title: Estimating the completeness of physician billing claims for diabetes case ascertainment using population-based prescription drug data.
abstract: BACKGROUND
  Changes in physician reimbursement policies may hinder the collection of billing claims in administrative data; this can result in biased estimates of disease prevalence and incidence. However, the magnitude of data loss is largely unknown. The purpose of this study was to estimate completeness of capture of disease cases for Manitoba physicians paid by fee-for-service (FFS) and non-fee-for-service (NFFS) methods.
  
  
  METHODS
  Manitoba's administrative data were used to identify a cohort (≥ 20 years) with a new diabetes medication between 1 April, 2007, and 31 March, 2009. Cohort members were classified by payment method of the prescribing physician (i.e. FFS vs. NFFS). The cohort was then classified as missing or not missing a diabetes diagnosis using physician claims and hospital records. Then, χ2 statistics were used to test for differences in the characteristics of the two groups.
  
  
  RESULTS
  The cohort consisted of 12 394 individuals; 86.4% had a prescription for a diabetes medication from an FFS physician. A total of 1172 physicians (81.8% FFS) prescribed these medications for the cohort. Cohort members with a prescription from an FFS physician were older and more likely to reside in the urban Winnipeg health region than those with a prescription from a NFFS physician. A greater percentage of NFFS physicians' cases were missing a diabetes diagnosis (18.7%vs. 14.9% for FFS physicians).
  
  
  CONCLUSIONS
  The results suggest minimal loss of physician claims associated with remuneration policies in Manitoba. This method of assessing data completeness could be applied to other chronic diseases and jurisdictions to estimate completeness.
authors.affiliation: Department of Community Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: L M
authors.initials: LM
authors.lastname: Lix
authors.affiliation: Department of Community Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: J P
authors.initials: JP
authors.lastname: Kuwornu
authors.affiliation: Department of Community Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: K
authors.initials: K
authors.lastname: Kroeker
authors.affiliation: Department of Community Health and Epidemiology, Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Kephart
authors.affiliation: Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada.
authors.forename: K C
authors.initials: KC
authors.lastname: Sikdar
authors.affiliation: Manitoba Centre for Health Policy, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Smith
authors.affiliation: Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada.|Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Quan
mesh_terms: D000328:Adult; D003920:Diabetes Mellitus / Q000191:economics / Q000453:epidemiology / Q000628:therapy; D018588:Fee-for-Service Plans / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007345:Insurance Claim Review; D008297:Male; D008350:Manitoba / Q000453:epidemiology; D008875:Middle Aged; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D055553:Prescription Drugs / Q000627:therapeutic use; D015995:Prevalence; D012959:Socioeconomic Factors
chemical_list: D007004:Hypoglycemic Agents; D055553:Prescription Drugs
keywords: chronic disease; data quality; medical records; surveillance