EuropeanUrology European Urology 43 (2003) 591595

Review

Classic Papers in Urology$

K. Thomasa,*, C.M. Mooreb, E.W. Gerharzc, T. OBriend, M. Embertone

aUrology Department, Kingston Hospital, Gallsworthy Road, Kingston, Surrey KT2 7QB, UKbUrology Department, St. Georges Hospital, London, UKcDepartment of Urology, Julius Maximilians University Medical School, Wurzburg, GermanydUrology Department, Guys and St. Thomas Hospitals, London, UKeInstitute of Urology and Nephrology, University College, London, UK

Accepted 3 March 2003

AbstractObjective: Most clinicians are aware of the importance of using evidence based medicine to support their clinicalpractice, butwhere does the evidence comefrom?Theaimof this studywas toexamine the concordance between papersdeemed important by urologists compared with those selected by the more objective criteria of the citation index.Method: To achieve this, two approaches were used; firstly experts in various fields of urology were asked toselect what they felt were classic papers and secondly urology journals were searched to find the 100 most citedpapers for 19821997 and 19351997. The results of both of these league tables were then combined.Results: The most cited papers varied depending on the time period studied. When the experts selections werecombined with those obtained via citation index it was found that the experts had chosen papers with a high citationindex from non-urological as well as urological journals.Conclusion: It is possible to collate the classic papers within urology and the most effective means of doing so is tocombine objective selection with expert choice. This is an exercise that can be repeated within any specialty.# 2003 Elsevier Science B.V. All rights reserved.

Keywords: Evidence based medicine; Impact factor; Citation index

1. Introduction

Most clinicians are aware of the importance of usingevidence based medicine to support their clinicalpractice, but where does the evidence come from?There are a range of potential sources; textbooks(frequently out of date at the time of publication),journals, conferences, meetings and expert opinion.The widespread use of the internet and the ease ofelectronic searching has exposed clinicians to a broaderrange of literature than previously. Often, however,clinicians restrict themselves to the journals and stan-dard texts related to their specialty, complemented bymeetings and conferences. Only researchers trying to

gain knowledge of a specific area search for informa-tion outside their own specialty.

The aim of this study was, therefore, to examine theconcordance between papers deemed important byurologists compared with those selected by the moreobjective criteria of the citation index [1].

2. Methods

The purpose was to select key papers within one specialty(urology). To achieve this, two approaches were used. Firstly,internationally recognised experts from each of the main urologyspecialties were approached and asked to select what they con-sidered the top 10 classic papers that had significantly contrib-uted to clinical practice and the management of patients in theirfield (Table 1). For each paper chosen they were asked to provide acritique by following a pre-defined template (Table 2).

Secondly, a literature search of all the urological journals wasconducted by the Institute for Scientific Information (Table 3) [2].A league table of the 100 most cited papers in the literature wasconstructed. To overcome the bias of older papers having more

$ Statement of potential conflict of interest: The following authors

were involved in the compilation of the Classic Papers in Urology

book [1]: Gerharz EW, OBrien T, Emberton M.* Corresponding author. Tel. 44-7976-218195;

Fax: 44-208-934-3269.E-mail address: specialkthomas@hotmail.com (K. Thomas).

0302-2838/03/$ see front matter # 2003 Elsevier Science B.V. All rights reserved.doi:10.1016/S0302-2838(03)00143-X

citations, two tables were produced. The first table was for papersbetween 1981 and 1997 and the second between 1935 and 1992.The papers from these tables were then combined with thoseselected by the experts forming the basis of a third league table.

3. Results

The top 20 papers of the 100 cited in urologicaljournals for 1981 to 1997 and 1935 to 1992 are dis-played in Tables 4 and 5. It can be noted that dependingon the time period examined different papers are

Table1Subject headings for papers chosen

Book I Book II Book III

Benign prostatic

hyperplasia

Paediatric Urology

1 2Erectile Dysfunction

Male Infertility

Urinary tract infection Reconstructive Stone Disease

Prostate Cancer Urology 1 2 Female UrologyBladder Cancer Urological Trauma

Renal Cancer

Testicular Cancer

Table 2Template for critique of papers chosen

Title Related references

Authors Key message

Reference Why the paper is important

Abstract Strengths

Summary by expert Weaknesses

Citation count Relevance

Table 3Urological journals in print

Act Urol J Endourol Prostate Urol Res

Ann Urol J Urol Prostate C Urologe

BJU J Urologie Scand J Urol Neph Urology

Eur Urol Mol Urol Urol Clin North Am Urol Surv

Infect Urol Neurourol U Urol Intern World J Urol

Table 4The 20 most cited papers in urology 19811997

Citation index Author Paper title Journal reference

538 Oesterling JE Prostate specific antigena critical assessment of the most useful tumor marker

for adenocarcinoma of the prostate

J Urol 1991;145:907

465 Mebust WK Transurethral prostatectomy: immediate and post-operative complications.

A cooperative study of 13 participating institutions evaluating 3,885 patients

J Urol 1989;141:2437

388 Berry SJ The development of human benign prostatic hyperplasia with age J Urol 1984;132:4749

384 Stamey TA Prostate specific antigen in the diagnosis and treatment of adenocarcinoma

of the prostate. 2 radical prostatectomy treated patients

J Urol 1989;141:1076

370 Oesterling JE Prostate specific antigen in the pre-operative and post-operative evaluation

of localised prostatic cancer treated with radical prostatectomy

J Urol 1998;139:766

342 Cooner WH Prostate cancer detection in a clinical urological practice by ultrasonography,

digital rectal examination and prostate specific antigen

J Urol 1990;143:1146

324 Drach GW Report of the United States cooperative study of extra-corporeal shock wave

lithotripsy

J Urol 1986;135:1127

320 Lange PH The value of serum prostate specific antigen determinations before and

after radical prostatectomy

J Urol 1989;141:873

315 Barry MJ The American Urological Association symptom index for benign prostatic

hyperplasia

J Urol 1992;148:154957

315 Hudson MA Clinical use of prostate specific antigen in patients with prostate cancer J Urol 1989;142:1011

314 Chaussy C 1st clinical experience with extracorporeally induced destruction of kidney

stones by shock waves

J Urol 1982;127:417

307 Lue TF Physiology of erection and pharmacological management of impotence J Urol 1987;137:829

303 Heney NM Superficial bladder cancerprogression and recurrence J Urol 1983;130:10836

293 Walsh PC Impotence following radical prostatectomyinsight into aetiology and prevention J Urol 1982;128:492

289 Kock NG Urinary diversion via a continent ileal reservoirclinical results in 12 patients J Urol 1982;128:46975

284 Catalona WJ Comparison of digital rectal examination and serum prostate-specific antigen

in the early detection of prostate cancerresults of a multi-center clinical trial

of 6,630 men

J Urol 1994;151:1283

283 Partin AW Prostate specific antigen in the staging of localized prostate cancerinfluence

of tumor differentiation, tumor volume and benign hyperplasia

J Urol 1990;143:747

277 Partin AW The use of prostate-specific antigen, clinical stage and Gleason score to

predict pathological stage in men with localised prostate cancer

J Urol 1993;150:110

267 Brawer MK Screening for prostatic carcinoma with prostate specific antigen J Urol 1992;147:841

262 Zorgniotti AW Auto-injection of the corpus cavernosum with a vasoactive drug combination

for vasculogenic impotence

J Urol 1985;133:39

592 K. Thomas et al. / European Urology 43 (2003) 591595

ranked more highly i.e. Table 4 has Oesterling et al. asnumber one whereas Table 5 has Robson et al.

The results of the combination of these papers withthose selected by the experts are shown in Table 6.The top three papers in this table are not from urologyjournals and, therefore, were missed when searchingthe urological literature. Of the 100 papers in this table,61 were not cited by the experts and of the 39 cited bythe experts 24 were from non-urological journals.

4. Discussion

When experts chose the papers they considered themost important, they chose from a wide range ofjournals not just the urological literature. The papersthey selected from the urology journals often had a low

citation index. Using citation index alone to search thedatabase of urology journals missed papers in non-urological journals with a high citation index andconsidered by experts to be seminal work in the fieldof urology.

Expert opinion is by definition subjective and bytheir own admission many had chosen papers thathighlighted an important step in the evolution of theirspecialty and the ideas they represented may now beobsolete [1]. This may explain the difference betweenthe papers selected by the experts versus those from thedatabase. Using the citation index to rank publicationshas its own inherent bias as certain journals tend torefer to themselves thereby increasing their citationindex [3]. Citation index tends to reflect the particulararea of research interest at the time of publication i.e.prostate cancer which accounted for more than half of

Table 5The 20 most cited papers in urology 19351992

Citation

index

Author Paper title Journal reference

498 Robson CJ The results of radical nephrectomy for renal cell carcinoma J Urol 1969;101:297

472 Gleason DF Prediction of prognosis for prostatic adenocarcinoma by combined histological

grading and clinical staging

J Urol 1974;111:58

404 Politano VA An operative technique for the correction of vesicoureteral reflux J Urol 1958;79:932941

399 Jewett HJ Infiltrating carcinoma of the bladder. Relation of depth of penetration of the

bladder wall to incidence of local extension and metastases

J Urol 1946;55:366

382 Herbut P In: Myron Tannebaum (Editor)Urological Pathology, Lea

and Febiger, Philadelphia, 1977,

17197

370 Gleason DF &

the VACURG

Histological grading and clinical staging of prostatic carcinoma In: Myron Tannebaum (Editor)

Urological Pathology, Lea and

Febiger, Philadelphia, 1977,

17197

347 Ormond JK Bilateral ureteral obstruction due to envelopment and compression by an

inflammatory retroperitoneal process

J Urol 1948;59:1072

334 Berger J Les depot intercapillaries dIgA-IgG J Urologie 1968;74:694

325 Brown M The urethral pressure profile Br J Urol 1969;41:211

317 Morales A et al. Intracavity bacillus Calmette-Guerin in the treatment of superficial bladder tumours J Urol 1976;116:1803

308 Franzen S Cytological diagnosis of prostatic tumours by transrectal aspiration

biopsya preliminary report

Br J Urol 1960;32:193

305 Oesterling JE Prostate specific antigena critical assessment of the most useful tumor marker

for adenocarcinoma of the prostate

J Urol 1991;145:907

286 Stamey TA Prostate specific antigen in the diagnosis and treatment of adenocarcinoma of

the prostate. 2 radical prostatectomy treated patients

J Urol 1989;141:1076

285 Drach GW Report of the United States cooperative study of extra-corporeal shock

wave lithotripsy

J Urol 1986;135:1127

284 Jewett HJ The present staus of radical prostatectomy for stages A and B prostatic cancer Urol Clin N Am 1975;2:105

283 Chaussy C 1st clinical experience with extracorporeally induced destruction of kidney stones

by shock waves

J Urol 1982;127:417

282 Prien EL Studies in urolithiasis: 1. The composition of urinary calculi J Urol 1947;57:949

269 Oesterling JE Prostate specific antigen in the pre-operative and post-operative evaluation of

localised prostatic cancer treated with radical prostatectomy

J Urol 1998;139:766

263 Mebust WK Transurethral prostatectomy: immediate and post-operative complications.

A cooperative study of 13 participating institutions evaluating 3,885 patients

J Urol 1989;141:2437

262 Lapides J et al. Clean intermittent self-catheterisation in the treatment of urinary tract disease J Urol 1972;107:45861

: The database from which this table was taken was not able to supply all paper details.

K. Thomas et al. / European Urology 43 (2003) 591595 593

the papers in Table 4. For citation index to be moremeaningful it should be condition specific. The effectof time on citation index was highlighted by usingdifferent time periods for Tables 4 and 5. In addition,the nationality of the journal may influence the citationindex as this affects the readership and, therefore,impact factor. Researchers aim to publish in the journalwith the highest high impact factor [4]. Both of thesefactors may account for the predominance of papers inAmerican journals that appeared in Tables 4 and 5.Another problem occurs if a journal changes its namee.g. from British Journal of Urology to British Journalof Urology International as initially the impact factor

for this journal has to be calculated over only one yearrather than two [5].

The implication of these results for evidence basedmedicine is that if clinicians only consult journalswithin their own specialty they will inevitably missimportant research. Also by limiting themselves tojournals with a high impact factor they will be exposedmainly to work published in American journals whichmay not be applicable to their practice.

This novel approach to compiling the importantpapers can be applied to any other medical specialty.The exercise should be repeated again because as thetrends in scientific endeavour and activity change i.e.

Table 6Top 20 citation counts of papers chosen by experts combined with those in Tables 4 and 5

Citation

index

Author Paper title Journal references

1096 Einhorn &

Donohue

Cis diaminochloroplatinum, vinblastine, and bleomycin combination chemotherapy

in disseminated testicular cancer

Ann Intern Med 1977;87:2938

1037 Huggins & Hodges Studies on prostate cancer. The effect of castration, of estrogen and of androgen

injection on serum phosphatases in metastatic carcinoma of the prostate

Cancer Res 1941;1:2937

870 Stamey et al. Prostate specific antigen as a serum marker for adenocarcinoma of the prostate N Engl J Med 1987;317:90916

538 Oesterling JE Prostate specific antigena critical assessment of the most useful tumor marker

for adenocarcinoma of the prostate

J Urol 1991;145:907

528 Kass & Finland Asymptomatic infections of the urinary tract Trans Assoc Am Physicians

1956;69:56

498 Robson et al. The results of radical nephrectomy for renal cell carcinoma J Urol 1969;101:297

472 Gleason DF Prediction of prognosis for prostatic adenocarcinoma by combined histological

grading and clinical staging

J Urol 1974;111:58

465 Mebust WK Transurethral prostatectomy: immediate and post-operative complications.

A cooperative study of 13 participating institutions evaluating 3,885 patients

J Urol 1989;141:2437

415 Bricker Bladder substitution after pelvic evisceration Surg Clin North Am

1950;30:151121

404 Politano &

Leadbetter

An operative technique for the correction of vesicoureteral reflux J Urol 1958;79:93241

399 Jewett HJ Infiltrating carcinoma of the bladder. Relation of depth of penetration of the

bladder wall to incidence of local extension and metastases

J Urol 1946;55:366

388 Berry et al. The development of human benign prostatic hyperplasia with age J Urol 1958;79:93241

384 Stamey TA Prostate specific antigen in the diagnosis and treatment of adenocarcinoma

of the prostate. 2 radical prostatectomy treated patients

J Urol 1989;141:1076

382 Herbut P In: Myron Tannebaum (Editor)Urological Pathology, Lea

and Febiger, Philadelphia, 1977,

17197

374 Schwartz et al. A simple estimation of glomerular filtration rate in children derived from

body length and plasma creatinine

Pediatrics 1976;58:25963

370 Gleason DF &

the VACURG

Histological grading and clinical staging of prostatic carcinoma In: Myron Tannebaum (Editor)

Urological Pathology, Lea

and Febiger, Philadelphia, 1977,

17197

370 Oesterling JE Prostate specific antigen in the pre-operative and post-operative evaluation of

localised prostatic cancer treated with radical prostatectomy

J Urol 1998;139:766

359 Roos et al. Mortality and re-operation after open and transurethral resection of the prostate

for benign prostatic hyperplasia

N Engl J Med 1989;320:11204

354 Crawford et al. A controlled trial of leuprolide with and without flutamide in prostatic carcinoma N Engl J Med 1989;321:41924

347 Ormond JK Bilateral ureteral obstruction due to envelopment and compression by an

inflammatory retroperitoneal process

J Urol 1948;59:1072

: The database from which this data was taken was not able to supply all the paper details.

594 K. Thomas et al. / European Urology 43 (2003) 591595

laparoscopy, gene therapy so will the subject matter ofthe papers cited.

5. Summary

The authors proved that it was possible to collate allthe considered great urological works and thatgenerally the experts chose papers that had been citedfrequently in the literature. There is a tendency within asmall specialty such as urology for important findingsnot to be published in urological journals due to theirlow impact factor. The danger then is that the messagemay not reach the target audience or may be dissemi-

nated slowly. However, the experts had chosen papersfrom journals outside urology. Although urology jour-nals may have low impact factor in the general litera-ture they often have a high one within their owncommunity or target audience and, therefore, articlespublished in them can significantly affect practicewithin the specialty [5].

Acknowledgements

With special thanks to International ScientificInformation for allowing us to reproduce the leaguetables.

References

[1] Gerharz EW, OBrien T, Emberton M. Classic Papers in Urology. ISIS

Medical; 1999.

[2] http://www.isinet.com.

[3] Hansson S. Impact factor as a misleading tool in evaluation of medical

journals. Lancet 1995;346:906.

[4] Jemec GB. Impact factor to assess academic output. Lancet 2001;358:

1373.

[5] Whitfield H, Vale J, Taylor S. The impact factorfact and fantasy.

BJU Int 2002;89(1):iiii.

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Classic Papers in UrologyIntroductionMethodsResultsDiscussionSummaryAcknowledgementsReferences