Study Objective: To determine the predictive validity of the American Board of Internal Medicine (ABIM) certification process.
Design: Prospective measurement of the knowledge, skills, and attitudes of 185 ABIM-certified and 74 noncertified internists by a written examination; evaluation by professional associates; a patient questionnaire assessing satisfaction with care, physician's counseling role, and preventive care; and review of records of patients with common illnesses.
Subjects: Practicing internists who completed training or received ABIM certification 5 to 10 years previously.
Setting: Office-based practices in six western states.
Results of Data Analysis: Physicians certified by the ABIM had significantly higher scores on the written examination than the noncertified physicians, and scores on our examination correlated highly with the ABIM certification examination (r = 0.73). Ratings of clinical skills by professional associates were significantly higher for certified internists and also correlated highly with ABIM examination scores (r = 0.53 to 0.59). Regression analysis showed that ABIM certification status was the major variable affecting performance on these measures of clinical competence. Results from other measures did not show many differences between certified and noncertified physicians in the care of patients with common illnesses, but modest differences in preventive care and a few differences in outcome favored the certified physicians.
Conclusions: Comparison of findings from the written examination and the professional associate ratings with certification status and original ABIM certification examination scores shows predictive validity of ABIM certification. Further studies are needed to determine if certification status predicts important differences in the care of patients with complex illnesses.