OBJECTIVES: Use of online “managed physician panels” for outcomes research purpose is not yet common. This study aims to compare practice characteristics, prescribing patterns and attitudes between physicians in ‘TNS online managed panels’ and free-bound non-panel samples. METHODS: Physicians, especially Neurologists, were recruited from two sources in the United States for a Multiple Sclerosis (MS) research initiative: via online using TNS online managed panels (panelists), and via telephone (non-panelists). Practice characteristics (12-items), attitudes (76 items), treatment choices (8-items) and ratings of risk-factors (36-items) were measured in both cohorts using a standardized 45-minute-questionnaire; the results were analyzed to assess any statistical difference between the panelists and non-panelists across the measured domains. RESULTS: Survey results from Neurologists (167-panelists & 97-non-panelists) were assessed. Overall, the concordance rate between the cohort responses was 95% (126-out-of-132-items). In 1 (out-of-12; 8.3%) practice characteristic, namely, patient (pt) volume treated in a typical month, the cohorts differed (panelists-312pts/non-panelists-277pts). In 5 (out-of-76; 6.6%) attitudinal items (in 7-point likert-scales), the individual item-response-scores marginally differed: importance of considering patient lifestyle while selecting MS therapy (panelists-4.8/non-panelists-5.2), importance of brain lesions in measuring MS progression (panelists-5.1/non-panelists-5.4), patients experience more side-effects with interferons than with glatiramer-acetate (panelists-5.8/non-panelists-5.3), interferon therapies with more frequent dosing are more effective (panelists-4.5/non-panelists-4.1), and physician opinion of what is best for patient supercedes patient’s personal preferences (panelists-4.2/non-panelists-3.8). There were no statistically significant differences observed between the cohorts in treatment choices (all 8-items) and ratings of risk factors (all 36-items). CONCLUSIONS: The high concordance rates observed in the study cohort characteristics, attitudes and treatment practices strengthens the argument that online managed physician panels are viable options for scientific research studies, as they provide robust, cost-effective, quick sample of physicians, in addition to the well-known relatively high response rate.