title: Hospital episodes and physician visits: the concordance between self-reports and medicare claims.
abstract: BACKGROUND
  Health services use typically is examined using either self-reports or administrative data, but the concordance between the 2 is not well established.
  
  
  OBJECTIVE
  We evaluated the concordance of hospital and physician utilization data from self-reports and claims data, and identified factors associated with disagreement.
  
  
  METHODS
  We performed a secondary analysis on linked observational and administrative data. A national sample of 4310 respondents who were 70 years old or older at their baseline interviews was used. Self-reported and Medicare claims-based hospital episodes and physician visits for 12 months before baseline were examined. Kappa statistics were used to evaluate concordance, and multivariable multinomial logistic regression was used to identify factors associated with overreporting (self-reports > claims), underreporting (self-reports < claims), and concordant-reporting (self-reports approximately claims).
  
  
  RESULTS
  The concordance of hospital episodes was high (kappa = 0.767 for the 2 x 2 comparison of none vs. some and kappa = 0.671 for the 6 x 6 comparison of none, 1, ..., 4, or 5 or more), but concordance for physician visits was low (kappa = 0.255 for the 2 x 2 comparison of none versus some and kappa = 0.351 for the 14 x 14 comparison of none, 1, ..., 12, and 13 or more). Multivariable multinomial logistic regression indicated that over-, under-, and concordant-reporting of hospital episodes was significantly associated with gender, alcohol consumption, arthritis, cancer, heart disease, psychologic problems, lower body functional limitations, self-rated health, and depressive symptoms. Over-, under-, and concordant-reporting of physician visits were significantly associated with age, gender, race, living alone, veteran status, private health insurance, arthritis, cancer, diabetes, hypertension, heart disease, lower body functional limitations, and poor memory.
  
  
  CONCLUSIONS
  Concordance between self-reported and claims-based hospital episodes was high, but concordance for physician visits was low. Factors significantly associated with bidirectional (over- and underreporting) and unidirectional (over- or underreporting) error patterns were detected. Therefore, caution is advised when drawing conclusions based on just one physician visit data source.
authors.affiliation: Iowa City VA Health Care System, Iowa City, Iowa, USA. fredric-wolinsky@uiowa.edu
authors.forename: Fredric D
authors.initials: FD
authors.lastname: Wolinsky
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Miller
authors.forename: Hyonggin
authors.initials: H
authors.lastname: An
authors.forename: John F
authors.initials: JF
authors.lastname: Geweke
authors.forename: Robert B
authors.initials: RB
authors.lastname: Wallace
authors.forename: Kara B
authors.initials: KB
authors.lastname: Wright
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Chrischilles
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.forename: Claire B
authors.initials: CB
authors.lastname: Pavlik
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Cook
authors.forename: Robert L
authors.initials: RL
authors.lastname: Ohsfeldt
authors.forename: Kelly K
authors.initials: KK
authors.lastname: Richardson
authors.forename: Gary E
authors.initials: GE
authors.lastname: Rosenthal
mesh_terms: D000368:Aged; D014487:Centers for Medicare and Medicaid Services, U.S.; D017050:Episode of Care; D005260:Female; D006760:Hospitalization; D006801:Humans; D007345:Insurance Claim Review; D007407:Interviews as Topic; D008297:Male; D010820:Physicians / Q000706:statistics & numerical data*; D011785:Quality Assurance, Health Care / Q000379:methods*; D012650:Self Disclosure; D014481:United States