title: Development of a practice-based patient cohort for primary care research.
abstract: OBJECTIVE
  Efforts to develop "laboratories" for primary care research have largely focused on the development of networks that recruit subjects on a project-specific basis. We sought to develop an alternative model--a representative cohort of adult primary care patients maintained for use in multiple projects.
  
  
  METHODS
  In 2001, research assistants in waiting areas of a representative sample of 16 family medicine practices in North Carolina approached all adult patients during a 4-week period. Follow-up has been maintained for 3 years. In 2004 and 2005, the cohort was refreshed by adding eight new practices. Each consenting subject was administered a four-page self report questionnaire that included items on demographics, risk factors, health status, and quality of life.
  
  
  RESULTS
  Of 10,649 eligible patients approached in 2001, 6,811 (64%) completed the enrollment questionnaire, of whom 5,575 (81.9%) consented to be included in the cohort. African Americans, Latinos, and older persons were enrolled at rates paralleling the state's adult population. Poor general health, chronic illness, and risk factors for chronic disease were more prevalent in the cohort than in the general population. Over 3 years, cohort members were included in multiple studies, and 77% of the original cohort remained active. The per-subject enrollment cost varied between 27 US dollars and 45 US dollars; annual program maintenance costs were estimated at approximately 35,000 US dollars.
  
  
  CONCLUSIONS
  The research cohort has these advantages over traditional practice-based research networks: patient focus rather than physician focus, a structure that places few demands on practices, ability to target racial and ethnic minorities, and a better-defined patient population. As is true of all aspects of research infrastructure, the cost of development and maintenance is significant.
authors.affiliation: Department of Family Medicine, Cecil G. Sheps Center for Health Services Research, University of North Carolina, USA.
authors.forename: Philip D
authors.initials: PD
authors.lastname: Sloane
authors.forename: Leigh
authors.initials: L
authors.lastname: Callahan
authors.forename: Leila
authors.initials: L
authors.lastname: Kahwati
authors.forename: C Madeline
authors.initials: CM
authors.lastname: Mitchell
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D002986:Clinical Trials as Topic; D015331:Cohort Studies; D003362:Cost-Benefit Analysis; D005194:Family Practice / Q000458:organization & administration*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009657:North Carolina; D010349:Patient Compliance; D018579:Patient Selection; D011320:Primary Health Care / Q000458:organization & administration*; D018794:Problem-Based Learning; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D017678:Sex Distribution