The Symbol Digit Modalities Test as sentinel test for cognitive impairment in multiple sclerosis.

BACKGROUND AND PURPOSE: Cognitive impairment (CI) is found in about half of the multiple sclerosis (MS) population and is an important contributor to employment status and social functioning. CI is encountered in all disease stages and correlates only moderately with disease duration or Expanded Disability Status Scale scores. Most present neuropsychological test batteries are time-demanding and expensive. The Symbol Digit Modalities Test (SDMT) has been suggested as a screening tool for CI in MS. In this paper, we aim to assess the performance of the SDMT in predicting the outcome of an extensive battery. METHODS: Neuropsychological test results from 359 patients were assessed in a multidisciplinary MS center (National MS Center Melsbroek, Belgium). Using receiver operating characteristic curves, the performance of the SDMT in predicting the general cognitive outcome of the extensive Neuropsychological Screening Battery for MS (NSBMS) could be assessed. The performance of the SDMT was assessed for different levels of CI and compared with other cognitive tests. Finally, useful covariates were included in a logistic regression model. RESULTS: At a specificity of 0.60 a high sensitivity (0.91) was obtained indicating the potential of the SDMT as a sentinel test for CI in MS. The SDMT outperformed the individual tests included in the NSBMS, used as benchmark. As the logistic regression model did not result in a relevant improvement, it is concluded that most clinical variables influence both the SDMT and the NSBMS in a similar way. Excluding patients with possible practice effects, an optimal cutoff of 40 was found for the SDMT. CONCLUSION: As the SDMT is an easy, low-cost and fast test, this result may help to detect CI in everyday clinical practice.

The relationship between quality of life and self-determination: an international study.

BACKGROUND: The aim of this study was to evaluate the relationship between self-determination and quality of life (QOL) of persons with intellectual disabilities (ID) living in four countries (Canada, United States, Belgium and France). METHOD: Participants were 182 adults with mild ID living in community settings (with families, living independently or in supported living environments). QOL was measured with the Quality of Life Questionnaire. Self-determination was measured using the Adult version of The Arc's Self-Determination Scale. Discriminant function and correlational analyses were conducted. RESULTS: Discriminant function analysis indicated that essential characteristics of self-determination predicted membership in the high QOL group and that overall self-determination and QOL were significantly correlated, as were sub-scale scores. CONCLUSIONS: The study replicates findings from a previous study with an international sample and confirms the importance of self-determination to enhance QOL. Subsequent research should examine the direction of the relationship between self-determination and QOL and examine the relationship of essential characteristics of self-determined behaviour and core domains of QOL in greater detail.