| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Gustafson, Deborah, 1966, et al.
(författare)
-
Cerebrospinal fluid beta-amyloid 1-42 concentration may predict cognitive decline in older women.
- 2007
-
Ingår i: Journal of neurology, neurosurgery, and psychiatry. - : BMJ. - 1468-330X .- 0022-3050. ; 78:5, s. 461-4
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Low levels of cerebrospinal fluid (CSF) beta-amyloid 1-42 (Abeta42) and high total tau (T-tau) are diagnostic for manifest Alzheimer's disease. It is not known, however, whether these biomarkers may be risk indicators for cognitive decline in otherwise healthy older people. METHODS: The longitudinal relationship between CSF markers, Abeta42 and T-tau, measured in 1992, and change in Mini-Mental State Examination (deltaMMSE) score between 1992 and 2002 were investigated in 55 women (aged 70-84 years, mean (SD) MMSE score = 28.3 (1.5)), who were participants in the Prospective Population Study of Women in Gothenburg, Sweden. These women did not have dementia when they experienced lumbar puncture in 1992-3. RESULTS: Over the 8-year follow-up period, deltaMMSE (range = +3 to -21 points) was correlated with Abeta42 (Spearman's r = 0.40, p = 0.002), such that lower levels of Abeta42 were related to greater decline. This was also observed after excluding 4 women who developed dementia between 1992 and 2002 (Spearman's r = 0.34, p = 0.019). A multivariate logistic regression model predicting a decline of > or = 5 points on the MMSE (observed in six women), or a risk of developing dementia over the 8-year follow-up period (observed in four women), including age, education, Abeta42 and T-tau as covariates, showed that Abeta42 was the sole predictor of significant cognitive decline or dementia (OR per 100 pg/ml Abeta42 = 2.24, 95% CI 1.19 to 4.22, p = 0.013). CONCLUSIONS: Low levels of CSF Abeta42 may predict cognitive decline among older women without dementia.
|
|
| 8. |
|
|
| 9. |
- Hagell, Peter, et al.
(författare)
-
The 39-item Parkinson's disease questionnaire (PDQ-39) revisited: implications for evidence-based medicine.
- 2007
-
Ingår i: Journal of Neurology, Neurosurgery and Psychiatry. - : BMJ. - 1468-330X .- 0022-3050. ; 78:Apr 18, s. 1191-1198
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The 39 item Parkinson's disease questionnaire (PDQ-39) is the most widely used patient reported rating scale in Parkinson's disease. However, several fundamental measurement assumptions necessary for confident use and interpretation of the eight PDQ-39 scales have not been fully addressed. Methods: Postal survey PDQ-39 data from 202 people with Parkinson's disease (54% men; mean age 70 years) were analysed regarding psychometric properties using traditional and Rasch measurement methods. Results: Data quality was good ( mean missing item responses, 2%) and there was general support for the legitimacy of summing items within scales without weighting or standardisation. Score reliabilities were adequate (Cronbach's alpha 0.72-0.95; test-retest 0.76-0.93). The validity of the current grouping of items into scales was not supported by scaling success rates ( mean 56.2%), or factor and Rasch analyses. All scales represented more health problems than that experienced by the sample ( mean floor effect 15%) and showed compromised score precision towards the less severe end. Conclusions: Our results provide general support for the acceptability and reliability of the PDQ-39. However, they also demonstrate limitations that have implications for the use of the PDQ-39 in clinical research. The grouping of items into scales appears overly complex and the meaning of scale scores is unclear, which hampers their interpretation. Suboptimal targeting limits measurement precision and, therefore, probably also responsiveness. These observations have implications for the role of the PDQ-39 in clinical trials and evidence based medicine. PDQ-39 derived endpoints should be interpreted and selected cautiously, particularly regarding small but clinically important effects among people with less severe problems.
|
|
| 10. |
|
|
