BACKGROUND/AIMS: To evaluate the quality of longitudinal statistical applications in published studies on Alzheimer's disease (AD). METHODS: A 21-item instrument, the Quality of Longitudinal AD Studies (QLADS), was developed by the research team (4 biostatisticians, 1 neuroepidemiologist, and 1 neurologist). All items were extensively discussed within the team for content validity. After pilot testing on 5 publications, the instrument was revised and tested for reliability with a sample of 40 published longitudinal AD studies randomly sampled from MEDLINE. RESULTS: Item-specific test-retest reliability coefficients for QLADS ranged from 0.53 to 1.00 with the associated standard error (SE) ranging from 0.02 to 0.13. The test-retest reliability for the overall score over the 21 items was high (intraclass correlation coefficient (ICC) = 0.94, 95% CI 0.90, 0.97). Item-specific inter-rater reliability coefficients for QLADS ranged from 0.46 to 1.00 with the associated SE ranging from 0.07 to 0.18. The inter-rater reliability for the overall score was also high (ICC = 0.87, 95% CI 0.77, 0.93). CONCLUSIONS: This study indicates that the quality of longitudinal statistical applications in AD publications can be reliably assessed. 2008 S. Karger AG, Basel
BACKGROUND/AIMS: To evaluate the quality of longitudinal statistical applications in published studies on Alzheimer's disease (AD). METHODS: A 21-item instrument, the Quality of Longitudinal AD Studies (QLADS), was developed by the research team (4 biostatisticians, 1 neuroepidemiologist, and 1 neurologist). All items were extensively discussed within the team for content validity. After pilot testing on 5 publications, the instrument was revised and tested for reliability with a sample of 40 published longitudinal AD studies randomly sampled from MEDLINE. RESULTS: Item-specific test-retest reliability coefficients for QLADS ranged from 0.53 to 1.00 with the associated standard error (SE) ranging from 0.02 to 0.13. The test-retest reliability for the overall score over the 21 items was high (intraclass correlation coefficient (ICC) = 0.94, 95% CI 0.90, 0.97). Item-specific inter-rater reliability coefficients for QLADS ranged from 0.46 to 1.00 with the associated SE ranging from 0.07 to 0.18. The inter-rater reliability for the overall score was also high (ICC = 0.87, 95% CI 0.77, 0.93). CONCLUSIONS: This study indicates that the quality of longitudinal statistical applications in AD publications can be reliably assessed. 2008 S. Karger AG, Basel
Authors: Scott Marquis; M Milar Moore; Diane B Howieson; Gary Sexton; Haydeh Payami; Jeffrey A Kaye; Richard Camicioli Journal: Arch Neurol Date: 2002-04
Authors: Dorene M Rentz; Terri J Huh; Robert R Faust; Andrew E Budson; Leonard F M Scinto; Reisa A Sperling; Kirk R Daffner Journal: Neuropsychology Date: 2004-01 Impact factor: 3.295