Conclusions

Despite numerous experimental and analytical differences across studies, the literature does not clearly support a beneficial role in exposure to negative air ions and respiratory function or asthmatic symptom alleviation. Further, collectively, the human experimental studies do not indicate a significant detrimental effect of exposure to positive air ions on respiratory measures. Exposure to negative or positive air ions does not appear to play an appreciable role in respiratory function.

Public health interventions for asthma: an umbrella review, 1990-2010

CONTEXT

Asthma is a chronic respiratory disease increasingly prevalent in the U.S., particularly among children and certain minority groups. This umbrella review sought to assess and summarize existing systematic reviews of asthma-related interventions that might be carried out or supported by state or community asthma control programs, and to identify gaps in knowledge.

EVIDENCE ACQUISITION

Eleven databases were searched through September 2010, using terms related to four concepts: asthma, review, intervention, and NOT medication. Reviews of the effectiveness of medications, medical procedures, complementary and alternative medicine, psychological interventions, family therapy, and nutrients or nutritional supplements were excluded. Two coders screened each record and extracted data from the included reviews.

EVIDENCE SYNTHESIS

Data analysis was conducted from May to December 2010. Of 42 included reviews, 19 assessed the effectiveness of education and/or self-management, nine the reduction of indoor triggers, nine interventions to improve the provision of health care, and five examined other interventions. Several reviews found consistent evidence of effectiveness for self-management education, and one review determined that comprehensive home-based interventions including the reduction of multiple indoor asthma triggers are effective for children. Other reviews found limited or insufficient evidence because of study limitations.

CONCLUSIONS

State or community asthma control programs should prioritize (1) implementing interventions for which the present review found evidence of effectiveness and (2) evaluating promising interventions that have not yet been adequately assessed.

An integrative review of systematic reviews related to the management of breathlessness in respiratory illnesses

BACKGROUND

Breathlessness is a debilitating and distressing symptom in a wide variety of diseases and still a difficult symptom to manage. An integrative review of systematic reviews of non-pharmacological and pharmacological interventions for breathlessness in non-malignant disease was undertaken to identify the current state of clinical understanding of the management of breathlessness and highlight promising interventions that merit further investigation.

METHODS

Systematic reviews were identified via electronic databases between July 2007 and September 2009. Reviews were included within the study if they reported research on adult participants using either a measure of breathlessness or some other measure of respiratory symptoms.

RESULTS

In total 219 systematic reviews were identified and 153 included within the final review, of these 59 addressed non-pharmacological interventions and 94 addressed pharmacological interventions. The reviews covered in excess of 2000 trials. The majority of systematic reviews were conducted on interventions for asthma and COPD, and mainly focussed upon a small number of pharmacological interventions such as corticosteroids and bronchodilators, including beta-agonists. In contrast, other conditions involving breathlessness have received little or no attention and studies continue to focus upon pharmacological approaches. Moreover, although there are a number of non-pharmacological studies that have shown some promise, particularly for COPD, their conclusions are limited by a lack of good quality evidence from RCTs, small sample sizes and limited replication.

CONCLUSIONS

More research should focus in the future on the management of breathlessness in respiratory diseases other than asthma and COPD. In addition, pharmacological treatments do not completely manage breathlessness and have an added burden of side effects. It is therefore important to focus more research on promising non-pharmacological interventions.

Non-medical management of asthma in adults

Overview of reviews, compiling evidence from multiple Cochrane reviews into one accessible and usable document, is a new methodology being developed by the Cochrane methods group and mastered by the Child Health Network. Overviews of reviews are rapidly gaining in popularity as a 'friendly front end' to the Cochrane Library. Through collating the results of multiple reviews on a single subject, overview of reviews provides the reader with a quick bottom line regarding the quality and utility of existing evidence on the clinical decision at hand. This overview presents a summary of the results of all previous Cochrane reviews on the effect of complementary therapies (non-medical) for the treatment of asthma in adults. The Cochrane Database of Systematic Reviews was searched for all systematic reviews examining the complementary therapies (non-medical) treatment of asthma in adults. All reviews that were under the heading 'asthma' on the Cochrane Airways Group's Topic List were reviewed. Data were extracted and entered into tables; data were synthesized using qualitative and quantitative methods. Currently, twenty-three (23) reviews are published in the CDSR related to non-medical interventions for the management of asthma in adults. The known complexities associated with measuring the effect of complementary therapies resulted in all reviews being unable to find studies which--at least in the form reported--had the strength of evidence that could be generalized beyond the variables of the specific trial.

Asthma in childhood

Management decisions for pediatric asthma (in patients younger than 12 years of age) based on extrapolation from available evidence in adolescents and adults (age 12 years and older) is common but rarely appropriate. This article addresses the disparity in response between the two age groups, presents the available pediatric evidence, and highlights the important areas in which further research is required. Evidence-based recommendations for acute and interval management of pediatric asthma are provided.

Indoor air modification interventions for prolonged non-specific cough in children

BACKGROUND

Non-specific cough has been defined as non-productive cough in the absence of identifiable respiratory disease or known aetiology and is common in childhood. These children are treated with a variety of therapies, including non-pharmacological treatments. There is a wide variety and a growing market for these non-pharmacological treatments that include air-modification modalities.

OBJECTIVES

To determine the efficacy of air-modification modalities, (ionisers, vaporisers, humidifiers, air filters, regular vacuuming), in treating children with non-specific cough.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, OLDMEDLINE and EMBASE databases were searched by the Cochrane Airways Group. The latest searches were performed in November 2005.

SELECTION CRITERIA

All randomised controlled trials comparing air-modification modalities with a placebo treatment, for any duration.

DATA COLLECTION AND ANALYSIS

Results of searches were reviewed against pre-determined criteria for inclusion. Five papers were considered for inclusion but no eligible trials were identified and thus no data was available for analysis.

MAIN RESULTS

No randomised controlled trials that examined the efficacy of air-modification modalities in the management of prolonged, non-specific cough in children were found.

AUTHORS' CONCLUSIONS

Based on the evidence currently available, a recommendation can not be given for air-modification interventions in the treatment of prolonged, non-specific cough in children.