title: Adjusting for patient demographics has minimal effects on rates of adenoma detection in a large, community-based setting.
abstract: OBJECTIVE
  Reliable estimates of adenoma detection rates (ADRs) are needed to inform colonoscopy quality standards, yet little is known about the contributions of patient demographics to variation in ADRs. We evaluated the effects of adjusting for patient age, race/ethnicity, and family history of colorectal cancer on variations in ADRs and the relative rank order of physicians.
  
  
  METHODS
  In a retrospective cohort study, we collected data from Kaiser Permanente Northern California members who were ≥ 50 years old who received colonoscopies from 2006 through 2008. We evaluated ADRs (before and after adjustment for age, sex, race/ethnicity, and family history of colorectal cancer) for 102 endoscopists who performed 108,662 total colonoscopies and 20,792 screening colonoscopies. Adenomas were identified from the pathology database, and cancers were detected by using the Kaiser Permanente Northern California cancer registry.
  
  
  RESULTS
  About two-thirds of examiners had unadjusted ADRs for screening exams that met gastroenterology society guidelines (>25% for men and >15% for women), although rates of detection varied widely (7.7%-61.5% for male patients and 1.7%-45.6% for female patients). Adjusting for case mix reduced the variation in detection rates (from 8-fold to 3-fold for male patients and from 27-fold to 5-fold for female patients), but the median change in physician order by detection rate was just 2 ranks, and few physicians changed quartiles of detection. For example, only 3 of 102 endoscopists moved into and 3 out of the lowest quartile of ADR.
  
  
  CONCLUSIONS
  In a community-based setting, most endoscopists met the ADR standards, although there was wide variation in ADRs, which was similar to that reported from academic and referral settings. Case-mix adjustment reduced variability but had only small effects on differences in ADRs between physicians, and only a small percentage of physicians changed quartiles of detection. Adjustments to ADRs are therefore likely only needed in settings in which physicians have very different patient demographics, such as in sex or age. Moderate differences in patient demographics between physicians are unlikely to substantially change rates of adenoma detection.
authors.affiliation: Kaiser Permanente Division of Research, Oakland, California.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Jensen
authors.affiliation: Kaiser Permanente Division of Research, Oakland, California.
authors.forename: Chyke A
authors.initials: CA
authors.lastname: Doubeni
authors.affiliation: Kaiser Permanente Division of Research, Oakland, California.
authors.forename: Virginia P
authors.initials: VP
authors.lastname: Quinn
authors.affiliation: Kaiser Permanente Division of Research, Oakland, California.
authors.forename: Theodore R
authors.initials: TR
authors.lastname: Levin
authors.affiliation: Kaiser Permanente Division of Research, Oakland, California.
authors.forename: Ann G
authors.initials: AG
authors.lastname: Zauber
authors.affiliation: Kaiser Permanente Division of Research, Oakland, California.
authors.forename: Joanne E
authors.initials: JE
authors.lastname: Schottinger
authors.affiliation: Kaiser Permanente Division of Research, Oakland, California.
authors.forename: Amy R
authors.initials: AR
authors.lastname: Marks
authors.affiliation: Kaiser Permanente Division of Research, Oakland, California.
authors.forename: Wei K
authors.initials: WK
authors.lastname: Zhao
authors.affiliation: Kaiser Permanente Division of Research, Oakland, California.
authors.forename: Jeffrey K
authors.initials: JK
authors.lastname: Lee
authors.affiliation: Kaiser Permanente Division of Research, Oakland, California.
authors.forename: Nirupa R
authors.initials: NR
authors.lastname: Ghai
authors.affiliation: Kaiser Permanente Division of Research, Oakland, California.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Schneider
authors.affiliation: Kaiser Permanente Division of Research, Oakland, California.
authors.forename: Bruce H
authors.initials: BH
authors.lastname: Fireman
authors.affiliation: Kaiser Permanente Division of Research, Oakland, California.
authors.forename: Charles P
authors.initials: CP
authors.lastname: Quesenberry
authors.affiliation: Kaiser Permanente Division of Research, Oakland, California. Electronic address: Douglas.Corley@kp.org.
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Corley
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000453:epidemiology; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002140:California / Q000453:epidemiology; D015331:Cohort Studies; D003113:Colonoscopy / Q000379:methods*; D055088:Early Detection of Cancer / Q000379:methods; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D006302:Health Services Research; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
keywords: Colon Cancer; Endoscopy; Neoplasm; Polyp