The RBANS Effort Index: Base Rates in Geriatric Samples

Abstract

The Effort Index (EI) of the RBANS was developed to assist clinicians in discriminating patients who demonstrate good effort from those with poor effort. However, there are concerns that older adults might be unfairly penalized by this index, which uses uncorrected raw scores. Using five independent samples of geriatric patients with a broad range of cognitive functioning (e.g., cognitively intact, nursing home residents, probable Alzheimer's disease), base rates of failure on the EI were calculated. In cognitively intact and mildly impaired samples, few older individuals were classified as demonstrating poor effort (e.g., 3% in cognitively intact). However, in the more severely impaired geriatric patients, over one third had EI scores that fell above suggested cutoff scores (e.g., 37% in nursing home residents, 33% in probable Alzheimer's disease). In the cognitively intact sample, older and less educated patients were more likely to have scores suggestive of poor effort. Education effects were observed in three of the four clinical samples. Overall cognitive functioning was significantly correlated with EI scores, with poorer cognition being associated with greater suspicion of low effort. The current results suggest that age, education, and level of cognitive functioning should be taken into consideration when interpreting EI results and that significant caution is warranted when examining EI scores in elders suspected of having dementia.

Key words:

• geriatric assessment
• RBANS
• symptom validity testing

ACKNOWLEDGEMENTS

The project described was supported by research grants (K23 AG028417-01A2) from the National Institutes on Aging. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute on Aging or the National Institutes of Health.

Notes

Note. MCI = mild cognitive impairment; RBANS = Repeatable Battery for the Assessment of Neuropsychological Status.

^aThis Total Scale score used age- and education-corrected subtest scores (Duff et al., 2003) for all subtests.

Note. MCI = mild cognitive impairment; RBANS = Repeatable Battery for the Assessment of Neuropsychological Status.

Note. MCI = mild cognitive impairment; RBANS = Repeatable Battery for the Assessment of Neuropsychological Status.

^aEducation was coded as in Table 1.

^bOnly p values are reported for gender, because none were significant.

^cThis Total Scale score used age- and education-corrected subtest scores for all subtests except Digit Span and List Recognition.