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.

Quality assessment of observational studies in a drug-safety systematic review, comparison of two tools: the Newcastle-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.

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.

Risk of acute liver injury associated with the use of moxifloxacin and other oral antimicrobials: a retrospective, population-based cohort study.

STUDY OBJECTIVE: To estimate the incidence and relative risk of a hospitalization or emergency visit for noninfectious liver injury in users of eight oral antimicrobials-amoxicillin, amoxicillin-clavulanic acid, clarithromycin, cefuroxime, doxycycline, levofloxacin, moxifloxacin, telithromycin-compared with nonusers of these antimicrobials. DESIGN: Retrospective, observational cohort study with a nested case-control analysis. DATA SOURCE: HealthCore Integrated Research Database. PATIENTS: Adults with continuous health plan enrollment for at least 6 months before study entry who had a new dispensing of a study antimicrobial between July 1, 2001, and March 31, 2009. Cases had diagnoses indicating noninfectious liver injury during follow-up. To control for potentially confounding risk factors, 10 controls at risk for liver injury during follow-up were matched to each case by age, sex, and event date (liver injury date of the case), and analyses were adjusted for medical history, concomitant drugs, and health care service use. MEASUREMENTS AND MAIN RESULTS: Two physician reviewers (blind to exposure) validated the cases. Among 1.3 million antimicrobial users, we identified 607 cases of liver injury, including 82 cases of severe hepatocellular injury and 11 cases of liver failure. Liver injury incidence in nonusers of study antimicrobials was 35/100,000 person-years (95% confidence interval [CI] 29-42/100,000 person-years). For valid cases, the adjusted relative risk among current users of multiple antimicrobials was 3.2 (95% CI 1.6-6.7). Levofloxacin had the highest relative risk for current single use (3.2, 95% CI 1.8-5.8). Relative risks were also elevated for amoxicillin-clavulanic acid (2.5, 95% CI 1.3-5.0), doxycycline (2.5, 95% CI 1.2-5.2), moxifloxacin (2.3, 95% CI 1.1-4.7), and amoxicillin (2.3, 95% CI 1.1-4.7). CONCLUSION: The results support a comparatively high adjusted relative risk of liver injury among patients exposed concurrently to multiple antimicrobials and modest elevations in the risk for several antimicrobials used alone; however, we found little evidence of any strong effect of commonly used antimicrobials on the risk of liver injury.

Validation of acute liver injury cases in a population-based cohort study of oral antimicrobial users.

We conducted a cohort study of acute, noninfectious liver injury among oral antimicrobial users. Potential cases were identified in the HealthCore Integrated Research Database (HIRD(SM)) population between July 1, 2001, and March 31, 2009, using ICD-9-CM codes primarily for acute and subacute necrosis of the liver, hepatic coma, and unspecified hepatitis. Liver test results were used to confirm case status according to published criteria. Two physician reviewers experienced in studying acute liver injury (blinded to study drug exposures) evaluated data abstracted from hospital and emergency department records to validate potential cases. Of 715 potential cases having claims associated with any of the primary screening codes, 312 (44%) were valid cases, 108 (15%) were not cases, and 295 (41%) were of uncertain status (records inadequate for validation). Among potential cases with adequate medical records, the PPV for presence of any of the primary codes was 74% (95% CI, 70%-78%). The highest PPV for a single code was for acute and subacute necrosis of the liver (84%; 95% CI, 77%-90%). Evaluation of cases of noninfectious liver injury using hospital and emergency department medical records continues to represent the preferred approach in studies using insurance claims data.

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 84 years. 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.

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 (0.94­1.20), followed by celecoxib 1.12 (1.00­1.24), ibuprofen 1.14 (0.98­1.31), meloxicam 1.25 (1.04­1.49), rofecoxib 1.34 (1.22­1.48), diclofenac 1.38 (1.26­1.52), indometacin 1.40 (1.21­1.62), etodolac 1.55 (1.16­2.06), and etoricoxib 1.97 (1.35­2.89). Heterogeneity between studies was present. For new users, RRs (95% CIs) were for naproxen, 0.85 (0.73­1.00); ibuprofen, 1.20 (0.97­1.48); celecoxib, 1.23 (1.00­1.52); diclofenac, 1.41 (1.08­1.86); and rofecoxib, 1.43 (1.21­1.66).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 dose­response 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.

Risk of upper gastrointestinal complications in a cohort of users of nimesulide and other nonsteroidal anti-inflammatory drugs in Friuli Venezia Giulia, Italy.

PURPOSE: Information on the risk of upper gastrointestinal complications (UGIC) in users of nimesulide, the most used nonsteroidal anti-inflammatory drug (NSAID) in Italy, is scarce. In the context of the European regulatory review on nimesulide, we estimated and compared the risk associated with nimesulide and other individual NSAIDs with the risk in nonusers. METHODS: We used 2001-2008 data from regional health databases in Friuli Venezia Giulia (FVG), Italy, to conduct a cohort and nested case-control study of users of NSAIDs. Cases were identified by specific and nonspecific hospital discharge diagnoses in primary and secondary position and validated through hospital records. Ten controls per case were selected using density-based sampling from the cohort. Conditional logistic regression was used to estimate adjusted relative risks (RRs) and 95% confidence intervals (CIs). RESULTS: The cohort included 588,827 NSAIDs users and 3031 UGIC cases. Nonspecific codes contributed to 23% of cases and secondary codes to 5%. Among current users, IR per 1000 person-years decreased from 4.45 cases in 2001 to 2.21 cases in 2008. The RR (95%CI) for current use of NSAIDs was 3.28 (2.86, 3.76). RR was <2 for rofecoxib, celecoxib, and nimesulide; 2 to <5 for naproxen, ibuprofen, diclofenac, etoricoxib, and meloxicam; and ≥ 5 for ketoprofen, piroxicam, and ketorolac. CONCLUSIONS: IRs of UGIC in FVG decreased about 50% between 2001 and 2008. Nimesulide was in the low-medium range of RR. A complete ascertainment of UGIC cases in databases may require validation of nonspecific codes, secondary codes, and additional codes such as peritonitis and acute posthemorrhagic anemia.

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 1 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; 95% CI 1.90, 4.42), diclofenac (RR 3.34; 95% CI 2.79, 3.99), meloxicam (RR 3.47; 95% CI 2.19, 5.50), nimesulide (RR 3.83; 95% CI 3.20, 4.60) and ketoprofen (RR 3.92; 95% CI 2.70, 5.69); 4-5 for tenoxicam (RR 4.10; 95% CI 2.16, 7.79), naproxen (RR 4.10; 95% CI 3.22, 5.23), indometacin (RR 4.14; 95% CI 2.91, 5.90) and diflunisal (RR 4.37; 95% CI 1.07, 17.81); and greater than 5 for piroxicam (RR 7.43; 95% CI 5.19, 10.63), ketorolac (RR 11.50; 95% CI 5.56, 23.78) and azapropazone. RRs for the use of high daily doses of NSAIDs versus non-use were 2-3 times higher than those associated with low daily doses. 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.

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.