RESUMEN
OBJECTIVE: To evaluate the impact of bias-related study characteristics on treatment effects in osteoarthritis (OA) trials. STUDY DESIGN AND SETTING: Based on OA trials included in Cochrane reviews, the impact of study characteristics on treatment effect estimates was evaluated. Characteristics included items of the risk of bias (RoB) tool, trial size, single vs. multisite, and source of funding. Effect sizes (ESs) were calculated as standardized mean differences (SMDs). Meta-regression was performed to identify "relevant study-level covariates" that decrease the between-study variance (τË2). RESULTS: Twenty reviews, including 126 OA trials with a high degree of heterogeneity, were included (τË2 = 0.1247). Among the RoB domains, only patient blinding had an impact on the results (reducing heterogeneity according to τË2 < 7%). Inadequate blinding of patients yielded larger effects (SMDDifference = 0.15; 95% confidence interval [CI]: 0.01-0.29, P = 0.035). The most important study characteristic was trial size (heterogeneity reduced by 25%), with small trials reporting larger effects (SMDDifference = 0.29; 95% CI: 0.16-0.42, P < 0.001). CONCLUSION: In musculoskeletal reviews addressing pain, all the items included in the Cochrane RoB tool might not be equally important. OA trial results may be affected by bias constructs that are not yet fully elucidated.
Asunto(s)
Ensayos Clínicos como Asunto/normas , Osteoartritis/terapia , Sesgo , Métodos Epidemiológicos , Humanos , Análisis de RegresiónRESUMEN
BACKGROUND: Intranasal corticosteroids (INS) (corticosteroid nasal sprays) and oral antihistamines (OA) are two of the most common treatments for patients with allergic rhinitis (AR). To our knowledge, there are no systematic reviews on this topic including trials published after 2007. OBJECTIVE: To compare INS with nonsedating OAs as treatments for AR. METHODS: The systematic review and meta-analysis were based on the Grades of Recommendation, Assessment, Development, and Evaluation principles and the Patient, Intervention, Comparison, and Outcome approach. Primary literature was searched up to January 22, 2015. Criteria for eligibility were randomized controlled trials that compared the efficacy and/or adverse effects of INS and OA in patients with AR. Continuous outcome data were analyzed by using standardized mean differences (SMD) for multiple outcome measures, and mean differences in the case of a single study or outcome. Pooled estimates of effects, 95% confidence interval (CI), were calculated by using random-effects models. RESULTS: The meta-analysis included five randomized controlled trials with a total of 990 patients. INS were superior to OAs in improving total nasal symptoms score (SMD -0.70 [95% CI, -0.93 to -0.47]) and in relieving the following: nasal obstruction (SMD -0.56 [95% CI, -0.82 to -0.29]), rhinorrhea (SMD -0.47 [95% CI, -1.00 to 0.05]), nasal itching (SMD -0.42 [95% CI, -0.65 to -0.18]), sneezing (SMD -0.52 [95% CI, -0.73 to -0.32]), and quality of life mean difference -0.90 [95% CI, -1.18 to -0.62]). There was no difference in relief of ocular symptoms (SMD -0.08 [95% CI, -0.23 to 0.08]). In addition, four randomized controlled trials were included in a narrative analysis. The results in the narrative analysis were comparable with those found in the meta-analysis. CONCLUSION: INS were superior to OAs in improving nasal symptoms and quality of life in patients with AR.