Assessing Statistical Applications in Publications on Alzheimer’s Disease

Abstract

Background/Aims: To evaluate statistical applications in publications on Alzheimer’s disease (AD). Methods: Three instruments/checklists were developed: Assessment of Statistical Reporting (ASR; 44 items), Survey of Statistical Designs (SSD; 10 items), and Survey of Statistical Methods (SSM; 7 items). After a pilot testing on 5 AD publications, the instruments/checklists were revised and tested for reliability with a sample of 30 AD articles and for validity with another sample of 10 AD articles from MEDLINE. Results: Item-specific test-retest and interrater reliability for ASR ranged from 0.29 to 1.0 with the associated standard errors (SEs) ranging from 0.01 to 0.31. The test-retest reliability (intraclass correlation coefficient = 0.94, 95% CI: 0.88–0.97) and the interrater reliability (intraclass correlation coefficient = 0.84, 95% CI: 0.69–0.92) for the overall score of ASR were high. The correlational validity of the ASR with a published checklist was also high (r = 0.74, SE = 0.24). The item-specific test-retest reliability in SSD and SSM ranged from 0.58 to 1.00 with the associated SEs ranging from 0.01 to 0.32. The item-specific interrater reliability in SSD and SSM ranged from 0.17 to 1.00 with the associated SEs ranging from 0.01 to 0.22. Conclusions: This study suggested that it was feasible to assess statistical applications in AD publications.

Dietary patterns and risk of mild cognitive impairment among Chinese elderly: A cross-sectional study

“…An individual’s functional status was assessed using six items on the activities of daily living (ADL) scale and eight items instrumental activities of daily living (IADL) [ 19 ]. Both scales had been widely used and were subsequently adapted for use in Chinese participants [ 20 ]. The Chinese version of the ADL scale includes 20 items, and its reliability and validity had been verified among older Chinese participants [ 21 ], which had been reported previously.…”

Evaluating the Quality of Longitudinal Statistical Applications in Original Publications on Alzheimer’s Disease

“…Both types of longitudinal studies required specific types of statistical models which were valid only under certain distributional and regularity conditions, and the implementations of these models required complicated statistical computing techniques. Both types of longitudinal studies in AD were mostly observational in nature [9] , which usually implied variable baseline conditions and unequal follow-up times among individuals. Dropouts and loss to followup usually occurred in longitudinal studies of AD, resulting in either missing or censored data which were likely informative and not ignorable [10][11][12][13] .…”

“…The first component contained the statistical features that were shared by almost all AD studies. These statistical aspects were the main targets of our previous report and can be assessed in AD publications by the Assessment of Statistical Reporting [9] . The second statistical component contained statistical features specific to longitudinal studies which, when coupled with the specific analytic features associated with AD, had rather unique and complicated analytic implications in longitudinal AD studies and were the primary focus of this study.…”

“…We recently reported several instruments/checklists that were designed to systematically assess the types of statistical designs and analytic methods, and the quality of statistical reporting in published AD studies [9] . These checklists were intended to offer an understanding of the statistical characteristics common to all or most AD studies.…”