title: Physician Service Attribution Methods for Examining Provision of Low-Value Care.
abstract: OBJECTIVE
  There has been significant research on provider attribution for quality and cost. Low-value care is an area of heightened focus, with little of the focus being on measurement; a key methodological decision is how to attribute delivered services and procedures. We illustrate the difference in relative and absolute physician- and panel-attributed services and procedures using overuse in cervical cancer screening.
  
  
  METHODS
  A retrospective, cross-sectional study in an integrated health care system.
  
  
  METHODS
  We used 2013 physician-level data from Group Health Cooperative to calculate two utilization attributions: (1) panel attribution with the procedure assigned to the physician's predetermined panel, regardless of who performed the procedure; and (2) physician attribution with the procedure assigned to the performing physician. We calculated the percentage of low-value cervical cancer screening tests and ranked physicians within the clinic using the two utilization attribution methods.
  
  
  RESULTS
  The percentage of low-value cervical cancer screening varied substantially between physician and panel attributions. Across the whole delivery system, median panel- and physician-attributed percentages were 15 percent and 10 percent, respectively. Among sampled clinics, panel-attributed percentages ranged between 10 percent and 17 percent, and physician-attributed percentages ranged between 9 percent and 13 percent. Within a clinic, median panel-attributed screening percentage was 17 percent (range 0 percent-27 percent) and physician-attributed percentage was 11 percent (range 0 percent-24 percent); physician rank varied by attribution method.
  
  
  CONCLUSIONS
  The attribution method is an important methodological decision when developing low-value care measures since measures may ultimately have an impact on national benchmarking and quality scores. Cross-organizational dialogue and transparency in low-value care measurement will become increasingly important for all stakeholders.
authors.affiliation: RTI International.
authors.forename: Eva
authors.initials: E
authors.lastname: Chang
authors.affiliation: Group Health Research Institute, Group Health Cooperative.
authors.forename: Diana Sm
authors.initials: DS
authors.lastname: Buist
authors.affiliation: Group Health Physicians.
authors.forename: Matthew
authors.initials: M
authors.lastname: Handley
authors.affiliation: Group Health Research Institute, Group Health Cooperative.
authors.forename: Roy
authors.initials: R
authors.lastname: Pardee
authors.affiliation: RTI International.
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Gundersen
authors.affiliation: Group Health Research Institute, Group Health Cooperative; Trillium Health Partners - Institute for Better Health.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Reid
keywords: Informatics; Learning Health System; Quality measurement