The Workers' Compensation Research Institute (WCRI) issued a report entitled The Impact of Provider Choice on Workers' Compensation Costs and Outcomes. The report states panel physicians produce objectively better results, which WCRI attributes to an employer and carrier's superior resources in choosing physicians (Liberty Mutual is touting their system to put an even finer point on this).
WCRI's report admits employees report greater satisfaction with physicians they choose. The authors state this response is inconsistent with the poorer return to work outcomes and higher costs of employee chosen providers.
The rub of course is how the provider balances the conflicting interests of the employer and employee. A procedure that makes excessive medical and disability costs apparent to the employee would control costs without the dissatisfaction of restriction of choice.
Insurance Journal Article
Update: A similar study by the Public Policy Institute of California (using Pennsylvania among others as representative states) made similar findings, but with a twist. If the Claimant chose a physician not on the panel, but who the Claimant had seen before, outcomes vs. a panel doctor were not significantly different. The obvious inference would be that the pre-defined preexisting condition could not become part of the work injury in these cases. Article