Assessing Disability in Schizophrenia: Tools and Contributors

Philip D. Harvey, PhD

Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, Miami, Florida

Disability in patients with schizophrenia influences their social, occupational, and residential status.1 Impairments in these areas are present throughout the course of illness and hinder patients from achieving functional milestones, such as marriage, employment, and independent living.2 In addition to these objective impairments, patients with schizophrenia may have subjective impairments, which include their perceived illness burden and quality of life (AV 1).3 Clinicians must evaluate patients’ subjective impressions of impairment because these opinions can cause problems with treatment adherence and motivation. As clinicians work with patients to achieve symptom remission and functional recovery, they must be aware of tools that assess functional disability and the contributing factors that predict functional disability.

AV 1. Relationships Among Symptom Severity, Functional Capacity, and Cognitive Performance in Outpatients With Schizophrenia or Schizoaffective Disorder (N = 88) (00:37)

Based on Narvaez et al3
Thick arrows = hypothesized relationships that were supported in the multivariate analyses
Dotted arrows = hypothesized relationships that were not supported in the multivariate analyses
Thin arrow = unexpected significant relationship

Tools to Assess Functional Disability

Before clinicians can select an intervention (such as medication or psychotherapy) to improve patients’ functioning, they must determine which domains require attention. Tools to use for assessing real-world functioning include patient and informant reports, direct observation and objective information, and performance-based assessments.4

Patient and informant reports. Clinicians can collect information by patient self-report, although the accuracy of self-reports may be influenced by patients’ lack of insight or poor cognitive abilities.4 Reports may also be obtained from an informant, such as a friend, family member, case manager, or other clinician who has frequent contact with the patient. Sabbag and colleagues5 showed that clinicians with frequent patient contact produced ratings of everyday functioning that were more closely linked to patients’ ability scores than were friend or relative informants. This study5 also showed that patient self-reports did not correlate well with either informant reports or patients’ actual performance on tests of cognition or functional abilities. Another study6 found that case manager ratings were highly correlated with patients’ performance on tests of functional capacity and social skills.

Because patient and informant reports may be unreliable, rating scales for high-contact clinicians may provide the best information on everyday functioning. The following scales have shown evidence of good validity for high-contact clinician ratings.

Quality of Life Scale (QLS)7,8

  • 21-item scale to assess intrapsychic foundations, interpersonal relations, instrumental role category, and common objects and activities
  • Clinician performs a semistructured interview of the patient, which takes about 45 minutes

Specific Levels of Functioning Scale (SLOF)8,9

  • 43-item questionnaire to assess physical functioning, personal care skills, interpersonal relationships, social acceptability, activities of community living, and work skills
  • Clinician administers the questionnaire to a case manager or caregiver for about 20 minutes

Direct observation and objective information. Direct observation of patients in naturalistic settings (for example, at work) is ideal but impractical and time consuming.10 However, advances in technology (such as smart phones) have allowed for direct observation in a remotely deliverable format. As technology becomes less expensive and more available, this strategy will become more widely used.

AV 2. Overlap Between Lifetime Milestone Achievements in Patients With Schizophrenia (N = 195) (00:28)

Data from Harvey et al1

In place of direct observation, clinicians may try to obtain objective information, such as pay stubs, rent receipts, or utility bills, to assess patients’ occupational and residential functioning. Social outcomes are more challenging to assess, not only because objective information may be harder to obtain but also because definitions of good social outcomes vary.

A caution with assessing functional milestones (eg, employment, marriage, residential status) is that they do not necessarily overlap (AV 2).1 The skill sets for work, financial responsibility, independent living, and marriage appear to be relatively independent of each other.1 As a result, clinicians must keep in mind that achievement of one milestone does not mean that other milestones have been obtained.

AV 3. Tailoring Interventions to Improve Functional Disability (02:39)

 

Performance-based assessments. Cognitive performance is related to functional outcomes, and patients with cognitive deficits may experience difficulties performing everyday activities.10 Performance-based assessments can help clinicians measure patients’ cognitive and functional abilities throughout treatment. These tools are less dependent on patient insight than self-reports are, and they measure real-life functioning and impairments so that clinicians can direct treatment at specific targets and evaluate the efficacy of medications (AV 3).10 The following validated assessment tools can help clinicians evaluate their patients’ cognitive and functional abilities:

MATRICS Consensus Cognitive Battery11

  • 10 tests to assess change in 7 cognitive domains: (1) speed of processing, (2) attention/vigilance, (3) working memory, (4) verbal learning, (5) visual learning, (6) reasoning and problem solving, and (7) social cognition
  • Practical for assessing the effectiveness of cognitive remediation methods
  • 65 minutes for the clinician to administer all 10 tests to the patient

Schizophrenia Cognition Rating Scale (SCoRS)12

  • 18-item assessment of 6 cognitive domains: (1) attention, (2) memory, (3) reasoning and problem solving, (4) working memory, (5) language production, and (6) motor skills
  • Clinician interviews both a patient and an informant; 12–15 minutes to complete each interview

UCSD Performance-Based Skills Assessment (UPSA)13

  • Standardized role-play situations test patients’ skills in 5 areas: (1) household chores, (2) communication, (3) finance, (4) transportation, and (5) planning recreational activities
  • About 30 minutes to for the patient to complete role-play tasks assigned by the clinician

UPSA-Brief (UPSA-B)14

  • Shortened version of the UPSA featuring 2 role-play situations that assess: (1) communication and (2) finance
  • 10–15 minutes for the patient to complete

Social Skills Performance Assessment (SSPA)15

  • Two standardized role-play scenarios: (1) introduction to a stranger and (2) assertive behavior with a landlord
  • 12 minutes for the patient to complete the role play and the clinician to rate his/her performance

More

Contributors to Functional Disability

Cognitive impairments and negative symptoms contribute to functional disability, although often in different areas. For example, a study by Bowie et al16 of outpatients with schizophrenia (N = 222) found that depression, negative symptoms, processing speed, and executive functioning predicted outcomes in interpersonal behavior while processing speed and positive symptoms influenced community activities like living independently and paying bills. Several studies1,17 have also found associations between social dysfunction and cognitive deficits or negative symptoms. In a study by Leifker et al,18 the negative symptoms of blunted affect and social withdrawal were the primary predictors of poor social outcomes.

Successful treatment of negative symptoms can lead to social gains, but improvements in other aspects of everyday functioning may require improved cognitive function and social competence. Cognitive deficits and negative symptoms tend to respond differently to psychotherapy and pharmacologic treatments.19,20

Conclusion

Clinicians must be aware of objective and subjective impairments in their patients with schizophrenia because these impairments affect real-world functioning and quality of life. Using a combination of reports (patient and informant), objective information, and performance-based assessments (eg, SCoRS, UPSA, SSPA), clinicians can better gauge treatment efficacy and functional improvement. Cognitive deficits and negative symptoms are common predictors of functioning, but they impact different areas and likely require separate interventions.

Clinical Points

  • Recognize that functional disability can hamper patients’ success in occupational, social, and independent living domains
  • Assess disability using multiple sources and validated performance-based measures
  • Determine if cognitive deficits or negative symptoms are affecting patients’ disability and select appropriate interventions

Abbreviations

MATRICS = Measurement and Treatment Research to Improve Cognition in Schizophrenia
QLS = Quality of Life Scale
SCoRS = Schizophrenia Cognition Rating Scale
SLOF = Specific Levels of Functioning Scale
SSPA = Social Skills Performance Assessment
UCSD = University of California, San Diego
UPSA = UCSD Performance-Based Skills Assessment

References

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