Comparison of the effectiveness of inhaler devices in asthma and chronic obstructive airways disease: a systematic review of the literature

BACKGROUND

Asthma and chronic obstructive pulmonary disease (COPD) are common diseases of the airways and lungs that have a major impact on the health of the population. The mainstay of treatment is by inhalation of medication to the site of the disease process. This can be achieved by a number of different device types, which have wide variations in costs to the health service. A number of different inhalation devices are available. The pressurised metered-dose inhaler (pMDI) is the most commonly used and cheapest device, which may also be used in conjunction with a spacer device. Newer chlorofluorocarbons (CFC)-free inhaler devices using hydrofluoroalkanes (HFAs) have also been developed. The drug is dissolved or suspended in the propellant under pressure. When activated, a valve system releases a metered volume of drug and propellant. Other devices include breath-actuated pMDIs (BA-pMDI), such as Autohaler and Easi-Breathe. They incorporate a mechanism activated during inhalation that triggers the metered-dose inhaler. Dry powder inhalers (DPI), such as Turbohaler, Diskhaler, Accuhaler and Rotahaler, are activated by inspiration by the patient. The powdered drug is dispersed into particles by the inspiration. With nebulisers oxygen, compressed air, or ultrasonic power is used to break up solutions or suspensions of medication into droplets for inhalation. The aerosol is administered by mask or by a mouthpiece. There has been no previous systematic review of the evidence of clinical effectiveness and cost-effectiveness of these different inhaler devices.

OBJECTIVES

To review systematically the clinical effectiveness and cost-effectiveness of inhaler devices in asthma and COPD.

METHODS

The different aspects of inhaler devices were separated into the most clinically relevant comparisons. Methods involved systematic searching of electronic databases and bibliographies for randomised controlled trials (RCTs) and systematic reviews. Pharmaceutical companies and experts in the field were contacted for further information. Trials that met the inclusion criteria were appraised and data extraction was under-taken by one reviewer and checked by a second reviewer, with any discrepancies being resolved through agreement. RESULTS--IN VITRO CHARACTERISTICS VERSUS IN VIVO TESTING AND CLINICAL RESPONSE: There is evidence that when comparative testing is performed on inhaler devices using the same methods, there is some correlation between particle size measurements and clinical response. However, the measurements are dependent upon the methods used, and a single measure of a device in isolation is of limited value. Also, there is little data on comparing devices of different types. There is currently insufficient data to verify the ability of in vitro assessments to predict inhaler performance in vivo. RESULTS--EFFECTIVENESS OF METERED-DOSE INHALERS FOR THE DELIVERY OF CORTICOSTEROIDS IN ASTHMA: The review of three trials in children and 21 trials in adults demonstrated no evidence to suggest clinical benefits of any other inhaler device over a pMDI in corticosteroid delivery. RESULTS--EFFECTIVENESS OF METERED-DOSE INHALERS FOR THE DELIVERY OF BETA-AGONISTS IN STABLE ASTHMA: In children, 11 studies were reviewed, of which seven compared the Turbohaler with the pMDI. One study found a significant treatment difference in peak expiratory flow rate, although there were differences in the patients' baseline characteristics. In adults, a review of 70 studies found no demonstrable difference in the clinical bronchodilator effect of short-acting b2-agonists delivered by the standard pMDI compared with that produced by any other DPI, HFA-pMDI or the Autohaler device. The finding that HFA-pMDIs may reduce treatment failure and oral steroid requirement in beta-agonist delivery needs further confirmatory research in adequately randomised clinical trials. RESULTS--EFFECTIVENESS OF NEBULISERS VERSUS METERED-DOSE INHALERS FOR THE DELIVERY OF BRONCHODILATORS IN STABLE ASTHMA: In children, three included trials compared different devices with a nebuliser and demonstrated no evidence of clinical superiority of nebulisers over inhaler devices in bronchodilator delivery. A total of 23 studies in adults found no equivalence for the main pulmonary outcomes and no evidence of difference in other outcomes. RESULTS--EFFECTIVENESS OF METERED-DOSE INHALERS FOR THE DELIVERY OF BETA-AGONISTS IN COPD: Only two studies were included in this review. No evidence of clinical difference was found in beta-agonist delivery. RESULTS--EFFECTIVENESS OF NEBULISERS VERSUS METERED-DOSE INHALERS FOR THE DELIVERY OF BRONCHODILATORS IN COPD: Evidence from 14 trials demonstrated equivalence for the main outcomes of pulmonary function. For other outcomes there was no evidence of treatment difference in bronchodilator delivery. RESULTS--PATIENTS' ABILITY TO USE METERED-DOSE INHALERS: Differences among studies and the heterogeneity of the results make it difficult to draw conclusions about inhaler technique differences between device types. The review of technique after teaching the correct technique suggests that there is no difference in patients' ability to use DPI or pMDIs. RESULTS--ECONOMIC ANALYSIS: The total number of NHS prescriptions for inhaler therapy for asthma in 1998 was over 31 million, with a net ingredient cost in excess of 392 million GB pounds. This economic assessment uses decision analysis to estimate the relative cost-effectiveness of inhaler devices for the delivery of bronchodilator and corticosteroid inhaled therapy. Overall, there were no differences in patient outcomes among the devices. On the assumption that the devices were clinically equivalent, pMDIs were the most cost-effective devices for asthma treatment.

CONCLUSIONS

This systematic review examined the evidence from clinical trials evaluating the clinical effectiveness of different inhaler devices in the delivery of inhaled corticosteroids and beta2-bronchodilators for patients with asthma and COPD. The evidence from the published clinical literature demonstrates no difference in clinical effectiveness between nebulisers and alternative inhaler devices compared to standard pMDI with or without a spacer device. The cost-effectiveness evidence therefore favours pMDIs (or the cheapest inhaler device) as first-line treatment in all patients with stable asthma unless other specific reasons are identified. Patients can use pMDIs as effectively as other inhaler devices as long as the correct inhalation technique is taught. CONCLUSIONS--RECOMMENDATIONS FOR RESEARCH: Further clinical trials are required to demonstrate any differences in the clinical effectiveness and cost-effectiveness of inhaler devices and nebulisers compared with pMDIs. These should be of sufficient statistical power and methodological rigour to demonstrate any clinical benefit. Trials should be undertaken in community settings to ensure the generalisability of results. Outcome measures should be more patient-centred and report adverse effects more completely. Reporting of data from trials should be improved.

Effects of physical training in asthma: a systematic review

OBJECTIVES

To assess the evidence for the effects of physical training on pulmonary function, symptoms, cardiopulmonary fitness, and quality of life in subjects with asthma.

METHODS

A search was conducted for randomised controlled trials of subjects with asthma undertaking physical training using the Cochrane Airways Group register of controlled clinical trials, Medline, Embase, Sportdiscus, Science citation index, and Current contents index. Studies were included in the review if the subjects had asthma, were 8 years of age or older, and had undertaken physical training for at least 20 minutes per session, twice a week, for a minimum of four weeks. The eligibility of trials for inclusion in the review and the quality of the trials were independently assessed by two reviewers.

RESULTS

Eight studies with a total of 226 subjects met the inclusion criteria for this review. Physical training had no effect on resting lung function but led to an improvement in cardiopulmonary fitness as measured by an increase in maximum oxygen uptake of 5.6 ml/kg/min (95% confidence interval 3.9 to 7.2). None of the studies measured quality of life.

CONCLUSIONS

Physical training improves cardiopulmonary fitness without changing lung function. It is not clear if the improvement in fitness translates into a reduction in symptoms or an improvement in the quality of life. There is a need for further randomised controlled trials of the effects of physical training in the management of asthma.

Consent and coercion: examining unwanted sex among married young women in India

CONTEXT

Although there is a growing body of research examining the issue of nonconsensual sex among adolescents, few studies have looked at coerced sex within marriage in settings where early marriage is common, or at sex that may not be perceived as forced, but that is unwanted.

METHODS

A cross-sectional study, using both survey research and in-depth interviews, was conducted among 1,664 married young women in Gujarat and West Bengal, India. Descriptive data and multinomial logistic regression were used to identify the prevalence and risk factors for occasional and frequent unwanted sex. Qualitative data were analyzed to examine the context in which unwanted sex takes place.

RESULTS

Twelve percent of married young women experienced unwanted sex frequently; 32% experienced it occasionally. The risk of experiencing unwanted sex was lower among women who knew their husband fairly well at the time of marriage, regularly received support from their husband in conflicts with other family members or lived in economically better-off households. Frequent unwanted sex was associated with not yet having had a child or having become pregnant, with lower education and with agreeing with norms that justify wife beating.

CONCLUSION

For married young women, sex is not always consensual or wanted. Further research is required to determine the effects of unwanted sex on sexual and reproductive health outcomes and to help programs develop the best strategies for dealing with coerced sex within marriage.

Oral theophylline for chronic obstructive pulmonary disease

BACKGROUND

Oral theophylline has, for many years, been used as a bronchodilator in patients with COPD. Despite the introduction of new drugs, and its narrow therapeutic index, theophylline is still recommended for COPD treatment.

OBJECTIVES

To determine the effectiveness of oral theophylline when compared to placebo in patients with stable COPD.

SEARCH STRATEGY

The Cochrane Airways Review Group and Cochrane Controlled Clinical Registers were searched.

SELECTION CRITERIA

All studies were randomised controlled trials (RCTs).

DATA COLLECTION AND ANALYSIS

Data were independently abstracted and the methodological quality assessed by two reviewers.

MAIN RESULTS

Twenty RCTs met the inclusion criteria. Concomitant therapy varied from none to any other bronchodilator plus corticosteroid (oral and inhaled). The following outcomes were significantly different when compared to placebo. FEV1 improved with treatment: Weighted Mean Difference (WMD) 100 ml; 95% Confidence Interval (95%CI) 40, 160 ml. Similarly for FVC: WMD 210 ml 95%CI 100, 320. Two studies reported an improvement in VO2max; WMD 195 ml/min, 95%CI 113,27). At rest, PaO2 and PaCO2 both improved with treatment (WMD 3.2 mmHg; 95%CI = 1.2, 5., and WMD -2.4 mmHg; 95%CI = -3.5, -1.2, respectively). Walking distance tests did not improve (4 studies, Standardised Mean Difference 0.30, 95%CI -0.01, 0.62), neither did Visual Analogue Score for breathlessness isn two small studies (WMD 3.6, 95%CI -4.6, 11.8). The Relative Risk (RR) of nausea was greater with theophylline (RR 7.7; 95%CI 1.5, 39.9). However, patients' preference for theophylline was greater than that for placebo (RR 2.27; 95%CI = 1.26, 4.11). Very few patient withdrew from these studies for any reason.

REVIEWER'S CONCLUSIONS

Theophylline has a modest effect on FEV1 and FVC and slightly improves arterial blood gas tensions in moderate to severe COPD. These benefits were seen in patients receiving a variety of different concomitant therapies. Improvement in exercise performance depended on the method of testing. There was a very low dropout rate in the studies that could be included in this review, which suggests that recruited patients may have been known by the investigators to be theophylline tolerant. This may limit the generalisability of these studies.

Short-acting beta 2 agonists for stable chronic obstructive pulmonary disease

BACKGROUND

Chronic Obstructive Pulmonary Disease (COPD) is a chronic condition characterised by progressive airflow limitation that is at most partially reversible. Despite the lack of reversibility patients often report symptomatic improvement with short-acting beta 2 bronchodilator medications. They are used on either an "as required" or a "regular plus as required basis" and they may be used in conjunction with other bronchodilator medicines such as ipratropium and methylxanthines. These medicines are used in the management of both stable and acute exacerbations of COPD. This review examined the effect of short-acting beta 2 bronchodilators given by inhalation in stable COPD.

OBJECTIVES

To determine the clinical effect and assess the adverse effects of inhaled short-acting beta 2 agonist bronchodilators compared with placebo in stable COPD.

SEARCH STRATEGY

Only randomised controlled trials (RCTs) were considered. RCTs were identified using the Cochrane Airways Group database (CENTRAL). In addition, the reference lists of review articles and RCTs retrieved in full were searched for other potentially relevant citations.

SELECTION CRITERIA

Only trials with adult patients with stable COPD, as defined by internationally accepted guidelines (ATS, ERS or BTS) were included in this review. All trials had a minimum duration of 7 days of regular treatment with short-acting beta 2 bronchodilators given by inhalation and compared with placebo. Data from trials where beta 2 agonists were used alone or in combination with other medicines (e.g. ipratropium bromide) were used only if there was a direct comparison between beta 2 bronchodilator alone and placebo.

DATA COLLECTION AND ANALYSIS

Outcomes were analysed as continuous or dichotomous outcomes, using standard statistical techniques. For continuous outcomes, the weighted mean difference (WMD) and 95% confidence intervals were calculated and for dichotomous outcomes, the odds ratio was calculated with 95% confidence intervals by Peto's methods. Funnel plots were used to test for publication bias.

MAIN RESULTS

Thirteen studies were included in this review. Most had small sample sizes and some of the sutides used very short-acting outdated compounds. All the studies used a cross-over design and were of high quality. Spirometry done at the end of study period was measured after administration of treatment (post-bronchodilator) which showed both FEV1 (0.150 L/min, 95%CI: 0. 02-0.28) and FVC (0.310 L, 95%CI: 0.00-0.62) to improve significanly but slightly when compared to placebo. A few studies measured FRC, airway resistance or conductance at the end of the study period. In all cases these measurements were done several hours after treatment, and no significant differences (p>0.05 in all cases) were found between the bronchodilator and placebo groups. Walking test Large increases in 6MW distance was observed in two studies, however one study did not show any positive improvements. There was a large increase in the 12MW distance as shown by one study. Due to the small number of studies reporting this outcome no significant differences were found in the walking distance between the bronchodilator and placebo groups. Peak Flow Rate Both morning (36. 04 L/min; 95%CI: 0.80-71.27) and evening (36.68 L/min; 95%CI: 2. 47-70.89) PEFR were significantly higher during active treatment than during placebo. Symptoms Breatlessness was measured on various scales therefore data that were presented in a suitable form were combined using standardized means for inclusion in the analysis. A significant improvement (-0.33; 95%CI: -0.58 to -0.07 with p=0.01) in the breathlessness score was observed during treatment with beta-2 agonist when compared to placebo. Cough was reported to improve significantly (data not usable) during treatment with beta2 agonist in one study but not in two others. A non-significant decrease in sputum production was reported by Wilson 1980, however four other studies reported no

Inhaler devices for the treatment of asthma and chronic obstructive airways disease (COPD)

The research evidence on the effectiveness of inhaler devices for the treatment of asthma and chronic obstructive pulmonary disease published in a recent issue of Effective Health Care is reviewed.

Systematic review of clinical effectiveness of pressurised metered dose inhalers versus other hand held inhaler devices for delivering beta (2 )agonists bronchodilators in asthma

OBJECTIVES

To determine the clinical effectiveness of pressurised metered dose inhalers compared with other hand held inhaler devices for delivering short acting beta(2) agonists in stable asthma.

DESIGN

Systematic review of randomised controlled trials.

DATA SOURCES

Cochrane Airways Group specialised trials database (which includes hand searching of 20 relevant journals), Medline, Embase, Cochrane controlled clinical trials register, pharmaceutical companies, and bibliographies of included trials.

TRIALS

All trials in children or adults with stable asthma that compared the pressurised metered dose inhaler (with or without a spacer device) against any other hand held inhaler device containing the same beta(2) agonist.

RESULTS

84 randomised controlled trials were included. No differences were found between the pressurised metered dose inhaler and any other hand held inhaler device for lung function, blood pressure, symptoms, bronchial hyperreactivity, systemic bioavailability, inhaled steroid requirement, serum potassium concentration, and use of additional relief bronchodilators. In adults, pulse rate was lower in those using the pressurised metered dose inhaler compared with those using Turbohaler (standardised mean difference 0.44, 95% confidence interval 0.05 to 0.84); patients preferred the pressurised metered dose inhaler to the Rotahaler (relative risk 0.53, 95% confidence interval 0.36 to 0.78); hydrofluoroalkane pressurised metered dose inhalers reduced the requirement for rescue short course oral steroids (relative risk 0.67, 0.49 to 0.91).

CONCLUSIONS

No evidence was found to show that alternative inhaler devices are more effective than standard pressurised metered dose inhalers for delivering acting beta(2 )agonist bronchodilators in asthma. Pressurised metered dose inhalers remain the most cost effective delivery devices.

Can women's childbearing and contraceptive intentions predict contraceptive demand? Findings from a longitudinal study in Central India

CONTEXT

To predict the need for contraceptive services, family planning program managers often rely on levels of unmet need derived from measures of childbearing intentions. However, women's intention to use a method has not received as much attention as a measure of contraceptive demand.

METHODS

A survey was conducted in 1999 in rural Madhya Pradesh, India, among a subsample of women who had participated in the 1992-1993 National Family Health Survey (NFHS). The women's childbearing and contraceptive behaviors were compared with the intentions they had stated in the NFHS, and logistic regression was performed to analyze the association between socioeconomic and demographic variables and inconsistent behavior.

RESULTS

Among women who were fecund and married in 1992-1993, 29% of those who intended to have children and 61% of those who intended not to have children failed to adhere to their intentions by 1999. Furthermore, 51% of women who were not practicing contraception at the time of the NFHS but planned to do so acted against their intention by 1999, as did 29% of those who planned not to use a method. NFHS respondents who intended both not to have children and to use a method were more likely than others to have used a method by 1999 (63% vs. 25-41%). Age and history of child death were key factors associated with inconsistency between women's intentions and behavior.

CONCLUSIONS

In India, use of both contraceptive and childbearing intentions predicts contraceptive demand better than use of either indicator alone, and may thus help program planners estimate future demand for contraceptive services.

Physical training for asthma

BACKGROUND

Physical training programmes have been designed for asthmatic subjects with the aim of improving physical fitness, neuromuscular coordination and self-confidence. Habitual physical activity increases physical fitness and lowers ventilation during mild and moderate exercise thereby reducing the likelihood of provoking exercise -induced asthma. Exercise training may also reduce the perception of breathlessness through a number of mechanisms including strengthening respiratory muscles. Subjectively, many asthmatics report that they are symptomatically better when fit, but results from trials have varied and have been difficult to compare because of different designs and training protocols.

OBJECTIVES

The purpose of this review was to assess evidence for the efficacy and effectiveness of physical training in asthma.

SEARCH STRATEGY

We searched the Cochrane Airways Group trials register, Sportdiscus and Science citation index.

SELECTION CRITERIA

Randomised trials in asthmatic subjects undertaking physical training. Subjects had to be 8 years and older. Physical training had to be undertaken for at least 20 to 30 minutes, 2 to 3 times a week, over a minimum of four weeks.

DATA COLLECTION AND ANALYSIS

Eligibility for inclusion and quality of trials were assessed independently by two reviewers.

MAIN RESULTS

Eight studies could be included in this review. Physical training had no effect on resting lung function or the number of days of wheeze. Physical training improved cardiopulmonary fitness as measured by an increase in maximum oxygen uptake of 5.6 ml/kg/min (95% confidence interval 3. 9 to 7.2). There were no data concerning quality of life measurements.

REVIEWER'S CONCLUSIONS

In people with asthma, physical training can improve cardiopulmonary fitness without changing lung function. It is not known whether improved fitness is translated into improved quality of life.

Ambulatory oxygen for chronic obstructive pulmonary disease

BACKGROUND

Little is known about the effectiveness of ambulatory domicilary oxygen therapy. At present ambulatory oxygen in the UK is provided with small oxygen cylinders but in other countries such as the USA and Italy, liquid oxygen systems with higher oxygen carrying capacity are widely used. Both these systems are used without adequate evidence of their effectiveness.

OBJECTIVES

To determine the effectiveness of long-term ambulatory domicilary oxygen therapy in patients with chronic obstructive pulmonary disease.

SEARCH STRATEGY

The Cochrane Airways Group specialised trials register was searched. In addition, bibliographies of each trial retrieved were also searched for additional papers that may contain further studies. Authors of identified trials were contacted for other published and unpublished studies.

SELECTION CRITERIA

Only randomised controlled trials in patients with chronic obstructive pulmonary disease were considered for inclusion. Trials must have randomised patients into long-term ambulatory oxygen therapy or placebo while at home. Ambulatory oxygen can be provided either through portable oxygen cylinders or with liquid oxygen canisters and the placebo group using compressed or liquid air.

DATA COLLECTION AND ANALYSIS

Two reviewers assessed all potential trials independently. Data abstraction was completed by one reviewer and re-checked by the second reviewer.

MAIN RESULTS

Only two studies met the inclusion criteria. These provided data on 70 patients. Statistically significant effects of oxygen were found in only one of the studies, a crossover trial involving 9 patients with severe hypoxia at rest. This study reported a reduction in minute ventilation at maximal exercise (WMD -11.00 L/min; 95%CI -17.53, -4.47L/min) and an increase in PaO2 at rest (WMD 17.00 mmHg; 95%CI 9.13,24.87 L/min) with oxygen therapy when compared to placebo. The other study recruited patients who did not have resting hypoxaemia.

REVIEWER'S CONCLUSIONS

Evidence available to date does not allow any firm conclusions to be drawn concerning the effectiveness of ambulatory domicilary oxygen therapy in patients with COPD. Further studies are required in order to understand the role of ambulatory oxygen in the management of patients with COPD on long-term oxygen therapy. These studies should separate patients who desaturate from those who do not desaturate.

Factors Associated with Disposable Menstrual Absorbent Use Among Young Women in India

CONTEXT

Hygienic use of absorbent products during menstruation is a challenge for young women in India, especially among the underprivileged, who lack knowledge and access to resources. Reuse of menstrual absorbents can be unhygienic and result in adverse health and other outcomes.

METHODS

Data from the 2015-2016 National Family Health Survey-4 for 233,606 menstruating women aged 15-24 were used to examine levels and correlates of exclusive use of disposable absorbents during menstruation. Bivariate and logistic regression analyses were conducted to identify disparities in exclusive use by such characteristics as caste, mass media exposure and interaction with health workers.

RESULTS

Exclusive use of disposable absorbents was low among young women overall (37%), and varied substantially by caste and other characteristics. Compared with women from general castes, those from scheduled castes, scheduled tribes and other backward classes had reduced odds of exclusive disposable absorbent use (odds ratios, 0.8-0.9). Disposable absorbent use was negatively associated with lower levels of education and household wealth, and rural residence. Compared with women who reported daily media exposure, those exposed less frequently had reduced odds of disposable absorbent use (0.7-0.9). Among those who recently met with a health worker, odds of use were lower if menstrual hygiene had not been discussed (0.9).

CONCLUSIONS

Promoting awareness of proper menstrual hygiene-through education, media campaigns and discussion with reproductive health workers-and targeted interventions to disseminate and subsidize the purchase of disposable sanitary napkins should be pursued to address health disparities.

Tartrazine exclusion for allergic asthma

BACKGROUND

Tartrazine is the best known and one of the most commonly used food additives. Food colorants are also used in many medications as well as foods. There has been conflicting evidence as to whether tartrazine causes exacerbations of asthma with some studies finding a positive association especially in individuals with cross-sensitivity to aspirin.

OBJECTIVES

To assess the overall effect of tartrazine (exclusion or challenge) in the management of asthma.

SEARCH STRATEGY

A search was carried out using the Cochrane Airways Group specialised register. Bibliographies of each RCT was searched for additional papers. Authors of identified RCTs were contacted for further information for their trials and details of other studies.

SELECTION CRITERIA

RCTs of oral administration of tartrazine (as a challenge) versus placebo or dietary avoidance of tartrazine versus normal diet were considered. Studies which focused upon allergic asthma, were also included. Studies of tartrazine exclusion for other allergic conditions such as hay fever, allergic rhinitis and eczema were only considered if the results for subjects with asthma were separately identified. Trials could be in either adults or children with asthma or allergic asthma (e.g. sensitivity to aspirin or food items known to contain tartrazine).

DATA COLLECTION AND ANALYSIS

Study quality was assessed and data abstracted by two reviewers independently. Outcomes were analysed using RevMan 4.1.1.

MAIN RESULTS

Ninety abstracts were found, of which 18 were potentially relevant. Six met the inclusion criteria, but only three presented results in a format that permitted analysis and none could be combined in a meta-analysis. In none of the studies did tartrazine challenge or avoidance in diet significantly alter asthma outcomes.

REVIEWER'S CONCLUSIONS

Due to the paucity of available evidence, it is not possible to provide firm conclusions as to the effects of tartrazine on asthma control. However, the six RCTs that could be included in this review all arrived at the same conclusion. Routine tartrazine exclusion may not benefit most patients, except those very few individuals with proven sensitivity.

Written individualised management plans for asthma in children and adults

BACKGROUND

Non-adherence to treatment advice is a common phenomenon in asthma and may account for a significant proportion of the morbidity. Comprehensive care that includes asthma education, written self-management plan and regular review has been shown to improve asthma outcomes, but the contribution of these components has not been established.

OBJECTIVES

To determine whether the provision of a written asthma self-management plan increases adherence and improves outcome.

SEARCH STRATEGY

A search was carried out on the Cochrane Airways Group trials register. There was no language restriction. The search of the databases used the following terms: action plan OR self OR self-care OR self-manag* OR educ* AND adher* OR comply OR compli*. Authors of included studies were contacted for any unpublished or on-going studies and bibliographies of all included studies and reviews were searched for further studies.

SELECTION CRITERIA

Only randomised controlled trials (RCTs) in patients with asthma were considered. Participants must have been assigned to receive an individualised written asthma management plan (symptom or peak flow based) about the actions required for regular asthma management and/or the actions to take in the event of an asthma exacerbation.

DATA COLLECTION AND ANALYSIS

Study quality was assessed and data abstracted by two reviewers independently.

MAIN RESULTS

Six trials met the inclusion criteria. The written management plans were either peak flow or symptom based, which were compared against each other or compared to no written management plan. Reported outcomes included: hospitalisation, emergency department visits, oral corticosteroid use, lung function, days lost from school/work, unscheduled doctor visits and respiratory tract infections. There was no consistent evidence that written plans produced better patient outcomes than no written plan. For some outcomes, there appeared to an advantage of one type of plan over the other, but there was no consistency - one type of plan was not consistently more effective than another.

REVIEWER'S CONCLUSIONS

The available trials are too small and the results too inconsistent to form any firm conclusions as to the contribution of written self management plans in the known beneficial effects of a comprehensive asthma care programmes.

Primary care based clinics for asthma

BACKGROUND

Primary care clinics for asthma have been encouraged and are becoming widespread in some countries, particularly in the UK.

OBJECTIVES

To determine the effectiveness of organised asthma care via primary care based asthma clinics.

SEARCH STRATEGY

A search of the Cochrane Airways Group register and Cochrane Controlled Trials Register using the following search strategy: clinic* OR general pract* OR family pract* or primary care. Separate and additional searches were also conducted using MEDLINE, CINAHL and EMBASE databases.

SELECTION CRITERIA

Trials had to be performed in primary care and be restricted to patients with asthma. Care could be delivered by doctor or nurse. Two reviewers independently ascertained the relevance of trials from titles and abstracts obtained from the searches. Relevant full text articles were retrieved with two reviewers assessing each study for inclusion.

DATA COLLECTION AND ANALYSIS

Two reviewers independently conducted all data abstraction and analysis and all disagreements were resolved by discussion. For the dichotomous variables, odds ratio (OR) or relative risks (RR) with 95% Confidence Interval (95%CI) were calculated for individual outcomes.

MAIN RESULTS

Only one trial met the criteria for inclusion in the review. This trial provided 11 outcome measures of which two showed a significant effect of the intervention. More patients in the intervention group had peak flow meters (RR 1.30; 95%CI 1.05,1.61) and fewer patients in the intervention group were likely to wake up at nights due to their asthma (RR 0.30; 95%CI 0.16, 0.81).

REVIEWER'S CONCLUSIONS

There is limited evidence of benefit for primary care based asthma clinics, but firm conclusions cannot be formed until more good quality trials have been carried out.

Breathing exercises for asthma

BACKGROUND

There is much anecdotal evidence in Eastern and Western literature describing considerable benefits for patients with asthma when treated with breathing interventions. The term 'breathing exercise or training' has numerous interpretations depending on the nature of the therapy, therapist and cultural background.

OBJECTIVES

The objective of this review was to assess the evidence for the effectiveness of breathing re-training in the treatment of patients with asthma.

SEARCH STRATEGY

Trials were searched for in the Cochrane Airways Group trials register, Cochrane Complementary Medicine Field trials register, EMBASE: Physical Medicine & Rehabilitation Field, and Databases of the physiotherapy library of current research, World Congress of Physical Therapy Proceedings (1995) and AMED (Allied & Alternative Medicine). Hand searching of the Association of Chartered Physiotherapists in Respiratory Care Journals was undertaken. Chartered physiotherapists in the field of respiratory medicine were contacted and appeals made in the 'Physiotherapy' Journal and the Physiotherapy Respiratory Care magazine.

SELECTION CRITERIA

Randomised or quasi randomised controlled trials of breathing re-training in patients of all ages with a diagnosis of asthma. Breathing re-training should be a major component of the treatment intervention.

DATA COLLECTION AND ANALYSIS

Two reviewers (EH & FR) independently assessed trial quality and extracted data. Study authors were contacted for additional information. Information on adverse effects was collected from the included trials where possible.

MAIN RESULTS

Abstracts were identified and 32 full text papers were obtained for assessment and possible inclusion of studies in the review. Twenty seven papers were excluded. A total of five papers were included in this review. Most were small. One large study (106 patients) showed an improvement in PEFR and reduction in rescue bronchodilator use. Otherwise benefit of breathing exercises was found in isolated outcome measures in single small studies.

REVIEWER'S CONCLUSIONS

No reliable conclusions can be drawn concerning the use of breathing exercises for asthma in clinical practice.

Non-invasive positive pressure ventilation for treatment of respiratory failure due to exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Non-invasive positive pressure ventilation (NPPV) is being used increasingly in the management of patients admitted to hospital with acute respiratory failure secondary to an exacerbation of chronic obstructive pulmonary disease (COPD).

OBJECTIVES

To determine the effectiveness of NPPV in the management of patients with respiratory failure due to an acute exacerbation of COPD.

SEARCH STRATEGY

An initial search was performed using the Cochrane Airways Group trials register and other relevant electronic databases.

SELECTION CRITERIA

Randomised controlled trials comparing NPPV plus usual medical care versus usual medical care alone were selected. Trials needed to recruit adult patients admitted to hospital with respiratory failure due to an exacerbation of COPD and with PaCO2 > 6 kPa (45 mmHg).

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected articles for inclusion, evaluated methodological quality of the studies and abstracted the data.

MAIN RESULTS

Eight studies were included in the review. NPPV resulted in decreased mortality (Relative Risk [RR] 0.41; 95% Confidence Intervals [CI] 0.26, 0.64), decreased need for intubation (RR 0.42; 95%CI 0.31, 0.59), reduction in treatment failure (RR 0.51; 95%CI 0.39, 0.67), rapid improvement within the first hour in pH (Weight Mean Difference [WMD] 0.03; 95%CI 0.02, 0.04), PaCO2 (WMD -0.40 kPa; 95%CI -0.78, -0.03) and respiratory rate (WMD -3.08 bpm; 95%CI -4.26, -1.89). In addition, complications associated with treatment (RR 0.32; 95%CI 0.18, 0.56) and length of hospital stay (WMD -3.24 days; 95%CI -4.42, -2.06) were also reduced in the NPPV group.

REVIEWER'S CONCLUSIONS

Data from good quality randomised controlled trials permit NPPV to be recommended as the first line intervention, coupled with usual medical care, in all suitable patients with respiratory failure secondary to an acute exacerbation of COPD. A trial of NPPV should be considered early in the course of respiratory failure, and before severe acidosis ensures, as a means of avoiding endotracheal intubation, reducing mortality and treatment failure.

Vitamin C supplementation for asthma

BACKGROUND

Vitamin C is one of the key antioxidant vitamins which is abundant in the extracellular fluid lining the lung and low vitamin C intake has been associated with pulmonary dysfunction.

OBJECTIVES

To evaluate the evidence for the effectiveness of vitamin C in the treatment of asthma.

SEARCH STRATEGY

The Cochrane Airways Review Group asthma register was searched and bibliographies of studies identified were also checked for further trials.

SELECTION CRITERIA

Only randomised controlled trials were eligible for inclusion. Studies were considered for inclusion if they dealt with the treatment of asthma using vitamin C supplementation. Two independent reviewers identified potentially relevant studies using pre-defined criteria and selected studies for inclusion.

DATA COLLECTION AND ANALYSIS

Data were abstracted independently by two reviewers. Information on patients, methods, interventions, outcomes and results was extracted using standard forms.

MAIN RESULTS

A total of 65 abstracts and titles were identified. Ten studies were selected for potential inclusion, six met the inclusion criteria. All included studies were placebo-controlled and randomised. Only three provided data in a form that permitted further analysis and none could be aggregated in a meta analysis. The individual studies produced no significant effect on any asthma outcome.

REVIEWER'S CONCLUSIONS

At present, evidence from randomised-controlled trials is insufficient to recommend a specific role for vitamin C in the treatment of asthma. A methodologically strong and large-scale randomised controlled trial is warranted in order to address the question of the effectiveness of vitamin C in patients with asthma.

Pressurised metered-dose inhalers versus all other hand-held inhalers devices to deliver bronchodilators for chronic obstructive pulmonary disease

BACKGROUND

Bronchodilator therapy for COPD may be delivered by a number of different inhaler devices.

OBJECTIVES

To determine the efficacy of pressurised metered dose inhalers (pMDI) compared to any other handheld inhaler device for the delivery of bronchodilators in non-acute COPD.

SEARCH STRATEGY

The Cochrane Collaboration, Asthma and Wheeze Randomised Controlled Clinical Trials register was searched for studies. The UK pharmaceutical companies who manufacture inhaled COPD medication were also contacted.

SELECTION CRITERIA

Two reviewers independently reviewed the results of computerised search and any potentially relevant articles were obtained in full.

DATA COLLECTION AND ANALYSIS

One reviewer extracted details of each trial and a second reviewer checked all extracted data. Dichotomous outcomes such as exacerbation rate were assessed using relative risk, with 95% confidence interval (CI).

MAIN RESULTS

Fourteen studies appeared potentially relevant but only three studies (61 patients) met the entry criteria. Two studies compared a dry powder device (Turbuhaler or Rotahaler) with a pMDI for beta2-agonist delivery, and one (36 patients cross-over design) the Respimat (soft mist device for ipratropium) vs a pMDI. For the Turbuhaler and Rotahaler, none of the reported outcome measures were significantly different. The Rotahaler study used a high and low dose of medication with or without large volume spacer. The study using the Respimat showed significant increases in FEV1 when compared to a pMDI (difference in change from base line 70 ml, 95% CI 10, 130 ml). The effect on change in FVC was of similar size. There were no differences between these two devices for any other reported outcomes. Although none of the included studies required prior patient ability to use any of the inhalers (and no study mentioned device training), it was assumed that all patients randomised into the study would have undergone training in use of the study inhalers and were capable of using those devices.

REVIEWER'S CONCLUSIONS

In patients with stable COPD, pMDI produced similar outcomes to a dry powder device for delivering beta2-agonists, but the very small number of studies and included patients does not permit firm conclusions to be drawn. The soft mist device for ipratropium was more effective than a pMDI, but the data come from one small study. There need to be further well designed randomised controlled trials to define the role of inhaler devices using bronchodilators in stable COPD.

Cow's milk protein avoidance and development of childhood wheeze in children with a family history of atopy

BACKGROUND

In infants with a family history of atopy, food allergen avoidance has been advocated as means of preventing the development of atopic disease when breast-feeding is not possible or supplemental feeding is needed. Most infant formulas are based on cow's milk protein. Alternative choices include soya based and hydrolysed cows milk formulas.

OBJECTIVES

To estimate the effect of dietary avoidance of cow's milk protein on the development of asthma or wheeze in children.

SEARCH STRATEGY

The Cochrane database was searched for eligible trials until February 2002. The full text papers of all abstracts identified as RCTs were obtained and reviewed independently by two reviewers.

SELECTION CRITERIA

Randomised controlled trials involving children with a family history of atopy in at least one first degree relative were considered if feeding with cow's milk based standard formula was compared to dietary avoidance of cow's milk protein using soya or other hypoallergenic formula during the initial four months of life or longer.

DATA COLLECTION AND ANALYSIS

Two reviewers extracted data independently. A priori defined subgroups were the types of hypoallergenic artificial feed and dietary restrictions on mother and/or child's diet.

MAIN RESULTS

Six trials used hydrolysed formula for at least 4 months in addition to dietary restrictions and in some cases dust-mite reduction measures. The risk of infants experiencing asthma or wheeze during the first year of life was reduced compared to standard cow's milk based formula (Relative Risk =0.40, 95% Confidence Intervals 0.19, 0.85). Feeding soya-based formula as opposed to standard cow's milk formula did not reduce the risk of having asthma or wheeze at any age.

REVIEWER'S CONCLUSIONS

Breast-milk should remain the feed of choice for all babies. In infants with at least one first degree relative with atopy, hydrolysed formula for a minimum of 4 months combined with dietary restrictions and environment measures may reduce the risk of developing asthma or wheeze in the first year of life. There is insufficient evidence to suggest that soya-based milk formula has any benefit.

Inhaled steroids for bronchiectasis

BACKGROUND

Bronchiectasis is a progressive condition characterised by irreversible destruction and dilatation of airways, generally associated with chronic bacterial infection. The two distinct therapeutic goals are: symptom control and reduction in morbidity; and prevention of progression of the underlying disease.

OBJECTIVES

To determine whether regular inhaled corticosteroids produce improvement in symptom control and whether they beneficially influence the natural history of the disease.

SEARCH STRATEGY

The Cochrane Airways Group RCT register and Cochrane Controlled Clinical Trials Register were searched using the following search terms; bronchiectasis AND [corticosteroid* OR beclomethasone OR budesonide OR fluticasone OR triamcinolone OR flunisolide]. Bibliographies of each included RCT was searched for additional trials. Pharmaceutical companies that manufacture inhaled corticosteroids were also contacted.

SELECTION CRITERIA

Only randomised double blind studies controlled trials were included. Patients with radiographic evidence of bronchiectasis were included, but patients with cystic fibrosis were excluded.

DATA COLLECTION AND ANALYSIS

Data was extracted by one of the reviewers (FR). Continuous outcomes were analysed as effect sizes (weighted mean difference or as standardised mean difference with 95% confidence intervals).

MAIN RESULTS

Only two trials on a total of 54 patients could be included. The studies were of 4 and 6 weeks duration. Inhaled corticosteroids had no significant effect on any of the outcomes included in this review, however there was a trend towards improving: FEV1, FVC, PEFR, RV and DLco.

REVIEWER'S CONCLUSIONS

In bronchiectasis, regular use of inhaled corticosteroids may improve lung function. The available studies were too short and too small to provide any clear evidence to guide practice. Larger and longer studies should include rate of decline of lung function, exacerbation frequency, hospitalisations and healthy status as outcomes.

Pressurised metered dose inhalers versus all other hand-held inhaler devices to deliver beta-2 agonist bronchodilators for non-acute asthma

BACKGROUND

A number of different inhaler devices are available to deliver beta2-agonist bronchodilators in asthma. These include hydrofluoroalkane (HFA) or chlorofluorocarbon (CFC)-free propelled pressurised metered dose inhalers (pMDIs) and dry powder devices.

OBJECTIVES

To determine the clinical effectiveness of pMDI compared with any other available handheld inhaler device for the delivery of short-acting beta-2 agonist bronchodilators in non-acute asthma in children and adults.

SEARCH STRATEGY

The Cochrane Collaboration Clinical Trials register was searched for studies as well as separate additional searches carried out on MEDLINE, EMBASE, CINAHL and also on the Current Contents Index as well as the Science Citation Index. In addition, 17 individual online respiratory journals and 12 electronically available clinical trial databases were also searched. The UK pharmaceutical companies who manufacture inhaled asthma medication were contacted in order to obtain details of any published or unpublished studies.

SELECTION CRITERIA

- The full texts of all potentially relevant articles were reviewed independently by two reviewers.

DATA COLLECTION AND ANALYSIS

Fixed and random effect models were used. Dichotomous outcomes were assessed using Odds Ratios or Relative Risks (RR) with 95% Confidence Intervals (95%CI).

MAIN RESULTS

Eighty-four randomised controlled trials were included in this review, but few could be combined to assess a specific outcome for a given delivery device comparison. Only two studies required demonstration of adequate pMDI technique as an entry requirement. There were no difference between a standard CFC containing pMDI and any other device for most outcomes. Regular use of HFA-pMDI containing salbutamol reduced the requirement for short courses of oral corticosteroids (3 trials, 519 patients: RR 0.67; 95% CI 0.49, 0.91); however the total number of exacerbations were unchanged (3 trials, 1271 patients: RR 1.0; 95% CI 0.75, 1.33).

REVIEWER'S CONCLUSIONS

In patients with stable asthma, short-acting beta-2 bronchodilators in standard CFC-pMDI's are as effective as any other devices. The effect of HFA-pMDI on requirement for oral corticosteroid courses to treat acute exacerbations should be confirmed. Effectiveness studies that use an intention-to-treat analysis are required.

Dietary salt reduction or exclusion for allergic asthma

BACKGROUND

There is a wide geographical variation in asthma prevalence and one explanation may be in dietary salt consumption.

OBJECTIVES

To assess the effect of dietary sodium reduction in patients with asthma.

SEARCH STRATEGY

A search was conducted using the Cochrane Airways Group asthma register. Bibliographies of included randomised controlled trials (RCTs) were searched for additional studies. Authors of identified RCTs were contacted for other studies.

SELECTION CRITERIA

All studies were to be RCTs that involved dietary salt reduction or increased salt intake in patients with asthma. Studies of other allergic conditions such as hay fever, allergic rhinitis and eczema were considered patients with asthma were separately identified.

DATA COLLECTION AND ANALYSIS

Study quality was assessed and data extracted by two reviewers. All data analysis was conducted using the Cochrane Collaboration software (RevMan 4.1.1).

MAIN RESULTS

Fifty-six abstracts were identified and 15 studies were reviewed in full text. Five fulfilled the inclusion criteria. Nine were excluded. One was published in duplicate. Complete agreement was reached between the reviewers on inclusion or exclusion of all studies. All studies were small and of short duration. Data from only three could be pooled. Low sodium diet was associated with a significantly lower urine sodium excretion than normal or high salt diets. There were no significant differences in any asthma outcome between low salt and normal or high salt diets, but FEV1 was slightly higher with low salt compared to normal, WMD 0.09 L (95% confidence interval (CI) -0.26, 0.44 L, n=88), as was daily PEFR, WMD 11 l/min (95% CI -81, 103 l/min, n=78). With low compared to high salt, FEV1 was slightly higher WMD 0.22 L (95% CI -0.14, 0.59 L, n=88), as was daily PEFR, WMD 14 l/min (95% CI -41, 68 l/min, n=78). Bronchodilator use was slightly lower, WMD 0.7 puffs/day (95% CI -1.8, 0.5 puffs/day, n=62).

REVIEWER'S CONCLUSIONS

Based on currently available evidence it is not possible to conclude whether dietary salt reduction has any place in the treatment or management of asthma.

A modified procedure for calculating person years of life lost

"This study has proposed a modified procedure for the calculation of PYLL [person years of life lost] which takes competing risk of death into consideration. An application of the modified and old procedures to the data on ten leading causes of death in Bombay shows that the old procedure underestimates the actual PYLL in...all the causes of death under study except dysentery, pneumonia and prematurity. This study suggests tuberculosis, pneumonia, prematurity, heart disease and dysentery in males and pneumonia, prematurity, dysentery, tuberculosis and heart disease in females in that order, as the first five leading causes of death in Bombay in 1984."