Assessing health utilities in schizophrenia. A feasibility study

Time trade-off health state utility values for depression: a systematic review and meta-analysis

PURPOSE

This study aims to systematically review the literature on health utility in depression generated by time trade-off (TTO) method and to compare health state vignettes.

METHODS

Systematic literature search was conducted following PRISMA guideline in 2020 November (updated in 2022 March) in Pubmed, Web of Science, PsycInfo, and Cochrane Database of Systematic Reviews. Random effect meta-analysis was conducted to pool vignette-based utility values of mild, moderate, and severe depression and to compare the preferences of depressed and nondepressed population.

RESULTS

Overall, 264 records were found, 143 screened by title and abstract after removing duplicates, 18 assessed full text, and 14 original publications included. Majority of the studies (n = 9) used conventional TTO method, and most of the studies (n = 8) applied 10-year timeframe. Eight studies evaluated self-experienced health (own-current depression). Six studies assessed vignette-based health states of remitted, mild, moderate, and severe depression, half of them applied McSad measure based health description. Altogether, 61 different utility values have been cataloged, mean utility of self-experienced depression states (n = 33) ranged between 0.89 (current-own depression) and 0.24 (worst experienced depression). Pooled utility estimates for vignette-based mild, moderate, and severe depression was 0.75, 0.66 and 0.50, respectively. Meta-regression showed that severe depression (β = -0.16) and depressed sample populations (β =  -0.13) significantly decrease vignette-based utility scores.

CONCLUSION

Our review revealed extent heterogeneity both in TTO methodology and health state vignette development. Patient's perception of depression health states was worse than healthy respondents.

The seven key challenges for life-critical shared decision making systems

BACKGROUND

Shared decision making (SDM) for life-critical diseases or conditions is a crucial type of SDM. This type of SDM is still greatly underdeveloped and it faces a number of key challenges. The main goal of this study is to identify the challenges that impede the development and use of life-critical SDM.

METHODS

This is a hybrid research and systematic / narrative review paper. Its results were derived by analyzing reviews already conducted by the authors when they were working on six recently published papers. These papers had collectively required two systematic reviews and four narrative reviews. The topics covered in the six published papers were related to computer-aided diagnosis (CAD) in medicine, the analysis of health state utilities, and the selection of the best treatment for life-critical diseases / conditions. A new narrative review was also executed to explore some new issues.

RESULTS

The key challenges for life-critical SDM relate to the following aspects: The mathematical models used to make the decisions, the data used to feed these models, the role the patient plays within the SDM framework, and finally, the role healthcare professionals play along with the pertinent rules and regulations that guide the use of this type of SDM today.

CONCLUSIONS

Life-critical SDM is the most important type of SDM. However, some challenges impede its successful development and use. A number of developments and enhancements need to be made urgently for this type of SDM to become widely acceptable and useful. The seven key challenges identified in this study and the suggested directions for future research offer a compelling path towards elevating life-critical SDM to the next level and do so both effectively and efficiently.

Health State Utility Values in Schizophrenia: A Systematic Review and Meta-Analysis

OBJECTIVES

Patient preferences are increasingly important in informing clinical and policy decisions. Health-state utility values (HSUVs) are quantitative measures of people's preferences over different health states. In schizophrenia, there is no clarity about HSUVs across the symptoms' severity spectrum. This meta-analysis aims to synthesize the literature on HSUVs in people with schizophrenia.

METHODS

We searched Medline, PsycInfo, Embase, EconLit, The Cochrane Library, and specialized databases. The studies reporting HSUVs in people with schizophrenia were selected and pooled in a random-effects meta-analysis. The primary outcome was the mean HSUV obtained from participants.

RESULTS

A total of 54 studies involving 87 335 participants were included. The pooled estimate using direct elicitation was a mean HSUV of 0.79 (95% CI: 0.70-0.88) for mild symptomatic states, 0.69 (95% CI: 0.54-0.85) in moderate states, and 0.34 (95% CI: 0.13-0.56) in severe states. Studies using indirect techniques resulted in a pooled mean HSUV of 0.73 (95% CI: 0.67-0.78) applying the EuroQol 5-dimension, 0.66 (95% CI: 0.62-0.71) in the Short-Form 6-dimension, and 0.59 (95% CI: 0.57-0.61) using the Quality of Well-Being scale. All the estimates resulted in considerable heterogeneity, partially reduced by meta-regression.

CONCLUSION

Our findings suggest that the severity of psychotic symptoms has an important effect on HSUVs in schizophrenia, with values mirroring patients with disabling physical conditions such as cancer and stroke. Decision makers should be aware of these results when including people's preferences in trials, models, and policy decisions.

The capacity of schizophrenia and bipolar disorder individuals to make autonomous decisions about pharmacological treatments for their illness in real life: A scoping review

BACKGROUND AND AIM

Having decision making capacity is central to the exercise of autonomy in mental health care. The objective of this scoping review is to summarize the evidence on the capacity of people with schizophrenia or bipolar disorder to make decisions about their treatment in real life to support medical practice.

METHODS

Systematic search of observational studies on the assessment of capacity of patients with schizophrenia, psychosis, or bipolar disorder to make healthcare and treatment-related decisions, conducted in any clinical setting published up to January 31, 2020 was performed. Free text searches and medical subject headings in English were combined in PubMed, Scopus, CINAHL, and PsycInfo. Publications were selected as per inclusion and exclusion criteria. The Newcastle-Ottawa Scale for observational studies was used to assess the quality of publications.

RESULTS

Thirty publications were reviewed. According to the Newcastle-Ottawa Scale criteria, the publications reviewed were good quality. Findings showed that more than 70% of schizophrenia and schizoaffective disorder outpatients understood treatment options at the point of making decisions about their illness and healthcare. Patients treated voluntarily had considerably better scores for decisional capacity than those treated involuntarily. The burden of psychiatric symptoms could compromise decisional capacity temporarily. Decision-making capacity improved over time from admission to discharge from hospital, and with treatment among psychiatry inpatients. Schizophrenia and bipolar disorder patients could be as competent as nonpsychiatric individuals in making decisions about their treatments in everyday life.

CONCLUSIONS

This scoping review provides a body of evidence for healthcare professionals in need of assessing the capacity of schizophrenia and bipolar disorder patients for autonomously decide about their treatments. Decisional capacity judgements should consider variations in capacity over time and be based on the type of decision to be made, the severity of symptoms, and the specific phase of the mental disorder.

A systematic literature review identifying associations between outcomes and quality of life (QoL) or healthcare resource utilization (HCRU) in schizophrenia

AIMS

There have been no systematic literature reviews (SLRs) evaluating the identified association between outcomes (e.g. clinical, functional, adherence, societal burden) and Quality-of-Life (QoL) or Healthcare Resource Utilization (HCRU) in schizophrenia. The objective of this study was to conduct a SLR of published data on the relationship between outcomes and QoL or HCRU.

MATERIALS AND METHODS

Electronic searches were conducted in Embase and Medline, for articles which reported on the association between outcomes and QoL or HCRU. Inclusion and exclusion criteria were applied to identify the most relevant articles and studies and extract their data. A summary table was developed to illustrate the strength of associations, based on p-values and correlations.

RESULTS

One thousand and two abstracts were retrieved; five duplicates were excluded; 997 abstracts were screened and 95 references were retained for full-text screening. Thrirty-one references were included in the review. The most commonly used questionnaire, which also demonstrated the strongest associations (defined as a p < 0.0001 and/or correlation ±0.70), was the Positive and Negative Syndrome Scale (PANSS) associated with HCRU and QoL (the SF-36, the Schizophrenia Quality-of-Life questionnaire [S-QOL-18], the Quality-of-Life Scale [QLS]). Other robust correlations included the Clinical Global Impression-Severity (CGI-S) with QoL (EQ5D), relapse with HCRU, and remission with QoL (EQ5D). Lastly, functioning (Work Rehabilitation Questionnaire [WORQ] and Personal and Social Performance Scale [PSP]) was found to be associated to QoL (QLS and Subjective Well-being under Neuroleptics Questionnaire [SWN]).

LIMITATIONS

This study included data from an 11-year period, and other instruments less frequently used may be further investigated.

CONCLUSIONS

The evidence suggests that the PANSS is the clinical outcome that currently provides the most frequent and systematic associations with HCRU and QoL endpoints in schizophrenia.

What utility scores do mental health service users, healthcare professionals and members of the general public attribute to different health states? A co-produced mixed methods online survey

Background

Utility scores are integral to health economics decision-making. Typically, utility scores have not been scored or developed with mental health service users. The aims of this study were to i) collaborate with service users to develop descriptions of five mental health states (psychosis, depression, eating disorder, medication side effects and self-harm); ii) explore feasibility and acceptability of using scenario-based health states in an e-survey; iii) evaluate which utility measures (standard gamble (SG), time trade off (TTO) and rating scale (RS)) are preferred; and iv) determine how different participant groups discriminate between the health scenarios and rank them.

Design and methods

This was a co-produced mixed methods cross-sectional online survey. Utility scores were generated using the SG, TTO and RS methods; difficulty of the completing each method, markers of acceptability and participants’ preference were also assessed.

Results

A total of 119 participants (58%) fully completed the survey. For any given health state, SG consistently generated higher utility scores compared to RS and for some health states higher also than TTO (i.e. SG produces inflated utility scores relative to RS and TTO). Results suggest that different utility measures produce different evaluations of described health states. The TTO was preferred by all participant groups over the SG. The three participant groups scored four (of five) health scenarios comparably. Psychosis scored as the worst health state to live with while medication side-effects were viewed more positively than other scenarios (depression, eating disorders, self-harm) by all participant groups. However, there was a difference in how the depression scenario was scored, with service users giving depression a lower utility score compared to other groups.

Conclusion

Mental health state scenarios used to generate utility scores can be co-produced and are well received by a broad range of participants. Utility valuations using SG, TTO and RS were feasible for use with service users, carers, healthcare professionals and members of the general public. Future studies of utility scores in psychiatry should aim to include mental health service users as both co-investigators and respondents.

What matters to patients? A systematic review of preferences for medication-associated outcomes in mental disorders

OBJECTIVE

To investigate patients' preferences for outcomes associated with psychoactive medications.

SETTING/DESIGN

Systematic review of stated preference studies. No settings restrictions were applied.

PARTICIPANTS/ELIGIBILITY CRITERIA

We included studies containing quantitative data regarding the relative value adults with mental disorders place on treatment outcomes. Studies with high risk of bias were excluded.

PRIMARY AND SECONDARY OUTCOME MEASURES

We restricted the scope of our review to preferences for outcomes, including the consequences from, attributes of, and health states associated with particular medications or medication classes, and process outcomes.

RESULTS

After reviewing 11 215 citations, 16 studies were included in the systematic review. These studies reported the stated preferences from patients with schizophrenia (n=9), depression (n=4), bipolar disorder (n=2) and attention deficit hyperactive disorder (n=1). The median sample size was 81. Side effects and symptom outcomes outnumbered functioning and process outcomes. Severe disease and hospitalisation were reported to be least desirable. Patients with schizophrenia tended to value disease states as higher and side effects as lower, compared to other stakeholder groups. In depression, the ability to cope with activities was found to be more important than a depressed mood, per se. Patient preferences could not consistently be predicted from demographic or disease variables. Only a limited number of potentially important outcomes had been investigated. Benefits to patients were not part of the purpose in 9 of the 16 studies, and in 10 studies patients were not involved when the outcomes to present were selected.

CONCLUSIONS

Insufficient evidence exists on the relative value patients with mental disorders place on medication-associated outcomes. To increase patient-centredness in decisions involving psychoactive drugs, further research-with outcomes elicited from patients, and for a larger number of conditions-should be undertaken.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42013005685.

Utility decrements associated with side effects in schizophrenia

OBJECTIVE

Most of the existing studies investigating the impact of schizophrenia on utility have focused on the different stages of the disease. The objective of this study was to describe and quantify the impact of treatment-related side-effects on utility in patients with schizophrenia, using data from an observational study.

METHODS

This study used data from the European Schizophrenia Cohort (EuroSC), a multi-center 2-year cohort study conducted in France, England, and Germany. The EQ-5D questionnaire was completed every 6 months, as well as the Subjective Side Effect Rating Scale, assessing patient distress over extrapyramidal symptoms (EPS), weight gain, sedation, and sexual dysfunction, used to assess whether or not the patient experienced the side-effect. At first a bivariate analysis was conducted to describe utility values with and without side-effects. Then, a random effects regression analysis was performed on utility, where random effects were controlled for repeated measures on the same subjects, with potential confounding factors. Finally, findings were compared with those of previous publications.

RESULTS

This sample consisted of 1208 patients with schizophrenia. At the baseline visit, the most reported side-effect was EPS (almost 60% of patients), followed by sedation and weight gain (∼50% of patients for each), and sexual dysfunction (almost 30% of patients). Significant association with severity of symptoms, functioning abilities, and utility were found. Patients reporting none of the studied side-effects had an average EQ-5D index score of 0.81, found to be higher than scores of patients reporting EPS (0.70), sexual dysfunction (0.67), sedation (0.70), or weight gain (0.72). The random effects model reported a utility decrement of 0.042 for EPS, 0.022 for weight gain, 0.022 for sexual dysfunction, and 0.019 for sedation. Although the external validation was difficult due to the different methods or definitions of the side-effects, as well as the paucity of data for weight gain, sedation and sexual dysfunction, the results were generally consistent with previous studies.

CONCLUSION

This study aimed at quantifying the direct impact of main side-effects associated with antipsychotics on patients' utility. RESULTS suggested a significant direct impact of side-effects, with EPS being the most impactful.

Valuation of depression co-occurring with a somatic condition: feasibility of the time trade-off task

BACKGROUND

Health state valuations obtained from the general population are used for cost-utility analyses of health-care interventions. Currently, most studies have focused on valuations of somatic conditions, to a much lesser extent of mental states, that is, depression and even less on valuations of depression co-occurring with somatic conditions.

OBJECTIVE

We tested the feasibility of the time trade-off (TTO) task to elicit valuations for depression solitary or co-occurring with a somatic condition. Moreover, we explored person- and state-related factors that may affect valuations.

DESIGN

During semi-structured interviews, 10 individuals (five women, mean age: 36 years) used a TTO task to value vignettes describing mild and severe depression; and mild depression co-occurring with moderate and severe states of cancer, diabetes or heart disease. During valuations, participants were thinking aloud. Feasibility criteria were successful completion and difficulty/concentration (1-10); logical consistency of values; and comprehension of the TTO, based on qualitative analysis of think aloud data. Factors influencing valuations were generated from think aloud data.

RESULTS

Participants reported satisfactory levels of difficulty (mean: 1.9) and concentration (mean: 8.3) and assigned consistent values. Qualitative analysis revealed difficulties with imagining: living with depression for lifetime (n = 4); reaching the age of 80 (n = 6); and living with a somatic condition and mentally healthy (n = 6). Person- and state-related factors, for example perceived susceptibility to depression (n = 4), appeared to affect valuations.

CONCLUSION

Quantitative findings supported feasibility of the valuation protocol, yet qualitative findings indicated that certain task aspects should be readdressed. Factors influencing valuations can be explored to better understand valuations.

Measuring quality of life in patients with schizophrenia: an update

In 1997, we published a review in PharmacoEconomics about quality of life (QOL) measurement in patients with schizophrenia. The objective of this article is to provide an update, as well as to revisit the development of the construct of QOL and its measurement as applied to schizophrenia. Since our previous article, there has been significant growth in the number of publications about QOL in schizophrenia. Unfortunately, alongside this significant increase in research interest, a number of concerns have also risen about the limitations and lack of impact the concept of QOL has on clinical care and health-policy decision making. A number of concerns previously outlined (such as lack of consensus on a uniform definition of QOL) continue to be an issue. However, we believe that a uniform definition may not be possible, and instead, it may be preferable to have several definitions, which may enrich the concept and broaden its usefulness. Some of the scales we reviewed in 1997 continue to be in use, while others are now rarely or never used. New scales with better psychometrics have been introduced, but most are without theoretical or conceptual foundation. On the other hand, the field of scaling in general has been changing over the past few years and is moving towards a new approach for scale development, based on item response theory, item banks and computer adaptive testing. Unfortunately, this has not extended to QOL in schizophrenia. There continues to be a dearth of theoretical and conceptual models for QOL in schizophrenia, which seems to create the perception that the construct lacks a good theoretical and scientific foundation. One of the major gaps identified in this review is the recognized lack of impact of QOL measurements on clinical management or policy decision making. The majority of publications continue to focus on measurement rather than what to do with the data. The lack of strategies to integrate QOL data in clinical care, as well as the failure to contribute to policy decisions, particularly in cost analysis or resource allocations, has created the perception that the construct of QOL in schizophrenia is not that useful. It is evident that, for QOL in schizophrenia to regain its promise, researchers must take the ultimate next step beyond measurement: to develop credible strategies for integrating QOL data in clinical practice. Additionally, more focused research is needed to demonstrate the role of QOL, not only as an outcome in itself but also as a contributor to other outcomes, such as adherence to medications, more satisfaction, less resource utilization and so on. Since self-appraisal of QOL does not happen in a vacuum but relates to the total human experience in all its biological, psychosocial and environmental aspects, particular attention must also be focused on important neurobiological dimensions such as affect and cognition. Both are significantly affected by the illness itself and its treatment.

Quality of life of people with schizophrenia, bipolar disorder and other psychotic disorders

BACKGROUND

Health utility and quality of life (QoL) are increasingly important outcome measures in healthcare and health economics.

AIMS

To compare the loss of subjective QoL and utility-based health-related quality of life (HRQoL) associated with psychotic disorders.

METHOD

A representative sample of 8028 Finns was screened for psychotic disorders and bipolar I disorder. Lifetime psychotic disorders were diagnosed using the Structured Clinical Interview for DSM-IV and/or case records. Health-related quality of life was measured with EQ-5D and 15D, and QoL was measured with a 10-point scale.

RESULTS

Schizoaffective disorder was associated with the largest losses of QoL and HRQoL, with bipolar I disorder associated with similar or smaller losses than schizophrenia. Current depressive symptoms explained most of the losses.

CONCLUSIONS

Depressive symptoms are the strongest predictors of poor QoL/HRQoL in psychotic disorders. Subjective loss of QoL associated with psychotic disorders may be smaller than objective loss of functioning suggests. The EQ-5D is problematic as an outcome measure in psychotic disorders.

Valuing health in a racially and ethnically diverse community sample: an analysis using the valuation metrics of money and time

PURPOSE

Limited research in health valuation analyzes samples with high proportions of racial/ethnic minorities within the United States. The primary objective was to explore patterns of health valuation across race/ethnicity using the Collaborative Psychiatric Epidemiology Surveys. A secondary objective was to analyze whether mental health disorder and immigrant status were associated with these estimates.

METHODS

Health valuation questions using different metrics (time and money) were analyzed. Ordered logit models stratified across poor and moderate health tested differences by race/ethnicity, with mental health disorder and immigrant status as covariates.

RESULTS

Asians in moderate health and Latinos were willing to pay more for health than non-Latino whites. Asians in moderate health were willing to trade more time for health. Latinos in poor health were less willing to trade time and gave disproportionate zero-trade responses. Lifetime history of anxiety disorder was positively associated with both metrics. Immigrant status confounded money valuation for Asians in moderate health, and time valuation for Latinos in poor health.

CONCLUSIONS

Health valuation estimates vary across race/ethnicity depending upon the metric. Time valuation scenarios appear less feasible for Latinos in poor health. More research is necessary to understand these differences and the role of immigrant status in health valuation.

A review and critique of studies reporting utility values for schizophrenia-related health states

Economic evaluation of health technologies in the form of cost-utility analysis is increasingly advocated. The most common outcome measure in this type of analysis is the QALY. In order to estimate QALYs, appropriate utility values are required. The objective of this review was to identify and critique utility values for schizophrenia-related health states. A critical appraisal was performed on utility values for schizophrenia identified in the systematic literature review that informed the economic analysis of the updated edition of the National Institute for Health and Clinical Excellence (NICE) clinical guideline on schizophrenia for England and Wales. Seven studies reporting utility values for schizophrenia were identified. The studies employed a variety of methods for generating utility values. None of the reported sets of utility values for schizophrenia were generated using the EQ-5D, which is a measure widely used in cost-utility analysis and preferred by NICE. Nevertheless, the EQ-5D may be less sensitive in capturing aspects of health-related quality of life in patients with schizophrenia. A condition-specific preference-based instrument may be more appropriate than a generic measure to inform cost-utility analyses of interventions for schizophrenia.

Measuring and valuing mental health for use in economic evaluation

This article presents research undertaken as part of a wider programme of work concerned with measuring and health and wellbeing for economic evaluation. The focus is on developing quality adjusted life years (QALYs) in mental health, but the issues are common across all areas of health care. The article begins by reviewing the issues of what should be valued (health or broader notions of wellbeing), how mental health and wellbeing should be described, how mental health states should be valued and who should do the valuing. The article presents four pieces of work. The first is a re-analysis of the ONS Psychiatric Morbidity 2000 Survey to provide evidence on the relevance of generic measures across different mental health disorders. It found that common mental health problems, such as anxiety and depression, had a significant impact on the generic preference-based measure of health in the SF-6D, but psychosis and personality disorders did not. The article then presents two studies using the ratings of people experiencing the states of health. Both studies found that people experiencing different health states gave mental health greater weight than physical health compared to members of the general public trying to imagine the health states. Finally, the article presents a study developing a condition-specific preference-based measure for calculating QALYs from an existing measure of mental health, the CORE-OM, using modern psychometric methods to construct health states amenable to valuation. It also considers a proposal to develop an entirely new QALY measure in mental health.

Utility assessment in patients with mental disorders: validity and discriminative ability of the time trade-off method

BACKGROUND

Preference-based health-state values, also referred to as utility scores, are considered an important measure of outcome in the evaluation of healthcare. A common approach to elicit utility scores is the use of the time trade-off (TTO) method; however, the data on TTO utility scores in patients with mental disorders are scarce.

OBJECTIVE

To analyse the TTO method in patients with mental disorders in terms of discriminative ability, validity and the refusal to trade life time (zero trade).

METHODS

In patients with affective (n = 172), schizophrenia spectrum (n = 166) and alcohol-related (n = 160) mental disorders, TTO utilities were administered through a standardized interview. Measures of quality of life (QOL) EQ-5D, WHOQOL-BREF, subjective (SCL-90R) and objective (CGI-S) psychopathology, and functioning (GAF, GARF, SOFAS, HoNOS) provided comparison. Discriminative ability was analysed by assessing frequency distributions of TTO utilities. Validity was analysed by assessing the correlation of TTO utilities with all other scores. The association of a patient's QOL, sociodemographic and disease-related variables with zero trade was analysed by logistic regression.

RESULTS

Of patients with affective/schizophrenic/alcohol-related mental disorders, 153/143/145 (89/86/91%), respectively, completed the TTO elicitation; 29/43/28% of the respondents were zero traders. The mean TTO utility was 0.66/0.75/0.61 and the median was 0.85/0.95/0.75. TTO utility scores discriminated well among more impaired mental health states, but discrimination was limited among less impaired health states. In patients with affective and alcohol-related mental disorders, TTO utility scores were significantly correlated (mostly moderate: 0.3 < r < 0.5) with all other scores. However, in schizophrenic patients, TTO utility scores were only a little correlated with other subjective measures and not correlated with objective measures. QOL was significantly associated with zero trade; the influence of the other variables on zero trade was negligible.

CONCLUSIONS

TTO utility scores in patients with affective or alcohol-related mental disorders were reasonably valid, but discriminative ability was compromised by a ceiling effect due to zero trade. In schizophrenic patients, validity of TTO utility scores was not demonstrated.

Impact of schizophrenia and schizophrenia treatment-related adverse events on quality of life: direct utility elicitation

Objective

To examine the impact of schizophrenia, its treatment and treatment-related adverse events related to antipsychotics, on quality of life from the perspective of schizophrenia patients and laypersons.

Methods

Health state descriptions for stable schizophrenia, extra pyramidal symptoms (EPS), hyperprolactinemia, diabetes, weight gain and relapse were developed based on a review of the literature and expert opinion. The quality of life impact of each health state was elicited using a time trade-off instrument administered by interview to 49 stable schizophrenia patients and 75 laypersons. Regression techniques were employed to examine the importance of subject characteristics on health-related utility scores.

Results

Patients and laypersons completed the interview in similar times. Stable schizophrenia had the highest mean utility (0.87 and 0.92 for laypersons and patients respectively), while relapse (0.48 and 0.60) had the lowest mean utility. Of the treatment-related adverse events, EPS had the lowest mean utility (0.57 and 0.72, respectively). Age, gender and PANSS score did not influence the utility results independently of health state. On average, patient utilities are 0.077 points higher than utilities derived from laypersons, although the ranking was similar between the two groups.

Conclusion

Events associated with schizophrenia and treatment of schizophrenia can bring about a significant detriment in patient quality of life, with relapse having the largest negative impact. Results indicate that patients with stable schizophrenia are less willing to trade years of life to avoid schizophrenia-related symptoms compared to laypersons. Both sets of respondents showed equal ability to complete the questionnaire.

[Health economics of psychological diseases]

This article provides an overview of the characteristics and problems of the economic evaluation of mental health care. At first, the problems and methods of measuring direct and indirect costs of mental illness are discussed using cost of illness studies for depression and schizophrenia from the literature as examples. It is shown that, due to methodological problems of measuring costs of the wide range of mental health services as well as productivity losses, various cost of illness studies rendered very different results. Thereafter, the measurement of effects in the economic evaluation of mental health services is discussed whereby the problems of measuring quality-adjusted life years (QALYs) are addressed in particular. Despite the subjectivity of symptoms, preference-based valuation of health-related quality of life has rarely been attempted in psychiatric patients. Finally, frequent flaws of published cost-effectiveness analyses of mental health care are presented. These flaws make the interpretation and comparison of study results difficult. As there are hardly any German cost-effectiveness analyses of mental health care, more research efforts in this field seem to be necessary in Germany.

Outcome revealed by preference in schizophrenia (OPS): development of a new class of outcome measurements

The objective of this paper is to describe the development of a new type of outcome measurement, based on revealed preference, which can be used in serious chronic illnesses. Fifteen texts of about 200 words each were written by one of the authors on the day-to-day life of 15 schizophrenic patients. These 15 'slices of life' thus described were then ranked in terms of acceptability by a second group of 10 schizophrenic patients and by a group of 12 relatives of schizophrenic patients. From these rankings, six situations were selected so as to obtain evenly distributed positioning on an axis of acceptability. These six situations comprised the final instrument. In administration, the patients were first asked if the 'slices of life' that were described were acceptable or not, then if the 'slices of life' described were more or less acceptable than their own lives. Two scores were derived, one for an absolute level and the other for a relative level of the patient's satisfaction with his or her existence. Validation results were presented to a new sample of 229 schizophrenic patients. Internal consistency appeared good and the initial ranking of the six situations in terms of acceptability was confirmed. This study encourages the development of global outcome measures based on revealed preference in chronic serious illnesses.

Patient-based utilities for bipolar disorder-related health states

BACKGROUND

Bipolar disorder is a psychiatric disorder which impacts patient functioning and well-being. With increasing interest in cost-effectiveness of treatments, it is necessary to provide estimates of patient's perspectives on treatment outcomes. This study estimated health state utilities for hypothetical bipolar-related health states and patient's current health from bipolar I patients.

METHODS

Clinicians completed Young Mania Rating Scale, Montgomery-Asberg Depression Rating Scale, and Global Assessment Score. Patients completed structured standard gamble (SG) utility assessment interviews, and the other patient-based measures. Interviews obtained utilities for hypothetical bipolar-related health states describing symptom severity, functioning and well-being, and treatment-related side effects.

RESULTS

Ninety-six patients were recruited from psychiatry outpatient practices. Mean utilities for inpatient states ranged from 0.12 to 0.33; outpatient mania states ranged from 0.29 to 0.64; outpatient stable states ranged from 0.53 to 0.85. Mean utility for current health was 0.80 (S.D.=0.22). Patients preferred monotherapy compared with combination therapy health states. Ordinary least squares regression indicated weight gain was associated with a 0.066 decrease in health state utilities (P=0.013).

LIMITATIONS

Study sample consisted of selected stable and educated patients and small sample sizes may limit generalizability for some utilities.

CONCLUSIONS

Bipolar disorder patients are capable of participating in utility assessment and providing ratings for hypothetical health states associated with different mood stabilizer treatments.

Impact of atypical antipsychotics on quality of life in patients with schizophrenia

Schizophrenia is a long-term disabling illness that affects approximately 1% of the population. Its course is generally chronic with acute psychotic exacerbations that may require frequent hospitalisations. The clinical picture includes a range of symptoms such as delusions, hallucinations, agitation, suspiciousness, hostility, conceptual disorganisation, blunted affect, emotional and social withdrawal, lack of spontaneity, poverty of speech and a wide range of neurocognitive deficits. Over the past 50 years, antipsychotic medications have emerged as the cornerstone of management in concert with other important interventions, such as psychosocial and economic support and rehabilitation efforts. However, the unrivalled role of conventional antipsychotic medications has been continuously challenged by the wide range of adverse effects of these medications and their lack of usefulness in the treatment of neurocognitive deficits as well as deficit and negative symptoms. In addition, the lack of subjective tolerability of these agents and their negative impact on quality of life have complicated management for a large number of patients. Over the last 15 years, several new atypical antipsychotic medications have been introduced, including amisulpride, remoxipride, risperidone, sertindole, olanzapine, zotepine, quetiapine, ziprasidone and aripiprazole. In general, the new antipsychotics have shown themselves to be at least comparable in efficacy to conventional antipsychotics but with superior subjective tolerability and a more favourable adverse effect profile. The majority of quality of life studies involving new antipsychotic agents have evaluated the benefits of risperidone, olanzapine and clozapine; only a few studies have examined the effects of other new antipsychotics. While most of these studies have methodological and design limitations, the weight of evidence from them nevertheless points to a trend towards a more positive impact on quality of life with atypical agents. A number of recommendations can be made. First, more independent well designed and controlled studies are urgently needed to evaluate the effects of antipsychotic therapy on quality of life in patients with schizophrenia. New comparative studies should explore not only the differences between new and old antipsychotics but also identify any potential differences between individual new agents. The role of cost-effectiveness studies such as cost utility approaches in schizophrenia needs to be revisited, notwithstanding the fact that these types of studies have been reported to be feasible in schizophrenia. Finally, quality-of-life-based pharmacoeconomic studies of antipsychotic agents should not concentrate solely on cost reduction or containment, as it is likely that in order to maximise the benefits of new antipsychotic medications, greater expenditure on rehabilitation programmes and other support services will be necessary in the short-term at least.

Reducing exposure of clinical research subjects to placebo treatments

The ethics of pill placebo and placebo psychotherapy conditions in clinical research are controversial. Even when not life threatening, mental disorders dramatically diminish the quality of life. Pill-placebo conditions in drug treatment research have been justified on the grounds that a placebo versus standard drug comparison is necessary to test the quality of the study, viz., the assay sensitivity method. The assay sensitivity method of judging study quality, however, results in misclassification of the quality of some studies, leading to bias in effect size estimation in the context of meta-analyses. This bias is of particular concern in relation to studies comparing psychotherapies to psychotropic drugs, which are conducted outside of the Food and Drug Administration (FDA) context. In cases in which control conditions may be justified on grounds other than as essential elements of an assay sensitivity test, statistical methods to reduce the number of study participants exposed to placebo should be strongly considered. Of the methods available, group sequential methods are the most widely used. Group sequential methods involve successive looks at accumulating data, with rules for terminating a trial (or an arm of a trial) early if results are strong enough.

Ethnicity and diagnostic patterns in veterans with psychoses

BACKGROUND

Differential diagnosis of schizophrenia and bipolar disorder is a challenging but important task. These conditions often exhibit overlapping clinical symptomatology, but have different prognoses and pharmacological management strategies. Factors other than clinical presentation may influence diagnosis. Past studies suggest that ethnicity is one such factor, with variations observed in diagnostic rates of serious mental illness (SMI). With increasing attention paid to provider cultural competency, we investigate current diagnostic practices within a veteran population.

METHOD

Controlling for patient need characteristics and illness severity, we examine whether ethnic differences in diagnosis continue to exist. If so, race may adversely enter the evaluation process. A national database of all SMI veterans explores the relationship between ethnicity and diagnosis. The role of symptomatology is also examined. Given minimal variation in veteran socioeconomic status, the Department of Veterans Affairs (VA) provides a natural setting to address this confounding factor. The 1999 National Psychosis Registry provides a sample of 134,523 veterans diagnosed with schizophrenia, schizoaffective disorder, or bipolar disorder. Multinomial logistic regression yielded odds ratios (OR) for being diagnosed with schizophrenia versus bipolar disorder; the schizoaffective versus bipolar risk was likewise assessed, exploring theoretical aspects of a psychosis-affective 'continuum'.

RESULTS

Small effects were observed for being male, single or rural resident. However, the demographic characteristic most strongly associated with a schizophrenia diagnosis was race. The OR for African Americans was 4.05, and 3.15 for Hispanics. Similar though less dramatic results were revealed for schizoaffective disorder.

CONCLUSIONS

This study confirms continued ethnic disparities in diagnostic patterns, and highlights the importance of recognizing ethnic differences in symptom presentation while emphasizing greater cultural competency.

Estimation and comparison of derived preference scores from the SF-36 in lung transplant patients

The purpose of this study was to estimate and compare preference scores derived from MOS Short Form-36 (SF-36) data for a sample of lung transplant patients using three methodologies: Fryback et al. (Med Decis Making 1997; 17: 1-9), Nichol et al. (Med Decis Making 2001; 21: 105-112) and Brazier et al. (J Health Econ 2002: 21: 271-292). Data were gathered from 99 lung transplant recipients using a mail survey, which included the SF-36 and other health-related quality of life (HRQL) measures. The mean preference score for the sample was 0.643 (range 0.43-0.83), 0.765 (range 0.36-1.0), and 0.697 (range 0.33-1.00) for Fryback, Nichol and Brazier methods, respectively. Correlations between the derived scores and visual analogue ratings of health (0.58-0.68) and pulmonary symptoms (-0.59 to -0.62) were moderate to good and in the expected directions. The mean preferences of patients grouped by levels of dyspnea, depression symptoms, illness burden, and self-rated general health differed significantly with all methods and supported the construct validity of the derived scores as measures of preference. The Nichol and Brazier scores, both derived with standard gamble utilities, were generally higher than Fryback scores, which are not utility-based. Given the popularity of the SF-36, these three methods could be useful where direct elicitation of preferences is not feasible. Researchers must be cognizant of the derivation method used, as absolute preference levels, hence quality adjusted life years (QALYs), will differ by method.

Use of willingness to pay to study values for pharmacotherapies for migraine headache

BACKGROUND

There is a wide range of therapeutic options for migraine headaches, yet little is known about how patients value different treatment alternatives nor how to tailor treatments to patients' preferences.

OBJECTIVE

Assess patients' preferences for outcomes of treatment of migraine headache based on their marginal willingness to pay (WTP) for treatment attributes.

MATERIALS AND METHODS

In an Internet-based study, we used computer software to measure participants' WTP for a hypothetical ideal drug (one that was 100% effective, worked quickly, and had no adverse effects) and for other hypothetical drugs, each with one "less than ideal" attribute of performance.

SUBJECTS

Two hundred fifty-seven self-identified migraineurs recruited via an Internet Web site.

RESULTS

A high proportion of participants in the study had symptoms consistent with migraine etiology of headache (99%). Median "out-of-pocket" monthly WTP cost for an ideal migraine therapy was 130 dollars. WTP was associated with participants' own migraine experience: severity of pain, frequency of headaches, and the types of medications used in the past. WTP was reduced when pharmaceuticals offered less benefit, ranging from a mean of 74% of ideal for treatments that failed to relieve nausea, to 43% of ideal in treatments associated with a 50% chance of a rebound headache.

CONCLUSIONS

There is wide variability in patients' strength of preference for different attributes of migraine therapy. Choice of therapy for migraine headache should be individualized based on patients' preferences. WTP measures appear to be a valid and feasible metric for quantifying treatment preferences for migraine therapies.