Background: Valid measurement of physician performance requires accurate identification of patients for whom a physician is responsible. Among all patients seen by a physician, some will be more strongly connected to their physician than others, but the effect of connectedness on measures of physician performance is not known.
Objective: To determine whether patient-physician connectedness affects measures of clinical performance.
Design: Population-based cohort study.
Setting: Academic network of 4 community health centers and 9 hospital-affiliated primary care practices.
Patients: 155 590 adults with 1 or more visits to a study practice from 2003 to 2005.
Measurements: A validated algorithm was used to connect patients to either 1 of 181 physicians or 1 of 13 practices in which they received most of their care. Performance measures included breast, cervical, and colorectal cancer screening in eligible patients; hemoglobin A(1c) measurement and control in patients with diabetes; and low-density lipoprotein cholesterol measurement and control in patients with diabetes and coronary artery disease.
Results: Overall, 92 315 patients (59.3%) were connected to a specific physician, whereas 53 669 patients (34.5%) were connected only to a specific practice and 9606 patients (6.2%) could not be connected to a physician or practice. The proportion of patients in a practice who could be connected to a physician varied markedly (45.6% to 71.2% of patients per practice; P < 0.001). Physician-connected patients were significantly more likely than practice-connected patients to receive guideline-consistent care (for example, adjusted mammography rates were 78.1% vs. 65.9% [P < 0.001] and adjusted hemoglobin A(1c) rates were 90.3% vs. 74.9% [P < 0.001]). Receipt of preventive care varied more by whether patients were more or less connected to a physician than by race or ethnicity.
Limitation: Patient-physician connectedness was assessed in 1 primary care network.
Conclusion: Patients seen in primary care practices seem to be variably connected with a specific physician, and less connected patients are less likely to receive guideline-consistent care.
Funding: National Cancer Institute.