Health Services Research in Radiation Oncology: Toward Achieving the Achievable for Patients With Cancer

Need for Health Services Research in Radiation Oncology

Clinical radiation oncology is a mature science. It has a sound theoretical basis in both biology and physics. We have a universal language for describing the diseases we treat, the treatments we use, and the outcomes we achieve. Much is now known about the factors that influence outcomes in the individual case. We have a well-established process for evaluating the efficacy of treatment, and a large body of empirical information now permits evidence-based decisions about the use of radiotherapy (RT) in the majority of cases.

In contrast, the science of HSR in radiation oncology is at a very much earlier stage of development. There is no comparable universal language for describing the performance of RT programs. There is only limited information available about the factors that influence the performance of RT programs in the population at large. There is no well-established process for measuring the effectiveness of RT programs at the population level. In the absence of empirical evidence, most decisions about the design and management of RT services are guided only by theory and expert opinion, and their consequences are unpredictable. Given that we would no longer tolerate this unscientific approach to decision-making in the care of individual patients, it is anomalous that it should still be used in making decisions about health systems that may affect tens of thousands of patients.

The challenges for the HSR community in radiation oncology are to create the knowledge required for evidence-based management of RT programs and to promote the use of evidence in their design and management.

How Can Health Services Research Help to Improve the Outcomes of Cancer?

At any point in time, the state of scientific knowledge and technological development sets an upper limit on what is achievable for patients with cancer. What is achievable in any particular society is also limited by how much that society is able and willing to spend on cancer care. However, what is actually achieved depends not only on what would be achievable if we made optimal use of the available knowledge, technology, and resources, but also on how close we get to attaining the achievable, a quantity that we have termed the attainment factor :

The achieved and the achievable outcomes are measured in units that correspond to the outcome of interest. Attainment can have any value between 0 and 1 or may be multiplied by 100 and expressed as a percentage. The equation may be rewritten as:

Cancer outcomes can be improved by increasing the achievable or by increasing the attainment factor. Biomedical and clinical research aim to improve outcomes by increasing the achievable. HSR aims to improve outcomes by increasing the attainment of what is already potentially achievable within the limits of existing knowledge, technology, and resources.

What Is the Scope of Health Services Research?

Health system performance has three dimensions: accessibility, quality, and efficiency. Together, these determine the extent to which we attain the achievable in health care. Accessibility describes the extent to which patients are able to get the care they need when they need it. Quality describes the extent to which the right care is delivered in the right way. Efficiency describes the extent to which accessibility and effectiveness are optimized in relation to the resources expended. HSR is concerned with measuring these quantities, understanding the factors that influence them, and discovering and evaluating ways of enhancing them.

The scope of health services research in oncology covers the entire continuum of cancer care. In a systematic cross-sectional study of 1113 HSR publications from 2009, the majority of HSR focused on active treatment (32%), with fewer studies addressing survival rates (19%) or screening (16%), and even fewer focused on diagnosis/assessment (10%), palliation (8%), or prevention (4%). Across this continuum, the focus of HSR was most commonly on quality of care (56%), with fewer studies focused on accessibility (25%), efficiency (5%), or general well-being of subjects (14%).

Fig. 15.1 shows a general framework for a program of HSR aimed at improving a specific aspect of health system performance. The first step is to select, define, and validate appropriate indicators of the aspect of performance that has been targeted for investigation. The next two steps are (1) to develop methods of measuring system performance in terms of the chosen indicator(s) and (2) to prescribe standards or targets for system performance in terms of the chosen indicators. These two steps, which often involve the use of very different methods, can sometimes be undertaken in parallel. Once standards have been set and methods for measuring performance have been established and validated, it becomes possible to evaluate the performance of the system against the standards. This, in turn, permits further explanatory studies aimed at identifying factors that are associated with better or worse performance. This information can be used to design interventions aimed at improving performance. The interventions may then be implemented and systematically evaluated. Interventions may be refined through further cycles of improvement before they are suitable for dissemination and incorporation into routine practice.

Concept of Health Care Accessibility

The term accessibility was originally used narrowly to describe the ability of patients to obtain entry into the health system. It is now used more broadly to represent the overall “degree of fit between the clients and the system.” Accessibility can be seen as having a number of dimensions that determine that overall degree of fit ( Box 15.1 ). Availability describes the total volume of the service available in relation to the total number of clients that would benefit from it. Availability depends on the adequacy of supply of health care workers and on the adequacy of facilities and equipment. For any given level of resources, availability also depends on the degree of efficiency in production of services. Spatial accessibility describes the geographic relationships between the places where services are provided and the places where potential clients reside. The term accommodation describes the extent to which the system is designed and operated to facilitate clients’ access to service, for example, by operating at convenient hours or by providing transportation for patients who may need it. Affordability describes the relationship between the cost of health services and clients’ ability and willingness to pay. It depends not only on the direct cost of services but also indirect costs, for example, loss of earnings during a protracted course of treatment. Awareness describes the extent to which those who need the service know that it is available and that they might benefit from it. In the context of a specialized service such as RT, patients’ awareness of the potential benefits of RT depends largely on their attending physician's awareness of the indications for RT.

Need for Studies of Access to Radiotherapy

There are compelling reasons for doing research aimed at optimizing the accessibility of RT. In order to achieve optimal cancer outcomes at the population level, it is necessary to make effective treatments accessible to every patient who needs them. RT is known to be effective in many clinical situations; the World Health Organization (WHO) recognizes RT as a key component of any overall program of cancer control. In its 2005 declaration on Cancer Control, the WHO states that “…recognizing that the technology for treatment of cancer is mature and that many cases of cancer can be cured…., all nations should improve access to appropriate technologies.” Many nations aspire to providing adequate and equitable access to health care for all of their citizens, but there is remarkably little information available about how successful they are in achieving this laudable goal with respect to RT. In reality, the widespread reports of waiting lists for RT in the medical literature and news media and the limited supply of radiotherapy equipment and personnel in many developed and developing countries suggest that access to RT remains suboptimal in many parts of the world.

Waiting Lists for Radiotherapy

Long waiting times for RT were first identified as a cause for concern in the medical literature in a report from Norway from three decades ago. Waiting lists for RT have since been reported in many other countries, including Australia, the UK, Canada, New Zealand, Denmark, Germany, Spain, and Italy. In countries affected by waiting lists for RT, they have been a major concern for both patients and providers. The problem of waiting lists for RT is an ongoing challenge for health services researchers in radiation oncology, but the first step in dealing with the problem is to learn how to measure waiting times for RT.

Measuring Waiting Times for Radiotherapy

Different methods are available for quantifying waiting times and waiting lists for RT, including mail surveys, retrospective reviews of preexisting administrative data, and prospective collection of information about delays as patients pass through the system.

Mail surveys and email surveys can provide a lot of information about waiting times from multiple institutions and can also be used to compare waiting times between different centers within one country or to compare waiting times between different countries. In the 1990s, a survey of heads of radiation oncology at comprehensive cancer centers in the United States and Canada showed that waiting lists for RT were widespread throughout Canada but revealed no evidence of similar problems anywhere in the United States. Median waiting times for a range of indications for RT were two to three times longer in Canada than in the United States _. Fig. 15.2 shows, for example, that at almost every Canadian center, patients with laryngeal cancer waited longer for RT than they did at almost any US center. However, the validity of such surveys may be questioned because they rely on the veracity of self-reports and because the primary information on which each report is based may differ from center to center.

Retrospective analysis of data that have been gathered for other purposes can provide more objective information about waiting times for RT. This may be an important first step in addressing this type of problem. At the beginning of the 1990s, reports of long waiting lists for RT in Ontario were frequently in Canadian news media. Health system managers felt that these reports were unduly alarmist and at first denied that there was any systemic problem. To clarify the situation, we undertook an analysis of waiting times for RT based on computerized electronic records of all visits to the province's radiotherapy centers over the preceding decade. Once these administrative records had been linked to the province's cancer registry, we were able to describe waiting times for RT for various specific conditions. For example, Fig. 15.3A shows that waiting times from diagnosis to start of radical RT for laryngeal cancer increased dramatically through the late 1980s and early 1990s. Similar large increases in waiting times were found in many other clinical situations. Further, as shown in Fig. 15.3A , the observed increases in overall waiting time between diagnosis and treatment were entirely due to increases in the waiting time between the first visit to a radiation oncologist and the start of RT. There was no increase in the interval between diagnosis and referral to radiation oncology or between referral and consultation. These findings pointed to rate-limiting problems in access to planning and/or treatment machines. It is useful, whenever possible, to report observed waiting times in relation to standards or guidelines. At the time of this first report, the Canadian Association of Radiation Oncology (CARO) had already set standards for acceptable waiting times for RT: the maximum acceptable delay between referral to, and consultation by, a radiation oncologist was deemed to be 2 weeks, and the maximum acceptable delay between consultation and the start of RT was deemed to be 2 weeks. Although these standards were based only on expert opinion, they provided a useful framework for comparison. Fig. 15.3B shows trends in compliance with these standards over time. Most patients met the CARO standard for prompt consultation throughout the study period, but the proportion of patients meeting the CARO standard for prompt start of RT fell from 90% to 10%. This simple study, which merely quantified the magnitude of the problem in our community, was useful because it led to public recognition of the seriousness of the problem. This proved to be an important first step in promoting reinvestment in the infrastructure of the provincial RT system.

There are limitations to the retrospective analysis of waiting times. First, this approach is blind to patients who dropped off the waiting list before they were treated, because it starts by identifying patients treated with RT and then follows them backwards to measure waiting times from date of diagnosis or some other milestone. Second, it is unlikely that any database created for other purposes will provide all of the information necessary to identify the rate-limiting step in the RT process. The date of the decision to treat with RT, for example, is an important milestone that signals the transition from pretreatment assessment to planning, and this is collected only in systems designed specifically to monitor flow through the RT process. Administrative databases may also lack information about other elements of the patient's care that are necessary to interpret waiting times for RT. For example, planned deferral of the start of postoperative RT because of delayed wound healing is indistinguishable from unscheduled delay unless the date when the patient is ready to be treated is recorded prospectively. Finally, the retrospective approach does not provide the real-time information needed to fine-tune the performance of an RT program. Prospective collection of the pertinent information is the preferred approach for tracking patients through the system. This approach has now been adopted by the Ontario RT system (see “A Canadian Case Study” section to come).