| Ref ID | 10 |
| First Author | A. Bilandzic |
| Journal | PLOS MEDICINE |
| Year Of Publishing | 2016 |
| URL | https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1001987 |
| Keywords |
• Risk of bias • Cardiology • Observational studies • Cochrane |
| Problem(s) |
• Inclusion of observational / non-randomised studies • Meta-analyses and forest plots presented without considering risk of bias / quality • Flawed risk of bias undertaken |
| Article Type | Empirical |
| Article Subtype | Inter-rater agreement study |
| First Author Country | Canada |
| Aim | To assess the reliability and usability of a new Cochrane risk of bias tool for non-randomized studies of interventions and to determine whether restricting analysis to studies with low or moderate Risk of Bias made a material difference to the results of two systematic reviews of Adverse Cardiovascular Effects of Thiazolidinediones and Cyclooxygenase-2 Inhibitors published in 2006 and 2011. Two epidemiologists applied the Cochrane Risk of Bias tool and made assessments across the seven specified domains of bias for each of 37 included component studies. Inter-rater agreement was measured using the weighted Kappa statistic. |
| Level of Investigation | Descriptive |
| Summary of Findings | The Cochrane Risk of Bias tool highlighted a wide range of risks of bias in observational studies included in the two widely cited included systematic reviews and this had the potential to change the conclusions of the reviews. The pooled odds ratios for myocardial infarction, heart failure, and death for rosiglitazone versus pioglitazone remained significantly elevated when analyses were confined to studies with low or moderate Risk of Bias. However, the estimate for myocardial infarction declined from 1.14 (95% CI 1.07–1.24) to 1.06 (95% CI 0.99–1.13) when analysis was confined to studies with low Risk of Bias. Estimates of pooled relative risks of cardiovascular events with COX-2 inhibitors compared with no nonsteroidal anti-inflammatory drug changed little when analyses were confined to studies with low or moderate Risk of Bias. The exception was a rise in the relative risk associated with ibuprofen from 1.07 (95% CI 0.97–1.18) to 1.14 (95% CI 1.03–1.26). |
| Number of systematic reviews included | 2 |
| Number of eligible systematic reviews assessed | 2 |
| Treatment impacted | Yes |
| Treatment impacted description | |
| Interpretation impacted | Yes |
| Interpretation impacted description | The pooled odds ratios for myocardial infarction, heart failure, and death for rosiglitazone versus pioglitazone remained significantly elevated when analyses were confined to studies with low or moderate Risk of Bias. However, the estimate for myocardial infarction declined from 1.14 (95% CI 1.07–1.24) to 1.06 (95% CI 0.99–1.13) when analysis was confined to studies with low Risk of Bias. |