Decision analysis in surgery

Original communications Decision analysis in surgery John D. Birkmeyer, MD,: and Nancy O'Connor Birkmeyer, MS, Hanover, N.H., and

White River Junction, Vt. Background. The technique of decision analysis is often applied to clinical policy and economic issues in surgery. Because surgeons may be unfamiliar with such work, this article catalogues decision analysis studies in the surgical specialties. Methods. We reviewed the medical literature (1966 to 1994) to identify surgical decision analysis studies and to assess trends over time. Each article was categorized according to the type of journal (surgical, other clinical, or technical) in which it was published and content, including surgical specialty, clinical topic, article focus (individual patient decision making, clinical policy, or cost-effectiveness), and prima U findings. Results. Publication rates of surgical decision analysis have increased dramatically over time. Of the 86 total studies only six were published before 1980. In contrast, 44 studies appeared between 1990 and 1994. Although 77% were published in nonsurgical journals, decision analyses have begun to appear more regularly in surgical forums. Studies addressing all of the surgical specialties were found, although more than one half addressed topics in general surgery (34 %) or cardiothoracic surgery (22%). The most frequent topics were gallstones (11 articles), head and neck cancer (five articles), coronary artery disease (four articles), and cerebral arteriovenous malformations (four articles). Articles focusing on clinical policy O.e., those assessing surgical efficacy for broad groups of patients) now account for large majority of published decision analyses. Conclusions. The use of decision analysis in surgery is growing steadily. Because decision analysis is being used to influence clinical policy, it is important for surgeons to be aware of these studies and to be able to review them critically. (Surgery 1996;120:7-15.) From the Departments of Surgery and of Community and Family Medicine and the Centerfor the Evaluative Clinical Sciences, Dartmouth Medical School, Hanover, N.H., and Department of Surgery, Veterans Affairs Medical Center, White River Junction, Vt.

FOR A NUMBEROF REASONSdecision analysis is well suited to many topics in surgery. Surgical decisions generally involve a limited n u m b e r of options (e.g., whether to operate) and discrete, categorizable outcomes with known probabilities of occurrence. They often hinge on explicit trade-offs between risks and benefits and between patient longevity and quality of life. Finally, surgical decisions often involve the commitment of substantial health care resources and costs. Although decision analysis has long been r e c o m m e n d e d for complex decision-making dilemmas faced by individual patients, increasingly it is being used to address clinical policy and economic issues in surgery. Despite the increased use of decision analysis in surgery, surgeons may be unaware of many such studies published in their specialty fields. Because researchers trained in decision analysis are generally nonsurgeons, decision analyses of surgical procedures are frequently Accepted for publicationJan. 10, 1996. Reprint requests:John Birkmeyer,MD, Department of Surgery,Veterans Affairs Medical Center, White RiverJunction, VT 05001.

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published in nonsurgicaljournals. In this article we catalogue all surgical decision analyses published since 1966. We also examine general trends in the application of this outcomes research technique to surgery.

METHODS Decision analyses of surgical procedures were identified in the Engiish-language medical literature from 1966 to 1994. With consultation from a medical librarian a broad MEDLINE search based on mesh terms decision analysis, Markov, cost-effectiveness, cost-benefit, and surgery produced more than 1000 potential articles. We considered only studies comparing a surgical procedure with other options (including an alternative procedure) by using explicit decision analytic techniques. Titles and abstracts were used to screen articles obtained from the MEDLINE search. Articles identified as potential candidates for inclusion were reviewed in full, producing 77 surgical decision analyses. An additional nine studies were identified by means of manual search techniques (including use of an earlier reviewt), resulting in 86 decision analysis studies of surgical procedures. SURGERY 7

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50'

40

Articles published

30, 20

10 84

0 -

1980

1980-84

1985-89

1990-94

Year Fig. 1. Column chart shows number of surgical decision analysis articles published in surgical, other clinical, and technical journals over time.

T a b l e I. Characteristics of different types of decision analysis studies

Article focus Individual patient decision making

Clinical policy

Costs/costeffectiveness

Objective Describe use of decision analysis for managing an individual patient (generally with a complex or unusual clinical dilemma) Assess surgical efficacy in a broad group of patients (may serve as basis for practice guidelines) Assess economic implications of surgical procedure

Subject of analysis

Intended user

Example (reference)

Single patient (case report)

Clinicians

Should a patient with prior nephrectomy undergo exploration for an ambiguous mass in remaining kidney?2

Hypothetical group of patients

Clinicians, policy makers, or payers

Hypothetical group of patients

Policy makers or payers

Is cholecystectomy indicated in diabetic patients with asymptomatic gallstones?3 Is angioplasty or bypass surgery more cost-effective for patients with angina and single-vessel coronary disease?4

We categorized each decision analysis by surgical specialty a n d by the type of j o u r n a l in which it was published. Specialties considered included cardiothoracic surgery, general surgery, neurosurgery, orthopedics, otolaryngology, pediatric surgery, urology, a n d vascular surgery. J o u r n a l types were identified as surgical (e.g., Surgery, Journal of Vascular Surgery), o t h e r clinical (e.g.,

New England Journal of Medicine, Journal of Pediatrics), a n d technical (e.g., Medical Decision Making). Finally, we n o t e d the primary focus o f each decision analysis by using three defined categories (Table I). Articles emphasizing individual patient decision making, often published as case reports, describe how clinicians

can use decision analysis in caring for patients facing c o m p l e x clinical dilemmas. Clinical policy articles use decision analysis to provide guidelines or indications for a given surgical procedure. Finally, some published decision analyses center primarily on the costs o r cost-effectiveness o f a surgical procedure. Although some decision analyses contain elements of each of these three types, we selected the primary focus of each article in this review. RESULTS

Publication trends. Publication rates o f surgical decision analysis have increased dramatically over time (Fig. 1). O f the 86 total studies only six studies a p p e a r e d in

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Pediatric Surgery (2%) Om~yngology (8%) Urology (14%)

Orfl~cs

(I%)

Vascular (12%)

Neumsurgery(7%)

Cardiothoracic (22%) General Surgery (

Fig. 2. Pie chart shows percentage of surgical decision analyses published in each specialty.

50 4O

Articles 30 published 20 I0 0 - 1980

1980-84

1985-89

1990-94

Year

Fig. 3. Column chart shows increasing number of surgical decision analysis articles published over time. Shadingreflects proportion of articles focusing on clinical policy, costs or cost-effectiveness, or individual patient decision making.

the medical literature before 1980. In contrast, 44 decision analyses of surgical procedures were published between 1990 and 1994. Although most articles continue to be published in nonsurgical journals, decision analyses have recently begun to appear more regularly in surgical forums. Surgical journals published 17 such studies between 1990 and 1994, c o m p a r e d with only three articles before 1990. Publication rates in technical journals have been lower but more stable over time. Content. Decision analysis studies were published in each of the surgical subspecialties. Table II lists these studies by specialty and summarizes the primary findings of each analysis. More than one half concerned topics in general surgery (34%) and cardiothoracic surgery (22%) (Fig. 2). Surgical topics addressed most frequently involved high-volume surgical procedures with

relatively categorizable indications and quantifiable clinical outcomes. These included gallstones (11 articles), head and neck cancer (five articles), and coronary artery disease (four articles). Articles focusing on clinical policy now represent t]he vast majority of all published decision analyses (Fig. '3). Studies addressing cost-effectiveness are less prevalent but also seem to be increasing over time. Articles focusing on individual patient decision making have become infrequent, perhaps because of their limited generalizability. DISCUSSION

Publication of decision analysis articles addressing surgical topics has increased dramatically during the last two decades. Although most decision analyses of surgical procedures continue to be published in nonsurgical

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T a b l e II. C a t a l o g u e o f p u b l i s h e d surgical d e c i s i o n analyses

Clinical topic Cardiothoracic surgery Aortic valve regurgitation Coronary artery disease

Article focus 2 2 2 3 2

Defective prosthetic heart valves High-risk noncardiac surgery

Rereplacement vs watchful waiting

2

Prophylactic coronary bypass surgery Prophylactic coronary bypass surgery Prophylactic intraaortic balloon pumps

2

Lung cancer staging

Mediastinoscopy vs computed tomography 3 3 3 2

Solitary pulmonary nodule

2

2

Tetralogy of Fallot

Transposition of the great arteries General surgery Agnogenic myeloid metaplasia Appendicitis

2

2

2

Breast cancer Cholecystectomy

Early vs delayed surgery Coronary bypass surgery vs medical therapy Coronary bypass surgery vs medical therapy Coronary bypass surgery vs medical therapy Coronary bypass surgery vs percutaneous angioplasty vs medical therapy

2

I

Recurrent ventricular dysrhythmias

Options considered

3

Mediastinoscopy vs transbronchial biopsy vs computed tomography Implantable defibrillator vs medical therapy Imptantable defibrillator vs medical therapy Implantable defibrillator vs medical therapy Immediate thoracotomy vs percutaneous biopsy vs watchful waiting Immediate thoracotomy vs percutaneous biopsy vs watchful waiting Primary vs delayed intracardiac repair vs initial palliative operation Arterial switch vs atrial baffle procedures Splenectomy vs medical therapy Early surgery vs watchful waiting Early surgery vs watchful waiting Mastectomy vs breast-conserving surgery Routine vs selective intraoperative cholangiography

Primary findings *efe~e~ce Early surgery recommended 5 Surgery recommended for patients with severe angina 6 Surgery recommended for severe angina 7 Surgery costs $4,000 to $30,000 per QALY saved 8 Surgery recommended for 3-vessel disease; angioplasty for 1- or 2-vessel disease; medical prescription for mild angina 4 Watchful waiting recommended for most patients 9 Choice depends on patient factors 1~ Surgery recommended ll Intraaortic balloon pump recommended for highest-risk patients 12 Computed tomography with selective mediastinoscopy recommended 13 Bronchoscopy with transbronchial biopsy recommended 14 Defibrillators cost $7,400 per QALY saved 15 Defibrillators cost $t4,000 to $29,000 per QALY saved TM Choice depends on pretherapy sudden death risk 17 Toss-up is

Choice depends on likelihood of cancer and operative risk 19 Initial palliative operation not recommended 2~ Choice depends on operative mortality of arterial switch21 Choice depends on patient preferences 22 Article not prescriptive z3 Article not prescriptive 24 Breast-conserving surgery for most subgroups 25 Selective use recommended 26

Ardcle focuscategorizedas individualpatient decisionmaking (1),clinicalpolicy(2),or costs/cost-effectiveness(3).Primaryfindingsof each articleare abbreviatedby necessity.Completefindingsand qualificationsare availablein originalstudies. QALY,Quality-adjustedyear of life.

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Table II. C o n t ' d

Clinical topic

Article focus 3

Options considered

Colonic polyps---early invasive cancer Duodenal ulcer disease

2

End-stage kidney disease

1

Routine vs selective intraoperative cholangiography Partial colectomy vs endoscopic surveillance Selective vagotomy vs medical therapy Kidney transplantation vs dialysis

3

Kidney transplantation vs dialysis

2

With vs without gastric drainage procedure

Esophagectomy/ esophagogastrectomy Gallstones General

2

Laparoscopic vs open cholecystectomy vs lithotripsy vs dissolution therapy (Open) cholestectomy vs lithotripsy vs watchful waiting

3

Asymptomatic.

2 2

Asymptomatic in diabetics

2

Symptomatic

2 2

Symptomatic in patient with hepatitis and Grave's disease Gastric carcinoma without known metastases Hepatic hemangiomas Hereditary spherocytosis Spleen injuries in blunt trauma Temporal arteritis

1

(Open) cholestectomy vs dissolution therapy vs watchful waiting (Laparoscopic) cholecystectomy vs watchful waiting Open cholecystectomy vs watchful waiting (Open) cholecystectomy vs watchful waiting (Open) cholecystectomy vs lithotripsy (Open) cholecystectomy vs watchful waiting Timing of cholecystectomy

Selective use recommended 27 Partial colectomy recommended in patients with low operative risk 28 Medical therapy recommended ~ Kidney transplantation recommended 3~ Kidney transplantation less expensive, better survival~1 Choice depends on risk factors for gastric outlet obstruction ~2 Laparoscopic cholecystectomy generally recommended; nonsurgical prescription reasonable in "optimal" settings 3~ Lithotripsy less expensive than surgery for symptomatic stones; watchful waiting recommended for asymptomatic stones ~4 Dissolution therapy more cost-effective than surgery ~5 Watchful waiting recommended 36 Watchful waiting recommended ~7 Watchful waiting recommended 3 Lithotripsy recommended s8 Cholecystectomy favored 39 Nine-month delay4~

Gastrectomy vs no surgery'

Article not prescriptive 41

Resection vs watchful waiting Early splenectomy vs watchful waiting Early splenectomy vs watchful waiting Biopsy vs empiric steroids

Watchful waiting recommended 42 Watchful waiting recommended 43

Biopsy vs empiric steroids

Thyroid nodules

P~imary findinggef~nce

Bilateral biopsy vs unilateral biopsy vs empiric steroids Immediate surgery vs aspiration biopsy vs medical suppression Surgery vs further diagnostic testing vs watchful waiting

Article not prescriptive 44 Choice depends on likelihood of disease 45 Choice depends on likelihood of disease 46 Choice depends on likelihood of disease 47 Article not prescriptive 48 Article not prescriptive 49

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T a b l e II. C o n t ' d

Clinical topic

Article focus

Ulcerative cofitis, cancer risk

2

Early protocolectomy vs endoscopic surveillance

Endoscopic surveillance r e c o m m e n d e d 5~

2

Surgery vs watchful waiting

2 2

Surgery vs watchful waiting Surgery vs watchful waiting

Surgery r e c o m m e n d e d for most patients 51 Watchful waiting recommended52 Surgery r e c o m m e n d e d for low-graded arteriovenous malformations, patients u n d e r 60 yr of age 53 Radiosurgery r e c o m m e n d e d for arteriovenous malformations <3

Neurosurgery Cerebral arteriovenous malformations

Options considered

Surgery vs stereotactic radiosurgery vs watchful waiting

Primary findings"@"....

Cn154 Concurrent intracranial aneurysms a n d moderate carotid stenosis Familial cerebral aneurysms

Orthopedics Mid-shaft femur fractures Otolaryngology Cleft palate

Aneurysm clipping vs carotid endarterectomy vs both vs watchful waiting Screening angiography and elective surgery vs watchful waiting

Endarterectorny not recommended; value of aneurysm clipping depends on patient factors 55 Choice depends on aneurysm prevalence and patient age 56

1

Surgery vs traction

Article not prescriptive 57

1

Pharyngeal flap vs V-u p u s h b a c k

Article not prescriptive r's

2

2

vs o b t u r a t i o n Head and neck cancer Oral cancer without known node metastases

Radical neck dissection vs local resection alone

T3 laryngeal cancer

1

Laryngectomy vs radiation

T2 glottic carcinoma Stage I floor-of-mouth cancer

2 2

Surgery vs radiation therapy Local resection vs radiation therapy, with or without neck dissection Neck dissection vs neck radiation therapy vs local therapy alone Tympanotomy tubes vs antibiotic chemoprophylaxis

Clinical stage NO head a n d neck cancer Otitis media, recurrent Pediatric surgery h n m u n e thrombocytopenic purpura Splenic tranma (blunt) Urology Benign prostatic hypertrophy

Bladder cancer In patient with recent myocardial infarction Screening of superficial tumors

Prophylactic neck dissection r e c o m m e n d e d for primary tumors >2 cm 59 Choice depends on patient use for speech 6~ Radiation therapy r e c o m m e n d e d 61 Resection with neck dissection r e c o m m e n d e d 62 Article not prescriptive 63 T ~ n p a n o t o m y tubes reserved for failure of antibiotic prophylaxis 64

Splenectomy vs intravenous ~/-globulin Splenectomy vs splenorrhaphy vs watchful waiting

~/,-globulin recommended, cost $8,000 per life-year saved 65 Watchful waiting r e c o m m e n d e d for most cases 66

Transurethral prostatectomy vs watchful waiting Transurethral prostatectomy vs watchful waiting Transurethral prostatectomy vs transurethral dilatation

Choice depends on patient symptonls 67 Article not prescriptive 68

Timing of radical cystectomy

Operate immediately 7~

Random cystoscopic biopsies vs no biopsies of normal-appearing urothelium

No biopsies r e c o m m e n d e d 71

Dilatation r e c o m m e n d e d 69

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T a b l e II. C o n t ' d

Clinical topic Circumcision (medical aspects) Prostate cancer

Article focus

Options considered

Primary findings refe~e~c*

2

Circumcision vs no circumcision

No circumcision recommended72

3 2

Circumcision vs no circumcision Radical prostatectomy vs radiation therapy vs watchful waiting

Toss-up73 Surgery or radiation for young patients with aggressive tumors;

Laparoscopic pelvic node dissection before radical prostatectomy Radical prostatectomy vs radiation therapy

Choice depends on Gleason score, prostate specific antigen test75

Surgical exploration vs watchful waiting Surgery vs lithotripsy

Toss-up2

Above-knee vs below-knee amputation Early repair vs watchful waiting

Below-knee amputation unless failure rate >80% 78 Early repair recommended for most patients79 Choice depends on multiple factors s~

toss-up otherwise 74

In patient with human immunodeficiency virus infection Renal mass Ureterolithiasis 9 Vascular surgery Amputation level Abdominal aortic aneurysms In patient with colorectal cancer

Aneurysm repair vs colectomy--neither, simultaneous, or sequential Carotid endarterectomy vs watchful waiting Carotid endarterectomy vs watchful waiting

Carotid artery disease With concomitant coronary artery disease Intermittent claudication Mesenteric ischemia

2 1

Popliteal aneurysms, asymptomatic Renovascular disease

2 1

Distal bypass vs watchful waiting Laparotomy vs angiography vs watchful waiting Early repair vs watchful waiting Surgical revascularization vs renal artery angioplasty vs medical therapy Surgical revascularization vs medical therapy

forums, an increasing n u m b e r are appearing in surgery journals. Although these studies most c o m m o n l y address topics in general surgery or cardiothoracic surgery, the use of decision analysis is extending across all of the surgical subspecialties. Increasing use of decision analysis in surgery is likely related to increasing emphasis o n health care costs a n d quality improvement. Efforts to contain surgical costs a n d improve quality include practice guidelines, which attempt to eliminate unnecessary surgery a n d streamline necessary care. Decision analysis is one popular, quantitative m e t h o d of achieving these goals. Surgical procedures with categorizable indications a n d quantifiable clinical outcomes are particularly amenable to examination with decision analytic techniques. High-

Radical prostatectomy76

Lithotripsy recommended77

Choice depends on operative risk, stroke risk 81

Carotid endarterectomy recommended, but benefit small82 Article not prescriptive 83 Observation recommended84 Early repairs5 Renal artery angioplasty recommended86 Article not prescriptive 87

volume, high-cost operations performed primarily for symptom relief are also readily assessed with decision analysis. For these reasons it is n o t surprising to note the large n u m b e r of decision analyses published o n gallstones, prostatism, a n d coronary artery disease. Trends toward increasing application of decision analysis to surgery are likely to continue. For this reason surgical j o u r n a l editors, reviewers, a n d readers must learn to examine decision analysis studies critically. The appropriateness of the decision analysis model a n d its assumptions must be considered. The data o n which the decision analysis is based must also be scrutinized. Finally, readers must consider whether the resuits warrant the author(s)' conclusions. Because decision analysis is being used to shape clinical policy in sur-

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g e r y , it is i m p o r t a n t

f o r s u r g e o n s to p a r t i c i p a t e i n t h e

process. W e gratefully a c k n o w l e d g e R i c h a r d W. Dow, MD, a n d H. Gilbert Welch, MD, M P H , for their insightful c o m m e n t s o n earlier versions o f this article. W e also t h a n k K a r e n O d a t o for h e r assistance with t h e literature search. REFERENCES

1. KassirerJP. Decision analysis: a progress report. Ann Intern Med 1987;106:275-91. 2. Dunn VH. An ambignlous renal cyst in a patient with a prior nephrectomy: what to do when there is only one more to lose. Med Decis Making 1986;6:49-62. 3. Friedman LS, Roberts MS, Brett AS, Marton KI. Management of asymptomatic gallstones in the diabetic patient: a decision analysis. Ann Intern Med 1988;109:913-9. 4. WongJB, Sonnenberg FA, Salem DN, Pauker SG. Myocardial revascularization for chronic stable angina: analysis of the role of percutaneous transluminal coronary angioplasty based on data available in 1989. Ann Intern Med 1990;113:852-71. 5. Biem HJ, Detsky AS, Armstrong PW. Management of asymptomatic chronic aortic regurgitation with left ventricular dysfunction: a decision analysis. J Gen Intern Med 1990;5:394-401. 6. Pauker SG. Coronary artery surgery: the use of decision analysis. Ann Intern Med 1976;85:8-18. 7. Pliskin JS, Stason WB, Weinstein MC, et al. Coronary artery bypass graft surgery: clinical decision making and cost-effectiveness analysis. Med Decis Making 1981;1:10-28. 8. Weinstein MC, Stason WB. Cost-effectiveness of coronary artery bypass surgery. Circulation 1982;66:III56-66. 9. BirkmeyerJD, Marrin CAS, O'Connor GT. Should patients with Bjork-Shiley valves undergo prophylactic replacement? Lancet 1992;340:520-3. 10. Fleisher LA, Skolnick ED, Holroyd KJ, Lehmann HP. Coronary artery revascularization before abdominal aortic anem'ysm surgery: a decision analytic approach. Anesth Analg 1994;79:661-9. 11. Hagen MD, Eckman MH, Pauker SG. Aortic aneurysm in a 74year-old man with coronary disease and obstructive lung disease: is double jeopardy enough? Med Decis Making 1989;9:285-99. 12. Georgeson S, Coombs AT, Eckman MH. Prophylactic use of the intra-aortic balloon pump in high-risk cardiac patients undergoing noncardiac surgery: a decision analytic view. Am J Med 1992;92:665-78. 13. Eddy RJ. Cost-effectivenessof CT scanning compared with mediastinoscopy in the preoperative staging of lung cancer. J Can Assoc Radiol 1989;40:189-93. 14. Malenka DJ, Colice GL,Jacobs C, Beck JR. Mediastinal staging in non-small-cell lung cancer. Med Decis Making 1989;9:23142. 15. Kuppermann M, Luce BR, McGovern B, Podrid PJ, Bigger JJ, RuskinJN. An analysis of the cost effectiveness of the implantable defibrillator. Circulation 1990;81:91-100. 16. Larsen GC, Manolis AS, Sonnenberg FA, BeshanskyJR, Estes NA, Pauker SG. Cost-effectiveness of the implantable cardioverterdefibrillator: effect of improved battery life and comparison with amiodarone therapy. J Am Coll Cardiol 1992;19:1323-34. 17. Middlekauff HR, Stevenson WG, Tillisch JH. Prevention of sudden death in survivors of myocardial infarction: a decision analysis approach. Am HeartJ 1992;123:475-80. 18. Cummings SR, Lillington GA, Richard RJ. Managing solitary puhnonary nodules. Am Rev Respir Dis 1986;134i453-60. 19. Knnstaetter R, Wolkove N, Kreisman H, Cohen C, Frank H. The solitary pulmonary nodule: decision analysis. Med Decis Making 1985;5:61-75. 20. Garson A Jr, Gorry AG, McNamara DG, Cooley DA. The surgical

Surgery July 1996 decision in tetralogy of Fallot: weighing risks and benefits with decision analysis. Am J Cardiol 1980;45:108-15. 21. Danford DA. Factors influencing choice of procedure in transposition of the great arteries: a decision analysis approach. J Am Coll Cardiol 1990;16:471-5. 22. Benbassat J, Gilon D, Penchas S. The choice between splenectomy and medical treatment in patients with advanced agnogenic myeloid metaplasia. Am J Hematol 1990;33:128-35. 23. Clarke JR. A concise model for the management of possible appendicitis. Med Decis Making 1984;4:331-8. 24. Clarke JR, Badawy SB. Acute pain over the appendix: a model of the surgical decision. Ann Chir 1991;45:279-83. 25. Verhoef LC, Stalpers LJ, Verbeek AL, Wobbes T, van DW. Breast-conserving treatment or mastectomy in early breast cancer: a clinical decision analysis with special reference to the risk of local recurrence. EurJ Cancer 1991;27:1132-7. 26. Holmin T,Jonsson B, Lingren B, et al. Selective or routine intraoperative cholangiography: a cost-effectiveness analysis. World J Surg 1980;4:315-22. 27. Scott TE, Jacoby I. Clinical decision analysis as a means of technology assessment: the effectiveness of intraoperative cholangiography. IntJ Technol Assess Health Care 1992;8:185-97. 28. Wilcox GM, Beck JR. Early invasive cancer in adenomatous colonic polyps (malignant polyps): evaluation of the therapeutic options by decision analysis. Gastroenterology 1987;92:1159-68. 29. Sonnenberg A. Comparison of different strategies for treatment of duodenal ulcer. Br Med J 1985;290:1185-7. 30. PliskinJS, Beck CH. Decision analysis in individual clinical decision making: a real-world application in treatment of renal disease. Methods Inf Med 1976;15:43-6. 31. Roberts SD, Maxwell DR, Gross TL. Cost-effective care of endstage renal disease: a billion dollar question. Ann Intern Med 1980;92:243-8. 32. Olak J, Detsky A. Surgical decision analysis: esophagectomy/ esophagogastrectomy with or without drainage. Ann Thorac Surg 1992;53:493-7. 33. Habu Y, Hayashi K, Watanabe Y, Kawal K. A clinical decision analysis to assess the value oflaparoscopic cholecystectomy in the treatment of gallstone disease. Endoscopy 1992;24:709-16. 34. Sonnenberg A, Derfus GA, Soergel KH. Lithotripsy versus cholecystectomy for management of gallstones: a decision analysis by Markov process. Dig Dis Sci 1991;36:949-56. 35. Weinstein MC, Coley CM, Richter JM. Medical management of gallstones: a cost-effectiveness analysis. J Gen Intern Med 1990; 5:277~4. 36. Fendrick AM, Gleeson SP, Cabana MD, Schwartz JS. Asymptomatic gallstones revisited: is there a role for laparoscopic cholecystectomy? Arch Fam Med 1993;2:959-68. 37. Ransohoff DF, Gracie WA, Wolfenson LB, Neuhauser D. Prophylactic cholecystectomy or expectant management for silent gallstones: a decision analysis to assess survival. Ann Intern Med 1983;99:199-204. 38. FendrickAM, de Pouvourville G, Bitker C, Pelletier G. Treatment of symptomatic cholelithiasis in France: a decision analysis comparing cholecystectomy and biliary lithotripsy. IntJ Technol Assess Health Care 1992;8:166-84. 39. Ransohoff DF, Gracie WA. Management of patients with symptomatic gallstones: a quantitative analysis. AmJ Med 1990;88:15460. 40. Beck JR, Sackel SG, Pauker SG. Elective surgery in the setting of comorbid anesthesia risk: timing of cholecystectomy in a patient with Graves' disease and hepatitis. Med Decis Making 1982;2:97115. 41. Doubilet P, McNeil BJ. Treatment choice in gastric carcinoma: a decision-analytic approach. Med Decis Making 1982;2:261-74. 42. Gilon D, Slater PE, BenbassatJ. Can decision analysis help in the

Surgery Volume 120, Number 1 management of giant hemangioma of the liver? J Clin Gastroenterol 1991;13:255-8. 43. Manno CS, Cohen AR. Splenectomy in mild hereditary spherocytosis: is it worth the risk? A m J Pediatr Hematol Oncol 1989; 11:300-3.

44. Feliciano PD, Mnllins RJ, Trunkey DD, Crass RA, Beck JR, Helfand M. A decision analysis of traumatic splenic injuries.J Trauma 1992;33:340-7. 45. Buchbinder R, Detsky AS. Management of suspected giant cell arteritis: a decision analysis. J Rheumatol 1992;19:1220-8. 46. Nadean SE. Temporal arteritis: a decision-analytic approach to temporal artery biopsy. Acta Neurol Scand 1988;78:90-100. 47. Elliot DL, Watts WJ, Reuler JB. Management of suspected temporal arteritis: a decision analysis. Med Decis Making 1983;3:63-8. 48. Molitch ME, Beck JR, Dreisman M, Gottlieb JE, Panker SG. The cold thyroid nodule: an analysis of diagnostic and therapeutic options. Endocr Rev 1984;5:185-99. 49. Sisson JC, Bartold SP, Bartold SL. The dilemma of the solitary thyroid nodule: resolution through decision analysis. Semin Nucl Med 1978;8:5%71. 50. Gage TP. Managing the cancer risk in chronic ulcerative colitis: a decision-analytic approach. J Clin Gastroenterol 1986;8:50-7. 51. Auger RG, Wiebers DO. Management ofunruptured intracranial arteriovenous malformations: a decision analysis. Neurosurgery 1992;30:561-9. 52. Iansek R, Elstein AS, BallaJI. Application of decision analysis to management of cerebral arteriovenous malformation. Lancet 1983;1:1132-5. 53. Ter Berg JW, Dippel DW, Habbema JD, Westermann CJ, Tulleken CA, Willemse J. Unruptured intracranial arteriovenous malformations with hereditary haemorrhagic telangiectasia: neurosurgical treatment or not? Acta Neurochir 1993;121:34-42. 54. Hudgins WR. Decision analysis of the treatment of AVMs with radiosurgery. Stereotact Funct Neurosurg 1993;1:11-9. 55. Dippel DW, Vermeulen M, Braakman R, HabbemaJD. Transient ischemic attacks, carotid stenosis, and an incidental intracranial aneurysm: a decision analysis. Neurosnrgery 1994;34:449-57. 56. Leblanc R, Worsley KJ, Melanson D, Tampieri D. Angiographic screening and elective surgery of familial cerebral aneurysms: a decision analysis. Neurosurgery 1994;35:9-18. 57. Bunch WH, Andrew GM. Use of decision theory in treatment selection. Clin Orthop 1971;80:3%52. 58. KrischerJP. A decision analytic approach to cleft palate treatment evaluation. Cleft PalateJ 1980;17:31%25. 59. Henschke UK, Flehinger BJ. Decision theory in cancer therapy. Cancer 1967;20:1819-26. 60. McNeil BJ, Weichselbaum R, Pauker SG. Speech and survival: tradeoffs between quality and quantity of life in laryngeal cancer. N EnglJ Med 1981;305:982-7. 61. Stalpers LJ, Verbeek AL, van DW. Radiotherapy or surgery for T2NOM0 glottic carcinoma? a decision-analytic approach. Radiother Oncol 1989;14:209-17. 62. Velanovich V. Choice of treatment for stage I floor-of-mouth cancer: a decision analysis. Arch Otolaryngol Head Neck Surg 1990;116:951-6. 63. Weiss MH, Harrison LB, Isaacs RS. Use of decision analysis in planning a management strategy for the stage NO neck. Arch Otolaryngol Head Neck Surg 1994;120:699-702. 64. Bisonni RS, Lawler FH, Pierce L. Recurrent otitis media: a costutility analysis of simulated treatment using tympanostomy tubes vs antibiotic prophylaxis. Fam Pract ResJ 1991;11:371-8. 65. HollenbergJP, Subak LL, Ferry.lJ, BusselJB. Cost-effectivenessof splenectomy versus intravenous gamma globulin in treatment of chronic immune thrombocytopenic purpura in childhood.J Pediatr 1988;112:530-9. 66. Velanovich V, Tapper D. Decision analysis in children with blunt

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splenic trauma: the effects of observation, splenorrhaphy, or splenectomy on quality-adjusted life expectancy. J Pediatr Surg 1993;28:179-85. 67. Barry MJ, Mulley AJ, Fowler FJ, WennbergJW. Watchful waiting vs immediate transurethral resection for symptomatic prostatism: the importance of patients' preferences. JAMA 1988;25'9: 3010-7. 68. Krumins PE, Fihn SD, Kent DL. Symptom severity and patien& values in the decision to perform a transurethral resection of the prostate. Med Decis Making 1988;8:1-8. 69. Bisonni RS, Lawler FH, Holtgrave DR. Transurethral prostatectomy versus transurethral dilatation of the prostatic urethra fi~r benign prostatic hyperplasia: a cost-utility analysis. Fam Pract Res J 1993;13:25-36. 70. Eckman MH, McNutt RA, Parkinson DR, Pauker SG. The timing of radical cystectomy after recent myocardial infarction. Med Decis Making 1987;7:52-66. 71. Kiemeney LA, Witjes JA, Heijbroek RP, Koper NP, Verbeek AL, Debruyne FM. Should random urothelial biopsies be taken from patients with primary superficial bladder cancer? a decision analysis. BrJ Urol 1994;73:164-71. 72. Chessare JB. Circumcision: is the risk of urinary tract infection really the pivotal issue? Clin Pediatr 1992;31:100-4. 73. Lawler FH, Bisonni RS, Holtgyave DR. Circumcision: a decision analysis of its medical value. Fam Med 1991;23:587-93. 74. Fleming C, Wasson JH, Albertsen PC, Barry MJ, WennbergJE. A decision analysis of alternative treatment strategies for clinically localized prostate cancer. JAMA 1993;269:2650-8. 75. WolfJJ, Shinohara K, Kerlikowske KM, Narayan P, StoUer ML, Carroll PR_ Selection of patients for laparoscopic pelvic lymphadenectomy prior to radical prostatectomy: a decision analysis. Urology 1993;42:680-8. 76. Roach PJ, Fleming C, Hagen MD, Pauker SG. Prostatic cancer in a patient with asymptomatic HIV infection. Med Decis Making 1988;8:132-44. 77. Hatziandreu EE, Carlson K, Mulley AJ, Weinstein MC. Costeffectiveness study of the extracorporeal shock-wave lithotriptor. IntJ Technol Assess Health Care 1990;6:623-32. 78. MichaelsJA. The selection of amputation level: an approach using decision analysis. EurJ Vasc Snrg 1991;5:451-7. 79. Katz DA, Littenberg B, CronenwettJL. Management of small abdominal aortic aneurysms: early surgery vs watchful waiting. JAMA 1992;268:2678-86. 80. Velanovich V, Andersen CA. Concomitant abdominal aortic aneurysm and colorectal cancer: a decision analysis approach to a therapeutic dilemma. Ann Vasc Surg 1991;5:44%55. 81. Matchar DB, Pauker SP. Endarterectomy in carotid artery disease: a decision analysis. JAMA 1987;258:793-8. 82. Matchar DB, Pauker SG. Transient ischemic attacks in a man with coronary artery disease: two strategies neck and neck. Med Decis Making 1986;6:239-49. 83. Troeng T, Bergqvist D, Janzon L, Jendteg S, Lindgren B. The choice of strategy in the treatment of intermittent claudication--a decision tree approach. EurJ Vasc Surg 1993;7:438-4:3. 84. Cormier RE, Chase BA, Peterson GS, Pauker SG. Abdominal pain, atherosclerosis, and atrial fibrillation: the case for mesenteric ischemia. Med Decis Making 1982;2:323-39. 85. MichaelsJA, Galland RB. Management of asymptomatic poplite.al aneurysms: the use of a Markov decision tree to determine the criteria for a conservative approach. EurJ Vasc Surg 1993;7:136-43. 86. Kopelman RI, McNutt RA, Pauker SG. Use of decision analysis in a complicated case of renovascular hypertension. Hypertension 1988; 12:611-9. 87. McNeil BJ, Adelstein SJ. Measures of clinical efficacy: the value of case finding in hypertensive renovascular disease. N Engl J Med 1975;293:221-6.