International Assessment of Functional Skills in People with Schizophrenia

| January 21, 2011 | 0 Comments

by Philip D. Harvey, PhD, and Dawn I. Velligan, PhD

Dr. Harvey is from the University of Miami School of Medicine, Miami, Florida; and Dr. Velligan is from University of Texas San Antonio Health Science Center, San Antonio, Texas.

Innov Clin Neurosci. 2011;8(1):15–18

Funding: There was no funding for the development and writing of this article.

Financial Disclosures: The authors have no conflicts of interest relevant to the content of this article.

Keywords: Disability, functional capacity, severe mental illness

Abstract: Disability is very common in schizophrenia and is related to cognitive impairments, some illness symptoms, and deficits in skills needed to function in the everyday environment (i.g., functional capacity). Research on measurement of the ability to perform the skilled acts required for successful everyday functioning has advanced considerably in the past five years. However, different environmental situations require different skill sets, and one of the major challenges in research on functional capacity is identification of the differences in skills that are required across environments. This article reviews the challenges associated with international measurement of functional capacity. The authors present their perspectives on what can be done with existing measures and what needs to be done in the future. As America becomes more multicultural, these challenges will also occur close to home as well.


One of the recent developments in the study of cognition and disability in schizophrenia has been the introduction of performance-based assessments of everyday living skills.[1–3] These performance-based assessments have been referred to as indices of “functional capacity,” the ability to perform critical, everyday living skills in controlled, observational settings. In contrast to the measurement of real-world outcomes, measurement of functional capacity is not as greatly affected by factors such as opportunities and incentives that influence functioning in everyday situations.[4] As we know from multiple studies, real-world functioning is influenced by factors such as disability compensation and motivation. In contrast, scores on performance-based measures of functional capacity has been shown in studies in the United States to be very minimally affected by symptoms, disability compensation status, and current environmental situation.

The differentiation between measures of the ability to perform skilled acts and the likelihood of performing them has been referred to as the “competence-performance” distinction. This conceptualization is informed by the findings noted above that real-world functioning is correlated with the ability to perform skilled acts, but also influenced, often substantially, by other factors.[2] A primary importance of this distinction is that the interventions typically aimed at reducing disability in schizophrenia, such as pharmacological cognitive enhancement, cognitive remediation, or social skills training, are designed to improve skills. Thus, if successful, they improve the ability to succeed in everyday activities, which is only a prerequisite to improving real-world outcomes. It has become clear that concurrent psychosocial interventions, aimed at increasing motivation to perform skilled acts, improving access to opportunities for functional gains, or reducing barriers toward functional success, are also required for these interventions to lead to improvements in real-world functional outcomes.[6,7]

Researchers in the field of schizophrenia have known for many years that the symptomatic presentation of schizophrenia is quite similar across different countries in the Western and developing world, leading to the conclusion that schizophrenia may be a similar illness on a worldwide basis. With the increased acceptance of the idea that cognitive and functional deficits are central features of the illness, it is important to understand whether these aspects of schizophrenia are also cross-culturally similar as well. Some evidence has suggested that, at least in some contexts, there is cross-cultural consistency in cognitive impairments and their correlates. Results from a large-scale, first-episode treatment study suggested that baseline performance on a wide-ranging cognitive assessment battery was quite similar across patients assessed in 11 countries in eight different languages.[7]

Differences between countries in performance were largely eliminated when differences in educational attainment were considered. In a study of older hospitalized patients, cognitive performance was very similar in the United States and United Kingdom, and the correlations between cognitive performance and indices of everyday disability were essentially identical.8 Finally, in a study comparing cognitive performance, functional capacity measures, and clinician ratings of the ability to function in the community, patients in New York City and rural areas of Sweden were found to be essentially indistinguishable in levels of impairment.[4] Also, the correlations between these variables were also virtually identical. These data suggest that, at least in developed countries, cognition, functional abilities, and real-world functional deficits are intrinsic features of the illness.

When considering cross-national variation in cognition and disability, one of the issues that arises is whether the specific domains of critical functional skills and demands for real-world functioning are culturally similar. For instance, even in Western cultures, there are regional differences in the abilities required to manage everyday activities, such as transportation, with some areas being largely served by public transportation and other areas with none available. These differences are likely accentuated in developing countries where financial skills may not include banking and communication skills may not include the use of telephones. Further, in some parts of the developing world, reliance on other people, such as parents, spouses, or caregivers, to perform critical skills on behalf of the patients would not be viewed as reflecting disability, while in the United States reliance on others to perform everyday tasks, such as making a telephone call, certainly would.

As an outgrowth of the Measurement and Treatment Research to Improve Cognition in Schizophrenia (co-primary and translation (MATRICS CT) initiative that we described in our last column,[9] cultural adaptation of functional capacity measures was also a research priority. This cultural adaptation was aimed at increasing the validity of studies directed toward cognitive enhancement in developing countries, as it was clear to all participants in MATRICS-CT that simply translating functional capacity measures developed in the United States was not likely to be a valid strategy for functional assessment in other locations.

As a first step toward understanding the potential barriers that may arise in the cultural adaptation of functional capacity measures, we conducted a survey of expert raters at clinical research sites in eight different countries.10 A total of 56 English-speaking investigators and front-line staff examined three functional capacity measures and rated their opinions about the extent to which each subscale of each measure could be applied to their culture and to subgroups within their culture based on gender, geographic region, ethnicity, and socioeconomic status. The three measures examined were the Independent Living Scales,11 the UCSD Performance-based Skills Assessment,[1] and the Test of Adaptive Behavior in Schizophrenia.[2] Problems in adaptation were identified for specific subscales on all three functional capacity measures across multiple countries. The problems included the following: Context of the test was unfamiliar (e.g., specific locations, such as a water park, or a transportation system that was wildly different from the one in their location); the specific props used did not represent things common in the culture (e.g., pictures of specific types of grocery stores or bathrooms); and the tasks that the person was asked to do were not relevant to everyday life (e.g., paying a bill, making a phone call). Raters indicated that India, China, and Mexico presented the greatest challenges in adaptation. In fact, raters in India assigned a failing grade to all three performance-based capacity measures. Significant anticipated difficulties in adaptation across multiple countries were also identified for rural dwellers, those from lower socioeconomic status (SES) backgrounds, and ethnic minority subgroups. While the results of the above survey suggest clear concerns about the direct application of functional-capacity measures developed in the United States to other countries and cultures, this was an opinion survey. There is at least one completed study that directly examined the applicability of functional capacity measures developed in the United States to developing countries. In this study,[12] a brief version of the UCSD Performance-Based skills assessment (UPSA-B) was translated and the items culturally adapted for use in China. After forward and back translation, the Chinese UPSA-B was administered to large samples of healthy individuals and patients with severe mental illness in Beijing. Of special interest was the fact that we were able to recruit individuals to participate in our research whose levels of educational attainment were widely variable, ranging in both samples from 2 to over 20 years of completed formal education. Thus, we were able to separate the influences of educational attainment and illness on functional-capacity measures. Of particular interest are the low levels of performance of less-educated, healthy people in China on complex functional skills, such as banking and telephone usage, which may not be part of their everyday activities. Given the rapid advancement of technology in China, it seemed reasonable to expect that well-educated, healthy individuals in China would demonstrate high levels of skill in the complex activities that are not part of the repertoire of less-educated individuals.

The results of the study were consistent with our expectations. Educational attainment was a consistent predictor of the ability to perform everyday skills. Healthy people with an education of middle school level (completed 8 years) performed at levels similar to those seen in schizophrenia patients in United States studies. However, high school- and college-educated healthy people did not perform markedly differently than United States normative standards for similarly educated, healthy individuals. People with schizophrenia had a performance disadvantage at all levels of educational attainment that was substantial compared to the healthy reference group, performing 25 to 40 points lower (on a 100-point scale) across all educational attainment milestones.

These data suggest that in developing countries, substantial caution should be applied in the direct extrapolation of United States-developed functional-capacity measures, particularly in less-educated individuals and probably in rural areas with minimal access to modern telecommunication and financial management opportunities. However, in the well-educated, the level of performance of healthy people and the performance disadvantage associated with schizophrenia were consistent with the results of previous Western studies. Thus, depending on where a treatment study was to be conducted and the standards for recruitment of patients regarding educational attainment, similarity to Western samples may be achieved. It may be required that organizations conducting clinical trials in developing countries consider whether the extra effort required to find better educated participants offsets the need to implement and validate major procedural changes in clinical trials methods.

1. Patterson TL, Goldman S, McKibbin CL, et al. UCSD performance-based skills assessment: development of a new measure of everyday functioning for severely mentally ill adults. Schizophr Bull. 2001;27:235–245.
2. Velligan DI, Diamond P, Glahn, DC, et al. The reliability and validity of the test of adaptive behavior in schizophrenia. Psychiatry Res. 2007;151:55–66.
3. Leifker FR, Bowie CR, Harvey PD. The determinants of everyday outcomes in schizophrenia: influences of cognitive impairment, clinical symptoms, and functional capacity. Schizophr Res. 2009;115:82–87.
4. Harvey PD, Helldin L, Bowie CR, et al. Performance-based measurement of functional disability in schizophrenia: a cross-national study in the United States and Sweden. Am J Psychiatry. 2009;166:821–827.
5. McGurk SR, Mueser KT, Feldman K, et al. Cognitive training for supported employment: 2–3 year outcomes of a randomized controlled trial. Am J Psychiatry. 2007;164:437–441
6. Velligan DI, Diamond PM, Mintz J, et al. The use of individually tailored environmental supports to improve medication adherence and outcomes in schizophrenia. Schizophr Bull. 2008;34:483–493.
7. Harvey PD, Artiola L, Vester-Blockland E, DeSmedt G. Cross national cognitive assessment in schizophrenia clinical trials: a feasibility study. Schizophr Res. 2003;59:243–251.
8. Harvey PD, Leff J, Trieman N, et al. Cognitive impairment in geriatric chronic schizophrenic patients: a cross-national study in New York and London. Int J Geriatr Psychiat. 1997;12:1001–1007
9. Harvey PD, Green MF, Nuechterlein KH. The latest developments in the MATRICS process. Psychiatry (Edgmont). 2010;7:49–52.
10. Velligan DI, Rubin M, Fredrick MM, et al. The cultural adaptability of intermediate measures of functional outcome in schizophrenia. Schizophr Bull. In press.
11. Loeb PA. Independent Living Scales. San Antonio: Harcourt Assessent; 1996
12. McIntosh BJ, Zhang XY, Kosten T, et al. Performance based assessment of functional skills in severe mental illness: Results of a large-scale study in China. J Psychiatric Res. In press.

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Category: Behavioral and Cognitive Neurology, Cognition, Past Articles, Psychiatry, Schizophrenia, Trial Methodology, Update on Cognition

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