Development of a decision support tool for primary care management of patients with abnormal liver function tests without clinically apparent liver disease: A record-linkage population cohort study and decision analysis (ALFIE)

Health Technology Assessment

Volumn 13, Issue 25, 2009, Pages

  Donnan, P T ^a   McLernon, D ^a   Dillon, J F ^b   Ryder, S ^c   Roderick, P ^d   Sullivan, F ^a   Rosenberg, W ^d  

^a UNIVERSITY OF DUNDEE   (United Kingdom)

^b UNIVERSITY OF DUNDEE   (United Kingdom)

^c QUEEN S MEDICAL CENTRE   (United Kingdom)

^d UNIVERSITY OF SOUTHAMPTON   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

ALANINE AMINOTRANSFERASE; ALKALINE PHOSPHATASE; ANALGESIC AGENT; ANTIBIOTIC AGENT; ANTILIPEMIC AGENT; ASPARTATE AMINOTRANSFERASE; AUTOANTIBODY; BILIRUBIN; GAMMA GLUTAMYLTRANSFERASE; HYDROXYMETHYLGLUTARYL COENZYME A REDUCTASE INHIBITOR; METHADONE; NONSTEROID ANTIINFLAMMATORY AGENT; SERUM ALBUMIN;

ALANINE AMINOTRANSFERASE BLOOD LEVEL; ALBUMIN BLOOD LEVEL; ALCOHOLISM; ALGORITHM; ALKALINE PHOSPHATASE BLOOD LEVEL; ANXIETY; ASPARTATE AMINOTRANSFERASE BLOOD LEVEL; BILIRUBIN BLOOD LEVEL; CALIBRATION; CAUSE OF DEATH; CINAHL; CLINICAL DECISION MAKING; COCHRANE LIBRARY; COHORT ANALYSIS; COST EFFECTIVENESS ANALYSIS; COST OF ILLNESS; COST UTILITY ANALYSIS; DATA BASE; DATA SYNTHESIS; DECISION SUPPORT SYSTEM; DECISION TREE; DECOMPENSATED LIVER CIRRHOSIS; DIAGNOSTIC ACCURACY; DISEASE SEVERITY; DRUG ABUSE; DRUG USE; ECHOGRAPHY; EMBASE; EXPERT SYSTEM; FOLLOW UP; GAMMA GLUTAMYL TRANSFERASE BLOOD LEVEL; GENERAL PRACTITIONER; HAZARD RATIO; HEALTH CARE COST; HEALTH STATUS; HEALTH SURVEY; HEPATITIS A VIRUS; HEPATITIS B VIRUS; HEPATITIS C VIRUS; HUMAN; IMMUNOASSAY; JAUNDICE; LIVER BIOPSY; LIVER CIRCULATION; LIVER DISEASE; LIVER FUNCTION TEST; LIVER TRANSPLANTATION; MEDLINE; MORTALITY; OUTCOME ASSESSMENT; PATIENT REFERRAL; PILOT STUDY; POPULATION RESEARCH; PREDICTION; PREGNANCY; PRIMARY MEDICAL CARE; PROBABILITY; QUALITY ADJUSTED LIFE YEAR; QUALITY OF LIFE; QUANTITATIVE ANALYSIS; QUESTIONNAIRE; RETROSPECTIVE STUDY; REVIEW; RISK ASSESSMENT; SCORING SYSTEM; SENSITIVITY ANALYSIS; SENSITIVITY AND SPECIFICITY; SEX DIFFERENCE; SOCIAL ISOLATION; SURVIVAL; SYSTEMATIC REVIEW; UNITED KINGDOM; VALIDITY; VIRUS DETECTION; VISUAL ANALOG SCALE; ADOLESCENT; ADULT; AGED; ARTICLE; FEMALE; LIVER; MALE; MEDICAL RECORD; MIDDLE AGED; PATHOPHYSIOLOGY; PRIMARY HEALTH CARE; YOUNG ADULT;

ADOLESCENT; ADULT; AGED; COHORT STUDIES; DECISION SUPPORT SYSTEMS, CLINICAL; DECISION SUPPORT TECHNIQUES; FEMALE; HUMANS; LIVER; LIVER DISEASES; LIVER FUNCTION TESTS; MALE; MEDICAL RECORD LINKAGE; MIDDLE AGED; PRIMARY HEALTH CARE; RETROSPECTIVE STUDIES; SCOTLAND; YOUNG ADULT;

EID: 70449559090     PISSN: 13665278     EISSN: None     Source Type: Journal    
DOI: 10.3310/hta13250     Document Type: Review

References (102)

1. Van Walraven C, Naylor CD. Do we know what inappropriate laboratory utilization is? A systemic review of laboratory clinical audits. JAMA 1998;280:550-558 (Pubitemid 28377676)
2. Pratt DS, Kaplan MM. Evaluation of abnormal liver-enzyme results in asymptomatic patients. N Engl J Med 2000;342:1266-1271 (Pubitemid 30235957)
3. Sherman D, Finlayson NDC, Camillari M, Carter DC, editors. Diseases of the gastrointestinal tract and liver. 3rd edn. Edinburgh: Churchill Livingstone; 1997. pp. 1097-1114
4. Smith J. Redesigning health care. BMJ 2001;322:1257-1258
5. Gandhi TK, Puopolo AL, Dasse P, Haas JS, Burstin HR, Cook EF, et al. Obstacles to collaborative quality improvement: the case of ambulatory general medical care. Int J Qual Health Care 2000;12:115-123 (Pubitemid 30262227)
6. Kerr FA, Krein SL, Vijan S, Hofer TP, Hayward RA. Avoiding pitfalls in chronic disease quality measurement: a case for the next generation of technical quality measures. Am J Manag Care 2001;7:1033-1043 (Pubitemid 33080954)
7. Bellentani S, Tiribelli C, Saccoccio G, Sodde M, Fratti N, Martin D, et al. Dionysus Study Group. Prevalence of chronic liver disease in the general population of north Italy - the Dionysus study. Hepatology 1994:20;1442-1449
8. Futatsuka M, Kitano T, Nagano M, Inaokat T, Arimatsu Y, Ueno T, et al. An epidemiological study with risk analysis of liver disease in the general population living in a methyl mercury polluted area. J Epidemiol Commun Health 1992;46:237-240
9. Sorensen HT, Moller-Petersen JF, Felding P, Andreasen C, Nielsen JO. Epidemiology of abnormal liver function tests in general practice in a defined population in Denmark. Dan Med Bull 1991;38:420-422
10. Almdal TP, Sorensen TIA. Danish Association for the Study of the Liver. Incidence of parenchymal liver disease in Denmark. 1981 to 1985: analysis of hospitalised registry data. Hepatology 1991;3:650-655
11. Duh M, Walker A, Kronlund K. Descriptive epidemiology of acute liver enzyme abnormalities in the general population of central Massachusetts. Pharmacoepidemiology Drug Safety 1999;8:275-283 (Pubitemid 29358553)
12. Kim HC, Nam CM, Jee SH, Han KH, Oh DK, Suh I. Normal serum aminotransferase concentration and risk of mortality from liver disease: prospective cohort study. BMJ 2004;328:983-986 (Pubitemid 38530367)
13. Roderick P. Commentary: liver function tests: defining what's normal. BMJ 2004;328:987.
14. Sherwood P, Lyburn I, Brown S, Ryder S. How are abnormal results for liver function tests dealt with in primary care? Audit of yield and impact. BMJ 2001;322:276-278 (Pubitemid 32178555)
15. Evans JMM, MacDonald TM. Record-linkage for pharmacovigilance in Scotland. Br J Clin Pharmacol 1999;47:105-110
16. Steinke D, Weston T, Morris A, MacDonald T, Dillon J. The epidemiology of liver disease in Tayside (ELDIT) database: a population based record linkage study. J Biomed Informatics 2003;35:186-193
17. Donnan PT, Wei L, Steinke DT, Phillips G, Clarke R, Noone A, et al. Presence of bacteriuria caused by trimethoprim resistant bacteria in patients prescribed antibiotics: multilevel model with practice and individual patient data. BMJ 2004;328:1297-1301
18. McLone P. Carstairs codes for Scottish postcode sectors from the 1991 census. Glasgow Public Health Unit, University of Glasgow, 1994.
19. Steinke DT, Weston TL, Morris AD, MacDonald TM, Dillon JF. Epidemiology and economic burden of viral hepatitis: an observational population based study. Gut 2002;50:100-105
20. Hosmer DW, Lemeshow S. Applied survival analysis; regression modelling of time to event data. New York: John Wiley and Sons; 1999.
21. Aalen OO. Effects of frailty in survival analysis. Stat Methods Med Res 1994;3:227-243
22. Anderson KM. A non-proportional hazards Weibull accelerated failure time model. Biometrics 1991;47:281-288
23. Donnan PT, Donnelly L, New J, Morris AM. Predicting the absolute risk of major coronary heart disease (CHD) events in type 2 diabetes in the United Kingdom population. Diabetes Care 2006;29:1231-1236
24. Morris AD, Boyle DIR, MacAlpine R, Emslie-Smith A, Jung RT, Newton RW, et al. The Diabetes Audit and Research in Tayside Scotland (DARTS) Study: electronic record linkage to create a district diabetes register. BMJ 1997;315:524-528 (Pubitemid 27359106)
25. Donnan PT, Dougall HT, Sullivan F. Optimal strategies for identifying patients with myocardial infarction in general practice. Family Pract 2003;20:706-710 (Pubitemid 38054721)
26. Donnan PT, McLernon D, Steinke D, Ryder S, Roderick P, Sullivan F, et al. Development of a decision support tool to facilitate primary care management of patients with abnormal liver function tests without clinically apparent liver disease. BMC Health Serv Res 2007;7:54.
27. The Health Informatics Centre. Dundee; 2007. URL: www.dundee.ac.uk/hic.
28. Begg CB, Greenes RA. Assessment of diagnostic tests when disease verification is subject to selection bias. Biometrics 1983;39:207-215
29. McLernon DJ, Donnan PT, Gray M, Weller D, Sullivan F. Receiver operating characteristics of the prostate specific antigen test in an unselected population. J Med Screen 2006;13:102-107 (Pubitemid 43925926)
30. Rubin DB. Multiple imputation for nonresponse in surveys. New York: Wiley; 1987.
31. Prati D, Taioli E, Zanella A, Della Tore E, Butelli S, Del Vecchio E, et al. Updated definitions of healthy ranges for serum alanine aminotransferase levels. Ann Intern Med 2002;137:1-9. (Pubitemid 34705370)
32. Schalk BWM, Visser M, Bremmer MA, Penninx BWJH, Bouter LM, Deeg DJH. Change of serum albumin and risk of cardiovascular disease and all-cause mortality: longitudinal aging study Amsterdam. Am J Epidemiol 2006;164:969-977 (Pubitemid 44729838)
33. Soriano S, Gonzalez L, Martin-Malo A, Rodriguez M, Aljama P. C-reactive protein and low albumin are predictors of morbidity and cardiovascular events in chronic kidney disease (CKD) 3-5 patients. Clin Nephrol 2007;67:352-357 (Pubitemid 46894799)
34. Fitzmaurice GM, Laird NM, Ware JH. Applied longitudinal analysis. New York: Wiley; 2004.
35. Schwarz G. Estimating the dimension of a model. Ann Stat 1978;6:461-464
36. Pencina MJ, D'Agostino RB. Overall c as a measure of discrimination in survival analysis model specific population value and confidence interval estimation. Stat Med 2004; 23:2109-23. 2004.
37. Chambless LE, Diao G. Estimation of time-dependent area under the ROC curve for long-term risk prediction. Stat Med 2006;25:3474-3486
38. Anderson KM, Odell PM, Wilson PWF, Kannel WB. Cardiovascular disease risk profiles. Am Heart J 1990;121:293-298
39. May S, Hosmer DW. A simplified method of calculating an overall goodness-of-fit test for the Cox proportional hazards model. Lifetime Data Anal 1998;4:109-120 (Pubitemid 128480552)
40. D'Agostino RB Sr, Grundy S, Sullivan LM, Wilson P, for the CHD risk prediction group. Validation of the Framingham coronary heart disease prediction scores. JAMA 2001;286:180-187
41. Petitti DB. Meta-analysis, decision analysis and cost-effectiveness. New York: Oxford University Press; 2000.
42. Cordoba J, Flavia M, Jacas C, Sauleda S, Esteban JI, Vargas V. Quality of life and cognitive function in hepatitis C at different stages of liver disease. J Hepatol 2003;39:231-238 (Pubitemid 36920559)
43. Foster G, Goldin R, Thomas H. Chronic hepatitis C virus infection causes a significant reduction in quality of life in the absence of cirrhosis. Hepatology 1998;27:209-212
44. Hussain KB, Fontana RJ, Moyer CA, Su GL, Sneed- Pee N, Lok AS. Comorbid illness is an important determinant of health-related quality of life in patients with chronic hepatitis C. Am J Gastroenterol 2001;96:2737-2744
45. Poupon RE, Chretien Y, Chazouilleres O, Poupon R, Chwalow J, French-PBC Study Group. Quality of life in patients with primary biliary cirrhosis. Hepatology 2004;40:489-494 (Pubitemid 39062868)
46. Torrance GW, Feeny DH, Furlong W. Multiattribute utility function for a comprehensive health status classification system: health utilities index mark 2. Med Care 1996;34:702-722 (Pubitemid 126433265)
47. Torrance GW. Measurement of health state utilities for economic appraisal. J Health Econ 1986;5:1-30. (Pubitemid 16098443)
48. The EuroQol Group. EuroQol: a new facility for the measurement of health-related quality of life. Health Policy 1990;16:199-208.
49. Brazier J, Roberts J, Deverill M. The estimation of a preference-based measure of health from the SF-36. J Health Econ 2002;21:271-292 (Pubitemid 34143147)
50. Wong JB, Bennett WG, Koff RS, Pauker SG. Pretreatment evaluation of chronic hepatitis C: risks, benefits and costs. JAMA 1998;280:2088-2093
51. Post PN, Stiggelbout AM, Wakker PP. The utility of health states after stroke. A systematic review of the literature. Stroke 2001;32:1425-1429
52. Tengs TO, Lin TH. A meta-analysis of utility estimates for HIV/AIDS. Med Decis Making 2002;22:475-481
53. Tengs TO, Lin TH. A meta-analysis of quality-of- life estimates for stroke. Pharmacoeconomics 2003;21:191-200.
54. Bremner KE, Chong CAKY, Tomlinson G. A review and meta-analysis of prostate cancer utilities. Med Decis Making 2007;27:288-298 (Pubitemid 46801746)
55. Egger M, Smith GD, Altman DG. Systematic reviews in health care: meta-analysis in context. London: BMJ Books; 2001.
56. Kalaian HA, Raudenbush SW. A mulitivariate mixed linear model for meta-analysis. Psychol Methods 1996;1:227-235
57. Younossi ZM, Boparai N, McCormick M, Price LL, Guyatt G. Assessment of utilities and health-related quality of life in patients with chronic liver disease. Am J Gastroenterol 2001;96:579-583
58. Jacobs RJ, Moleski RJ, Meyerhoff AS. Valuation of symptomatic hepatitis A in adults: estimates based on time trade-off and willingness-to-pay measurement. Pharmacoeconomics 2002;20:739-747
59. Crowley S, Tognarini D, Desmond P, Lees M, Saal G. Introduction of lamivudine for the treatment of chronic hepatitis B: expected clinical and economic outcomes based on 4-year clinical trial data. J Gastroenterol Hepatol 2002;17:153-164 (Pubitemid 34415668)
60. Owens DK, Cardinalli AB, Nease RF Jr. Physicians' assessments of the utility of health states associated with human immunodeficiency virus (HIV) and hepatitis B virus (HBV) infection. Qual Life Res 1997;6:77-86.
61. Dusheiko GM, Roberts JA. Treatment of chronic type B and C hepatitis with interferon alfa: an economic appraisal. [see comment] Hepatology 1995;22:1863-1873.
62. Wong JB, Koff RS, Tine F, Pauker SG. Cost-effectiveness of interferon-alpha 2b treatment for hepatitis B e antigen-positive chronic hepatitis B. [see comment] Ann Intern Med 1995;122:664-675
63. Chong CA, Gulamhussein A, Heathcote EJ, Sherman M, Naglie G, Krahn M. Health-state utilities and quality of life in hepatitis C patients. [see comment] Am J Gastroenterol 2003;98:630-638 (Pubitemid 36348537)
64. Gutteling JJ, De Man RA, Van Der Plas SM, Schalm SW, Busschbach JJV, Darlington ASE. Determinants of quality of life in chronic liver patients. Aliment Pharmacol Ther 2006;23:1629-1635 (Pubitemid 43727472)
65. Patil R, Cotler SJ, Banaad-Omiotek G, McNutt RA, Brown MD, Cotler S, et al. Physicians' preference values for hepatitis C health states and antiviral therapy: a survey. BMC Gastroenterol 2001;1:6. (Pubitemid 38750972)
66. Sherman KE, Sherman SN, Chenier T, Tsevat J. Health values of patients with chronic hepatitis C infection. Arch Intern Med 2004;164:2377-2382 (Pubitemid 39532251)
67. Siebert U, Ravens-Sieberer U, Greiner W, Sroczynski G, Wong JB, Kallinowski B, et al. Patient-based health-related quality of life in different health stages of chronic hepatitis C. Hepatology 2001;44:222A.
68. Siebert U, Sroczynski G, Rossol S, Wasem J, Ravens- Sieberer J, Kurth BM, et al. Cost effectiveness of peginterferon a-2b plus ribavirin versus interferon a-2b plus ribavirin for initial treatment of chronic hepatitis C. Gut 2003;52:425-432
69. Wright M, Grieve R, Roberts J, Main J, Thomas HC. Health benefits of antiviral therapy for mild chronic hepatitis C: randomised controlled trial and economic evaluation. Health Technol Assess 2006;10(21).
70. Saab S, DeRosa V, Nieto J, Durazo F, Han S, Roth B. Costs and clinical outcomes of primary prophylaxis of variceal bleeding in patients with hepatitis cirrhosis: a decision analytic model. Am J Gastroenterol 2003;98:763-770 (Pubitemid 36576299)
71. Unal G, De Boer JB, Borsboom GJ, Brouwer JT, Essink-Bot M, De Man RA. A psychometric comparison of health-related quality of life measures in chronic liver disease. J Clin Epidemiol 2001;54:587-596 (Pubitemid 32453352)
72. Wells CD, Murrill WB, Arguedas MR. Comparison of health-related quality of life preferences between physicians and cirrhotic patients: implications for cost-utility analyses in chronic liver disease. Dig Dis Sci 2004;49:453-458
73. Longworth L, Bryan S. An empirical comparison of EQ-5D and SF-6D in liver transplant patients. Health Econ 2003;12:1061-1067 (Pubitemid 38035310)
74. Ratcliffe J, Longworth L, Young T, Bryan S, Burroughs A, Buxton M. Assessing health-related quality of life pre- and post-liver transplantation: a prospective multicenter study. Liver Transpl 2002;8:263-270 (Pubitemid 34257209)
75. Ratcliffe J, Young T, Longworth L, Buxton M. An assessment of the impact of informative dropout and nonresponse in measuring health-related quality of life using the EuroQol (EQ-5D) descriptive system. Value Health 2005;8:53-58 (Pubitemid 40293641)
76. Bryan S, Ratcliffe J, Neuberger JM, Burroughs AK, Gunson BK, Buxton MJ. Health-related quality of life following liver transplantation. Qual Life Res 1998;7:115-120 (Pubitemid 28097898)
77. Lewis MB, Howdle PD. Cognitive dysfunction and health-related quality of life in long-term liver transplant survivors. [see comment] Liver Transpl 2003;9:1145-1148
78. Midgley DE, Bradlee TA, Donohoe C, Kent KP, Alonso EM. Health-related quality of life in long-term survivors of pediatric liver transplantation. [see comment] Liver Transpl 2000;6:333-339
79. Krabbe PF, Peerenboom L, Langenhoff BS, Ruers TJ. Responsiveness of the generic EQ-5D summary measure compared to the disease-specific EORTC QLQ C-30. Qual Life Res 2004;13:1247-1253 (Pubitemid 39149608)
80. Bryce CL, Angus DC, Switala J, Roberts MS, Tsevat J. Health status versus utilities of patients with end-stage liver disease. Qual Life Res 2004;13:773-782 (Pubitemid 38509977)
81. Adams PC, Kertesz AE, Valberg LS. Screening for hemochromatosis in children of homozygotes: prevalence and cost-effectiveness. Hepatology 1995;22:1720-1727
82. Zug KA, Littenberg B, Baughman RD, Kneeland T, Nease RF, Sumner W, et al. Assessing the preferences of patients with psoriasis. A quantitative utility approach. Arch Dermatol 1995;131:561-568
83. Hessel FP, Mitzner SR, Rief J, Gress S, Guellstorff B, Wasem J. Economic evaluation of MARS - preliminary results on survival and quality of life. Liver 2002;22(Suppl 2):26-29
84. Bennett WG, Inoue Y, Beck JR, Wong JB, Pauker SG, Davis GL. Estimates of the cost-effectiveness of a single course of interferon-a2b in patients with histologically mild chronic hepatitis C. Ann Intern Med 1997;127:855-865 (Pubitemid 27490622)
85. Kim WR, Poterucha JJ, Hermans JE, Therneau TM, Dickson ER, Evans RW, et al. Cost-effectiveness of 6 and 12 months of interferon-alpha therapy for chronic hepatitis C. Ann Intern Med 1997;127:866-874 (Pubitemid 27490623)
86. McLernon D, Dillon JF, Donnan PT. Health-state utilities in liver disease: a systematic review. Med Decis Making 2008;28:582-592
87. Hawthorne G, Richardson J, Osborne R. The assessment of quality of life (AQoL) instrument: a psychometric measure of health-related quality of life. Qual Life Res 1999;8:209-224 (Pubitemid 29367290)
88. Milholland AV, Wheeler SG, Heieck JJ. Medical assessment by a Delphi group opinion technic. N Engl J Med 1973;288:1272-1275
89. Conner-Spady B, Suarez-Almazor ME. Variation in the estimation of quality-adjusted life-years by different preference-based instruments. Med Care 2003;41:791-801.
90. Kopec JA, Willison KD. A comparative review of four preference-weighted measures of health-related quality of life. J Clin Epidemiol 2003;56:317-325 (Pubitemid 36593310)
91. Marra CA, Esdaile JM, Guh D, Kopec JA, Brazier JE, Koehler BE, et al. A comparison of four indirect methods of assessing utility values in rheumatoid arthritis. Med Care 2004;42:1125-1131 (Pubitemid 39472119)
92. Szende A, Svensson K, Stahl E, Meszaros A, Berta GY. Psychometric and utility-based measures of health status of asthmatic patients with different disease control level. Pharmacoeconomics 2004;22:537-547 (Pubitemid 38858296)
93. Froberg DG, Kane RL. Methodology for measuring health-state preferences - II: scaling methods. J Clin Epidemiol 1989;42:459-471 (Pubitemid 19165912)
94. Panel on Cost-effectiveness in Health Medicine. Appendix A: Summary recommendations. In Gold M, Siegel J, Russell L, Weinstein M, editors. Cost-effectiveness in health and medicine. New York: Oxford University Press; 1996. pp. 304-311
95. Stiggelbout AM, De Haes JCJM. Patient preferences for cancer therapy: an overview of measurement approaches. J Clin Oncol 2001;19:220-230
96. Inoue Y. Medical economics - hepatitis C virus infection and cost-effectiveness of interferon therapy. Hepatol Res 2002;24(Suppl 1):57-67. (Pubitemid 40013708)
97. Stein K, Rosenberg W, Wong J. Cost effectiveness of combination therapy for hepatitis C: a decision analytic model. Gut 2002;50:253-258 (Pubitemid 34087941)
98. Grieve R, Roberts J, Wright M, Sweeting M, DeAngelis D, Rosenberg W, et al. Cost effectiveness of interferon alpha or peginterferon alpha with ribavirin for histologically mild chronic hepatitis C. Gut 2006;55:1332-1338 (Pubitemid 44277366)
99. Sonnenberg FA, Beck JR. Markov models in medical decision making: a practical guide. Med Decis Making 1993;13:322-338
100. Curtis L, Netten A. Unit costs of health and social care 2006. Canterbury: Personal Social Services Research Unit (PSSRU); 2006.
101. Shepherd J, Jones J, Takeda A, Davidson P, Price A. Adefovir dipivoxil and pegylated interferon alfa-2a for the treatment of chronic hepatitis B: a systematic review and economic evaluation. Health Technol Assess 2006;10(28).
102. Arguedas MR, Chen VK, Eloubeidi MA, Fallon MB. Screening for hepatocellular carcinoma in patients with hepatitis C cirrhosis: a cost-utility analysis. Am J Gastroenterol 2003;98:679-690 (Pubitemid 36348544)