Stroke risk and NSAIDs: A systematic review of observational studies

Aims: To perform a quantitative systematic review of observational studies on the risk of stroke associated with the use of individual NSAIDs. Methods and results: Searches were conducted using the Medline database within PubMed (1990-2008). Observational cohort or case-control studies were eligible if reported on the risk of cardiovascular events associated with individual NSAIDs versus the nonuse of NSAIDs. We found 3193 articles, in which 75 were eligible for review and abstraction. Of the 75 articles, 6 reported relative risk (RR) of stroke. Data were abstracted into a database using a standardized entry form. Two authors assessed study quality, and discrepancies were resolved by consensus. The pooled RR of all subtypes of incident stroke was increased with the current use of rofecoxib (RR=1.64, 95% CI=1.15-2.33) and diclofenac (RR=1.27, 95% CI=1.08-1.48). The pooled estimates for naproxen, ibuprofen, and celecoxib were close to unity. The risk of ischemic stroke was also increased with rofecoxib (RR=1.82, 95% CI=1.09-3.04) and diclofenac (RR=1.20, 95% CI=0.99-1.45). Data were inadequate to estimate the pooled RR by dose and duration, for other individual NSAIDs or nonischemic stroke subtypes. Conclusion: This meta-analysis supports an increased risk of ischemic stroke with the current use of rofecoxib and diclofenac. Additional studies are required to evaluate most individual NSAIDS, the effect of dose and duration, and the subtypes of stroke

Cardiovascular risk associated with the use of glitazones, metformin and sufonylureas: meta-analysis of published observational studies

BACKGROUND: The results of observational studies evaluating and comparing the cardiovascular safety of glitazones, metformin and sufonylureas are inconsistent.To conduct and evaluate heterogeneity in a meta-analysis of observational studies on the risk of acute myocardial infarction (AMI) or stroke in patients with type 2 diabetes using non-insulin blood glucose-lowering drugs (NIBGLD). METHODS: We systematically identified and reviewed studies evaluating NIBGLD in patients with type 2 diabetes indexed in Medline, Embase, or the Cochrane Library that met prespecified criteria. The quality of included studies was assessed with the RTI item bank. Results were combined using fixed- and random-effects models, and the Higgins I(2) statistic was used to evaluate heterogeneity. Sensitivity analyses by study quality were conducted. RESULTS: The summary relative risk (sRR) (95% CI) of AMI for rosiglitazone versus pioglitazone was 1.13 (1.04-1.24) [I(2) = 55%]. In the sensitivity analysis, heterogeneity was reduced [I(2) = 16%]. The sRR (95% CI) of stroke for rosiglitazone versus pioglitazone was 1.18 (1.02-1.36) [I(2)  = 42%]. There was strong evidence of heterogeneity related to study quality in the comparisons of rosiglitazone versus metformin and rosiglitazone versus sulfonylureas (I (2) ≥ 70%). The sRR (95% CI) of AMI for sulfonylurea versus metformin was 1.24 (1.14-1.34) [I(2) = 41%] and for pioglitazone versus metformin was 1.02 (0.75-1.38) [I(2) = 17%]. Sensitivity analyses decreased heterogeneity in most comparisons. CONCLUSION/INTERPRETATION: Sulfonylureas increased the risk of AMI by 24% compared with metformin; an imprecise point estimate indicated no difference in risk of AMI when comparing pioglitazone with metformin. The presence of heterogeneity precluded any conclusions on the other comparisons. The quality assessment was valuable in identifying methodological problems in the individual studies and for analysing potential sources of heterogeneity

Myocardial infarction and individual nonsteroidal anti‐inflammatory drugs meta‐analysis of observational studies

OBJECTIVE: To conduct a systematic review of observational studies on the risk of acute myocardial infarction (AMI) with use of individual nonsteroidal anti-inflammatory drugs (NSAIDs). METHODS: A search of Medline (PubMed) for observational studies published from 1990 to 2011 identified 3829 articles; 31 reported relative risk (RR) of AMI with use of individual NSAIDs versus nonuse of NSAIDs. Information abstracted in a standardized form from 25 publications was used for the meta-analysis on 18 independent study populations. RESULTS: Random-effects RR (95% confidence interval (CI)) was lowest for naproxen 1.06 (0.94–1.20), followed by celecoxib 1.12 (1.00–1.24), ibuprofen 1.14 (0.98–1.31), meloxicam 1.25 (1.04–1.49), rofecoxib 1.34 (1.22–1.48), diclofenac 1.38 (1.26–1.52), indometacin 1.40 (1.21–1.62), etodolac 1.55 (1.16–2.06), and etoricoxib 1.97 (1.35–2.89). Heterogeneity between studies was present. For new users, RRs (95% CIs) were for naproxen, 0.85 (0.73–1.00); ibuprofen, 1.20 (0.97–1.48); celecoxib, 1.23 (1.00–1.52); diclofenac, 1.41 (1.08–1.86); and rofecoxib, 1.43 (1.21–1.66). Except for naproxen, higher risk was generally associated with higher doses, as defined in each study, overall and in patients with prior coronary heart disease. Low and high doses of diclofenac and rofecoxib were associated with high risk of AMI, with dose–response relationship for rofecoxib. In patients with prior coronary heart disease, except for naproxen, duration of use ≤3 months was associated with an increased risk of AMI. CONCLUSIONS: Most frequently NSAIDs used in clinical practice, except naproxen, are associated with an increased risk of AMI at high doses or in persons with diagnosed coronary heart disease. For diclofenac and rofecoxib, the risk was increased at low and high doses. Copyright © 2013 John Wiley & Sons, Ltd

The risk of heart failure associated with the use of noninsulin blood glucose-lowering drugs: Systematic review and meta-analysis of published observational studies

Background: Patients with type 2 diabetes mellitus (T2DM) are at high risk of heart failure. A summary of the effects of blood glucose-lowering drugs other than glitazones on the risk of heart failure in routine clinical practice is lacking. The objective of this study was to conduct a systematic review and meta-analysis of observational studies on the risk of heart failure when using blood glucose-lowering drugs. Methods: We systematically identified and reviewed cohort and case-control studies in which the main exposure of interest was noninsulin blood glucose-lowering medications in patients with T2DM. We searched Medline, Embase, and the Cochrane Library to identify publications meeting prespecified eligibility criteria. The quality of included studies was assessed with the Newcastle-Ottawa Scale and the RTI item bank. Results were combined using fixed and random-effects models when at least 3 independent data points were available for a drug-drug comparison. Results: The summary relative risk of heart failure in rosiglitazone users versus pioglitazone users (95% CI) was 1.16 (1.05-1.28) (5 cohort studies). Heterogeneity was present (I2 = 66%). For new users (n = 4) the summary relative risk was 1.21 (1.14-1.30) and the heterogeneity was reduced (I2 = 31%);. The summary relative risk for rosiglitazone versus metformin was 1.36 (95% CI, 1.17-1.59) (n=3). The summary relative risk (95% CI) of heart failure in sulfonylureas users versus metformin users was 1.17 (95% CI, 1.06-1.29) (5 cohort studies; I2 = 24%) and 1.22 (1.02-1.46) when restricted to new users (2 studies). Information on other comparisons was very scarce. Information on dose and duration of treatment effects was lacking for most comparisons. Few studies accounted for disease severity; therefore, confounding by indication might be present in the majority of the within-study comparisons of this meta-analysis. Conclusions: Use of glitazones and sulfonylureas was associated with an increased risk of heart failure compared with metformin use. However, indication bias cannot be ruled out. Ongoing large multidatabase studies will help to evaluate the risk of heart failure in treated patients with diabetes, including those using newer blood glucose-lowering therapies.</p

Quality assessment of observational studies in a drug-safety systematic review, comparison of two tools: the Newcastle&ndash;Ottawa Scale and the RTI item bank

BACKGROUND: The study objective was to compare the Newcastle–Ottawa Scale (NOS) and the RTI item bank (RTI-IB) and estimate interrater agreement using the RTI-IB within a systematic review on the cardiovascular safety of glucose-lowering drugs. METHODS: We tailored both tools and added four questions to the RTI-IB. Two reviewers assessed the quality of the 44 included studies with both tools, (independently for the RTI-IB) and agreed on which responses conveyed low, unclear, or high risk of bias. For each question in the RTI-IB (n=31), the observed interrater agreement was calculated as the percentage of studies given the same bias assessment by both reviewers; chance-adjusted interrater agreement was estimated with the first-order agreement coefficient (AC1) statistic. RESULTS: The NOS required less tailoring and was easier to use than the RTI-IB, but the RTI-IB produced a more thorough assessment. The RTI-IB includes most of the domains measured in the NOS. Median observed interrater agreement for the RTI-IB was 75% (25th percentile [p25] =61%; p75 =89%); median AC1 statistic was 0.64 (p25 =0.51; p75 =0.86). CONCLUSION: The RTI-IB facilitates a more complete quality assessment than the NOS but is more burdensome. The observed agreement and AC1 statistic in this study were higher than those reported by the RTI-IB’s developers

Quality assessment of observational studies in a drug-safety systematic review, Comparison of two tools: The Newcastle-Ottawa scale and the RTI item bank

Methods: We tailored both tools and added four questions to the RTI-IB. Two reviewers assessed the quality of the 44 included studies with both tools, (independently for the RTI-IB) and agreed on which responses conveyed low, unclear, or high risk of bias. For each question in the RTI-IB (n=31), the observed interrater agreement was calculated as the percentage of studies given the same bias assessment by both reviewers; chance-adjusted interrater agreement was estimated with the first-order agreement coefficient (AC1) statistic.Background: The study objective was to compare the Newcastle-Ottawa Scale (NOS) and the RTI item bank (RTI-IB) and estimate interrater agreement using the RTI-IB within a systematic review on the cardiovascular safety of glucose-lowering drugs.Results: The NOS required less tailoring and was easier to use than the RTI-IB, but the RTI-IB produced a more thorough assessment. The RTI-IB includes most of the domains measured in the NOS. Median observed interrater agreement for the RTI-IB was 75% (25th percentile [p25] =61%; p75 =89%); median AC1 statistic was 0.64 (p25 =0.51; p75 =0.86).Conclusion: The RTI-IB facilitates a more complete quality assessment than the NOS but is more burdensome. The observed agreement and AC1 statistic in this study were higher than those reported by the RTI-IB’s developers.</p

Accuracy of International Classification of Diseases, 9th Revision, Clinical Modification codes for upper gastrointestinal complications varied by position and age: a validation study in a cohort of nonsteroidal anti-inflammatory drugs users in Friuli Venezia Giulia, Italy

Purpose: To validate the International Classification of Diseases, 9th Revision, Clinical Modification discharge codes used to identify cases of upper gastrointestinal complications (UGICs) in hospitals of Friuli Venezia Giulia, Italy. Methods: Cohort study on the risk of UGIC in users of nonsteroidal anti-inflammatory drugs conducted in Friuli Venezia Giulia between 2001 and 2008. Cases were identified through primary and secondary International Classification of Diseases, 9th Revision Clinical specific codes 531 (gastric ulcer), 532 (duodenal ulcer), 533 (peptic ulcer), 534 (gastrojejunal ulcer), and nonspecific code 578 (gastrointestinal hemorrhage). Potential cases were confirmed through hospital chart review. Results: The chart retrieval percentage was 98.4%.The positive predictive value (PPV) was 94.3% for primary codes 531 and 532, 79.5% for code 533, 83.1% for code 534, 40.2% for code 578. The PPV for secondary codes was 34.7% but increased to 88.9% and 79.2% when the primary code was for peritonitis or acute post-hemorrhagic anemia, respectively. Validation of secondary codes increased case ascertainment by 4.9%. Endoscopy confirmed 79.4% of cases but only 67.2% of those above age 84years. Conclusions: The PPV was high for specific primary codes and moderate to low for nonspecific primary and secondary codes. The inclusion of confirmed cases identified by nonspecific and secondary codes can be of value in studies that need a complete ascertainment of cases occurring in the study population. In this cohort, not including these cases would underestimate the incidence of UGICs. A potential for case misclassification exists in particular in eldest ages

Individual NSAIDs and Upper Gastrointestinal Complications A Systematic Review and Meta-Analysis of Observational Studies (the SOS Project)

Background: The risk of upper gastrointestinal (GI) complications associated with the use of NSAIDs is a serious public health concern. The risk varies between individual NSAIDs; however, there is little information on the risk associated with some NSAIDs and on the impact of risk factors. These data are necessary to evaluate the benefit-risk of individual NSAIDs for clinical and health policy decision making. Within the European Community's Seventh Framework Programme, the Safety Of non-Steroidal anti-inflammatory drugs (NSAIDs) [SOS] project aims to develop decision models for regulatory and clinical use of individual NSAIDs according to their GI and cardiovascular safety. Objective: The aim of this study was to conduct a systematic review and meta-analysis of observational studies to provide summary relative risks (RR) of upper GI complications (UGIC) associated with the use of individual NSAIDs, including selective cyclooxygenase-2 inhibitors. Methods: We used the MEDLINE database to identify cohort and case-control studies published between I January 1980 and 31 May 2011, providing adjusted effect estimates for UGIC comparing individual NSAIDs with non-use of NSAIDs. We estimated pooled RR and 95% CIs of UGIC for individual NSAIDs overall and by dose using fixed- and random-effects methods. Subgroup analyses were conducted to evaluate methodological and clinical heterogeneity between studies. Results: A total of 2984 articles were identified and 59 were selected for data abstraction. After review of the abstracted information, 28 studies met the meta-analysis inclusion criteria. Pooled RR ranged from 1.43 (95% CI 0.65, 3.15) for aceclofenac to 18.45 (95% CI 10.99, 30.97) for azapropazone. RR was less than 2 for aceclofenac, celecoxib (RR 1.45; 95% CI 1.17, 1.81) and ibuprofen (RR 1.84; 95% CI 1.54, 2.20); 2 to less than 4 for rofecoxib (RR 2.32; 95% CI 1.89, 2.86), sulindac (RR 2.89; Conclusions: We confirmed variability in the risk of UGIC among individual NSAIDs as used in clinical practice. Factors influencing findings across studies (e.g. definition and validation of UGIC, exposure assessment, analysis of new vs prevalent users) and the scarce data on the effect of dose and duration of use of NSAIDs and on concurrent use of other medications need to be addressed in future studies, including SOS