title: Provider practice characteristics that promote interpersonal continuity.
abstract: OBJECTIVE
  Becoming certified as a patient-centered medical home now requires practices to measure how effectively they provide continuity of care. To understand how continuity can be improved, we studied the association between provider practice characteristics and interpersonal continuity using the Usual Provider Continuity Index (UPC).
  
  
  METHODS
  We conducted a mixed-methods study of the relationship between provider practice characteristics and UPC in 4 university-based family medicine clinics. For the quantitative part of the study, we analyzed data extracted from monthly provider performance reports for 63 primary care providers (PCPs) between July 2009 and June 2010. We tested the association of 5 practice parameters on UPC: (1) clinic frequency; (2) panel size; (3) patient load (ratio of panel size to clinic frequency); (4) attendance ratio; and (5) duration in practice (number of years working in the current practice). Clinic, care team, provider sex, and provider type (physicians versus nonphysician providers) were analyzed as covariates. Simple and multiple linear regressions were used for statistical modeling. Findings from the quantitative part of the study were validated using qualitative data from provider focus groups that were analyzed using sequential thematic coding.
  
  
  RESULTS
  There were strong linear associations between UPC and both clinic frequency (β = 0.94; 95% CI, 0.62-1.27) and patient load (β = -0.37; 95% CI, -0.48 to -0.26). A multiple linear regression including clinic frequency, patient load, duration in practice, and provider type explained more than 60% of the variation in UPC (adjusted R(2) = 0.629). UPC for nurse practitioners and physician assistants was more strongly dependent on clinic frequency and was at least as high as it was for physicians. Focus groups identified 6 themes as other potential sources of variability in UPC.
  
  
  CONCLUSIONS
  Variability in UPC between providers is strongly correlated with variables that can be modified by practice managers. Our study suggests that patients assigned to nurse practitioners and physician assistants have continuity similar to those assigned to physicians.
authors.affiliation: the School of Medicine, Department of Surgery, the Divisions of Biostatistics and Epidemiology, Oregon Health & Science University, Portland, USA.
authors.forename: Tyler S
authors.initials: TS
authors.lastname: Mittelstaedt
authors.forename: Motomi
authors.initials: M
authors.lastname: Mori
authors.forename: William E
authors.initials: WE
authors.lastname: Lambert
authors.forename: John W
authors.initials: JW
authors.lastname: Saultz
mesh_terms: D003266:Continuity of Patient Care; D005194:Family Practice; D005260:Female; D017144:Focus Groups; D006801:Humans; D016014:Linear Models; D008297:Male; D015999:Multivariate Analysis; D009722:Nurse Practitioners; D018802:Patient-Centered Care; D010823:Physician Assistants; D010818:Practice Patterns, Physicians'; D011369:Professional-Patient Relations; D012189:Retrospective Studies; D014481:United States; D016526:Workload
keywords: Continuity of Patient Care; Medical Home; Patient-Centered Care