The next generation of research in provider optimization.

Some say that all topics are equally vexing on close-enough scrutiny, but having worked in many areas in health, I find the topic of specialty differences particularly problematic. At the root of the frustration I experience when interpreting studies about specialty differences is trying to figure out what the question is. The usual research question is something like this: Are family practitioners, or general internists, or subspecialists, or nurse practitioners better than each other in containing cost, producing outcomes, adhering to guidelines, or knowing more? It may have been fine to ask questions like these in the past, but the insights gained from answering “Who is better?” are now of diminishing importance. In the current era, we should be trying to figure out not who is better, but what the optimal arrangements are for the care of specific patients, including which types of providers should be delivering that care. If patients hospitalized for acute myocardial infarction have higher mortality rates when they are cared for by generalists than by cardiologists, should generalists be prohibited from taking care of these patients? If generalists do as well as subspecialists taking care of patients with back pain, should patients with this problem have restricted access to subspecialists? To answer these questions, we need more information than can be found in most published studies, which is what the excellent review in this issue by Harrold and colleagues tells us.1 Specific features of this review allow us to appreciate the strengths and weaknesses of past studies. In the review, studies are segregated by organ systems and diseases and are not aggregated in ways that obscure the methods. The review considers whether the dependent variable is self-reported or observed and whether that variable is knowledge, process, or outcome. Summaries of the individual studies preserve critical details, such as the effect of consultation in the AIDS study 2and the implied level of severity in the asthma study, which was limited to patients referred from the emergency department.3 To be able to tell patients what kind of doctor is best for them, we have to possess a few critical pieces of information. First, we need to know the level of the condition's complexity. To be optimally managed by generalists, the condition has to be “uncomplex.” It has to fall into the mild part of the disease's spectrum, and it should be limited to the common, not the rare, complications of that disease. Even if the condition is uncomplex, according to these two definitions, the research about this condition cannot be so fast moving that only experts can keep up with it, as it is for HIV infection. Second, we need to know whether timely and appropriate consultation reduces the competence gap, even when the condition is complex. In the Medical Outcomes Study, for example, approximately 20% of the patients had a subspecialty consultation at least once a year4 and though not mentioned in the review, one study found that a cardiac consultation decreased the difference in death rates for myocardial-infarction patients cared for by cardiologists versus generalists.5 Finally, we need to know whether care is less effective than reported in research studies because of patient nonadherence, inability to afford treatment, weak education efforts, or “competing comorbidities” that interfere with the achievement of optimal outcomes. If these processes prevent better outcomes in real-life settings, then knowing more or even doing more may not matter, uncomfortable as that makes us. When the case is uncomplex, the consultation is timely, knowing more does not lead to better outcomes, and there are comorbidities outside the subspecialist's expertise, a generalist may well be the optimal provider. When the case is complex, requires more than a consultation, and will have a better outcome because of the subspecialist's greater knowledge or skill, then the subspecialist is the optimal provider. Most studies of specialty differences have not examined all three of these critical pieces of information because we lack the methodologic sophistication for studying them. This situation should not be surprising, because only recently have clinical measures of illness severity and comorbidity been shown to be accurate.6–10 We have not even developed good criteria for appropriate referrals, although the work of Ladenson and colleagues is a superb start.11 Finally, most studies do not examine both outcomes and processes, so the relation between the two cannot be examined. The study of acute myocardial infarction mortality by Ayanian and colleagues is an exception to this rule.12 More research needs to be done to improve measures for all three of these concepts so that they can be applied to studies of quality of care as well as studies designed to determine optimal providers. If the next generation of work in this field takes the relevant factors into account, it could not only help patients but also heal the wounds incurred in the unnecessary and unfruitful specialty wars.