Level of Evidence in Plastic Surgery Research:

Revisiting Level of Evidence Ratings in Plastic Surgery: A Call to Action

BACKGROUND

Evidence-based medicine underpins medical and surgical practice, with level of evidence (LOE) being a key aspect that allows clinicians and researchers to better discriminate the methodological context by which studies are conducted and appropriately interpret their conclusions, and more specifically the strength of their recommendations.

OBJECTIVES

The aim of this study was to reassess the LOE of articles published in plastic surgery journals.

METHODS

To assess the overall LOE of publications from January 1 to December 31, 2021, a review of the following plastic surgery journals was performed: Aesthetic Surgery Journal (ASJ), Annals of Plastic Surgery (Annals), Journal of Plastic Reconstructive and Aesthetic Surgery (JRPAS), Plastic and Reconstructive Surgery (PRS), and Plastic and Reconstructive Surgery Global Open (PRS GO).

RESULTS

Of 3698 PUBMED articles, 1649 original articles and systematic reviews were analyzed. The average LOE for each journal was: ASJ 3.02 ± 0.94, Annals 3.49 ± 0.62, JPRAS 3.33 ± 0.77, PRS 2.91 ± 0.77, and PRS GO 3.45 ± 0.70. The collective average LOE was 3.28 ± 0.78. Only 4.4% were LOE 1 and 7.3% were LOE 2. Compared to past studies, PRS showed a significant LOE improvement (P = .0254), while ASJ and JPRAS saw nonsignificant changes; Annals experienced a significant decrease (P = .0092).

CONCLUSIONS

ASJ and PRS showed the highest LOE among the journals analyzed. Despite this, low LOE studies remain prevalent in plastic surgery. This paper serves as a call to action for both researchers and academic journals to elevate the standard, offering several strategies to help improve the LOE in plastic surgery.

A Review of Meta-Analyses in Plastic Surgery: Need for Adequate Assessment of Publication Bias

INTRODUCTION

Publication bias describes a phenomenon in which significant positive results have a higher likelihood of being published compared to negative or nonsignificant results. Publication bias can confound the estimated therapeutic effect in meta-analyses and needs to be adequately assessed in the surgical literature.

METHODS

A review of meta-analyses published in five plastic surgery journals from 2002 to 2022 was conducted. The inclusion criteria for meta-analyses were factors that demonstrated an obligation to assess publication bias, such as interventions with comparable treatment groups and enough power for statistical analysis. Acknowledgment of publication bias risk, quality of bias assessment, methods used in assessment, and individual article factors were analyzed.

RESULTS

318 unique meta-analyses were identified in literature search, and after full-text reviews, 143 met the inclusion criteria for obligation to assess publication bias. 64% of eligible meta-analyses acknowledged the confounding potential of publication bias, and only 46% conducted a formal assessment. Of those who conducted an assessment, 49% used subjective inspection of funnel plots alone, while 47% used any statistical testing in analysis. Overall, only 9/143 (6.3%) assessed publication bias and attempted to correct for its effect. Journals with a higher average impact factor were associated with mention and assessment of publication bias, but more recent publication year and higher number of primary articles analyzed were not.

CONCLUSIONS

This review identified low rates of proper publication bias assessment in meta-analyses published in five major plastic surgery journals. Assessment of publication bias using objective statistical testing is necessary to ensure quality literature within surgical disciplines.

Ten-Year Trends in Level of Evidence in Hand Surgery

BACKGROUND

The purposes of this study were to analyze the trends in Oxford level of evidence (LOE), LOE of most-cited articles, and association between LOE and journal impact factor (IF) and SCImago Journal Rank (SJR) over a 10-year period (2009-2018) in 3 prominent hand surgery journals, specifically HAND, Journal of Hand Surgery (American Volume) (JHS), and Journal of Hand Surgery (European Volume) (JHSE).

METHODS

All articles published from 2009 to 2018 in HAND, JHS, and JHSE were reviewed for assigned or available LOE. Data were pooled and analyzed for trends in LOE; relationship among IF, SJR, and LOE; and citation density.

RESULTS

A total of 3921 total publications were tabulated from 2009 to 2018, with the majority of studies being level V (1700, 43%) and fewer studies being level I (146, 4%). Over the 10-year study period, there was no significant change in frequency of level I studies for any journal. HAND trended significantly toward higher LOE, JHS trended toward higher LOE, and JHSE trended toward decreased LOE without significance. Among all journals, the annual number of articles and the average LOE were independent significant predictors of IF and SJR. Statistically significant correlations were found between citation density and LOE for JHS and HAND.

CONCLUSIONS

Higher quality evidence is becoming more prevalent in the hand surgery literature over the past 10 years. Annual articles, average LOE, and level I and II and level IV articles were significant predictors of increasing IF and SJR.

The Top 100 Cited Articles in the Microsurgical Treatment for Lymphedema

BACKGROUND

 Evidence-based medicine uses the current best evidence for decisions about patient care. Lymphedema is a chronic debilitating medical condition caused by a dysfunctional lymphatic system. This study analyzes the most cited articles, including the levels of evidence, for the surgical treatment of lymphedema.

METHODS

 The Web of Science Sci-Expanded Index was utilized to search for surgical treatment of lymphedema. Articles were examined by three independent reviewers and the top 100 articles were determined. The corresponding author, citation count, publication year, topic, study design, level of evidence, journal, country, and institution were analyzed.

RESULTS

 Since 1970, the top 100 articles have been cited 7,300 times. The average citation count was 68 and standard deviation was 55. The majority was case series (71), followed by retrospective cohort (8), prospective cohort (7), retrospective case-control (5), and randomized controlled trials (2). Based on the "Level of Evidence Pyramid," 71 articles were level IV, 13 articles were level III, and 9 articles were level II. On the Grading of Recommendations Assessment, Development, and Evaluation Scale, there were 71 articles with "very low," 20 articles with "low," and 2 articles with "moderate" quality of evidence.

CONCLUSION

 The top 100 cited articles were mostly case series and lacked high levels of evidence. Most studies are retrospective case series with short-term outcomes. However, low level evidence for new surgical procedures is to be expected. Current trends suggest the treatment and understanding of lymphedema will continue to improve.

Characterizing Clinical Trials in Plastic and Reconstructive Surgery: A Systematic Review of ClinicalTrials.gov From 2007 to 2020

BACKGROUND

Clinical trials form the backbone of evidence-based medicine. ClinicalTrials.gov is the world's largest clinical trial registry, and the state of clinical trials in plastic and reconstructive surgery (PRS) within that database has not been comprehensively studied. To that end, we explored the distribution of therapeutic areas that are under investigation, impact of funding on study design and data reporting, and trends in research patterns of all PRS interventional clinical trials registered with ClinicalTrials.gov.

METHODS

Using the ClinicalTrials.gov database, we identified and extracted all clinical trials relevant to PRS that were submitted between 2007 and 2020. Studies were classified based on anatomic locations, therapeutic categories, and specialty topics. Cox proportional hazard was used to calculate adjusted hazard ratios (HRs) for early discontinuation and results reporting.

RESULTS

A total of 3224 trials that included 372,095 participants were identified. The PRS trials grew at an annual rate of 7.9%. The therapeutic classes most represented were wound healing (41.3%) and cosmetics (18.1%). Funding for PRS clinical trials is largely provided through academic institutions (72.7%), while industry and US government constituted a minority. Industry-funded studies were more likely to be discontinued early than those funded by academics (HR, 1.89) or government (HR, 1.92) and to be nonblinded and nonrandomized. Academic-funded studies were the least likely to report results data within 3 years of trial completion (odds ratio, 0.87).

CONCLUSIONS

A gulf exists in the representation of different PRS specialties among clinical trials. We highlight the role of funding source in trial design and data reporting to identify a potential source of financial waste and to stress the need for continued appropriate oversight.

A Primer for Success as an Early Career Academic Plastic Surgeon

The early career academic plastic surgeon strives to be an expert surgeon, an innovative researcher, and an impactful educator. Navigating these challenges is difficult in a healthcare landscape with diminishing public research funding, increasing demand from institutions for clinical productivity, and decreased value of surgical education. To help the junior academic plastic surgeon, this article discusses the fundamental aspects of developing an early academic plastic surgery practice, rooted in clinical care, research, and education.

AAPS Podium Presentations-Has the Level of Evidence Changed over the Past Decade?

An increase in the number and quality of randomized controlled trials (RCTs) and trends toward higher levels of evidence (LOE) in the plastic surgery literature has been reported; however, there has not been a specific focus on the LOE of presentations at scientific meetings. The purpose of this study was to ascertain trends in the LOE of studies presented at the annual meeting of the American Association of Plastic Surgeons.

Level of Evidence on Platelet-rich Plasma in Plastic Surgery

Background:

Despite the increased popularity of platelet-rich plasma (PRP) in plastic surgery, there is no detailed analysis on the level of evidence on PRP use in plastic surgery. As the number of applications of PRP in plastic surgery increases, it is important for plastic surgeons to understand the scientific and validated evidence behind its use. Therefore, we performed a literature review to identify current level of evidence on platelet-rich plasma in plastic surgery.

Methods:

We performed a computerized search of platelet-rich plasma in plastic surgery using the MEDLINE, Cochran Library, and EMBASE databases. Data regarding the type of study, PRP application, and outcomes were collected. Then, the level of evidence was assigned using the American Society of Plastic Surgeons Level of Evidence Rating.

Results:

Our search identified 105 articles, and about 78.1% of studies were lower-quality studies: 37 level-III articles (35.2%), 32 level-IV articles (30.5%), and 13 level-V articles (12.4%). There were only 6 level-I articles and 17 level-II studies. Level-I studies were on facial rejuvenation using a laser, carpal tunnel release, cleft lip repair, trauma wounds, breast reconstruction using latissimus dorsi, and hair regrowth.

Conclusions:

Our review of the literature shows that the level of evidence on PRP use in plastic surgery is low (21.9%). Nevertheless, we believe level-III to level-V studies are still valuable, as performing high-level quality studies in plastic surgery is difficult due to variability in surgical techniques, experiences, and materials.

Levels of Evidence in Plastic Surgery Research: A 10-Year Bibliometric Analysis of 18,889 Publications From 4 Major Journals

BACKGROUND

Improving the quality of research published in plastic surgery literature has been recognized as a difficult and time-intensive process. Despite significant progress over the last decade, leaders in the field continue to advocate for higher-quality studies to better inform clinical practice.

OBJECTIVES

The aim of this study was to evaluate and analyze trends in the levels of evidence (LOEs) of the plastic surgery literature over the last decade in 4 major journals.

METHODS

After systematic review of all articles published between 2008 and 2017 in Plastic and Reconstructive Surgery, Annals of Plastic Surgery, Journal of Plastic, Reconstructive, and Aesthetic Surgery, and Aesthetic Surgery Journal (ASJ), included articles were assigned an LOE and classified according to study design and category.

RESULTS

In total, 8211 articles were included. Case series and reports represented 36.1% and 13.6% of studies, respectively. Additionally, 27.2% were retrospective cohort studies, 8.2% prospective cohort studies, 3.9% systematic reviews, and 2.9% randomized controlled trials (RCTs). Overall, the percentage of Level I/II studies has increased from 10.9% in 2008 to 17.3% in 2017. ASJ published the greatest proportion of Level I/II studies (23.2%) and RCTs (5.1%) of all the journals. There were significant differences in the distribution of Level I/II studies by journal (P < 0.001) and category (P < 0.001).

CONCLUSIONS

Over the past decade, plastic surgery journals have published higher-quality research and a significantly greater proportion of Level I and II studies. The field must continue to strive for robust study designs, while also recognizing the importance of lower-LOE research.

Writing an Evidence-based Article in Plastic Surgery: Translating Research into High-quality Care

Evidence-based medicine (EBM) is a triad that integrates the physician's medical expertise and the patient's individual characteristics with the best available scientific evidence. As patients become more active in the clinical decision-making process, the application of evidence-based practice in the field of plastic surgery is more critical now than ever. As a field that is recognized by its innovation, plastic surgeons must understand the various aspects of EBM to enhance and keep the field at the top of medical discovery. Many initiatives have been implemented to guide researchers in the collection, analysis, and distribution of high-quality evidence. In particular, Plastic and Reconstructive Surgery introduced a new EBM series to provide plastic surgeons with the appropriate resources to generate and integrate high-quality evidence into their practices. As a part of this initiative, this article will assist researchers in producing an evidence-based article that is well-written, relevant, and impactful to incorporate evidence-based practice into the specialty.

Publication Rates and Author Characteristics From 3 Plastic Surgery Journals in 2006 and 2016

BACKGROUND

Areas of surgical care in which, traditionally, plastic surgeons were exclusively involved are now routinely offered by other surgical specialists. Whether this shift in clinical responsibilities influenced publication rates of plastic surgeons remains unknown. The current article investigates the proportion of contributions in plastic surgery journals originating from authors with a plastic surgery background as well as publication rates and author demographics.

METHODS

A cross-sectional sample study of every publication originating from Annals of Plastic Surgery, Journal of Plastic, Reconstructive and Aesthetic Surgery, and Plastic and Reconstructive Surgery was performed for 2006 and 2016. Data about the articles' methodological design and branch of plastic surgery as well as authors' country of origin, educational degree and specialty training were analyzed.

RESULTS

From 1721 publications included, head and neck reconstruction was the branch of plastic surgery with the highest number of publications at 18% and most articles (30%) were retrospective cohort studies. From 3381 authors analyzed, a significant proportion originated from United States (34%). More than 85% of authors were physicians as opposed to other health care professionals. The specialty with the highest representation was plastic surgery at 72%, but the proportion decreased in all 3 journals by a mean rate of 3.8% in 2016.

CONCLUSIONS

A slight decrease in publication rates from plastic surgeons occurred in Annals of Plastic Surgery, Journal of Plastic, Reconstructive and Aesthetic Surgery, and Plastic and Reconstructive Surgery from 2006 to 2016. Publications rates and author characteristics in plastic surgery journals provide valuable insight on plastic surgeons' contribution to contemporary scientific literature.

The Use of Twitter by Plastic Surgery Journals

BACKGROUND

Social media have revolutionized the way we access information. Twitter is the most popular microblogging website and has become a tool for plastic surgery journals to connect with the greater academic community and public. The purpose of this study was to objectively assess the use of Twitter by plastic surgery journals.

METHODS

Twelve plastic surgery journals were searched on Twitter. The following data were collected: age of Twitter profile, number of followers and tweets posted, and whether the journal's website had a link to Twitter or another social media website. All tweets were reviewed from May to July of 2017 inclusive, and the level of evidence of each original article posted in the tweets was recorded. Impact factor and Klout score (a social media influence score) were collected for all journals.

RESULTS

Six of 12 plastic journals had a Twitter profile. The most social media-influencing journal in plastic surgery was Plastic and Reconstructive Surgery. This was followed by the Aesthetic Surgery Journal and the Journal of Hand Surgery (American and European Volumes). The presence of a Twitter profile was not associated with a higher impact factor for the journal. The Klout score was correlated with impact factor. Since joining Twitter, five of the six journals with Twitter profiles experienced increases in their impact factor.

CONCLUSION

Twitter can be a quick and easy-to-use tool to increase exposure to evidence-based information from academic journals in plastic surgery.

BREAST-Q Measurement of the Patient Perspective in Oncoplastic Breast Surgery: A Systematic Review

Background

Since BREAST-Q was developed in 2009, it has been widely used by clinicians and researchers to capture information regarding health-related quality of life (HRQoL) and patient satisfaction related to breast surgery. Yet clinical guidelines regarding the use of BREAST-Q for assessment of success of surgery in women with breast cancer remain limited. To maximize the benefits of using BREAST-Q to inform clinical decision making, this systematic review aimed to identify and appraise current evidence on patient-reported outcomes (PROs) assessed by BREAST-Q associated with breast oncoplastic surgery.

Methods

A detailed search strategy was implemented and electronic databases searched include PubMed, MEDLINE, CINAHL, and PsycINFO. Review was limited to peer-reviewed studies published in English from 2009 to January 2018. Any interventional and observational studies that used BREAST-Q to assess PROs in the assessment of breast oncoplastic surgery were included.

Results

Fifty-four peer-reviewed articles met inclusion criteria. Fifty-three studies were observational, 1 study was interventional. Current comparative studies using BREAST-Q indicated that abdominal flap, buttock flap, or thigh flap reconstruction offered highest satisfaction with breast; contralateral prophylactic mastectomy with immediate reconstruction offered higher levels of satisfaction with breast, but poor postsurgical physical well-being. Silicone implant and no radiation therapy offered higher level satisfaction and HRQoL.

Conclusions

Current evidence showed that BREAST-Q can effectively measure patient's satisfaction and HRQoL in relation to different type of breast oncoplastic surgeries. BREAST-Q captured meaningful and reliable information from the patients' perspective and may be useful for clinical decision making.

Has the Objective Quality of Evidence in Imaging Papers Changed Over the Last 20 Years?

RATIONALE AND OBJECTIVES

We aimed to determine if both evidence level (EL) as well as clinical efficacy (CE) of imaging manuscripts have changed over the last 20 years.

MATERIALS AND METHODS

With our review of medical literature, Institutional Review Board approval was waived, and no informed consent was required. Using Web of Science, we determined the 10 highest impact factor imaging journals. For each journal the 10 most cited and 10 average cited papers were compared for the following years: 1994, 1998, 2002, 2006, 2010, and 2014. EL was graded using the same criteria as the Journal of Bone and Joint Surgery (Wright et al., 2003). CE was graded using the criteria of Thornbury and Fryback (1991). Statistical software R and package lme4 were used to fit mixed regression models with fixed effects for group, year, and a random effect for journal.

RESULTS

EL has improved -0.03 every year on average (P < .001). The more cited papers had better ELs (group effect = -0.23, SE 0.09, P = .011). CE is lower in top cited compared to average cited articles, although the differences were not statistically significant (group effect = -0.14, SE = 0.09, P = .16). CE level increased modestly in both groups over this 20-year time period (0.06 per year, SE = 0.007, P < .001).

CONCLUSION

Over the last 20 years, imaging journal articles have improved modestly in quality of evidence, as measured by EL and CE.

Trapezius flaps for reconstruction of head and neck defects following oncological resection - A systematic review

OBJECTIVE

Head and neck (H&N) reconstruction after cancer resection is challenging. Myocutaneous trapezius flaps provide an alternative reconstruction for patients not suitable for microvascular free tissue transfer.

METHODS

A systematic review was performed on studies involving trapezius flaps for H&N reconstruction post oncological resection between the years 1985-2015. Data extracted included patient numbers and demographics, operative technique and complications. Complication rates, for the study cohort, were calculated and a univariate analysis was preformed evaluating patient and flap-related risk factors.

RESULTS

Seventeen studies met the inclusion criteria, with a total of 157 trapezius flaps. Intraoral defects were the most frequent recipient site (74.5%). The mean skin paddle width was 6.84 cm (range 3-15 cm) and length was 11.1 cm (range 4-25 cm). Type 2 (superficial branch of transverse cervical artery) accounted for 77.1% (118/153) of all trapezius flaps performed. The complication rate was 15.9%, with 15 reported flap related and 7 donor site complications. Skin paddle size, pedicle selection, primary versus salvage reconstruction and radiotherapy were not identified risk factors for complications.

CONCLUSION

Trapezius flaps are a reliable and versatile myocutaneous flap for both primary and salvage surgery reconstruction of H&N defects following oncological resection.

Is Article Methodological Quality Associated With Conflicts of Interest?: An Analysis of the Plastic Surgery Literature

PURPOSE

Conflicts of interest (COI) are an emerging area of discussion within the field of plastic surgery. Recently, several reports have found that research studies that disclose COI are associated with publication of positive outcomes. We hypothesize that this association is driven by higher-quality studies receiving industry funding. This study aimed to investigate the association between industry support and study methodological quality.

METHODS

We reviewed all entries in Plastic and Reconstructive Surgery, Annals of Plastic Surgery, and Journal of Plastic, Reconstructive, and Aesthetic Surgery within a 1-year period encompassing 2013. All clinical research articles were analyzed. Studies were evaluated blindly for methodology quality based on a validated scoring system. An ordinal logistic regression model was used to examine the association between methodology score and COI.

RESULTS

A total of 1474 articles were reviewed, of which 483 met our inclusion criteria. These articles underwent methodological quality scoring. Conflicts of interest were reported in 28 (5.8%) of these articles. After adjusting for article characteristics in the ordinal logistic regression analysis, there was no significant association between articles with COI and higher methodological scores (P = 0.7636).

CONCLUSIONS

Plastic surgery studies that disclose COI are not associated with higher methodological quality when compared with studies that do not disclose COI. These findings suggest that although the presence of COI is associated with positive findings, the association is not shown to be driven by higher-quality studies.

Plastic Surgery Residents' Understanding and Attitudes Toward Biostatistics: A National Survey

BACKGROUND

An understanding of biostatistics is a critical skill for the practicing plastic surgeon. The purpose of the present study was to assess plastic surgery residents' attitudes and understanding of biostatistics.

METHODS

This was a cross-sectional study of plastic surgery residents. A survey assessing resident attitudes regarding biostatistics, confidence with biostatistical concepts, and objective knowledge of biostatistics was distributed electronically to trainees in plastic surgery programs in the United States. Bivariate and regression analyses were used to identify significant associations and adjust for confounders/effect modifiers.

RESULTS

One hundred twenty-three residents responded to the survey (12.3% response rate). Respondents expressed positive attitudes regarding biostatistics in plastic surgery practice, but only moderate levels of confidence with various biostatistical concepts. Both attitudes and confidence were positively associated with the number of plastic surgery journals read monthly and formal coursework in biostatistics (P < 0.01). Resident attitudes were positively correlated with confidence (r = 0.33, P < 0.01). The mean percentage of correct responses on knowledge-assessments was 43.6% (20.8%). Integrated residents performed better than independent track residents (P = 0.04). Residents had difficulty with study design, the correct use of analysis of variance, regression analysis, and identifying a statistically significant result. Resident confidence was moderately correlated with performance (r = 0.31, P = 0.01).

CONCLUSIONS

Plastic surgery residents place a high degree of importance on knowledge of biostatistics in the practice of plastic surgery but have only a fair understanding of core statistical concepts.

An Update on the Level of Evidence for Plastic Surgery Research Published in Plastic and Reconstructive Surgery

In 2011, Plastic and Reconstructive Surgery (PRS) implemented a level-of-evidence (LOE) pyramid to bring attention to evidence-based medicine and to promote quality of research. The objective of our study was to examine the current, overall quality of plastic surgery research when compared with that of the previous 30 years. Articles from PRS published in 2013 were culled for information, including LOE based on the assigned score from the LOE pyramid. (Animal, cadaver, and basic science studies; reviews; correspondence; and continuing medical education articles were excluded.) The LOE grades were compared with those from 1983, 1993, and 2003. In 2013, 536 articles were published in PRS; of these, 247 met the inclusion criteria and were included in the analysis. The mean LOE in PRS for 2013 was 3.42. For the year 2003, the mean LOE was 4.16; 1993, 4.25; and 1983, 4.42. Analysis of variance indicated significant improvement in research quality over time (P < 0.001). In 2014, 216 of 489 published articles met the inclusion criteria. The mean LOE of PRS articles in 2014 was 3.33, demonstrating continued higher LOE. There was also a decrease in the percentage of level IV and V studies to 47.2% (from 51.4% in 2013), whereas higher quality level I and II studies had increased to 18.1% (from 17.4%). The quality of plastic surgery research has shown a continued upsurge as evidenced by overall improvement in LOE in published articles over the past 3 decades.

A pilot study of neurointerventional research level of evidence and collaboration

Introduction

No studies have sought to provide a quantitative or qualitative critique of research in the field of neurointerventional surgery.

Objective

To analyze recent publications from the Journal of Neurointerventional Surgery (JNIS) to test a new method for assessing research and collaboration.

Methods

We reviewed all JNIS Online First publications from 25 February 2015 to 24 February 2016. All publications—human or non-human research, systematic reviews, meta-analyses, or literature reviews—were included; editorials and commentaries were excluded. For each publication, study design, number of patients, authors, contributing centers, and study subject were recorded. Level of evidence was defined using a new scale.

Results

A total of 206 articles met inclusion criteria. Only 4% were prospective studies. Twenty-eight per cent of scientific research featured patient series of nine or less. The majority of publications were categorized as low-level evidence (91%). Forty-seven per cent involved individuals from a single center, with 87% having collaboration from three or fewer centers. International collaboration was present in 19%. While 256 institutions from 31 countries were represented, 66% were represented in only one publication.

Conclusions

We queried JNIS Online First articles from a 1-year period in a pilot study to test a new method of analyzing research quality and collaboration. The methodology appears to adequately quantify the studies into evidence tiers that emulate previously published, widely accepted scales. This may be useful for future comparison of peer-reviewed journals or for studying the quality of research being performed in different disease processes or medical specialties.

Level of Evidence Descriptions With Examples

The level of evidence (LOE) method provides journal readers with a quick appraisal of study quality. The most widely recognized LOE assessment tool is that from the Oxford Centre for Evidence-Based Medicine, and these guidelines are often adapted for other purposes. The assigned LOE typically depends on the design and quality of the study as well as the impact of the results. Because of the differing methods for classifying LOE, the author or journal reader should fully understand the criteria before assimilating data.

Methodologic Quality of Systematic Reviews Published in the Plastic and Reconstructive Surgery Literature: A Systematic Review

BACKGROUND

Well-conducted systematic reviews have a critical role in informing evidence-based decision-making in plastic surgery. The authors' objective was to assess the methodologic quality of systematic reviews in the plastic surgery literature.

METHODS

The authors systematically assessed all systematic reviews in 10 high-impact plastic surgery journals using MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews from 2003 to 2013. These were evaluated for methodologic quality using A Measurement Tool to Assess Systematic Reviews (AMSTAR), a validated 11-point instrument.

RESULTS

After removal of duplicates and screening titles and abstracts, 190 systematic reviews met eligibility criteria. The majority of systematic reviews were published in Plastic and Reconstructive Surgery (n = 88). The most common domain covered was reconstruction (17.9 percent). Using AMSTAR, the median score was 4 (interquartile range, 2.25 to 6.00) on a scale of 1 to 11. No increase in AMSTAR score was observed with time (p = 0.18). Almost half of all systematic reviews (48.4 percent) included at least two independent data extractors, and less than one-third of them (15.3 percent) searched unpublished studies or provided a list of both included and excluded studies (14.8 percent). The methodologic quality of included primary studies was evaluated in 35.3 percent.

CONCLUSIONS

Systematic reviews in plastic surgery demonstrated inadequate adherence to methodologic standards of quality, which raises concerns about validity. There has been an increase in the number of systematic reviews published in plastic surgery over the past decade, yet there has been no significant improvement observed in methodologic quality.

Low Levels of Evidence on the Plastic Surgery In-Service Training Exam

BACKGROUND

The Plastic Surgery In-Service Training Exam is written by the American Society of Plastic Surgeons. Examinees reasonably infer that tested material reflects the Society's vision for the core curriculum in plastic surgery. The purpose of this study was to determine the levels of evidence on which credited answers to the examination questions are based.

METHODS

Two recent Plastic Surgery In-Service Training Exams (2014 and 2015) were analyzed. Questions were categorized using a taxonomy model. Recommended journal article references for Level III (decision-making) questions were assigned a level of evidence. Exam sections were analyzed for differences in question taxonomy distribution and level of evidence. To look for studies with higher levels of evidence, a PubMed search was conducted for a random sample of 10 questions from each section.

RESULTS

One hundred three Level I (25.8 percent), 138 Level II (34.5 percent), and 159 Level III (39.8 percent) questions were analyzed (p < 0.001). The hand and lower extremity section had the highest percentage of Level III questions (50.0 percent; p = 0.005). Journal articles had a mean level of evidence of 3.9 ± 0.7. The number of articles with a low level of evidence (IV and V) (p = 0.624) and the percentage of questions supported by articles with a high level of evidence (I and II) (p = 0.406) did not vary by section. The PubMed search revealed no instances of a higher level of evidence than the recommended reading list.

CONCLUSIONS

A significant percentage of Plastic Surgery In-Service Training Exam questions test clinical management, but most are supported with a low level of evidence. Although that is consistent with low level of evidence of plastic surgery literature, educators should recognize the potential for biases of question writers.

Breast Microsurgery in Plastic Surgery Literature: A 21-Year Analysis of Publication Trends

Introduction Microsurgical reconstruction of the breast represents an area of continual evolution, as new autologous flaps are introduced and principles are refined. This progression can be demonstrated by bibliometric analysis of the scientific literature. Methods The top 10 plastic surgery journals were determined by impact factor (IF). Each issue of every journal from 1993 to 2013 was accessed directly, and all articles discussing microsurgery on the female breast were classified by authors' geographic location, study design, and level of evidence (LOE, I-V). The productivity index and productivity share of each geographic region was calculated based on number of articles published and IF. Results A total of 706 breast microsurgery articles were analyzed. There was a significant increase in microsurgical breast research (p < 0.01), with an average 33.6 ± 31.1 articles per year and a mean increase of 4.4 articles per year. Most research was of lower LOE, with level I constituting 0.14% and level II constituting 5.21% of all articles. United States contributed the most research with 336.4 articles, followed by Western Europe with 242.2. However, Western Europe experienced the greatest increase in productivity share, with + 0.50 ± 0.29 growth, while United States demonstrated the greatest decrease in productivity share with - 1.23 ± 0.31 growth. Among autologous flaps, transverse rectus abdominis muscle research had the greatest yearly publication volume until 2002, when overtaken by deep inferior epigastric perforator flap research. Conclusion Over the 21-year study period, the United States not only contributed the greatest volume of research on female breast microsurgery but also demonstrated the greatest decline in research productivity. Efforts should be made to increase the LOE in breast microsurgery research.

A Systematic Review of Levels of Evidence in Auricular Defects Literature: How Far Has It Been During the Past Three Decades?

BACKGROUND

Evidence-based medicine has been increasingly applied in clinical practice. The objective of this study was to identify the trends of levels of evidence and the relevant factors of higher level evidence in external auricular defects literature over 3 decades.

METHODS

The publications of external auricular defects published on 10 plastic surgery journals with higher impact factors from 1980 to 2011 were reviewed. Articles were appraised for level of evidence and other characteristics.

RESULTS

Of 245 eligible articles reviewed, no level I study was identified, 1 (0.41%) was level II, 10 (4.1%) were level III, 152 (62%) were level IV, 82 (33.5%) were level V. There was an increase of the levels of evidence (P ≈ 0) from 1980 to 2011. Studies with larger sample size (P = 0.014) and the application of P values or confidence intervals (P ≈ 0.000), those related to prevalence questions (P = 0.000004) were significantly associated with higher levels of evidence.

CONCLUSIONS

In the last 3 decades, the levels of evidence have increased significantly in external auricular defects literature. However, the predominant study remained levels IV and V.

Levels of Evidence in the Plastic Surgery Literature: A Citation Analysis of the Top 50 'Classic' Papers

Background

The plastic surgery literature is vast, consisting of a plethora of diverse articles written by a myriad of illustrious authors. Despite this considerable archive of published material, it remains nebulous as to which precise papers have had the greatest impact on our specialty. The aim of this study was to identify the most cited papers in the plastic surgery literature and perform a citation analysis paying particular attention to the evidence levels of the clinical studies.

Methods

We identified the 50 most cited papers published in the 20 highest impact plastic surgery journals through the Web of Science. The articles were ranked in order of number of citations acquired and level of evidence assessed.

Results

The top 50 cited papers were published in six different journals between the years 1957 and 2007. Forty-two of the papers in the top 50 were considered as level IV or V evidence. No level I or II evidence was present in the top 50 list. The average level of evidence of the top 50 papers was 4.28.

Conclusions

In the plastic surgery literature, no positive correlation exists between a high number of citations and a high level of evidence. Anatomical reconstructive challenges tend to be the main focus of plastic surgery rather than pathologic diseases and consequently, papers with lower levels of evidence are relatively more valuable in plastic surgery than many other specialties.

Levels of Evidence in the Clinical Sports Medicine Literature: Are We Getting Better Over Time?

BACKGROUND

There has been an increased emphasis on improving the level of evidence used as the basis for clinical treatment decisions. Several journals now require a statement of the level of evidence as a basic gauge of the study's strength.

PURPOSE

To review the levels of evidence in published articles in the clinical sports medicine literature and to determine if there has been an improvement in the levels of evidence published over the past 15 years.

STUDY DESIGN

Systematic review.

METHODS

All articles from the years 1995, 2000, 2005, and 2010 in The American Journal of Sports Medicine (AJSM), Arthroscopy, and sports medicine-related articles from The Journal of Bone and Joint Surgery-American (JBJS-A) were analyzed. Articles were categorized by type and ranked for level of evidence according to guidelines from the Centre for Evidence-Based Medicine. Excluded were animal, cadaveric, and basic science articles; editorials; surveys; special topics; letters to the editor; and correspondence. Statistical analysis was performed with chi-square.

RESULTS

A total of 1580 articles over the 4 periods met the inclusion criteria. The percentage of level 1 and 2 studies increased from 6.8% to 12.6%, 22.9%, and 23.5%, respectively (P < .0001), while level 4 and 5 studies decreased from 78.9% to 72.4%, 63.9%, and 53.0% (P < .0001). JBJS-A had a significant increase in level 1 and 2 studies (4.1%, 5.1%, 28.2%, 27.8%; P < .0001), as did AJSM (9.4%, 17.1%, 36.1%, 30.1%; P < .0001). Arthroscopy showed no significant change over time. Diagnostic, therapeutic, and prognostic studies all showed significant increases in level 1 and 2 studies over time (P < .05).

CONCLUSION

There has been a statistically significant increase in the percentage of level 1 and 2 studies published in the sports medicine literature over the past 15 years, particularly in JBJS-A and AJSM. The largest increase was seen in diagnostic studies, while therapeutic and prognostic studies demonstrated modest improvement. The emphasis on increasing levels of evidence to guide treatment decisions for sports medicine patients may be taking effect.

Levels of Evidence in Cosmetic Surgery: Analysis and Recommendations Using a New CLEAR Classification

BACKGROUND

The Level of Evidence rating was introduced in 2011 to grade the quality of publications. This system evaluates study design but does not assess several other quality indicators. This study introduces a new "Cosmetic Level of Evidence And Recommendation" (CLEAR) classification that includes additional methodological criteria and compares this new classification with the existing system.

METHODS

All rated publications in the Cosmetic Section of Plastic and Reconstructive Surgery, July 2011 through June 2013, were evaluated. The published Level of Evidence rating (1-5) and criteria relevant to study design and methodology for each study were tabulated. A new CLEAR rating was assigned to each article, including a recommendation grade (A-D). The published Level of Evidence rating (1-5) was compared with the recommendation grade determined using the CLEAR classification.

RESULTS

Among the 87 cosmetic articles, 48 studies (55%) were designated as level 4. Three articles were assigned a level 1, but they contained deficiencies sufficient to undermine the conclusions. The correlation between the published Level of Evidence classification (1-5) and CLEAR Grade (A-D) was weak (ρ = 0.11, not significant). Only 41 studies (48%) evaluated consecutive patients or consecutive patients meeting inclusion criteria.

CONCLUSIONS

The CLEAR classification considers methodological factors in evaluating study reliability. A prospective study among consecutive patients meeting eligibility criteria, with a reported inclusion rate, the use of contemporaneous controls when indicated, and consideration of confounders is a realistic goal. Such measures are likely to improve study quality.

What is the ultimate fate of presented abstracts? The conversion rates of presentations to publications over a five-year period from three North American plastic surgery meetings

BACKGROUND

Advancements in clinical decision-making are influenced by presentations made at scientific conferences or publications in journals with extensive readership. However, many ideas shared at annual conferences fail to be published, and most surgeons attend these meetings only sporadically.

OBJECTIVE

To quantify the conversion rates of meeting presentations to publications in North American plastic surgery.

METHODS

MEDLINE (OvidSP) and PubMed databases were cross-referenced with abstracts accepted for podium presentation at the Canadian Society of Plastic Surgeons, American Society of Plastic Surgeons, and American Association of Plastic Surgeons annual meetings from 2003 to 2007. Parameters reviewed included publication rate, time to publication, subspecialty, trial type, publication journal and journal impact factor.

RESULTS

Over the five-year study period, 45.00% of the 888 presentations were published in peer-reviewed journals. The mean time to publication was 22 months (range 1.00 to 85.90 months). In total, 57.00% of the 400 publications appeared in Plastic and Reconstructive Surgery; 47.20% of publications were case series study design. The majority of publications were of the reconstruction subspecialty (31.00%). Abstracts from the American Society of Plastic Surgeons had the highest conversion rate (57.70%). Publications based on abstracts presented at the American Association of Plastic Surgeons had the highest mean journal impact factor (2.33). The Canadian Society of Plastic Surgeons had the highest total number of publications (n=161).

CONCLUSIONS

From the three North American annual general meetings reviewed, there was a modest conversion rate of mainly reconstructive case series published predominantly in a single journal, Plastic and Reconstructive Surgery. Several years often pass from the genesis of a research hypothesis to final publication, and because the majority of presentations fail to be published, presentations should be observed with a critical eye given the more stringent peer review process and time required for final publication. In an effort to improve conversion rates, departments and faculty members must foster a culture that prioritizes publication.

How to Link outcomes data to quality initiatives in plastic surgery?

In recent decades, the expansion of health services research has created an opportunity to crate salient, evidence-based guidelines for diagnosis, treatment, and prognosis. However, for many aspects of care, incorporation of new scientific knowledge into clinical practice often lags, particularly among the surgical subspecialties. This article highlights the development of evidence-based medicine, the principles of innovation diffusion, and successes and challenges in developing plastic surgery quality initiatives.

Measuring treatment effectiveness: a guide to incorporating the principles of evidence-based medicine

Every year, hundreds of new surgical devices and techniques are introduced, and plastic surgeons must determine the associated risks, benefits, and costs of these options when incorporating these advances into their armamentarium. This article will discuss the elements of treatment effectiveness by applying the principles of evidence-based medicine to therapeutics. Current efforts to measure plastic surgery outcomes are evolving and rely on case series and retrospective cohort studies. This review will highlight the basic evidence-based medicine concepts and how they can potentially be applied to understand best practices in plastic surgery.

Level of evidence in hand surgery

Background

Few investigations have been done to analyze the level of evidence in journals related to hand surgery, compared to other related research fields. The objective of this study was to assess the level of evidence of the clinical research papers published in the Ibero-american (RICMA), the European (JHSE) and American (JHSA) Journals of Hand Surgery.

Methods

A total of 932 clinical research papers published between 2005 and 2009 (RICMA 60, JHSE 461, and JHSA 411) were reviewed. Two independent observers classified the level of evidence based on the Oxford International Classification, 5 being the lowest level and 1 the highest level. The observed frequencies of the level of evidence for each journal were compared with the expected frequencies by a chi-square (χ ²) test for categorical variables with a significance level of 0.05.

Results

Inter-observer agreement analysis showed a Kappa of 0.617. Intra-observer agreement analysis presented a Kappa of 0.66 for the observer 1, and a Kappa of 0.751 for the observer 2. More than 80% of the papers in RICMA and JHSE and a 67.6% in the JHSA presented a level of 4. No level 1 or 2 studies were published in RICMA, compared to JHSE (0.9% level 1 and 5.0% level 2) and JHSA (8.3% level 1 and 10% level 2). The percentage of papers with level 3 published in RICMA (16.7%) was higher compared to the JHSE (11.1%) and the JHSA (14.1%). All the results were statistically significant (χ²=63.945; p<0.001).

Conclusions

The level of evidence in hand surgery is dependent on the type of journal; being the highest level evidence papers those published in the JHSA, followed by the JHSE and finally the RICMA. Knowing the status of the level of evidence published in hand surgery is the starting point to face the challenges of improving the quality of our clinical research