title: Difference in performance of fecal immunochemical tests with the same hemoglobin cutoff concentration in a nationwide colorectal cancer screening program.
abstract: OBJECTIVE
  We investigated whether 2 quantitative fecal immunochemical tests (FITs) with the same cutoff concentration of fecal hemoglobin perform equivalently in identifying patients with colorectal cancer (CRC).
  
  
  METHODS
  A total of 956,005 Taiwanese subjects, 50 to 69 years old, participated in a nationwide CRC screening program to compare results from 2 FITs; 78% were tested using the OC-Sensor (n = 747,076; Eiken Chemical Co, Tokyo, Japan) and 22% were tested using the HM-Jack (n = 208,929; Kyowa Medex Co Ltd, Tokyo, Japan), from 2004 through 2009. The cutoff concentration for a positive finding was 20 μg hemoglobin/g feces, based on a standardized reporting unit system. The tests were compared using short-term and long-term indicators of performance.
  
  
  RESULTS
  The OC-Sensor test detected CRC in 0.21% of patients, with a positive predictive value of 6.8%. The HM-Jack test detected CRC in 0.17% of patients, with a positive predictive value of 5.2%. The rate of interval cancer rate was 30.7/100,000 person-years among subjects receiving the OC-Sensor test and 40.6/100,000 person-years among those receiving the HM-Jack test; there was significant difference in test sensitivity (80% vs 68%, P = .005) that was related to the detectability of proximal CRC. After adjusting for differences in city/county, age, sex, ambient temperature, and colonoscopy quality, significant differences were observed between the tests in the positive predictive value for cancer detection (adjusted relative risk = 1.29; 95% confidence interval, 1.14-1.46) and the rates of interval cancer (0.75; 95% confidence interval, 0.62-0.92). Although each test was estimated to reduce CRC mortality by approximately 10%, no significant difference in mortality was observed when the 2 groups were compared.
  
  
  CONCLUSIONS
  Different brands of quantitative FITs, even with the same cutoff hemoglobin concentration, perform differently in mass screening. Population-level data should be gathered to verify the credibility of quantitative laboratory findings.
authors.affiliation: Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Integrated Diagnostics and Therapeutics, National Taiwan University Hospital, Taipei, Taiwan; Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Tsung-Hsien
authors.initials: TH
authors.lastname: Chiang
authors.affiliation: Graduate Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Shu-Lin
authors.initials: SL
authors.lastname: Chuang
authors.affiliation: School of Oral Hygiene, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Sam Li-Sheng
authors.initials: SL
authors.lastname: Chen
authors.affiliation: Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; Graduate Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Han-Mo
authors.initials: HM
authors.lastname: Chiu
authors.affiliation: School of Oral Hygiene, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Amy Ming-Fang
authors.initials: AM
authors.lastname: Yen
authors.affiliation: Department and Graduate Institute of Health Care Management, Chang Gung University, Tao-Yuan, Taiwan.
authors.forename: Sherry Yueh-Hsia
authors.initials: SY
authors.lastname: Chiu
authors.affiliation: Department of Health Industry Management, Kainan University, Tao-Yuan, Taiwan.
authors.forename: Jean Ching-Yuan
authors.initials: JC
authors.lastname: Fann
authors.affiliation: Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; Division of Gastroenterology and Hepatology, Chia-Yi Christian Hospital, Chia-Yi, Taiwan.
authors.forename: Chu-Kuang
authors.initials: CK
authors.lastname: Chou
authors.affiliation: Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; Graduate Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan. Electronic address: yichialee@ntu.edu.tw.
authors.forename: Yi-Chia
authors.initials: YC
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Ming-Shiang
authors.initials: MS
authors.lastname: Wu
authors.affiliation: Graduate Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Hsiu-Hsi
authors.initials: HH
authors.lastname: Chen
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000453:epidemiology; D000368:Aged; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000401:mortality; D005243:Feces / Q000737:chemistry*; D005260:Female; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D007120:Immunochemistry / Q000379:methods / Q000706:statistics & numerical data; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008403:Mass Screening / Q000379:methods* / Q000706:statistics & numerical data; D008875:Middle Aged; D008954:Models, Biological; D009780:Occult Blood; D011237:Predictive Value of Tests; D012017:Referral and Consultation / Q000706:statistics & numerical data; D012307:Risk Factors; D012680:Sensitivity and Specificity
chemical_list: D006454:Hemoglobins
keywords: Colorectal Cancer; Interval Cancer; Population Screening; Screening Test Sensitivity