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Ann Thorac Surg 2001;71:337-339
© 2001 The Society of Thoracic Surgeons

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Original article: general thoracic

Duration of knowledge in general thoracic surgery

^a Department of Surgery, McMaster University, Hamilton, Ontario, Canada

Accepted for publication August 18, 2000.

Address reprint requests to Dr Urschel, St. Joseph’s Hospital, 50 Charlton Ave East, Hamilton, Ontario L8N 4A6, Canada
e-mail: urschelj{at}fhs.mcmaster.ca

	Abstract

Top Abstract Introduction Material and methods Results Comment References

 
Background. Medical knowledge changes rapidly, so current medical education approaches emphasize the development of life-long learning skills ("teaching the learner to learn") as opposed to the simple acquisition of contemporary medical knowledge. Because there are no data on the rapidity of change of general thoracic surgical knowledge, we do not know whether this trend in medical education is appropriate for thoracic surgical trainees. We undertook a study to assess the duration of knowledge in general thoracic surgery.

Methods. The first general thoracic surgery article from each issue of The Annals of Thoracic Surgery between 1965 and 1997 was abstracted into a summary statement. A form, made up of 360 summary statements in random order, was assessed by 6 general thoracic surgeons. They assessed statement validity on a 5-point scale (1 = statement false; 5 = statement true). Average statement validity scores for 30 time intervals were calculated. The relationship between time of publication and statement validity was analyzed.

Results. Average validity scores ranged from 2.24 (represents 1965 to 1966) to 4.32 (represents 1969 to 1970). Validity scores increased with time (y = 3.46 + 0.017x, where y is validity score and x is time), and this was significant (r = 0.40; p = 0.027). However, the absolute change in average validity scores over the 33-year study period was only 0.52 or 13.1% of the "modern" era scores.

Conclusions. The assumption that medical knowledge changes quickly may not be true in general thoracic surgery. Although life-long learning skills are important, general thoracic surgery training programs should continue to emphasize fundamental knowledge in the specialty.

	Introduction

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Medical education is a process of acquisition of medical knowledge and development of self-learning skills. Both areas of medical education are important. The rapidity of change of medical knowledge dictates the relative importance of these two medical education goals. In previous decades, when medical knowledge changed relatively slowly, medical education was synonymous with learning medical facts and dogma. We now recognize that medical knowledge changes rapidly, so current medical education approaches emphasize the development of life-long learning skills ("teaching the learner to learn") as opposed to the simple acquisition of contemporary medical knowledge [1]. Because there are no data on the rapidity of change of general thoracic surgical knowledge, we do not know whether this trend in medical education is appropriate for thoracic surgical trainees. We undertook a study to assess the duration of knowledge (rapidity of change) in general thoracic surgery.

	Material and methods

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The Annals of Thoracic Surgery came into existence in 1965 as a journal that broadly served the needs of the thoracic surgical community. We considered its articles to be representative of contemporary thoracic surgical opinion. We reviewed the first clinical general thoracic surgery article from each issue of The Annals between 1965 and 1997. Editorials and case reports were excluded. Over the 33-year period there were 360 issues that contained a general thoracic paper suitable for review. (The Annals was initially published in six issues per year, and an occasional issue was devoid of general thoracic papers.) Each article was abstracted into a summary statement. The summary statements were prepared by one surgeon and then revised according to the suggestions of another surgical coauthor. The following summary statements serve as examples:

"Marlex mesh can be used to reduce the size of the postresectional pleural space after lung resection, and thereby decrease complications such as empyema and fistula."

"Mediastinal seminomas should be treated by resection followed by radiotherapy."

"High-grade dysplasia in Barrett’s esophagus is an indication for esophageal resection."

The 360 statements, in random order, were compiled into a form. Six general thoracic surgeons, ranging in age from 36 to 66 years, assessed the statements for validity on a 5-point Likert scale (1 = statement false; 5 = statement true). The surgeons were certified by the American Board of Thoracic Surgery or the Royal College of Physicians and Surgeons of Canada. Five were in academic practice; one practiced in an academically oriented, but nonuniversity-affiliated, private hospital. The 360 statements were placed in chronological order and divided into 30 equal groups of 12 statements. We used these 30 time-interval groups instead of calendar years because the number of statements per year was not consistent (see preceding). Average statement validity scores for the 30 individual time intervals were calculated (average of 72 scores = 12 statements x 6 surgeons). The relationship between time interval (time of publication) and statement validity was analyzed. Regression statistics were estimated with Statistica (Statsoft, Tulsa, OK) software. A p value less than 0.05 was considered significant.

	Results

Top Abstract Introduction Material and methods Results Comment References

 
Average validity scores for the time intervals ranged from 2.24 (represents 1965 to 1966) to 4.32 (represents 1969 to 1970) on a 1 to 5 Likert scale. Validity scores increased with time (y = 3.46 + 0.017x, where y is validity score and x is time), and this was significant (r = 0.40; p = 0.027; Fig 1). However, the absolute change in average validity scores over the 33-year study period was only 0.52. When expressed as a percentage, 0.52 is only 13.1% of the "modern" era validity scores. Considerable extrapolation of the regression line would be needed to calculate a "half-life" for general thoracic surgical knowledge. This was not done. We did not detect a relationship between statement scores and age of the surgeon-judges, but the small number of judges hindered any conclusive evaluation in this area.

View larger version (13K): [in this window] [in a new window]   Fig 1. Regression analysis of average validity scores as a function of time.

	Comment

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The evidence-based medicine movement emphasizes rigorous evaluation of diagnostic and therapeutic interventions, and discourages clinical practice based on intuitive application of basic science to patient care [2, 4]. In evidence-based medicine an understanding of clinical research methodology is arguably more important than an understanding of basic medical sciences, such as anatomy and physiology. In problem-based learning the development of life-long learning skills ("teaching the learner to learn") is emphasized as opposed to the memorization of medical facts [3, 5]. Both the evidence-based medicine and problem-based learning movements have devalued the acquisition of fundamental medical knowledge.

Our study was based on articles from The Annals. It showed, not surprisingly, that general thoracic surgical knowledge changed over time. However, the pace of change of knowledge over the 33-year study period was surprisingly slow, and seemed at odds with our general perception of change in the specialty. As clinical surgeons we may be very aware of change while ignoring the many enduring consistencies in our practice. Many fundamental concepts in our specialty have not really changed in 30 years: empyemas require drainage [6, 7], complete resections are the key to successful lung cancer operations [8, 9], and antireflux operations performed under tension are doomed to failure [10, 11]. Fundamental concepts should be stressed in thoracic surgery training programs.

We did not calculate a half-life of general thoracic surgical knowledge from our data, but this has been done for general surgical knowledge. Hall and Platell [12] calculated the "rate of loss of truth" in general surgery to be 0.75% per year. The half-life of general surgical knowledge (point at which half the knowledge was obsolete) was estimated at 45 years. Our study did not extend back beyond 1965. We limited the beginning of our study to that year for two reasons: it was the year The Annals came into existence, and it also gave us more than 30 years of literature to review, an interval similar to the length of a thoracic surgeon’s career. If we had included literature from before 1965 we suspect that our regression line might drop precipitously at that point. It is possible that our three-decade study period represented a relative plateau in general thoracic surgical knowledge. Therefore, it was not wise to extrapolate our regression line to estimate a half-life of thoracic surgical knowledge.

Our study has several important limitations in addition to the possible knowledge plateau mentioned above. Given the nature of scientific publishing, articles from The Annals may not accurately reflect mainstream general thoracic surgical opinion. We considered reviewing various editions of textbooks as an alternative, but it was difficult to abstract a textbook section or chapter into a brief summary statement. The study would have been strengthened by the participation of more surgeon-judges and greater representation from private-practice surgeons. However, participation required anywhere from 3 to 6 hours; this dampened the enthusiasm of many potential surgeon-judges.

General thoracic surgical education should have two components: acquisition of fundamental knowledge in the specialty and development of life-long learning strategies. The rate of change of general thoracic surgical knowledge is relatively slow. Although life-long learning skills are important, general thoracic surgery training programs should continue to emphasize fundamental knowledge in the specialty.

	References

Top Abstract Introduction Material and methods Results Comment References

 

1. Shatzer J.H. Instructional methods. Acad Med 1998;73(9 Suppl):S38-S45.[Medline]
2. Lee J.S., Urschel D.M., Urschel J.D. Is general thoracic surgical practice evidence based?. Ann Thorac Surg 2000;70:429-431.[Abstract/Free Full Text]
3. Itani K.M., Miller C.C., Church H.M., McCollum C.H. Impact of a problem-based learning conference on surgery residents’ in training exam (ABSITE) scores. J Surg Res 1997;70:66-68.[Medline]
4. Sauerland S., Lefering R., Neugebauer E.A. The pros and cons of evidence-based surgery. Langenbecks Arch Chir 1999;384:423-431.
5. Sweeney G. The challenge for basic science education in problem-based medical curricula. Clin Invest Med 1999;22:15-22.[Medline]
6. Langston H.T. Empyema thoracis. Ann Thorac Surg 1966;2:766-768.[Medline]
7. Ali I., Unruh H. Management of empyema thoracis. Ann Thorac Surg 1990;50:355-359.[Abstract]
8. Pearson F.G. An evaluation of mediastinoscopy in the management of presumably operable bronchial carcinoma. J Thorac Cardiovasc Surg 1968;55:617-625.[Medline]
9. Ginsberg R.J. Resection of non–small cell lung cancer: how much and by what route. Chest 1997;112(4 Suppl):S203-S205.[Abstract/Free Full Text]
10. Pearson F.G., Langer B., Henderson R.D. Gastroplasty, and Belsey hiatus hernia repair. An operation for the management of peptic stricture with acquired short esophagus. J Thorac Cardiovasc Surg 1971;61:50-63.[Medline]
11. Jobe B.A., Horvath K.D., Swanstrom L.L. Postoperative function following laparoscopic collis gastroplasty for shortened esophagus. Arch Surg 1998;133:867-874.[Abstract/Free Full Text]
12. Hall J.C., Platell C. Half-life of truth in surgical literature. Lancet 1997;350:1752.[Medline]

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This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): John D. Urschel Thomas A. Horan Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Urschel, J. D. Articles by Bennett, W. F. Search for Related Content PubMed PubMed Citation Articles by Urschel, J. D. Articles by Bennett, W. F. Related Collections Education Related Article