Current status of quality of life assessment in schizophrenic patients

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1 Eur Arch Psychiatry Clin Neurosci (2001) 251: Suppl. 2, II/38 II/42 Steinkopff Verlag 2001 Julio Bobes Current status of quality of life assessment in schizophrenic patients Abstract Though the need to evaluate the quality of life of schizophrenic patients is well recognized, there are significant issues that remain unsolved. Are these patients capable of judging their own quality of life or does their illness invalidate their responses? Are there any psychometrically valid instruments that enable us to assess quality of life in these patients? When should quality of life be assessed in schizophrenics? While the ERIQA European Group completes their work and provide us with some common guidelines concerning quality of life assessment in medicine, this article provides some simple action guidelines regarding these questions. These guidelines are the result of analyzing the most up-to-date literature in the field. It also takes a brief look at the most universally used tools. Key words Quality of life (QoL) assessment schizophrenia Introduction The field of assessment in psychiatry in general and in schizophrenia in particular has reached a high level of development and interest in the last two decades. The contribution made by Bech (1993) with his work Rating scales for psychopathology, health status and quality of life stands out among the efforts made to establish some kind of order in this field. The title of this work describes another area in which Bech has been a pioneer quality of life and the psychological well being of the mentally ill in general and schizophrenics in general (Bech 1990), as Julio Bobes ( ) Dep. of Psychiatry University of Oviedo Julian Claveria 6, Oviedo, Spain Phone and fax: bobes@correo.uniovi.es, bobes@ctv.es demonstrated by the numerous publications he has produced since the 1980s. Quality of life assessment is based on the principle of applying medical care and interventions, bearing in mind the principle of autonomy of these patients, which necessarily includes taking their opinions into account both in diagnostic evaluations and prognoses, as well as for therapeutic interventions and medical care management. One of the events that has propelled the spectacular advancement of quality of life assessment in schizophrenic disorders was the fact that, in 1989, the Congress of the United States passed the Patient Outcome Research Act, requiring that quality of life be included as a basic measure of outcome assessment for the approval and registration of all kinds of drugs. On the other hand, the appearance of new antipsychotics, with better tolerance profiles, pushed the development and implementation of quality of life studies in schizophrenics even further, thus, contributing to a progressive move forward in evaluation techniques of this outcome that has proven itself to be sensitive to mid- and long-term evolution. In Europe, things are different than they are in the USA, since the most recent guidelines put out by the European Committee for Proprietary Medicinal Products (1998) of the European Drug Agency do not include quality of life among the aspects that must be evaluated in antipsychotic drugs. However, as a result of the tremendous amount of information on quality of life being produced of varying levels of quality, a European group has been created with the aim of establishing clear assessment and action guidelines in this field. This group, called ERIQA European Regulatory Issues on HRQoL Assessment (Acquadro 2000), arose as a consequence of the following conclusions that were reached among researchers in the field of health related quality of life, the European regulating bodies and the Food and Drug Administration: The need to rationalize research into health-related quality of life.

2 The need for health-related quality of life to be considered by health authorities as a reliable criterion in the assessment of new treatments. To reach these two objectives, a collaborative effort must be made by the main players involved, that is, health authorities, researchers in the field of healthrelated quality of life, and the pharmaceutical industry. Within this reference framework, the ERIQA Group s work consists of responding to the following basic questions: What does health-related quality of life assessment add to conventional assessment (mainly clinical parameters)? Are the instruments for assessing health-related quality of life internationally well validated? Have all quality of life assessment instruments been proven to have adequate psychometric properties? Do we know how to analyze health-related quality of life data adequately? What do the observed changes in quality of life mean? The answer to this last question is particularly significant, since it is the issue researchers are currently facing; whereas the concept of statistically significant has become more familiar and easier to interpret, the clinical relevance and interpretation of that statistical significance continues to be a trickier and more obscure area that has been analyzed in very few studies (Bobes et al. 1999). While we wait for the ERIQA Group to provide general guidelines, this article attempts to answer the more pressing questions about the current status of quality of life assessment in schizophrenic patients. The objective, therefore, is to provide clinicians and researchers with guidelines to lead them in the complex task of assessing schizophrenic patients quality of life. The questions it answers are as follows and are discussed below. Given that quality of life is a subjective assessment, are schizophrenic patients in a position to judge their life situation, and therefore, can we accept the subjective assessments made by these patients as valid? Do we have instruments that are capable of evaluating schizophrenic patients quality of life? Are schizophrenic patients able to evaluate their own quality of life? Since the view that quality of life refers to a subjective evaluation is unanimously accepted, it seems logical to affirm that only the patients themselves are the ideal evaluators for this outcome. However, this conclusion is not entirely accepted in the field of mental disorders (Gill and Feinstein 1994). Specifically, this issue is of special concern in the case of schizophrenic patients. The credibility of their self-reports can be questioned due to the fact II/39 that they lack insight into their illness and suffer cognitive deficiencies (Orley et al. 1998). Since the 1980s many efforts have been made to determine if such patients are able to judge their own quality of life (Bobes and Gonzalez 1997). As early as 1983, Lehman (1983a, 1983b) demonstrated that from a methodological point of view, statistically reliable quality of life data could be collected from chronically, mentally ill patients, concluding that subjective quality of life assessments can indeed be applied to such patients. From a clinical perspective there is greater controversy; despite the fact that discrepancies between the assessments made by patients and other evaluators clinicians or proxies have been shown to exist, there are more and more data that support the validity of the assessments made by these patients (Skantze et al. 1992, Lehman et al. 1993, Voruganti et al. 1998, Franz et al. 2001). In light of these studies, it would seem reasonable to accept that the self-reports of stabilized schizophrenic patients are valid and reliable, whereas in the case of acute and/or too disorganized patients, proxy assessments would be better. Do we have the appropriate instruments to assess schizophrenic patients quality of life? Huxley (1999) explains how the initial development of quality of life instruments was clinimetric rather than psychometric. Consequently, some of the existing instruments may have one or more of the following drawbacks (Evenson and Vieweg 1998): they lack a theoretical basis, have unclear and overlapping definitions, lack data on the sensitivity of such measures in treatment outcome, have potential confounding elements between symptoms and functioning with quality of life, and a need for norms of target populations. However, several psychometrically reliable and valid, multidimensional questionnaires for measuring QoL in schizophrenic patients are now available. In psychiatry, the use of quality of life indexes which provide a single score reflecting the level of patients quality of life has been rejected in favor of multidimensional instruments that provide a profile with the level of quality of life in different life domains. This later approach is much richer and provides meaningful insight into relevant aspects of schizophrenics lives. Quality of life instruments can be classified into generic or specific; generic instruments are designed to measure health status quality of life in the general population and in any ill population while specific instruments are intended to measure the quality of life in severely, mentally ill patients. These two kinds of instruments are not antagonistic but rather complementary, making it preferable to use both kinds together whenever possible. We will now go on to briefly review the most relevant aspects of the currently most widely used instruments in assessing schizophrenic patients quality of life.

3 II/40 Generic quality of life instruments Generic instruments have some advantages over specific instruments that provide reason enough to support their use when assessing quality of life in schizophrenic patients: they provide broader information as they assess all aspects of life, not only those related to the specific illness, and they allow comparisons with other illnesses that are of crucial importance in resource allocation. The MOS 36-Item Short-Form Health Survey SF-36 Originally developed in 1992 by Ware and Sherbourne for assessing perceived health status, it is one of the most widely used quality of life instruments and has been applied to nearly all types of patients. The SF-36 has been subsequently adapted for use in several European countries in the context of the IQOLA Project (Ware et al. 1994). Conceptual framework A two-dimensional model of health status: physical and mental. Structure It consists of 36 items that measure eight health concepts: physical functioning (PF), role limitations attributed to physical health problems (RP), bodily pain (BP), general health (GH), vitality (VT), social functioning (SF), role limitations because of emotional problems (RE), and mental health (MH). These eight scales form two higher-ordered clusters or summary measures: physical (PCS) and mental component summary (MCS). Administration Self-rated. It takes approximately 15 minutes. Scoring procedure The scores given by the patients are aggregated and transformed into a scale of 0 to 100 for each scale, with a score of 100 indicating the best level of health. World Health Organization Quality of Life Instruments: the WHOQOL-100 and the WHOQOL-BREF The WHOQOL-100 was simultaneously developed by the WHOQOL Group at 15 international field centers (Orley and Kuyken 1994) and the WHOQOL-BREF, with data from these 15 field centers plus five new centers (The WHOQOL Group 1998). Conceptual framework Quality of life is defined as an individual s perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards and concerns (WHO 1993). WHOQOL-100 Structure The WHOQOL-100 consists of 100 items grouped into one overall quality of life and general health scale (4 items) and six broad domains of quality of life (96 items): physical health, psychological, level of independence, social relationships, environment and spirituality/religion/personal beliefs. These six domains are subdivided into 24 facets (each facet has 4 items). Items are formulated in terms of perceived objective questions and self-report subjective questions. WHOQOL-BREF structure The WHOQOL-BREF consists of 26 items selected from the WHOQOL-100. Twenty-four items are grouped into four quality of life domains: physical health, psychological, social relationships and environment, and the two items left provide a measure of overall quality of life and general health. Administration Self-rated. The WHOQOL-100 requires approximately 45 minutes, whereas the WHOQOL-BREF takes only minutes. Scoring Scores are based on a five-point scale (1-5). The WHOQOL-100 provides scores for each quality of life domain and facet and an overall quality of life and general health score. The WHOQOL-BREF only provides the overall quality of life and general health score and scores for each of the quality of life domains. Specific quality of life instruments In the past two decades many instruments for assessing quality of life in severe mentally ill patients have been developed. The rationale for this kind of instrument is twofold; on the one hand, there are particular issues which play a greater role in the quality of life of patients with certain diseases, and, on the other hand, it has been demonstrated that the more specific the instrument, the more sensitive it is to changes in their condition. The Quality of Life Scale QLS Originally developed by Heinrichs et al. (1984) as an instrument for assessing deficit symptoms in schizophrenic patients, it has been used as a quality of life rather than a deficit instrument. This is the only scale specifically designed for schizophrenia and not for severe, chronic mental disorders in general. Conceptual framework Deficit symptoms and impaired functioning need to be taken into account in the evaluation of schizophrenic patients. Structure The QLS is made up of 21 items that provide information on symptoms and level of functioning. Items are grouped into four categories: intro-psychic foundations, interpersonal relations, instrumental role, and common objects and activities.

4 II/41 Administration It is a clinician-rated, semi-structured interview, as opposed to the subjective nature of the concept of quality of life. It takes approximately 45 minutes. Scoring Scores are based on a 7-point scale (the higher the rating, the better the functioning). It provides a global score and scores in each of the four categories. The Quality of Life Interview QoLI Developed by Lehman et al. (1982) for assessing the life circumstances of severely, mentally ill patients in terms of both objective (what he/she does and experiences) and subjective (how he/she feels about these experiences) quality of life. Conceptual framework Quality of life is a subjective matter that is a product of personal characteristics, objective life conditions in various domains and subjective satisfaction with these life conditions in the same life domains (Lehman 1988). Structure The core version is made up of a global measure of general life satisfaction and objective and subjective measures of the eight following life domains: living situation, daily activities, family relations, social relations, finances, job, safety, health. The subjective general life satisfaction scale measures the patient s perceived global well-being by asking How do you feel about your life in general? at the beginning and at the end of the interview, using a 7-point scale that ranges from terrible (1) to delighted (7). Questions for each life domain are organized so that information about objective quality of life is obtained first and then subjective information is gathered. Administration It is a structured, self-report interview administered by trained lay interviewers. The interview requires about 45 minutes. Scoring All subjective quality of life information is rated using the terrible-delighted scale. It provides a global, general, life satisfaction score and objective and subjective scores on the eight life domains. The Wisconsin Quality of Life Index W-QLI This index was initially developed by Becker et al. (1993) with the name of Quality of Life Index for Mental Health QLI-MH for evaluating the effects of treatment on quality of life and caregiver burden. Conceptual framework Quality of life is defined as a person s sense of well-being that stems from satisfaction or dissatisfaction with the areas of life that are important to him/her. Structure The W-QLI consists of 113 items that assess the following nine semi-independent domains: life satisfaction, occupational activities, psychological well-being, physical health, social relations, economics, activities of daily living, symptoms, and goal attainment. Administration It is the only instrument that includes provider, patient and family perspectives. Each domain is independently rated by the patient, the clinician and a proxy rater if available (a family member or some other significant person). Conclusions Though we are still waiting for the report on quality of life assessment in the field of medicine, in the specific case of schizophrenic patients, we have sufficient data to allow us to establish certain preliminary guidelines. When in stable periods, these patients are capable of making valid and reliable assessments of their quality of life. We have psychometrically valid generic and specific instruments to evaluate schizophrenic patients quality of life. The choice of instrument(s), as well as the evaluation times, will depend upon the aim of the quality of life measurement, although it has been generally accepted that if possible, a generic instrument should be used combined with a specific one and that a basal assessment will always be made (before intervention) with later follow-up assessments based on the kind of intervention applied. References Acquadro C (for the ERIQA Group) (2000) The European Regulatory Issues on Health-Related Quality of Life Assessment (ERIQA) Project: preliminary results and plans for the future. Quality of Life News Letter 24: 1 3 Bech P (1993) Rating Scales for Psychopathology, Health Status and Quality of Life. A Compendium on Documentation in Accordance with the DSM-III-R and WHO Systems. Springer-Verlag, Berlin Heidelberg Bech P, Hjortso S (1990) Problems in measuring quality of life in schizophrenia. 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