What Is the PROMISe of Global Outcome Measures? 3 Things You Need to Know
By Jeff Houck, PT, PhD
As health care providers, we often indirectly gauge patient outcomes by quantifying process measures such as number of visits per episode, cost per visit, and compliance with standardized guidelines. These variables can answer important questions: Are we wasting resources? Do we have unwarranted variation in care within our facility? Are treatments consistent with published clinical practice guidelines? But process measures do not place the patient's voice at the center of their care.
Patient-reported outcome measures (PROMs) are pivotal to assessing and achieving high-quality care. Patient-reported outcomes represent the only direct input of health status from the patient, unfiltered by a provider. Patient advocates and agencies such as the Centers for Medicare and Medicaid Services (CMS) see patient-reported outcomes as a key avenue to give patients a voice in their health care.
Global (as opposed to condition- or disease-specific) outcome measures, such as the Patient Reported Outcome Measurement Information System (PROMIS) scales, use the newest approaches to outcomes assessment (computer-adaptive testing and item-response theory) to capture a patient's overall health and compare it with the national average. Measures such as PROMIS allow physical therapists to hear their patients' voices relative to overall health during rehabilitation and to champion wellness programs.
Physical therapists were leaders in adopting condition- and disease-specific outcome measures, so it's natural for us to do the same with global outcome measures.
1. Global measures change the assessment paradigm from disease-specific effects to holistic health assessment that includes the patient's perspective.
Global measures offer distinct advantages over condition- or disease-specific measures. In contrast to such measures, which target a diagnosis, global measures target a health domain independent of diagnosis. The goal is to capture a patient's overall health status. PROMIS, for example, includes over 300 different health domains assessing symptoms and physical, mental, and social health traits. The scales are designed to accurately measure health domains such as pain interference, physical function, fatigue, self-efficacy, or social isolation across a population.
The main benefit of global measures is that they combine different health domains to obtain an accurate picture of a patient's perceived overall (physical, mental, and social) health. For wellness and for patients with comorbidities—which are the majority of patients—global measures help clinicians determine when treating a local problem may have strong effects on overall health and, vice versa, when costly interventions that remedy a local problem have no influence on overall health.
Let's consider a fictional patient, Mary, who had a total knee replacement due to knee osteoarthritis.
Because of Mary's previous longstanding chronic knee pain, she had gained weight and now fatigues easily. Many patients do not increase physical activity after knee joint replacement and are therefore unable to correct these primary health concerns.
A condition-specific measure such as the Knee Injury and Osteoarthritis Outcomes Score (KOOS) would assess Mary's opinions about her pain, ADL function, sports, recreation, and quality of life specific to her knee. In contrast, the PROMIS physical function and pain interference scales would measure Mary's overall physical function and pain.
Fear of doing too much after the surgery and low endurance are not routinely detected using condition-specific assessments such as the KOOS, while the efficiency of PROMIS computer-adaptive scales (1-minute per health domain) allows for additional health domains to be assessed that are important to the patient or provider without burdening the patient.
In Mary's case, the PROMIS physical function and pain interference scales detected deficits similar to the KOOS. However, the addition of the fatigue and self-efficacy scales also detected Mary's low energy and low confidence in her ability to manage her health, which her physical therapist addressed.
By following her plan of care, Mary has lost weight and improved her cardiovascular fitness, in addition to experiencing improvement in physical function and pain interference.
2. Condition- and disease-specific measures are still valuable for some populations, but global measures often perform just as well.
An important issue for the switch to value-based care is documenting change. In statistical terms, a measure needs to be valid and responsive to be effective clinically. There may be some very specific problems, such as carpal tunnel syndrome, where global measures are not as responsive and may require the continuation of disease-specific measures in some specialty practice areas. However, for most conditions, from anterior cruciate ligament reconstruction to geriatric assessment, the PROMIS scales are performing as well or better than disease-specific scales.
(See the PROMIS Health Organization's website for published papers on validity and responsiveness of PROMIS scales.)
3. Global measures present opportunities for PTs to expand their role in the broader health care ecosystem.
Global assessments are agnostic to disease, so scales can be applied successfully across diagnoses and shared easily across multiple types of providers. Everyone speaks the same language! This frees up time for physical therapists and focuses outcomes on a common goal of improved overall patient health. For example, patients with abnormally low physical function may be flagged for physical therapist services such as fall prevention or presurgical screening.
Global measures also support the philosophy of value-based care, which is one reason that APTA's Physical Therapy Outcomes Registry—also rooted in the pursuit of value-based care—has integrated measures like PROMIS. They allow the Registry to develop quality measures that demonstrate value to the patient and multiple types of clinicians, as well as across episodes and provider types.
Wide-scale integration of global measures in electronic medical records has been implemented at major medical systems such as the University of Utah and University of Rochester. PROMIS also is available as an iPad app for users with less technical support or in a private practice setting who want to use computer-adaptive tests rather than long or short forms.
This places highly accurate, state-of-the-art assessment of over 300 health domains at the fingertips of clinicians working in both small practices and large-scale health systems. Patients and providers can easily understand and apply the scores to their clinical decision making. The health care ecosystem is ready to respond to new health care challenges based not on process outcomes but on the voice of patients who are seeking improved overall health.
Jeff Houck is director of research in the physical therapy program at George Fox University.