The published literature finds that different methods for attributing episodes of care to providers have yielded different results, in terms of which physicians are assigned responsibility and what proportion of episodes can be assigned. Our analyses of Medicare data produced similar results in terms of variability. However, it is notable that even with the dispersion of care noted above, a significant fraction of episodes were assigned to some provider(s) for most attribution rules and conditions we studied.
For example, the six attribution rules we tested assigned between 73 percent and 99 percent of AMI-related episodes to physicians and/or hospitals. - The lowest attribution rate occurred when accountability was assigned to a single physician based on a plurality of E&M visits, while the highest attribution rates occurred when accountability was assigned to a single physician and/or hospital based on a plurality of physician costs and hospital costs. The attribution results varied by the type of episode: using a plurality of visits to assign accountability to a single physician, successful attribution occurred for 73 percent of AMI-related episodes, 81 percent of bacterial pneumonia-related episodes, and 94 percent of breast cancer-related episodes. The sensitivity of attribution results to methods suggests careful consideration of the algorithm chosen and that the approach may need to vary depending on the condition, specific application and stated policy goals. For example, enhancing care coordination signals to providers may be the desired policy goal and holding multiple providers accountable may be a strategy that helps promote this change in culture; yet given the dispersion of care, gaining acceptance of joint responsibilities among providers could be challenging.
One unresolved issue is how the providers to whom care is attributed perceive the attribution. - Particularly for episodes in which care is highly dispersed across multiple providers, the question arises as to whether the provider(s) assigned accountability feels overall responsibility for the episode and is able to affect performance on either cost or quality metrics for the episode of care?- This may differ depending on what type of care is provided within the episode. For example, for episodes where the majority of episode costs are facility costs, which physicians should be held accountable if one were to use a single attribution model?- Should it be the physician who managed the patient in the facility or the physician who managed the physician prior to the admission or both?- Further, should the facility also be accountable for the episode costs?- The extent of involvement of various providers varied by type of episode, highlighting potential issues related to who is held responsible for and able to affect care trajectory in the episode. Given that the current performance measurement and payment environment is one that does not engender notions of joint accountabilities among providers, absent an already formed group or system, reforms could require a substantial culture shift in order to assign multiple accountabilities across an episode of care. - However, formation of these types of groups may be part of the policy goal. Testing alternative approaches with physicians to understand their reaction to various assignment methods could inform how best to proceed.