Spin within systematic review abstracts on antiplatelet therapies after acute coronary syndrome: a cross-sectional study

Funding and conclusions of network meta-analyses on targeted therapies in inflammatory diseases: an overview

OBJECTIVES

To explore the association between industry funding and network meta-analyses' (NMAs) conclusion, and the use in Clinical Practice Guidelines (CPGs) of NMAs.

STUDY DESIGN AND SETTING

This was an overview of NMAs and CPGs. We searched PubMed/MEDLINE, Epistemonikos, and several guideline databases up to February 18th 2023. We included CPGs from the last 5 years and NMAs of randomized controlled trials that evaluated targeted therapies in immune-mediated inflammatory diseases. Data extraction and outcome assessments were done in duplicate by independent authors.

RESULTS

We included 216 NMAs and 99 CPGs. 31% (67/216) were industry-funded. The proportion of industry-funded NMAs that cited one treatment as being best was 44% (25/57) compared to 26% (30/116) for nonindustry-funded (OR = 2.24 [1.15-4.39]; aOR = 1.76 [0.81-3.81]). The abstract's conclusion of 39/67 (58%) industry-funded and 69/149 (46%) nonindustry-funded NMAs were considered unsupported by the results (OR = 1.61 [0.90-2.89]; aOR = 1.40 [0.71-2.78]). All industry-funded NMAs that cited one treatment as best cited their own sponsored drug. 59/99 (60%) CPGs included at least one NMA, with 23/59 (39%) of them citing industry-funded NMAs.

CONCLUSIONS

We did not find evidence that industry-funded NMAs were more likely to have unsupported conclusions or to cite only one treatment as being best in their conclusions compared to non-industry-funded NMAs. However, almost all industry-funded NMAs favored their own treatments. Even though 40% of the CPGs did not rely on NMA, over a third of those who did used industry-funded NMAs. Limitations include the possible misclassification due to undisclosed funding and potential confounders that have not been accounted for.

Evaluation of Spin Bias in Systematic Reviews and Meta-analyses of Rotator Cuff Repair With Platelet-Rich Plasma

BACKGROUND

The use of platelet-rich plasma (PRP) in orthopaedics continues to increase. One common use of PRP is as an adjunct in rotator cuff repair surgery. Multiple systematic reviews and meta-analyses have summarized the data on PRP use in rotator cuff repair surgery. However, systematic reviews and meta-analyses are subject to spin bias, where authors' interpretations of results influence readers' interpretations.

PURPOSE

To evaluate spin in the abstracts of systematic reviews and meta-analyses of PRP with rotator cuff repair surgery.

STUDY DESIGN

Systematic review; Level of evidence, 3.

METHODS

A PubMed and Embase search was conducted using the terms rotator cuff repair and PRP and systematic review or meta-analysis. After review of 74 initial studies, 25 studies met the inclusion criteria. Study characteristics were documented, and each study was evaluated for the 15 most common forms of spin and using the AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews, Version 2) rating system. Correlations between spin types and study characteristics were evaluated using binary logistic regression for continuous independent variables and a chi-square test or Fisher exact test for categorical variables.

RESULTS

At least 1 form of spin was found in 56% (14/25) of the included studies. In regard to the 3 different categories of spin, a form of misleading interpretation was found in 56% (14/25) of the studies. A form of misleading reporting was found in 48% (12/25) of the studies. A form of inappropriate extrapolation was found in 16% (4/25) of the studies. A significant association was found between misleading interpretation and publication year (odds ratio [OR], 1.41 per year increase in publication; 95% CI, 1.04-1.92; P = .029) and misleading reporting and publication year (OR, 1.41 per year increase in publication; 95% CI, 1.02-1.95; P = .037). An association was found between inappropriate extrapolation and journal impact factor (OR, 0.21 per unit increase in impact factor; 95% CI, 0.044-0.99; P = .048).

CONCLUSION

A significant amount of spin was found in the abstracts of systematic reviews and meta-analyses of PRP use in rotator cuff repair surgery. Given the increasing use of PRP by clinicians and interest among patients, spin found in these studies may have a significant effect on clinical practice.