What is outcomes research?
Outcomes research seeks to understand the end results of particular health care practices and interventions. End results include effects that people experience and care about, such as change in the ability to function. In particular, for individuals with chronic conditions—where cure is not always possible—end results include quality of life as well as mortality. By linking the care people get to the outcomes they experience, outcomes research has become the key to developing better ways to monitor and improve the quality of care. Supporting improvements in health outcomes is a strategic goal of the Agency for Healthcare Research and Quality (AHRQ, formerly the Agency for Health Care Policy and Research).
The urgent need for outcomes research was highlighted in the early 1980s, when researchers discovered that "geography is destiny." Time and again, studies documented that medical practices as commonplace as hysterectomy and hernia repair were performed much more frequently in some areas than in others, even when there were no differences in the underlying rates of disease. Furthermore, there was often no information about the end results for the patients who received a particular procedure, and few comparative studies to show which interventions were most effective. These findings challenged researchers, clinicians, and health systems leaders to develop new tools to assess the impact of health care services.
Outcomes Information for Decisionmaking
For clinicians and patients, outcomes research provides evidence about benefits, risks, and results of treatments so they can make more informed decisions. One group of researchers, for example, studied the outcomes of patients with pneumonia, a common cause of hospitalization in elderly people. They developed a way for clinicians to determine which patients with pneumonia can be treated safely at home, an option that not only reduces Medicare costs but is preferred by many patients. In areas such as cancer, where outright cure is often not the only goal, outcomes research has provided the information to help patients make choices that will improve their quality of life (Figure 1, 9 KB).
For health care managers and purchasers, outcomes research can identify potentially effective strategies they can implement to improve the quality and value of care. AHRQ-sponsored outcomes studies, for example, have shown that even when treatments are known to be effective, many people who could benefit from them are not getting them. Beta blocker medication, given after heart attacks, can reduce mortality; blood-thinning medication can prevent strokes; and thrombolytic ("clot-buster") therapy given immediately after a heart attack can reduce the damage from the attack. Yet in each case, many eligible patients are not getting these treatments. By identifying and addressing the barriers to better care—for example, through development of a tool to help doctors know which patients with suspected heart attacks will benefit from thrombolytic treatment—AHRQ researchers have helped translate these findings into practical strategies to improve care.
Historically, clinicians have relied primarily on traditional biomedical measures, such as the results of laboratory tests, to determine whether a health intervention is necessary and whether it is successful. Researchers have discovered, however, that when they use only these measures, they miss many of the outcomes that matter most to patients. Hence, outcomes research also measures how people function and their experiences with care (Table 1).
Table 1. Examples of Health Outcomes
|Mortality||Infant death rate|
|Physiologic measures||Blood pressure|
|Functional measures||SF-36, a 36-item health survey|
|Patients' experiences with care||Consumer Assessment of Health Plans survey|
Source: Adopted from Clancy CM, Eisenberg, JM Outcomes research: Measure the end results of health care. Science 282:245-6, 1998.
Some outcomes instruments have focused on describing how individuals rate their health overall. General health surveys such as the SF-36 are now used in research studies, population surveys, and some health plans to assess patients' overall level of functioning. The Medicare program will use such a quality measure (the "Medicare Health Outcomes Survey") to assess how well health plans improve the functional status of Medicare patients.
Developing outcome instruments for specific diseases has been an especially prolific research area. Such instruments are more likely than general health survey measures to be able to detect changes in the disease due to treatment. For example, the VF-14, developed by AHRQ-supported researchers investigating the outcomes of cataract treatment, is now used in clinical practice and research to assess the impact of a variety of conditions affecting the eye (Table 2).
Table 2. Examples of abilities evaluated in the VF-14
Source: Steinberg EP, Tielsch JM, Schein OD et al. The VF-14: An index of functional impairment in patients with cataract. Archives of Ophthalmology 1994; 112:630-08.
The difference between traditional clinical measures for a disease and the outcomes that matter to patients can be dramatic. In one example, AHRQ-supported researchers found that men with identical symptoms of benign prostate disease (in which the prostate enlarges and interferes with urine flow) often had very different opinions about how severe their disease was and how much it bothered them. Furthermore, the biomedical measure (urine flow rate) most often used to evaluate the need for treatment bore almost no relationship to patients' symptoms. One of the fruits of this research was the development of a "symptom index" for benign prostate disease. Urologists and patients now use this self-administered patient questionnaire routinely to evaluate whether treatment is warranted and desired.
No longer just the domain of a small cadre of researchers, outcomes research has altered the culture of clinical practice and health care research by changing how we assess the end results of health care services. In doing so, it has provided the foundation for measuring the quality of care. The results of AHRQ outcomes research are becoming part of the "report cards" that purchasers and consumers can use to assess the quality of care in health plans. For public programs such as Medicaid and Medicare, outcomes research provides policymakers with the tools to monitor and improve quality both in traditional settings and under managed care. Outcomes research is the key to knowing not only what quality of care we can achieve, but how we can achieve it.