Along the continuum from cancer screening through diagnosis, treatment, and rehabilitation, little attention has focused on intervening to assure timely, effective diagnosis once an abnormality has been identified. To achieve the goal of reducing cancer morbidity and mortality, it is imperative that patients receive timely and appropriate follow-up for detected abnormalities, as a prerequisite to appropriate treatment. Failure to obtain appropriate diagnostic services can have a significant effect on psychosocial sequelae, morbidity, and mortality, as well as cost implications for the individual and the health care system. A recent review of studies on follow-up of abnormal screening examinations reported that, in the majority of studies, fewer than 75% of patients receive adequate follow-up care.1
The negative implications of failure to follow-up are substantial, especially at the population level.
Unlike routine cancer screening, which can be initiated by the patient and often can be obtained without the need for a physician’s or provider’s referral, the identification and resolution of an abnormal finding is inextricably tied to a clinical setting and a medical provider. Because the delivery of care for the follow-up of an abnormality necessarily involves contact with the health care system, this central theme is utilized throughout the article. In an attempt to synthesize the research findings to date and to formulate future directions, we have developed a conceptual framework that reflects this theme. We have named this the Model for Intervention Research, Dissemination, and Implementation (MIRDI; ).
Model for intervention research, dissemination, and implementation.
As shown in , we conceptualize the health care system in this country as comprising four levels: policy, practice, provider, and patient. The policy level refers to the larger organizational context within which health care is provided. This level includes the way in which health care in general is financed and delivered, as well as more specific public and private payer cancer screening-related policies at the federal, state, and/or local levels that can directly or indirectly affect follow-up care. An example is the National Breast and Cervical Cancer Early Detection Program (NBCCEDP). In all states, the District of Columbia, and 12 Native American tribes, the NBCCEDP provides funding for breast and cervical cancer screening and for clinical diagnostic services related to abnormal screening results. Policy-level influences form the broad context within which care for abnormal findings is provided and therefore have the potential to significantly influence background follow-up rates as well as to enhance the probability of success of interventions applied in research settings.
The practice level refers to the structural and operational features of the specific health care settings in which follow-up care is recommended and provided. This level includes sites such as hospitals, primary care offices, community clinics, and specialist practices. Here, decisions are made about the types of follow-up procedures required by the patient, the settings in which the procedures are to be performed, and the timing of follow-up. Characteristics of the practice setting (e.g., size, location, access to resources, staffing) are likely to influence the delivery of care and to affect the potential success of interventions designed to enhance the timeliness and appropriateness of follow-up.
The provider and patient levels of the health care system are the most proximal to the delivery/receipt of follow-up care, and are influenced by the more distal policy and practice levels. At the provider level, factors that may influence physicians’ recommendations and orders for follow-up include physicians’ background, training, and experience; perceptions related to cancer screening and follow-up; social influence; and characteristics of the patients themselves. Interactions in the physician–patient encounter help to shape patients’ understandings concerning the nature and importance of follow-up and the steps involved in diagnostic evaluation. Interventions designed to affect physicians’ knowledge, attitudes, and behaviors are key to actively engaging the patients who are in their care. Personal background, cognitive, and psychosocial characteristics of practitioners and patients are factors that are likely to shape patients’ response to recommended follow-up.
Factors operating across and within all four levels of the health care system can affect the quality and timeliness of follow-up care and can affect the success of research intervention trials designed to identify effective methods for improving follow-up patterns. One of the primary challenges associated with testing and implementing interventions to increase diagnostic follow-up of screening abnormalities is the interdependence of factors at the patient, provider, practice, and health policy levels. For example, routine reminders to patients with incomplete follow-up of an abnormal finding require the existence of information systems that can be used to identify and track abnormal findings and their evaluation. In addition, if individuals with abnormal findings are prompted by the reminders to visit their primary care physician for a specialty referral, that provider must also perceive the abnormal findings as important and recommend appropriate follow-up. Specialists must be available and then accept the referral from the primary care provider, if a referral is made. Patients must be able to pay for diagnostic workup, either out of pocket or by associated copayment within an insurance program. Financial constraints or lack of specialist capacity can also influence receipt of diagnostic evaluation. Policy-level factors, such as lack of or limited third-party coverage for diagnostic evaluation, can determine the effectiveness of interventions conducted at other levels in the health care system.
Although many challenges to testing and implementing interventions to improve follow-up are similar for the various levels of the health care system in our MIRDI framework, the scope of the challenge may vary across levels. Such challenges can also vary by intervention type and may include costs or resources, the need for development of intervention-specific infrastructures, and sustainability beyond the intervention period. For example, the costs associated with patient-level telephone counseling are likely to have both fixed and variable components, so that the cost of the intervention may increase for every additional patient. Conversely, development and integration of a system for tracking and monitoring screening abnormalities and follow-up may require large up-front investments in computer systems, but costs are mainly fixed, so that the overall cost of the intervention per patient may actually decline with larger numbers of patients or as more types of screening tests are included. The type of infrastructure required for intervention delivery and potential sustainability without additional investments also varies for these two intervention examples.
Penetrance, or the number of individuals reached by an intervention, is likely to vary by intervention level and is an important consideration. Over a lifetime of regular screening, a sizeable portion of individuals will have an abnormal screening test (either a true or false-positive result). However, most individuals will not have multiple screening abnormalities.2,3
As a result, interventions targeted to the level of the individual patient will likely affect only those patients to whom the intervention is directed and who actually receive the intervention. Conversely, interventions implemented at the provider or practice levels have the potential to affect the care of many more patients over a much longer period of time because, over a lifetime of practice, a provider may see hundreds of patients with screening abnormalities. Similarly, changes at the health policy level can have a very wide effect, over a long time period, because they are often not dependent on delivering a specific intervention to a specific patient but rather form the context within which follow-up care is provided.
As suggested by the heuristic model presented in the current article, research findings may be disseminated through a number of channels. Researchers routinely disseminate results of studies via presentations at professional meetings and through publications. Research findings are also disseminated through articles in the popular media and by campaigns promoted by advocacy groups. Furthermore, research findings can be disseminated in the form of guidelines developed by professional organizations and via rules and regulations adopted by public agencies. The processes of conducting intervention research, disseminating research findings, and implementing results into the health care system are not well documented in relation to follow-up care. It is often assumed that dissemination will occur if the results of intervention studies are published in the peer-reviewed literature. However, this is usually not the case. Increasingly, it has been recognized that targeted efforts need to focus on understanding the most effective means of dissemination and on ensuring that the process actually occurs.4
Relatively few studies conducted to date have evaluated the effectiveness of various methods of dissemination. More research is needed in this area. Although recognizing the importance of dissemination and ultimate implementation of research findings, the main focus of this article will be on intervention research to improve follow-up of abnormal findings in cancer screening, as depicted on the left side of our MIRDI framework ().
The current report is restricted to interventions designed to influence the recommendation, ordering, performance, or receipt of follow-up for abnormal findings. Our definition of abnormal screening results includes any clinical indications from a screening test or examination that suggest the need for further evaluation to determine the presence or absence of disease. Follow-up is defined as diagnostic procedures recommended, ordered, performed, or received to accomplish this goal. We refer mainly to randomized, controlled trials or concurrently controlled studies (also called quasiexperimental studies). Studies using pre–post or other observational designs are also mentioned, as they can provide information on the feasibility of implementing a specific type of intervention, although conclusions regarding efficacy or effectiveness of interventions are usually not warranted. lists the lessons learned from interventions to improve follow-up of abnormal findings in cancer screening.
Lessons Learned Regarding Interventions Aimed at Improving Follow-Up of Abnormal Cancer Screening Findings