Dataset Information

Industry sponsorship bias in research findings: a network meta-analysis of LDL cholesterol reduction in randomised trials of statins.

ABSTRACT:

Objective

To explore the risk of industry sponsorship bias in a systematically identified set of placebo controlled and active comparator trials of statins.

Design

Systematic review and network meta-analysis.

Eligibility

Open label and double blind randomised controlled trials comparing one statin with another at any dose or with control (placebo, diet, or usual care) for adults with, or at risk of developing, cardiovascular disease. Only trials that lasted longer than four weeks with more than 50 participants per trial arm were included. Two investigators assessed study eligibility.

Data sources

Bibliographic databases and reference lists of relevant articles published between 1 January 1985 and 10 March 2013.

Data extraction

One investigator extracted data and another confirmed accuracy.

Main outcome measure

Mean absolute change from baseline concentration of low density lipoprotein (LDL) cholesterol.

Data synthesis

Study level outcomes from randomised trials were combined using random effects network meta-analyses.

Results

We included 183 randomised controlled trials of statins, 103 of which were two-armed or multi-armed active comparator trials. When all of the existing randomised evidence was synthesised in network meta-analyses, there were clear differences in the LDL cholesterol lowering effects of individual statins at different doses. In general, higher doses resulted in higher reductions in baseline LDL cholesterol levels. Of a total of 146 industry sponsored trials, 64 were placebo controlled (43.8%). The corresponding number for the non-industry sponsored trials was 16 (43.2%). Of the 35 unique comparisons available in 37 non-industry sponsored trials, 31 were also available in industry sponsored trials. There were no systematic differences in magnitude between the LDL cholesterol lowering effects of individual statins observed in industry sponsored versus non-industry sponsored trials. In industry sponsored trials, the mean change from baseline LDL cholesterol level was on average 1.77 mg/dL (95% credible interval -11.12 to 7.66) lower than the change observed in non-industry sponsored trials. There was no detectable inconsistency in the evidence network.

Conclusions

Our analysis shows that the findings obtained from industry sponsored statin trials seem similar in magnitude as those in non-industry sources. There are actual differences in the effectiveness of individual statins at various doses that explain previously observed discrepancies between industry and non-industry sponsored trials.

SUBMITTER: Naci H

PROVIDER: S-EPMC4184241 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:BackgroundThe clinical benefit of LDL cholesterol lowering treatment in older patients remains debated. We aimed to summarise the evidence of LDL cholesterol lowering therapies in older patients.MethodsIn this systematic review and meta-analysis, we searched MEDLINE and Embase for articles published between March 1, 2015, and Aug 14, 2020, without any language restrictions. We included randomised controlled trials of cardiovascular outcomes of an LDL cholesterol-lowering drug recommended by the 2018 American College of Cardiology and American Heart Association guidelines, with a median follow-up of at least 2 years and data on older patients (aged ≥75 years). We excluded trials that exclusively enrolled participants with heart failure or on dialysis because guidelines do not recommend lipid-lowering therapy in such patients who do not have another indication. We extracted data for older patients using a standardised data form for aggregated study-level data. We meta-analysed the risk ratio (RR) for major vascular events (a composite of cardiovascular death, myocardial infarction or other acute coronary syndrome, stroke, or coronary revascularisation) per 1 mmol/L reduction in LDL cholesterol.FindingsData from six articles were included in the systematic review and meta-analysis, which included 24 trials from the Cholesterol Treatment Trialists' Collaboration meta-analysis plus five individual trials. Among 244 090 patients from 29 trials, 21 492 (8·8%) were aged at least 75 years, of whom 11 750 (54·7%) were from statin trials, 6209 (28·9%) from ezetimibe trials, and 3533 (16·4%) from PCSK9 inhibitor trials. Median follow-up ranged from 2·2 years to 6·0 years. LDL cholesterol lowering significantly reduced the risk of major vascular events (n=3519) in older patients by 26% per 1 mmol/L reduction in LDL cholesterol (RR 0·74 [95% CI 0·61-0·89]; p=0·0019), with no statistically significant difference with the risk reduction in patients younger than 75 years (0·85 [0·78-0·92]; pinteraction=0·37). Among older patients, RRs were not statistically different for statin (0·82 [0·73-0·91]) and non-statin treatment (0·67 [0·47-0·95]; pinteraction=0·64). The benefit of LDL cholesterol lowering in older patients was observed for each component of the composite, including cardiovascular death (0·85 [0·74-0·98]), myocardial infarction (0·80 [0·71-0·90]), stroke (0·73 [0·61-0·87]), and coronary revascularisation (0·80 [0·66-0·96]).InterpretationIn patients aged 75 years and older, lipid lowering was as effective in reducing cardiovascular events as it was in patients younger than 75 years. These results should strengthen guideline recommendations for the use of lipid-lowering therapies, including non-statin treatment, in older patients.FundingNone.