title: Identification of the physician workforce providing palliative care in Ontario using administrative claims data.
abstract: BACKGROUND
  Little is known about the physician workforce providing palliative care in Canada, and in Ontario specifically. We developed an algorithm to identify palliative care physicians using administrative claims data and validated it against a reference sample. We then applied the algorithm to all general practitioners/family physicians (GP/FPs) in the province of Ontario to describe and quantify those identified by the algorithm.
  
  
  METHODS
  W e reviewed Ontario Health Insurance Plan claims from Jan. 1, 2008, to Dec. 31, 2011, to determine each physician's proportion of claims that were for palliative care. We empirically selected a data-driven cut-off, whereby physicians whose proportion of palliative care claims was above the threshold were defined as palliative care physicians. We validated the cut-off against a reference sample of physicians who self-identified as providing mostly palliative care in a study-specific survey. We then applied this algorithm to all GP/FPs in the province.
  
  
  RESULTS
  We empirically selected 10% as the cut-off for the proportion of palliative care claims. This threshold had exceptional specificity and positive predictive value (97.8% and 90.5%, respectively) and adequate sensitivity (76.0%) when compared with the reference sample (n = 118). When applied to all GP/FPs in the province, the algorithm identified 276 practising mostly palliative care. Of these, 135 (48.9%) were women, 265 (96.0%) practised in urban locations, and 145 (52.5%) worked part time.
  
  
  CONCLUSIONS
  Our algorithm readily identified and quantified the workforce of palliative care physicians in Ontario. Such a tool has numerous applications for both health service planners and researchers.
authors.affiliation: Department of Radiation Oncology, University of Toronto, Toronto, Ont. ; Institute for Clinical Evaluative Sciences, Toronto, Ont.
authors.forename: Lisa
authors.initials: L
authors.lastname: Barbera
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ont.
authors.forename: Jeremiah
authors.initials: J
authors.lastname: Hwee
authors.affiliation: Department of Medicine, University of Ottawa, Ottawa, Ont.
authors.forename: Christopher
authors.initials: C
authors.lastname: Klinger
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ont.
authors.forename: Nathaniel
authors.initials: N
authors.lastname: Jembere
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ont. ; Department of Oncology, McMaster University, Hamilton, Ont.
authors.forename: Hsien
authors.initials: H
authors.lastname: Seow
authors.affiliation: Department of Medicine, University of Ottawa, Ottawa, Ont. ; Bruyère Research Institute, Ottawa, Ont.
authors.forename: José
authors.initials: J
authors.lastname: Pereira