BACKGROUND: Evaluating the quality of care provided by individual primary care physicians (PCPs) may be limited by failing to know which
patients the PCP feels personally responsible for.
OBJECTIVE: To develop and validate a model for linking patients to specific PCPs.
DESIGN: Retrospective convenience sample.
PARTICIPANTS: Eighteen PCPs from 10 practice sites within an academic adult primary care network.
MEASUREMENTS: Each PCP reviewed the records for all outpatients seen over the preceding 3 years (16,435 patients reviewed) and designated
each patient as “My Patient” or “Not My Patient.” Using this reference standard, we developed an algorithm with logistic regression
modeling to predict “My Patient” using development and validation subsets drawn from the same patient set. Quality of care
was then assessed by “My Patient” or “Not My Patient” designation by analyzing cancer screening test rates.
RESULTS: Overall, PCPs designated 11,226 patients (68.3%, range per provider 15% to 93%) to be “My Patient.” The model accurately
categorized patients in development and validation subsets (combined sensitivity 80.4%, specificity 93.7%, and positive predictive
value 96.5%). To achieve positive predictive values of >90% for individual PCPs, the model excluded 19.6% of PCP “My Patients”
(range 5.5% to 75.3%). Cancer screening rates were higher among model-predicted “My Patients.”
CONCLUSIONS: Nearly one-third of patients seen were considered “Not My Patient” by the PCP, although this proportion varied widely. We
developed and validated a simple model to link specific patients and PCPs. Such efforts may help effectively target interventions
to improve primary care quality.
Key words primary health care - health services research - quality of care - patient roster - provider denominator
Presented in part at the annual meeting of the Society of General Internal Medicine, New Orleans, LA in May, 2005.
Supported by institutional funding through the Massachusetts General Hospital Primary Care Operations Improvement program.