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%

Assessing quality of life in chronic non-specific lung disease--a review of empirical studies published between 1980 and 1994

Chronic non-specific lung disease (CNSLD), a chronic disease with considerable prevalence and mortality rates, is not only a medical problem, it also has significant psychological and social consequences for the patients concerned. Quality of life research on CNSLD has been rather underdeveloped for quite a long period of time, but has recently become an important topic in research as well as in patient care. In order to get insight into the state of the art of empirical research on quality of life (QOL) in CNSLD, a review of the literature between 1980-1994 on this topic is presented. Special attention is paid to definitions and operationalizations of the QOL concept as well as on questionnaires used to assess QOL and the aims of QOL research. Analysis reveals that QOL is seldom defined clearly and is operationalized in a variety of ways. Most studies have a descriptive nature or pertain to clinical trials. The negative impact of CNSLD on QOL is well-documented and shows the importance of incorporating assessment of QOL in research as well as in patient care. Future research is called for, which should be theory-driven, taking into account recent developments concerning disease-specific measures of QO