Evaluation of spin in the abstracts of systematic reviews and meta-analyses related to the treatment of proximal humerus fractures

Reporting Bias in Systematic Reviews and Meta-Analyses Related to the Treatment of Distal Radius Fractures: The Presence of Spin in the Abstract

BACKGROUND

Spin is a form of reporting bias which suggests a treatment is beneficial despite a statistically nonsignificant difference in outcomes. Our purpose was to define the prevalence of spin within the abstracts of distal radius fracture (DRF) systematic reviews (SRs) and meta-analyses (MA). We also sought to identify article characteristics that were more likely to contain spin.

METHODS

We performed a SR of multiple databases to identify DRF SRs and MAs. Articles were screened and analyzed by 3 reviewers. We recorded article and journal characteristics including adherence to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, funding disclosures, methodologic quality (AMSTAR 2 instrument), impact factor, and country of origin. Presence of the 9 most severe types of spin in abstracts were recorded. Unadjusted odds ratios (ORs) were calculated to analyze the association between article characteristics and the presence of spin.

RESULTS

A total of 112 articles were included. Spin was present in 46% of abstracts, with type 1 spin ("conclusions not supported by findings") most frequent (19%). Spin was present in 43% of abstracts in PRISMA-adhering journals compared to 49% in journals that did not (OR = 0.79, 95% confidence interval [CI] = 0.37-1.68). For articles originating from China, spin was present in 61% of abstracts compared to 39% of abstracts from other countries (OR = 2.55, 95% CI = 1.13-5.75).

CONCLUSIONS

In addition to low article quality, there are high rates of spin within the abstracts of SRs and MAs related to treatment of DRF. Articles within journals that adhere to PRISMA do not appear to contain less spin.

Evaluation of Spin in Systematic Reviews and Meta-Analyses of Minimally Invasive Surgical Techniques and Standard Microdiscectomies for Treating Lumbar Disc Herniation

STUDY DESIGN

Systematic review.

OBJECTIVES

Spin in scientific literature is defined as bias that overstates efficacy and/or underestimates harms of procedures undergoing review. While lumbar microdiscectomies (MD) are considered the gold standard for treating lumbar disc herniations (LDH), outcomes of novel procedures are being weighed against open MD. This study identifies the quantity and type of spin in systematic reviews and meta-analyses of LDH interventions.

METHODS

A search was conducted on the PubMed, Scopus, and SPORTDiscus databases for systematic reviews and meta-analyses evaluating the outcomes of MD against other LDH interventions. Each included study's abstract was assessed for the presence of the 15 most common types of spin, with full texts reviewed during cases of disagreement or for clarification. Full texts were used in the assessment of study quality per AMSTAR 2.

RESULTS

All 34 included studies were observed to have at least 1 form of spin, in either the abstract or full text. The most common type of spin identified was type 5 ("The conclusion claims the beneficial effect of the experimental treatment despite a high risk of bias in primary studies"), which was observed in ten studies (10/34, 29.4%). There was a statistically significant association between studies not registered with PROSPERO and the failure to satisfy AMSTAR type 2 (P < .0001).

CONCLUSION

Misleading reporting is the most common category of spin in literature related to LDH. Spin overwhelmingly tends to go in the positive direction, with results inappropriately favoring the efficacy or safety of an experimental intervention.

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.

Reporting Bias in the Form of Positive Spin Is Highly Prevalent in Abstracts of Systematic Reviews on Primary Repair of the Anterior Cruciate Ligament

PURPOSE

To analyze reporting bias in the form of spin present in systematic reviews and meta-analyses on the topic of primary anterior cruciate ligament (ACL) repair.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed throughout this study. Peer-reviewed systematic reviews were collected from 3 databases (PubMed, Scopus, and SPORTDiscus), and their abstracts were assessed for the 15 most common types of spin. Articles were excluded if they were not published in English, had no evidence, were retracted, were published without an abstract, did not have full text available, or included cadaveric or nonhuman subjects. Full text quality was assessed using AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews Version 2). Fisher exact tests were used to examine associations between the different types of spin and other study characteristics such as AMSTAR 2 confidence rating, study design, and level of evidence.

RESULTS

Spin was present in the abstracts of 13 of 15 articles (86.7%). There were significant associations between PRISMA adherence and lower incidences of spin types 3, 6, and 8 (P = .029 for each). A critically low AMSTAR 2 confidence rating was significantly associated with an increased incidence of spin type 9 (P = .01), and a higher AMSTAR 2 score was significantly associated with decreased spin type 4 and type 5 (P = .039 and P = .048, respectively). A more recent year of publication was correlated with a lower incidence of spin type 14 (P = .044).

CONCLUSIONS

Spin is present in most systematic reviews and meta-analyses regarding primary repair of the ACL, with two-thirds of abstracts spinning evidence in favor of ACL repair. Standardized guidelines including the PRISMA guidelines and the AMSTAR 2 assessment tool were negatively correlated with spin. More recently published articles were found to contain significantly less spin, as were articles published in journals with higher Clarivate Impact Factors and Scopus CiteScores.

LEVEL OF EVIDENCE

Level V, systematic review of Level III through V studies.

Evaluation of Spin in the Abstracts of Systematic Reviews and Meta-Analyses of Ulnar Collateral Ligament Reconstruction

Purpose

To identify the quantity and types of spin present in systematic reviews and meta-analyses of ulnar collateral ligament reconstruction (UCLR) outcomes and to characterize the studies with spin to determine if any patterns exist.

Methods

This study was conducted per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. In August 2022, PubMed, Scopus, and SportDiscus databases were searched using the terms "ulnar collateral ligament reconstruction" AND "systematic review" OR "meta-analysis." Each abstract was assessed for the presence of the 15 most common types of spin derived from a previously established methodology. General data that were extracted included study title, authors, publication year, journal, level of evidence, study design, funding source, reported adherence to PRISMA guidelines, preregistration of the study protocol, and methodologic quality per A Measurement Tool to Assess Systematic Reviews Version 2 (AMSTAR 2).

Results

In total, 122 studies were identified during the preliminary search, of which 19 met the inclusion criteria. Each study had at least 1 form of spin. The most common type of spin identified was type 5 ("The conclusion claims the beneficial effect of the experimental treatment despite a high risk of bias in primary studies") (7/19, 36.8%). AMSTAR type 9 ("Did the review authors use a satisfactory technique for assessing the RoB [risk of bias] in individual studies that were included in the review?") was associated with both a lower Clarivate Impact Factor (P = .001) and a lower Scopus CiteScore (P = .015). Studies receiving external funding were associated with the failure to satisfy AMSTAR type 3 ("Did the review authors explain their selection of the study designs for inclusion in the review?") (P = .047).

Conclusions

Spin is highly prevalent in the abstracts of systematic reviews and meta-analyses that investigate the outcomes of UCLR.

Clinical Relevance

Spin has been identified in peer-reviewed articles published on various topics, including many in orthopaedics. Systematic reviews and meta-analyses contain the most comprehensive evidence regarding a clinical question, so it is important to identify spin that may be included in these reports. Greater efforts are needed to ensure that the abstracts of papers accurately represent the results in the full text.

Prospective registration of randomized clinical trials for total shoulder arthroplasty is low: a systematic review

BACKGROUND

Prospective trial registration has become an important means of improving the transparency and reproducibility of randomized controlled trials (RCTs) and is recommended by the Journal of Shoulder and Elbow Surgery (JSES) per the Consolidated Standards of Reporting Trials (CONSORT) guidelines. Herein, we performed a cross-sectional evaluation of RCTs published in JSES from 2010 to present to determine the prevalence of trial registration and consistency of outcome reporting.

METHODS

The electronic database PubMed was searched to identify all RCTs on total shoulder arthroplasty (TSA) published in JSES from 2010 to 2022 using the search terms "randomized controlled trial" AND "shoulder" AND "arthroplasty OR replacement." RCTs were considered to be registered if they provided a registration number. For articles that were registered, authors also extracted the registry name, registration date, date of first enrollment, date of last enrollment, and if the primary outcomes reported in the registry were either (1) omitted, (2) newly introduced in the publication, (3) reported as a secondary outcome or vice versa, or (4) varied in timing of assessment compared to the publication. "Early" RCTs were considered those published from 2010 to 2016, whereas "later" RCTs were from 2017 to 2022.

RESULTS

Fifty-eight RCTs met inclusion criteria. There were 16 early RCTs and 42 later RCTs. Twenty-three of the 58 (39.7%) studies were registered, with 9 of 22 with an available registry (40.9%) of those being enrolled prior to patient enrollment. Nineteen of the registered studies (82.6%) provided the name of the registry and a registration number. The proportion of later RCTs that were registered was not significantly different from the early RCTs (45.2% vs. 25.0%, P = .232). Seven RCTs (31.8%) had at least 1 inconsistency compared with the registry. The most common discrepancy was the timing of the assessment (ie, follow-up period) reported in the publication vs. the registry.

DISCUSSION

Although JSES recommends prospective trial registration, less than half of shoulder arthroplasty RCTs are registered and more than 30% registered trials have at least 1 inconsistency with their registry record. More rigorous review of trial registration and accuracy is necessary to limit bias in published shoulder arthroplasty RCTs.

Spin on adverse effects in abstracts of systematic reviews of orthodontic interventions: a cross-sectional study (part 2)

BACKGROUND

It is critical that abstracts of systematic reviews transparently report both the beneficial and adverse effects of interventions without misleading the readers. This cross-sectional study assessed whether adverse effects of interventions were reported or considered in abstracts of systematic reviews of orthodontic interventions and whether spin on adverse effects was identified when comparing the abstracts with what was sought and reported in these reviews.

METHODS

This cross-sectional study (part 2 of 2) used the same sample of 98 systematic reviews orthodontic interventions as used in part 1. Eligible reviews were retrieved from the Cochrane Database of Systematic Reviews and the 5 leading orthodontic journals between August 1 2009 and July 31 2021. Prevalence proportions were sought for 3 outcomes as defined in the published protocol. Univariable logistic regression models were built to explore associations between the presence of spin in the abstract and a series of predictors. Odds ratios (OR) 95% confidence intervals (95% CI) were used to quantify the strength of associations and their precision.

RESULTS

76.5% (75/98) of eligible reviews reported or considered (i.e., discussed, weighted etc.) potential adverse effects of orthodontic interventions in the abstract and the proportion of spin on adverse effects was 40.8% (40/98) in the abstract of these reviews. Misleading reporting was the predominant category of spin, i.e., 90% (36/40). Our explorative analyses found that compared to the Cochrane Database of Systematic Reviews all 5 orthodontic journals had similar odds of the presence of spin on adverse effects in abstracts of systematic reviews of orthodontic interventions. The odds of the presence of spin did not change over the sampled years (OR: 1.03, 95% CI: 0.9 to 1.16) and did not depend on the number of authors (OR: 0.93, 95% CI: 0.71 to 1.21), or on the type of orthodontic intervention (OR: 1.1, 95% CI: 0.45 to 2.67), or whether conflicts of interests were reported (OR: 0.74, 95% CI: 0.32 to 1.68).

CONCLUSION

End users of systematic reviews of orthodontic interventions have to be careful when interpreting results on adverse effects in the abstracts of these reviews, because they could be jeopardized by uncertainties such as not being reported and misleading reporting as a result of spin.

Spin in the Abstracts of Meta-analyses and Systematic Reviews: Quadriceps Tendon Graft for Anterior Cruciate Ligament Reconstruction

BACKGROUND

Spin is a reporting bias that misrepresents research. Ultimately it can affect surgeon decision making and patient care. Anterior cruciate ligament (ACL) reconstruction is common, but debate continues over optimal treatment modalities.

PURPOSE

To identify the prevalence of spin in meta-analysis and systematic review abstracts regarding the treatment of ACL injuries with quadriceps tendon graft.

STUDY DESIGN

Cross-sectional study.

METHODS

Electronic libraries (MEDLINE, Embase, Web of Science, Google Scholar) were searched for meta-analyses and systematic reviews regarding the treatment of ACL tears with quadriceps tendon graft. The 9 most severe types of spin commonly found in abstracts were used as an evaluation tool to assess the articles. Two reviewers each performed a blinded assessment of each article for spin. A third reviewer helped after review was done to address any discrepancies between the original reviewers. Further evaluation included year of publication, number of citations, journal impact factor, and A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR-2) score.

RESULTS

The electronic database search resulted in 986 articles, of which 13 met our inclusion criteria. After review, we found that 53.8% (7/13) of the included articles contained 1 of the 9 most severe forms of spin. Of the 13 articles, 15.4% (n = 2) contained 2 types of spin, and 38.5% (n = 5) contained 1 type of spin. No studies contained ≥3 types of spin. Of the types of spin evaluated, the most prevalent (n = 4; 30.8%) was type 3 ("selective reporting of or overemphasis on efficacy outcomes or analysis favoring the beneficial effect of the experimental intervention"). All studies, regardless of the presence of spin, were found to be low or critically low quality according to the AMSTAR-2 assessment.

CONCLUSION

This study demonstrated the presence of spin in 53.8% of meta-analysis and systematic review abstracts pertaining to quadriceps tendon graft for ACL reconstruction. Orthopaedic surgeons should learn to recognize spin as they review articles when deciding the treatment course for ACL injuries. Additionally, strict criteria should be considered to reduce the prevalence of spin in orthopaedic literature.

Evaluation of Spin in the Clinical Literature of Suture Tape Augmentation for Ankle Instability

Background

Spin is defined as the use of specific reporting strategies to highlight the beneficial effect of a treatment despite nonsignificant results. The presence of spin in peer-reviewed literature can negatively impact clinical and research practices. The purpose of this study was to identify the quantity and types of spin present in primary studies and systematic reviews using suture tape augmentation for ankle instability as a model.

Methods

This study was conducted per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Each abstract was assessed for the presence of the 15 most common types of spin. Extracted data included study title, authors, publication year, journal, level of evidence, study design, funding, reported adherence to PRISMA guidelines, and PROSPERO registration. Full texts of systematic reviews were used in the assessment of study quality per A Measurement Tool to Assess Systematic Reviews Version 2 (AMSTAR 2).

Results

Nineteen studies were included in the final sample. At least 1 type of spin was identified in each study except one (18 of 19, 94.7%). The most common type of spin observed was type 3 ("selective reporting or overemphasis on efficacy outcomes or analysis favoring the beneficial effect of the experimental intervention") (6 of 19, 31.6%), The second most reported category of spin was type 4 ("the conclusion claims safety based on non-statistically significant results with a wide confidence interval") (4 of 19, 21.1%). Among systematic reviews, we identified type 5 ("the conclusion claims the beneficial effect of the experimental treatment despite a high risk of bias in primary studies") in 4 out of 6 (66.7%) of the articles that were included. No significant associations were found between study characteristics and type of spin.

Conclusion

In this exploration of the introduction of a new technology, we identified spin to be highly present in the abstracts of primary studies and systematic reviews concerning suture tape augmentation for ankle instability. Steps should be taken by scientific journals to ensure that spin is minimized in the abstract to accurately reflect the quality of the intervention.

A guide to appropriately planning and conducting meta-analyses-Part 1: indications, assumptions and understanding risk of bias

A meta-analysis is the quantitative synthesis of data from two or more individual studies and are as a rule an important method of obtaining a more accurate estimate of the direction and magnitude of a treatment effect. However, it is imperative that the meta-analysis be performed with proper, rigorous methodology to ensure validity of the results and their interpretation. In this article the authors will review the most important questions researchers should consider when planning a meta-analysis to ensure proper indications and methodologies, minimize the risk of bias, and avoid misleading conclusions.

Assessment of Spin in the Abstracts of Systematic Reviews and Meta-analyses on Platelet-Rich Plasma Treatment in Orthopaedics: A Cross-sectional Analysis

Background

Systematic reviews on the use of platelet-rich plasma (PRP) in orthopaedic surgery are abundant in current published literature. However, a beautification of results (referred to as spin) has been noted in abstracts across various aspects of medicine.

Purpose

To determine the prevalence of spin in systematic reviews of PRP-related orthopaedic surgery abstracts.

Study Design

Cross-sectional study.

Methods

Following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and Murad and Wang guidelines, we conducted a search in Medline, Embase, and the Cochrane Database for reviews on PRP-related orthopaedic surgery. The search included studies published from inception until June 30, 2021. Included were systematic reviews written in English that involved the use of PRP in the treatment of orthopaedic injuries in human participants. The abstracts of the included reviews were evaluated for the top 9 types of spin as described by Yavchitz et al in 2016. We determined the relationship between spin and study characteristics using odds ratios.

Results

Of an initial 1560 studies, 176 were included. We found that 50 studies (28.4%) contained at least 1 form of spin. The 2 most common forms of spin found in our sample were type 5 ("Conclusion claims the beneficial effect of treatment despite high risk of bias"; n = 27 [15.3%]) and type 3 ("Selective reporting or overemphasis of efficacy in outcomes favoring beneficial effect of intervention"; n = 18 [10.2%]). No statistical significance was found between study characteristics and the presence of spin.

Conclusion

Spin was present in 28% of the systematic reviews that covered PRP-related orthopaedic treatments. Spin was not associated with general study characteristics, including adherence to PRISMA guidelines or funding. Journals and authors should be aware of spin in articles and avoid its usage.

Spin in the Abstracts of Meta-analyses and Systematic Reviews: Midshaft Clavicle Fracture

OBJECTIVES

Spin is a reporting bias that presents the beneficial effect of an experimental treatment as greater than what is found in the results of the study. This bias can result in patient care recommendations that are more subjective than objective. The purpose of this study is to identify the prevalence of spin in meta-analysis and systematic review abstracts regarding treatment of midshaft clavicle fractures.

METHODS

Electronic libraries (MEDLINE, Embase, Web of Science, Google Scholar) were systematically searched. Meta-analyses and systematic reviews regarding treatment of midshaft clavicular fractures were analyzed. The nine most severe types of spin commonly found in abstracts were used as an evaluation tool to assess the articles. Other variables analyzed include year of publication, journal impact factor, number of citations, and methodologic quality according to A Measurement Tool to Assess Systematic Reviews (AMSTAR-2).

RESULTS

The database search resulted in 401 articles, of which 53 met inclusion criteria. After review, it was found that 52.8% (28/53) of the included articles contained spin within the abstract. Of the nine most severe types of spin found in abstracts, type 3 spin ("selective reporting of or overemphasis on efficacy outcomes or analysis favoring the beneficial effect of the experimental intervention") was found to be the most prevalent 28.3% (15/53).

CONCLUSION

This study demonstrated the presence of spin in the majority of meta-analyses and systematic review abstracts pertaining to midshaft clavicular fractures. Orthopedic surgeons should be aware and recognize spin as they review articles when deciding the treatment course for such injuries.

LEVEL OF EVIDENCE

Level 3. See Instructions for Authors for a complete description of levels of evidence.

Evaluation of spin in systematic reviews and meta-analyses of superior capsular reconstruction

BACKGROUND

Small, preliminary studies and the systematic reviews on superior capsular reconstruction (SCR) that collate data are at increased risk spin. This study's primary objective was to identify, describe, and account for the incidence of spin in systematic reviews of SCR. This study's secondary objective was to characterize the studies in which spin was identified to determine whether identifiable patterns of characteristics exist among studies with spin.

METHODS

This study was conducted per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using a predetermined protocol. A search was conducted on the PubMed and Embase databases for systematic reviews and meta-analyses on SCR. Screening and data extraction were conducted independently by 2 authors. Each included study's abstract was assessed for the presence of the 15 most common types of spin, with full texts reviewed during cases of disagreement or for clarification. General data that were extracted included study title, authors, publication year, journal, level of evidence, study design, funding source, reported adherence to PRISMA guidelines, preregistration of the study protocol, and primary and secondary outcome measures. Full texts were used in the assessment of study quality per AMSTAR 2.

RESULTS

We identified 53 studies during our search, of which 17 met the inclusion criteria. At least 1 form of spin was observed in all 17 studies. The most common types of spin were type 5 ("The conclusion claims the beneficial effect of the experimental treatment despite a high risk of bias in primary studies") and type 9 ("Conclusion claims the beneficial effect of the experimental treatment despite reporting bias"), both of which were observed in 11 studies (11 of 17, 65%). A statistically significant association between lower level of evidence and type 5 ("The conclusion claims the beneficial effect of the experimental treatment despite a high risk of bias in primary studies") was observed (P = .0175). A statistically significant association was also found between more recent year of publication and the spin category misleading interpretation (P = .0398), and between lower AMSTAR 2 score and type 13 ("Failure to specify the direction of the effect when it favors the control intervention") (P = .0260). No other statistical associations between other study characteristics were observed.

CONCLUSION

Spin is highly prevalent in abstracts of SCR systematic reviews and meta-analyses. An association was found between the presence of spin and lower level of evidence, year of publication, and AMSTAR 2 ratings.

Spin Infrequently Occurs in Abstracts of Systematic Reviews For The Pharmacological Treatment of Type 2 Diabetes Mellitus

AIMS

Currently, there is a growing body of research demonstrating that spin - the misinterpretation and distortion of a study's findings - is common in different fields of medicine. To our knowledge, no study has investigated its presence in systematic reviews focused on diabetic therapies.

METHODS

We performed a cross-sectional study by searching MEDLINE and Embase for systematic reviews focused on pharmacologic treatments for type 2 diabetes mellitus. Our search retrieved 26,490 records, from which 199 studies were extracted in a masked, duplicate fashion. Each study was evaluated for the nine most severe types of spin and other study design parameters. Spin was presented as frequencies and odds ratios to identify associations between study characteristics.

RESULTS

Spin was identified in the abstracts of 15 systematic reviews (15/199, 7.5%). Spin type 5 was the most common type identified (7/199, 3.5%). Spin types 1, 2, 4, and 8 were not identified. In the last 5 years (2016-2021), 7 systematic reviews contained spin within their abstract. There was no association between spins presence and any extracted study characteristic .

CONCLUSIONS

Our findings show that spin infrequently occurs in abstracts of systematic reviews focused on pharmacologic therapies for type 2 diabetes mellitus. However, any amount of spin can lead to the distortion of a reader's interpretation of the study's findings. Thus, we provide recommendations with rationale to prevent spin in future systematic reviews.

Spin in the abstracts of systematic reviews and metaanalyses focused on percutaneous coronary intervention

CONTEXT

"Spin" is a form of bias that involves highlighting study results in a way that presents the conclusions about benefit or efficacy beyond the scope of the data. Spin in the abstract of published studies has the potential to affect patient care, making investigations about its presence and prevalence important for readers.

OBJECTIVES

To evaluate the most severe types of spin in the abstracts of systematic reviews and metaanalyses focused on percutaneous coronary intervention.

METHODS

Using a cross sectional study design, the authors searched MEDLINE and Embase with the terms "percutaneous coronary intervention," "percutaneous coronary revascularization," "PCI," "systematic review," "meta analysis," and "meta-analysis." To be considered for this study, the article must have (1) focused on PCI; (2) had either a systematic review or metaanalysis study design; (3) been conducted on human subjects; and (4) been available in English. Reviews were excluded if these criteria were not met. Each included article was assessed for the nine most severe types of spin as defined in a previously published article, as well as other study characteristics (type of intervention being compared, date the review was received, adherence of systematic review and/or meta-analysis to Preferred Reporting for Systematic Reviews or Metanalyses (PRISMA) guidelines, requirement of PRISMA guidelines by the publishing journal, the publishing journal's five-year impact factor, and sources of funding).

RESULTS

Our database search retrieved 7,038 records; 2,190 duplicates were removed. Initial title and abstract screening led to the exclusion of 4,367 records, and an additional 281 records were excluded during full text screening. An arbitrary limit of 200 articles was applied for this analysis; five additional articles were excluded for ineligible study design, so 195 were included in our final analysis. Spin was present in the abstracts of 43 studies from that pool (22.1%). Spin type 3-selective reporting of or overemphasis on efficacy outcomes or analysis favoring the beneficial effect of the experimental intervention-occurred most frequently (29; 14.8%). The presence of spin was not associated with any of the extracted study characteristics.

CONCLUSIONS

Our data showed that spin occurred in more than one in every five systematic reviews or metaanalyses of PCI. Spin has the potential to distort a reader's ability to translate the true findings of a study; therefore, efforts are needed to prevent spin from appearing in article summaries.

Evaluation of spin in the abstracts of systematic reviews and meta-analyses focused on cataract therapies

PURPOSE

Spin-the misrepresentation of study findings such that the beneficial effects of an intervention are magnified beyond what the results actually show-is a reporting practice that has been shown to influence perceptions of treatment efficacy and clinical decision making. We evaluated the extent of spin in the abstracts of systematic reviews of cataract surgery and its complications. We also evaluated whether particular study attributes were associated with spin.

DESIGN

Cross-sectional study.

METHODS

We searched MEDLINE and Embase for systematic reviews and meta-analyses relating to cataract treatment. From these search records, screening for eligible studies was done in duplicate. Using a previously developed classification system for spin, we assessed the systematic reviews that met our eligibility criteria for the occurrence of the 9 most severe forms of spin. We performed the evaluation of spin, extracted study characteristics, and appraised the methodological quality of each study using the 16-question AMSTAR-2 scale in duplicate.

RESULTS

Searches retrieved 2,059 studies, of which 110 were eligible for data extraction. We found at least 1 form of spin in 30.0% of included systematic reviews (33/110). Six of the 9 types of spin were identified in our sample, the most common being type 3 in 18.2% (20/110) of abstracts. We found no significant association between spin in abstracts, AMSTAR-2 appraisal, and any of the extracted study characteristics.

CONCLUSION

Spin was evident in approximately one-third of the abstracts of evaluated systematic reviews and meta-analyses of cataract surgery and associated complications.