cantly lower scores on the Quality of Life Index than the patients with ... tients experienced more objectively aversive life circumstances than either of the ...
QUALITY ATKINSON, Am J Psychiatry OFZIBIN, LIFE 154:1, AND January CHUANG 1997
Characterizing Quality of Life Among Patients With Chronic Mental Illness: A Critical Examination of the Self-Report Methodology Mark Atkinson, Ph.D., Sharon Zibin, M.Sc., and Henry Chuang, M.D.
Objective: The purposes of the study were 1) to characterize the quality of life of three patient groups with chronic mental illness, 2) to evaluate differences in reported life quality among the three groups, and 3) to evaluate the validity of a self-report methodology by comparing these results with several objective indicators of life quality. Method: The study group consisted of chronically mentally ill patients with schizophrenia (N=69), bipolar disorder (N=37), or major depression (N=35). Subjects were administered the Quality of Life Index, and comparisons of both objective and self-report life quality indices were made among the three groups. Quality of life ratings of these subjects were also compared with those of patients with a chronic physical illness. Results: The two groups with mood disorders reported significantly lower scores on the Quality of Life Index than the patients with schizophrenia. Moreover, the scores on the Quality of Life Index for patients with schizophrenia were very similar to those of the comparison group of physically ill patients. The opposite trend emerged when groups were compared with respect to objective indicators of life quality. Schizophrenic patients experienced more objectively aversive life circumstances than either of the affectively disturbed groups. Conclusions: The validity of self-report measures of life satisfaction is questioned, particularly for use with affectively disturbed populations, since scores may be influenced by affective bias, poor insight, and recent life events. (Am J Psychiatry 1997; 154:99–105)
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ationwide attempts to curtail health expenditures have resulted in pressure to demonstrate treatment effectiveness in most areas of health. It is hoped that the use of clinical outcome evaluation will allow such cost cutting initiatives to occur while maintaining or improving delivery of health care (1–3). Medical specialties that service acutely ill patients are in a good position to define specific indicators of treatment outcome because of the strong relationship between treatment and treatment effects. These specialties may experience substantial advantages, since they are better able to concisely redress criticism with empirical evidence of treatment effectiveness. Presented in part at the 149th annual meeting of the American Psychiatric Association, New York, May 4–9, 1996. Received Aug. 1, 1995; revision received June 18, 1996; accepted July 1, 1996. From the Department of Psychiatry, University of Calgary, Foothills Hospital, and Regional Mental Health–Central Clinic, Calgary. Address reprint requests to Dr. Atkinson, University of Calgary, Foothills Hospital, 1403 29th St. N.W., Calgary, Alta., Canada T2N 2T9. Supported by funding from Provincial AIDS Program, Alberta Health. The authors thank Stacey Page, M.Sc., and Sonia Stewart, M.S.W., for their assistance with interviewing and data management and the staffs at Calgary Association of Self Help and Provincial Mental Health Central Clinic for their collaborative efforts.
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However, in psychiatry and other specialties that deal with chronic populations, the complex etiology and pervasive psychosocial effects of disorders present serious challenges to those who endeavor to assess program effectiveness (4). While not specific to mental health, such difficulties include 1) disease states of a chronic nature that involve intricate neuronal and endocrine systems, 2) treatment outcome indicators that tend to be multideterminant and lack clear causal specificity, 3) indicators of effectiveness that involve complex psychosocial systems, and 4) treatment approaches that often focus on the prevention or maintenance of psychosocial function as opposed to circumscribed curative goals. Such difficulties may have contributed to the heavy reliance on convenient, institutionally based outcome indices whose primary focus is the reduction of acute care utilization (e.g., length of hospital stay, readmissions, emergency room visits). Recent initiatives that have attempted to determine the benefits of services by using functional measures, disease-specific outcome indicators, and quality of life measures have uncovered new challenges to evaluators of mental health services. This article is intended to present our findings with respect to problematic issues that one is likely to encounter when engaging in quality
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of life measurement with chronically mentally ill patient populations. Four questions guided inquiry in the current study. 1) How do patients with chronic mental illness characterize the quality of their lives in the areas of health, socioeconomics, psychological/spiritual wellness, and familial status? 2) Do patients with schizophrenia, bipolar disorder, and depression differ in terms of the perceived importance of and satisfaction with each of these domains of life? 3) How do these groups compare with a sociodemographically similar group of patients with a chronic physical illness? 4) What instrument and measurement issues are brought to bear on the validity of self-report measures of life quality and data collection initiatives in general? With these questions in mind, what follows is a brief review of literature in the area of quality of life measurement with mentally ill patients and then results from our own research project. QUALITY OF LIFE: MEASUREMENT AND METHODOLOGICAL ISSUES
In a poignant critique of patient satisfaction methodology, Williams (5) asserted that the validity of self-report ratings is contingent on knowing what the patient means when making the rating—including the evaluations, comparisons, and situational events that influence a patient’s responses. In an attempt to account for the impact of evaluative factors on quality of life measures, a discrepancy model is often employed in which a patient’s rating of importance of an area or event is used to weigh their satisfaction or impact rating in that domain (6–8). This approach was used by Ferrans and Powers in their design of the Quality of Life Index (9). Typically, quality of life researchers who work with mentally sound populations also attempt to reduce measurement bias and error by reducing or controlling for the effects of evaluative sets, response bias, and coercive distortion. Within mental health, however, such concerns may take a back seat to more serious threats to the validity of self-report instruments and research methods (10). Psychopathology may affect the very mental, emotional, and social judgments on which patients’ responses to quality of life instruments are based, which would thereby distort self-report ratings of both quality of life and the impact of health-related life events (11). Jenkins (12) noted that although the responses of mental health patients to quality of life instruments should ideally reflect their current physical, psychological, and social situations, such responses are likely to be obscured by individuals’ expectations, personal desires, or mental states. Depression, for example, has been shown to result in an over self-reporting of poor social adjustment and negative life events as well as greater dissatisfaction with social roles (13, 14). As a result, Jenkins further argued, along with others in the field (15, 16), that quality of life data should be based on observable or specific descriptive phenomena as much as possible
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and warns against the use of self-ratings, which can be biased by medication, cognitive and emotional functioning, and motivation for life improvement. Despite these caveats, many health care evaluators continue to suggest reliance on self-report measurement tools for evaluation initiatives. A second set of issues arises with respect to individuals’ aspirations and awareness. Mental health patients may lack the insight or motivation to improve their life situation. Unless patients recognize life area deficits and exhibit motivation to improve, life quality is likely to be low. Yet life experiences may be rated as more satisfactory because of a lack of desire to affect change in one’s life. Moreover, patients’ lack of insight regarding the impact of illness on their lives may also result in elevated life satisfaction scores over what a more insightful person might report (12). In fact, helping a patient overcome denial has been considered by practitioners as a crucial step in the recovery or management of chronic mental illness (17). These issues cast uncertainty on the utility of self-report methodologies with certain patient populations, particularly when the intent is to gather objective life event or situational indicators of life quality. As a result of the impact of mental illness on self-report scores, some have suggested that self-report (for this purpose) be discarded in favor of assessment made by treatment professionals or proxy report measures (12, 18, 19). Indeed, the error introduced by perceptual distortions, lack of insight, delusions, and response bias may limit the use of self-report methodologies among psychiatric populations to situations in which assessment of symptoms is the primary focus (20, 21). METHOD Chronically mentally ill patients between the ages of 20 and 50 were recruited from the Provincial Mental Health Central Clinic in Calgary (N=110) and the Calgary Association of Self Help (N=31), an association that serves the needs of chronically needy persons on a drop-in basis. Participants from both groups were sought on a volunteer basis. A comparison of both groups on all demographic, health, and life quality variables revealed no significant differences. As a result, both groups were combined for a total of 141 subjects with DSM-III-R diagnoses of schizophrenia (N=69), bipolar disorder (N=37), or major depression (N=35). Each person who agreed to participate was provided a copy of the consent form and a copy of the composite interview questionnaire. After being informed of the study’s objectives and signing the consent form, each subject was privately interviewed for approximately 35– 40 minutes. During the interview, a research assistant read questionnaire items aloud as subjects read along. After each item, participants were asked for their response, which was noted on the research questionnaire. Factors that affected the validity of participants’ responses, such as their inability to answer or inapplicability of certain items, were also noted by the interviewer. Responses to questionnaires were subsequently tabulated, analyzed, and stored in such a way as to prevent identification of individual persons and violation of their anonymity within the research project.
Interview Questionnaires and Psychometric Properties The composite interview questionnaires consisted of two sections. The first section gathered demographic data, and the second was the
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Quality of Life Index (9). DemoTABLE 1. Self-Reported Ratings on Components of the Quality of Life Index of Patients With Schizographic data included information phrenia, Bipolar Disorder, or Depression such as age, sex, education, religion, Patients With living accommodations, hospitaliPatients With Patients With Bipolar zations, and medication. Schizophrenia Depression Disorder The Quality of Life Index ex(N=69) (N=35) (N=37) amines the quality of the responQuality of Life F dents’ lives in four areas: health and Mean SD Mean SD Mean SD Index Component (df=2, 138) functioning, socioeconomics, psychological/spiritual wellness, and Health and functioning family life (9). Reports on the psyImportance rating 5.2 0.6 5.2 0.6 5.1 0.9 chometric properties of the Quality Satisfaction rating 0.6 1.1 –0.1 1.1 –0.4 1.0 12.4*** of Life Index indicate that it is a Composite score 18.4 5.9 14.6 5.6 13.2 5.2 11.6*** sound instrument, with high interSocioeconomic nal consistency (total alpha=0.93, Importance rating 5.2 0.7 5.0 1.0 5.3 0.6 with alpha values for the four subSatisfaction rating 0.6 1.1 0.1 1.2 –0.2 1.0 7.1*** scales of 0.87, 0.82, 0.90, and 0.77, Composite score 18.3 6.2 15.3 6.2 13.9 5.2 7.3*** respectively). A factor analysis of Psychological/spiritual 800 hemodialysis patients has proImportance rating 5.4 0.6 5.2 0.7 5.3 0.7 vided some evidence for construct Satisfaction rating 0.7 1.2 –0.2 1.2 –0.5 1.0 15.2*** validity of the Quality of Life Index Composite score 19.2 5.9 14.1 6.6 12.7 5.6 14.6*** (9). The four-factor solution acFamily counted for 91% of the variance in Importance rating 5.5 0.5 5.4 0.9 5.4 0.8 the measure. Correlations between Satisfaction rating 1.0 0.9 0.5 1.2 0.4 0.8 4.6** each factor and other related inComposite score 20.7 5.3 18.3 6.8 17.9 4.7 3.9* struments or criteria provide eviOverall score 18.6 5.5 14.9 5.2 13.9 4.2 12.9*** dence for the convergent validity of *p
