Inhaled drugs to reduce exacerbations in patients with chronic obstructive pulmonary disease: a network meta-analysis

BACKGROUND: Most patients with chronic obstructive pulmonary disease (COPD) receive inhaled long-acting bronchodilators and inhaled corticosteroids. Conventional meta-analyses established that these drugs reduce COPD exacerbations when separately compared with placebo. However, there are relatively few head-to-head comparisons and conventional meta-analyses focus on single comparisons rather than on a simultaneous analysis of competing drug regimens that would allow rank ordering of their effectiveness. Therefore we assessed, using a networkmeta analytic technique, the relative effectiveness of the common inhaled drug regimes used to reduce exacerbations in patients with COPD. METHODS: We conducted a systematic review and searched existing systematic reviews and electronic databases for randomized trials of >=4 weeks' duration that assessed the effectiveness of inhaled drug regimes on exacerbations in patients with stable COPD. We extracted participants and intervention characteristics from included trials and assessed their methodological quality. For each treatment group we registered the proportion of patients with >=1 exacerbation during follow-up. We used treatment-arm based logistic regression analysis to estimate the absolute and relative effects of inhaled drug treatments while preserving randomization within trials. RESULTS: We identified 35 trials enrolling 26,786 patients with COPD of whom 27% had >=1 exacerbation. All regimes reduced exacerbations statistically significantly compared with placebo (odds ratios ranging from 0.71 (95%confidence interval [CI] 0.64 to 0.80) for long-acting anticholinergics to 0.78 (95% CI 0.70 to 0.86) for inhaled corticosteroids). Compared with long-acting bronchodilators alone, combined treatment was not more effective (comparison with long-acting beta-agonists: odds ratio 0.93 [95% CI 0.84 to 1.04] and comparison with long-acting anticholinergics: odds ratio 1.02 [95% CI 0.90 to 1.16], respectively). If FEV1 was 40% predicted. This effect modification was significant for inhaled corticosteroids (P=0.02 for interaction) and combination treatment (P=0.01) but not for long-acting anticholinergics (P=0.46). A limitation of this analysis is its exclusive focus on exacerbations and lack of FEV1 data for individual patients. CONCLUSIONS: We found no evidence that one single inhaled drug regimen is more effective than another in reducing exacerbations. Inhaled corticosteroids when added to long-acting beta-agonists reduce exacerbations only in patients with COPD with FEV1<=40%

A randomized trial about the perceived informativeness of new empirical evidence Does beta-carotene prevent (cervical) cancer?

The perceived informativeness of a publication can be assessed by measuring the change in belief it induces among the scientific public, regarding a certain hypothesis. In a randomized trial, we studied the effect of empirical evidence from a clinical experiment and a case-control study on the hypothesis that beta-carotene protects against (cervical) cancer. The study population consisted of first authors of recently published patient-oriented research papers. They received an abstract of the clinical experiment, of the case-control study, or a "placebo" abstract. The latter was used to assess the specific effect of the empirical evidence in the two real studies. The change in belief in the hypotheses was expressed as a likelihood ratio (LR). All three abstracts led to a decrease in belief in the hypothesis. The median LRs of the abstracts of the experiement, case-control study and "placebo" were 0.33, 0.45, 0.75 respectively. This paper shows that the belief in a certain hypothesis is influenced by the quality of empirical evidence in a study. The magnitude of change induced by the experimental and case-control abstract had the anticipated order, but the change in belief induced by the "placebo" abstract was larger than we had expected. Reasons for this may be the concise information in the abstract and the variable methodological training of the study population

Rational pain management in complex regional pain syndrome 1 (CRPS 1)--a network meta-analysis

OBJECTIVE Guidelines for complex regional pain syndrome (CRPS) 1 advocate several substance classes to reduce pain and support physical rehabilitation, but guidance about which agent should be prioritized when designing a therapeutic regimen is not provided. Using a network meta-analytic approach, we examined the efficacy of all agent classes investigated in randomized clinical trials of CRPS 1 and provide a rank order of various substances stratified by length of illness duration. DESIGN In this study a network meta-analysis was conducted. PATIENTS The participants of this study were patients with CRPS 1. METHOD Searches in electronic, previous systematic reviews, conference abstracts, book chapters, and the reference lists of relevant articles were performed. Eligible studies were randomized controlled trials comparing at least one analgesic agent with placebo or with another analgesic and reporting efficacy in reducing pain. Summary efficacy stratified by symptom duration and length of follow-up was computed across all substance classes. Two authors independently extracted data. RESULTS In total, 16 studies were included in the analysis. Bisphosphonates appear to be the treatment of choice in early stages of CRPS 1. The effects of calcitonin surpass that of bisphosphonates and other substances as a short-term medication in more chronic stages of the illness. While most medications showed some efficacy on short-term follow-up, only bisphosphonates, NMDA analogs, and vasodilators showed better long-term pain reduction than placebo. LIMITATION For some drug classes, only a few studies were available and many studies included a small group of patients. Insufficient data were available to analyze efficacy on disability. CONCLUSION This network meta-analysis indicates that a rational pharmacological treatment strategy of pain management should consider bisphosphonates in early CRPS 1 and a short-term course of calcitonin in later stages. While most medications showed some efficacy on short-term follow-up, only bisphosphonates, NMDA analogs and vasodilators showed better long-term pain reduction than placebo

Balneotherapy and quality assessment: Interobserver reliability of the Maastricht criteria list and the need for blinded quality assessment

This study investigates aspects of the reliability of the Maastricht criteria list for quality assessment in systematic reviews, and whether blinded reviewing is necessary to prevent review bias. We used the data set of 12 articles from a systematic review concerning the efficacy of balneotherapy in patients with arthritis. Twenty reviewers participated of which two reviewers, who have been involved in developing the Maastricht criteria list, acted as reference standard. Half of all assessments were performed blindly. A high level of agreement was found between the reviewers and a high level of correlation with the reference standard. The quality scores between the blinded and unblinded assessment did not differ much. Based on the results we conclude that the Maastricht criteria list is a reliable instrument in duality assessment of clinical trials. Within the limits of this study we found no evidence that blinding is necessary to prevent review bias

Taking baths: The efficacy of balneotherapy in patients with arthritis. A systematic review

Objective. To review English, French, German, and Dutch language studies of the effectiveness of balneotherapy. Balneotherapy (hydrotherapy or spa therapy) is one of the oldest forms of therapy for patients with arthritis. One of the aims of balneotherapy is to relieve pain. Methods. We performed a systematic review that included randomized and nonrandomized studies. Quality scores of the studies were determined using a criteria list. Results. Most studies report positive findings, but all studies showed methodological flaws. A quality of life measurement was never reported as an outcome measure. None of the randomized clinical trials included intention-to-treat analysis or comparison of effects between groups. Conclusion. Because of the methodological flaws a conclusion about the efficacy of balneotherapy cannot be provided from studies we reviewed. We conclude that most flaws found could be avoidable in future research

Comparative effectiveness of antibiotics for uncomplicated urinary tract infections: Network meta-analysis of randomized trials

The efficacies and adverse effects of different antibiotics for uncomplicated urinary tract infections (UTIs) have been studied by standard meta-analytic methods using pairwise direct comparisons of antimicrobial treatments: the effects of one treatment are compared to those of either another treatment or placebo. However, for clinical decisions, we need to know the effectiveness of each possible treatment in comparison with all relevant alternatives, not with just one. To compare the efficacies and adverse effects of all relevant antibiotics for UTI treatment simultaneously by performing a network meta-analysis using direct and indirect treatment comparisons. Using logistic regression analysis, we performed a network meta-analysis of randomized controlled trials (RCTs) published after 1999 that compared different oral antibiotic or placebo regimens for UTI treatment in general practice or outpatient settings. We looked at five binary outcomes: early clinical, early bacteriological, late clinical and late bacteriological outcomes, as well as adverse effects. Consequently, a ranking of the antibiotic regimens could be composed. Using a network structure, we could compare and rank nine treatments from 10 studies. Overall, ciprofloxacin and gatifloxacin appeared the most effective treatments, and amoxicillin-clavulanate appeared the least effective treatment. In terms of adverse effects, there were no significant differences. Network meta-analysis shows some clear efficacy differences between different antibiotic treatments for UTI in women. It provides a useful tool for clinical decision making in everyday practice. Moreover, the method can be used for meta-analyses of RCTs across primary care and beyon