Table 4.

Final multivariate model with physician characteristics independently associated with higher quality of care at follow-up. The dependent variable reflects 15 quality measures, including measures related to preventive care, chronic disease management and patient satisfaction. The model below is derived from generalized estimating equations and adjusts for all variables listed (selected through stepwise regression with backwards elimination) plus clustering of quality indicators within physician. Panel size was included as a log-transformed variable due to skewness.

Physician Characteristic	Odds Ratio (95% Confidence Interval)
Used electronic portal (yes vs. no) Jan – Jun 2006	1.42 (1.04, 1.95)
Number of physicians in group (per physician)	0.95 (0.92, 0.99)
Patient panel size (per 10-fold increase)	1.42 (1.06, 1.90)
Quality at baseline	15.98 (12.10, 21.12)