The 2020 Evidence-Based Promotion Ladder of Academic Plastic Surgery

Background Metrics were evaluated between academic plastic surgeons from different tiered training programs to determine promotion predictors within tiers and between tiers for those seeking promotion from assistant professor, associate professor, to full professors. Methodology We performed a retrospective, cross-sectional study by collecting 61 variables from full-time plastic surgery faculty affiliated with United States residency training programs during the 2020-2021 academic year. Surgeons were stratified into nine cohorts for comparison by professorship (assistant, associate, professor) and Doximity-ranked institution program tiers (Tier 1 = T1, Tier 2 = T2, Tier 3 = T3). Univariate followed by multivariate regressions with reciprocal transformation were performed to determine predictors more likely associated with promotion or lateral movement. Results A total of 98 programs listed 851 surgeons. T1/T2/T3 surgeon promotion predictors included more years in practice (p = 0.002; p < 0.001; p < 0.001) and greater number of last-author publications (p < 0.001; p < 0.001; p = 0.007). T1/T3 surgeon promotion predictors included higher h-indexes (p = 0.001; p = 0.002). T1 surgeon promotion predictors included being on journal editorial board (p = 0.040). T2 surgeon promotion predictors from assistant to associate included non-white race (p = 0.010). T3 surgeon promotion predictors included residency director (p = 0.009) and greater number of citations (p = 0.026). Promotion predictors from assistant, associate, and professors for T3/T2/T1 programs included greater number of last-author publications (p = 0.007; p = 0.002; p < 0.001). Movement from assistant and associate between T3/T2/T1 programs included plastic surgery department (p = 0.002; p < 0.001). Movement from assistant between programs included attending Top 10 US News medical schools (p = 0.012), attending more favorable Doximity-ranked research programs (p < 0.001), greater number of first-author publications (p = 0.017), and greater number of citations (p = 0.023). Movement from associate between programs included attending more favorable Doximity-ranked reputation programs (p = 0.017) and higher h-indexes (p = 0.017). Movement from professor between programs included receiving any American Association of Plastic Surgeons (AAPS) award (p = 0.039) and greater number of AAPS awards (p = 0.012). Conclusions Promotion predictors provided evidence to synthesize the Doximity-tiered Promotion Ladder of Academic Plastic Surgery.


Introduction
Promotion in an academic surgical career is categorized by three subsequent stages of professorship. One typically starts his/her career as an assistant professor, advances through promotion to become an associate professor, and finally becomes a professor. Excellence is the basis for promotion demonstrated by five classic principles that define an academic surgical career. These principles include teaching, clinical productivity, administrative duty, community service, and research [1]. Teaching may be measured by trainee assessments and institutional recognition; clinical productivity may be measured by relative value units (RVUs) and income; administrative duties and community service may be measured by appointment to local, regional, and national board committees, societies, and/or associations; and research may be measured by the quality and number of peer-reviewed publications [1,2]. However, criteria for promotion often vary from one academic institution to another based on metrics implemented within each institution.
These differences often create challenges when comparing professorship and faculty metrics from one institution to another. Categorizing institutional programs with similar characteristics into a tiered system may clarify institution-specific metrics for academic plastic surgeons and provide promotional insight. Metrics can then be compared within each institutional tier to predict promotion from assistant professor to associate professor to full professor for a surgeon advancing his/her career within the same institution, and lateral movements among institutional tiers for a surgeon changing institutions. Identifying recent objective metrics from academic plastic surgeons across different institutional tiers may provide an updated guide for students, trainees, and junior faculty who plan to pursue and/or advance their careers through academic plastic surgery. The purpose of this study was to evaluate metrics among academic plastic surgeons from different training programs to determine predictors and guide prospective surgeons seeking promotion or changing institutions.

Study design
We performed an Institutional Review Board-exempt, retrospective, comparative, cross-sectional online review to collect data from full-time academic plastic surgeons affiliated with the United States Accreditation Council for Graduate Medical Education (ACGME)-accredited integrated and/or independent residency training programs during the 2020-2021 academic calendar year. Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines were used throughout the review [3].

Study population
Plastic surgeons included full-time faculty from training programs available through the American Council of Academic Plastic Surgeons (ACAPS) website during the 2020-2021 academic calendar year. Each institution's plastic surgery residency website was queried for faculty rosters. Non-plastic surgeons, adjunct faculty, and faculty without publicly available professorship statuses were excluded from the study.

Variables analyzed
A total of 61 publicly available variables were measured for each of the three professorship statuses and three program tiers based on full-time plastic surgeon faculty positions at ACGME-accredited institutions during the 2020-2021 academic year. Variables were manually searched and collected for each plastic surgeon from institutional websites, Doximity, LinkedIn, private-practice websites, organizational websites, research databases, and National Institutes of Health (NIH) websites from October 1, 2020to November 19, 2020. A variable was considered if publicly available for each plastic surgeon. Four study members extracted study variables (KMK, JAM, AIM, FD). Following variable extraction, one of the four study members confirmed extracted variables for accuracy.
Variables included physician demographics (race, sex), current faculty academic institutions, medical degree backgrounds, advanced degrees, residency training, fellowship training, number of years in practice, program division or department status, residency and fellowship directorship, editorial board status, ACGME board membership, officer/director of the American Board of Plastic Surgeons (ABPS), regional society/association presidencies, national society/association presidencies, research metrics (Scopus; Reed Elsevier, London, United Kingdom), NIH grant funding, and American Association of Plastic Surgeons (AAPS) awards (Appendix 2).

Statistical analysis
Descriptive statistics were used to compare medians, interquartile ranges (IQR), ranges (minimum/maximum), odds ratios (OR), 95% confidence intervals (95% CI), area under the curves (AUC), frequencies, and percentages between variables based on the non-parametric population distribution assessed using the Shapiro-Wilk test. Analyses were performed to compare different professorship cohorts within the same tier (e.g., T1 assistant versus T1 associate versus T1 professor), followed by the same professorship cohorts between different institution tiers (e.g. T1 assistant versus T2 assistant versus T3 assistant). Dichotomous variables were assessed using Fisher's exact cross-tabulation tests followed by the post-hoc Bonferroni tests with an α of 0.008 to determine which cohorts were different [5]. Continuous variables were assessed using Kruskal-Wallis tests followed by Dunn's post-hoc tests. Univariate analyses were followed by multivariate stepwise logistic regressions using forward selection and reciprocal transformation to determine independent promotion predictors more likely associated with promotion or lateral movement. A receiver operating characteristic (ROC) curve was generated for each regression to assess the AUC for promotional predictor accuracy and discrimination. Analyses outcomes were two-tailed, with a significance level set at an α of 0.05. All analyses were performed using SPSS version 25.0 (IBM Corp., Armonk, NY).
Following multivariate analysis, plastic surgeons were more likely to be promoted from assistants to associates and professors with more years in practice
Following multivariate analysis, plastic surgeons were more likely to be promoted from assistants to associates if non-white (OR: 2.76, 95% CI: 1.27, 5.99; AUC: 0.64; p = 0.010). Plastic surgeons were more likely to be promoted from assistants to associates and professors with more years in practice
Following multivariate analysis, plastic surgeons were more likely to be promoted from assistants to associates and professors with more years in practice
Following multivariate analysis, plastic surgeons were more likely to move laterally from an associate at a T3 program to a T2 program and T1 program if they attended a more favorable Doximity-ranked reputation program

AAPS: American Association of Plastic Surgeons
Independent predictors of promotion from assistant to associate to professor within a program tier correspond to bottom-to-top advancement up the promotion ladder. Independent predictors of promotion from T3 to T2 to T1 programs correspond to left-to-right advancement across the promotion ladder.

Discussion
We evaluated objective metrics between academic plastic surgeons from three Doximity program tiers to determine predictors and guide future and/or current surgeons seeking promotion from assistant professors to associate professors to full professors. Furthermore, we evaluated academic plastic surgeons at the same professorship level from three different tiered programs to guide those seeking lateral movement between programs. Independent predictors following comparisons were used to synthesize the Doximity-tiered Promotion Ladder of Academic Plastic Surgery.
Increasing the number of last-author publications was the most impactful method that predicted promotion at every intersection of the promotion ladder. By increasing the number of last-author publications, a plastic surgeon can advance up and across the promotion ladder. Traditionally, first authorship designates a junior team member who collected data and synthesized the manuscript, while last authorship designates a senior faculty member who contributed intellectual property through experience [6]. In addition, the last author often carries the prestige and responsibility of the corresponding author. Corresponding authors are responsible for accurate manuscript content, criticisms, and addressing any comments [6]. In contrast, firstauthor publications only predicted promotion for assistant professors advancing across the ladder from T3 to T1 programs. The prestige and responsibility associated with last authorship may indicate a higher level of academic maturity than first authorship with subsequent advancement up and across the promotion ladder.
H-indexes are bibliometric measurements used to assess the quality of publications [1,2,[7][8][9][10]. Higher hindexes have previously had the greatest associations with tenure promotion following bibliometric comparisons among the h-index, g-index, hc-index, and number of peer-reviewed publications [2]. Others found the h-index, I-10 index, total number of publications, and total number of citations all had similar correlations with academic rank [1]. Our observations indicate h-indexes were predictors of promotion at T1 programs, T3 programs, and for associate professors moving laterally from T3 to T1 programs, while the number of citations was a predictor of promotion at T3 programs and for assistant professors moving laterally from T3 to T1 programs.
Dedicating more years in practice predicted promotion up the ladder within all program tiers. Years in practice were measured from the time of first becoming an attending physician to the 2020-2021 academic calendar year. More years in practice increase the opportunities of achieving excellence in all five classic principles that define an academic surgical career [11,12]. We were not able to assess the impact of duration at a single institution. Some academic surgeons remain at an institution for their entire career, while others seek promotion by leaving an institution. Only static variables in 2020 were assessable, but not specific reasons for promotion.
Plastic surgery programs designated as departments have the autonomy to eliminate bureaucracy and layers of administration, directly engage in educational decisions with the dean of the medical school, implement educational plans, and use surplus revenues to recruit and maintain faculty [13]. Departments predicted lateral movement for assistant and associate professors across the ladder from T3 to T1 programs. At the status level of full professorship, receiving any AAPS award and a greater number of AAPS awards predicted lateral movement for full professors across the ladder from T3 to T1 programs. Depending on a surgeon's current level of professorship, seeking programs designated as departments or applying for AAPS awards may provide opportunities for lateral movement across the promotion ladder.
Institutional programs were stratified into three tiers by Doximity research rankings. Doximity determines rankings by current resident and recent alumni satisfaction data, reputation data, and objective data [4]. Satisfaction data were determined by survey results from graduates within the past 15 years or current residents. Reputation data were determined by peer nominations from board-certified plastic surgeons. Objective data were determined by the currently available program, resident, and board certification metrics [4]. Although Doximity rankings may be subjected to criticism, these were the most universally accepted publicly available data. A three-tiered Doximity approach was selected to maintain study power for statistical comparisons while differentiating more stringent requirements between different plastic surgery programs. Data were evaluated from the 2020-2021 academic calendar year. A single-year assessment limited comparisons over years to determine yearly productivity for each academic surgeon or time intervals to promotion over a career. Only 851 plastic surgeons had publicly available professorship data and were eligible for inclusion from the sample of 951 plastic surgeons. Four programs were not Doximity ranked (University of Alabama; Mayo Clinic, Florida; Medical College of Georgia; University of Minnesota). These programs were added as T3 programs. Pediatric fellowships were not considered their own fellowship. They were combined with either craniofacial or hand depending on the primary focus of the fellowship. Publicly available leadership in regional and national societies/associations was limited to past presidents. Assessing other board leadership positions and overall member statuses would have provided greater insight into the impact of regional and national society/association affiliations. We were not able to assess the classic principle of clinical productivity. RVUs and incomes were not publicly available data, limiting assessments of the importance of case volume on an academic surgical career. In addition, we were not able to assess the impact of mentorship on promotion. Mentors impact career choices of students, residents, fellows, and junior faculty [14]. Due to individual variability of faculty and different career goals, the discrimination measured by AUCs ranged from 0.23 to 0.86. Not all academic plastic surgeons are seeking promotion. Fulltime plastic surgery faculty affiliated with United States training programs were evaluated, limiting the generalizability of promotion predictors to the United States.
Academic plastic surgeons should follow institution-specific promotion criteria. While we realize our model may not fit all institutions, our comprehensive data collection and rigorous methodology provided a generalized framework to assess independent predictors associated with promotion and lateral movement in academic plastic surgery from the 2020-2021 academic calendar year. Independent promotion predictors provided evidence to synthesize the Doximity-tiered Promotion Ladder of Academic Plastic Surgery.

Conclusions
Academic plastic surgeons were more likely to be promoted from assistant to associate and professor at T1 programs with more years in practice, being on a journal editorial board, a greater number of last-author publications, and higher h-indexes. Promotion from assistant to associate was more likely at T2 programs if surgeons were non-white. Surgeons were more likely to be promoted to associate and professor at T2 programs with more years in practice and a greater number of last-author publications. Surgeons were more likely to be promoted to associate and professor at T3 programs with more years in practice, as a residency director, a greater number of last-author publications, higher h-indexes, and a greater number of citations. Assistant professors at T3 programs were more likely to move laterally between T2 and T1 programs if they attended a Top 10 US News medical school, attended a more favorable Doximity-ranked research program, with a greater number of first-author publications, a greater number of last-author publications, a greater number of citations, and if plastic surgery was a department at T2 and T1 programs. Associate professors at T3 programs were more likely to move laterally between T2 and T1 programs if they attended a more favorable Doximity-ranked reputation program, with a greater number of last-author publications, higher hindexes, and if plastic surgery was a department at T2 and T1 programs. Professors at T3 programs were more likely to move laterally to T2 programs if they were a chief/chair. Professors at T3 programs were more likely to move laterally between T2 and T1 programs with a greater number of last-author publications, if they received any AAPS award, and a greater number of AAPS awards. These Independent predictors were used to provide evidence and synthesize the Doximity-tiered Promotion Ladder of Academic Plastic Surgery.

Appendices
Appendix 1: Doximity research-ranked plastic surgery program tiers