RE-DISCOVERING QUALITY OF LIFE AFTER A TRAUMATIC BRAIN INJURY
CHRISTINE BARANDA WEAVER, MAS, OTR/L, CLCP, C/NDT
Traumatic brain injury (TBI) is a major public health problem resulting in the death and disabilities of young and productive people. Though the mortality of TBI has decreased substantially in recent years the disability due to TBI has not appreciably reduced.
At 1 year after injury, many TBI survivors engage in a reduced number of leisure activities, which are more sedentary and less social, with a substantial fraction dissatisfied with these changes. While discontinuing some activities may be viewed as a positive change, there are few new ones to replace them.
Quality of life is an important consideration in medical care. Some medical treatments can seriously impair the quality of life without providing appreciable benefits, whereas others greatly enhance the quality of life. Various outcome scales have been proposed and used to assess disability after TBI. A few, commonly used are Glasgow Outcome Scale (GOS) with or without extended scores, Disability Rating Scale (DRS), Functional Independence Measure (FIM), Community Integration Questionnaire (CIQ), and the Functional Status Examination (FSE).
Although difficult to define precisely, quality of life has an inherent meaning to most people. It is comprised of broad concepts that affect global life satisfaction, including good health, adequate housing, employment, personal and family safety, interrelationships, education, and leisure pursuits. For matters related to health care, quality of life has been applied specifically to those life concerns that are most affected by health or illness, hence the term “health-related quality of life” (HRQL)
Specific measures to evaluate the outcome of an illness or its treatment include quantity and quality of life and economic cost. Although the length of survival was previously considered the most important among these, the impact of illness on quality of life has received increasing recognition.
HRQL can be formally defined as: “The extent to which one’s usual or expected physical, emotional and social well-being are affected by a medical condition or its treatment”. This definition incorporates the two widely accepted aspects of quality of life: subjectivity and multidimensionality.
HRQL represents a subjective appraisal of the impact of illness or its treatment; individual patients with the same objective health status can report dissimilar HRQL due to unique differences in expectations and coping abilities. As a result, HRQL must be measured from the individual’s viewpoint rather than that of outside observers (i.e., caregivers or healthcare professionals).
Multidimensionality is the other important component of HRQL. The multidimensionality of HRQL is reflected in the work of the Patient-Reported Outcomes Measurement Information System (PROMIS) Cooperative Group, an NIH-funded national effort that has produced a comprehensive, conceptual framework of self-reported health (figure 1) [12,13]. Developed with the input of hundreds of people with a wide variety of medical conditions, the healthcare providers who treat them, members of the general population, and extensive literature reviews, the framework is divided into Physical, Mental, and Social health. Each of these major components encompasses multiple subcomponents (e.g., the mental health component is comprised of effect, behavior, and cognition). These subdomains are further divided (e.g., negative affect is comprised of anxiety, depression, anger, the experience of stress, and the negative psychosocial impact of illness).
Neuro-QOL — The Quality of Life in Neurological Disorders (Neuro-QOL project, www.neuroqol.org) is a similar effort to PROMIS, funded by the National Institute of Neurological Disorders and Stroke, to develop and test HRQL instruments that are applicable across the many neurological conditions. Utilizing a methodology similar to PROMIS, these instruments have been validated in five adults and two pediatric diseases (stroke, amyotrophic lateral sclerosis [ALS or Lou Gehrig’s disease], multiple sclerosis, Parkinson’s disease, adult and pediatric epilepsy, and the muscular dystrophies). It is hoped that the resulting HRQL tools will be used to facilitate the comparison of results from clinical trials and other clinical research across conditions.
Proxy or caregiver evaluations of HRQL — There are situations (e.g., children, elderly, cognitively impaired patients) where patient self-reported HRQL must be substituted by proxy assessment. Where it has been studied, there appears to be general agreement between the patient’s assessment and that of the proxy in most studies [30-34]. However, the possibility of bias related to the subjective burden of caring for the individual must be considered when the proxy is a caregiver .
Capturing changes in clinical status during treatment — the opportunity to utilize the patient-reported quality of life to guide individual clinical care is increasingly important to clinicians. For instance, a brief multi-dimensional HRQL instrument might be administered at every chemotherapy visit. The treating nurse or physician can then review the current HRQL for indications of problems and compare it to the HRQL from the previous visit. Significant changes can be flagged for follow-up by the physician or nurse. This may be of significant benefit in busy practices where there is not always sufficient time to ask the questions one would like. A quick glance at a standardized computer-generated printout of HRQL scores and changes from the last visit’s scores could catch a problem that might otherwise be missed. In a study of patients with advanced lung cancer, acceptance of and compliance with a weekly assessment of HRQL was high . Most patients reported that weekly assessment aided in focusing discussions with their health care team. Providers found temporal changes in patient responses over time to be useful.
Defining a clinically meaningful change — what degree of change in HRQL is of sufficient magnitude to warrant a treatment modification by the physician? Identifying changes in HRQL that are clinically significant involves determining whether the change that is observed in response to an intervention is meaningful and important, or statistically significant yet clinically irrelevant.
One approach to answering this question is to compare changes in HRQL scores with global ratings of change in different life dimensions  or in life stress units . As an example, in one report, a minimally important difference (MID) was defined based on patients’ global ratings of change and applied to three studies measuring dyspnea, fatigue, and emotional function in patients with chronic heart and lung disease . The MID was represented by a mean change in score of approximately 0.5 per item on the HRQL instrument when responses were presented on a seven-point Likert scale.
The influence of nonmedical issues — a second challenge is to develop and test models of non-illness-related factors (e.g., psychological, social, cultural, and economic issues) that might influence the impact of a particular level of impairment on HRQL. In one model, the amount of distress and dissatisfaction experienced by the patient as a result of the symptoms and functional limitations induced by illness and its treatment is filtered by individual factors, sociocultural influences, and available resources. The field of psychology has made valuable contributions to the field of HRQL research. The development of valid and reliable instruments to measure the patient’s perspective of their illness and treatment was made possible by the demonstration of their psychometric properties.
Quality of life is comprised of broad concepts that affect global life satisfaction. For matters related to health care, quality of life has been applied specifically to those life concerns that are most affected by health or illness, hence the term “health-related quality of life” (HRQL). It is a tool used for assessing the efficacy and tolerability of treatment, capturing changes in clinical status during treatment that might otherwise be missed, and evaluating the need for further assessment, treatment, and rehabilitation.