Practice effects in a longitudinal, multi-center Alzheimer\u27s disease prevention clinical trial

BACKGROUND: Practice effects are a known threat to reliability and validity in clinical trials. Few studies have investigated the potential influence of practice on repeated screening measures in longitudinal clinical trials with a focus on dementia prevention. The current study investigates whether practice effects exist on a screening measure commonly used in aging research, the Memory Impairment Screen (MIS). METHODS: The PREADViSE trial is a clinical intervention study evaluating the efficacy of vitamin E and selenium for Alzheimer\u27s disease prevention. Participants are screened annually for incident dementia with the MIS. Participants with baseline and three consecutive follow-ups who made less than a perfect score at one or more assessments were included in the current analyses (N=1,803). An additional subset of participants with four consecutive assessments but who received the same version of the MIS at baseline and first follow-up (N=301) was also assessed to determine the effects of alternate forms on mitigating practice. We hypothesized that despite efforts to mitigate practice effects with alternate versions, MIS scores would improve with repeated screening. Linear mixed models were used to estimate mean MIS scores over time. RESULTS: Among men with four visits and alternating MIS versions, although there is little evidence of a significant practice effect at the first follow-up, mean scores clearly improve at the second and third follow-ups for all but the oldest participants. Unlike those who received alternate versions, men given the same version at first follow-up show significant practice effects. CONCLUSION: While increases in the overall means were small, they represent a significant number of men whose scores improved with repeated testing. Such improvements could bias case ascertainment if not taken into account

Mild Cognitive Impairment: Statistical Models of Transition Using Longitudinal Clinical Data

Mild cognitive impairment (MCI) refers to the clinical state between normal cognition and probable Alzheimer's disease (AD), but persons diagnosed with MCI may progress to non-AD forms of dementia, remain MCI until death, or recover to normal cognition. Risk factors for these various clinical changes, which we term “transitions,” may provide targets for therapeutic interventions. Therefore, it is useful to develop new approaches to assess risk factors for these transitions. Markov models have been used to investigate the transient nature of MCI represented by amnestic single-domain and mixed MCI states, where mixed MCI comprised all other MCI subtypes based on cognitive assessments. The purpose of this study is to expand this risk model by including a clinically determined MCI state as an outcome. Analyses show that several common risk factors play different roles in affecting transitions to MCI and dementia. Notably, APOE-4 increases the risk of transition to clinical MCI but does not affect the risk for a final transition to dementia, and baseline hypertension decreases the risk of transition to dementia from clinical MCI

Victim, Allegation, and Investigation Characteristics Associated With Substantiated Reports of Sexual Abuse of Adults in Residential Care Settings

The purpose of this study was to identify characteristics of investigations of sexual abuse concerning vulnerable adults residing in facility settings that were associated with case substantiation. Data on 410 reports of sexual abuse were collected prospectively from Adult Protective Services (APS) and state licensure agency staff in New Hampshire, Oregon, Tennessee, Texas, and Wisconsin over a six-month period. Specifically, we examined differences between reports that were substantiated and those that were not by comparing characteristics of alleged victims, alleged perpetrators, and aspects of investigation using logistic regression. We found that a relatively low proportion of cases (18%) were substantiated overall. Compared to cases that were not substantiated, cases that were substantiated were more likely to feature nursing home residents, older victims, female victims, and allegations of physical contact between the alleged perpetrator and victim. Despite the high proportion of alleged perpetrators who were facility staff (51%) compared to resident perpetrators (25%), cases with resident-to-resident allegations of abuse were much more likely to be substantiated, accounting for 63% of substantiated cases. In light of these findings, we believe it is important that investigators are trained to handle sexual abuse cases appropriately and that they are able to investigate the case thoroughly, promptly, and with as much information as possible. It is also critical that investigators make substantiation decisions using the appropriate standard for confirmation (e.g., preponderance of the evidence, beyond a reasonable doubt, clear and convincing evidence) as state law dictates

Victim, Allegation, and Investigation Characteristics Associated With Substantiated Reports of Sexual Abuse of Adults in Residential Care Settings

The purpose of this study was to identify characteristics of investigations of sexual abuse concerning vulnerable adults residing in facility settings that were associated with case substantiation. Data on 410 reports of sexual abuse were collected prospectively from Adult Protective Services (APS) and state licensure agency staff in New Hampshire, Oregon, Tennessee, Texas, and Wisconsin over a six-month period. Specifically, we examined differences between reports that were substantiated and those that were not by comparing characteristics of alleged victims, alleged perpetrators, and aspects of investigation using logistic regression. We found that a relatively low proportion of cases (18%) were substantiated overall. Compared to cases that were not substantiated, cases that were substantiated were more likely to feature nursing home residents, older victims, female victims, and allegations of physical contact between the alleged perpetrator and victim. Despite the high proportion of alleged perpetrators who were facility staff (51%) compared to resident perpetrators (25%), cases with resident-to-resident allegations of abuse were much more likely to be substantiated, accounting for 63% of substantiated cases. In light of these findings, we believe it is important that investigators are trained to handle sexual abuse cases appropriately and that they are able to investigate the case thoroughly, promptly, and with as much information as possible. It is also critical that investigators make substantiation decisions using the appropriate standard for confirmation (e.g., preponderance of the evidence, beyond a reasonable doubt, clear and convincing evidence) as state law dictates

Victim, Allegation, and Investigation Characteristics Associated With Substantiated Reports of Sexual Abuse of Adults in Residential Care Settings

The purpose of this study was to identify characteristics of investigations of sexual abuse concerning vulnerable adults residing in facility settings that were associated with case substantiation. Data on 410 reports of sexual abuse were collected prospectively from Adult Protective Services (APS) and state licensure agency staff in New Hampshire, Oregon, Tennessee, Texas, and Wisconsin over a six-month period. Specifically, we examined differences between reports that were substantiated and those that were not by comparing characteristics of alleged victims, alleged perpetrators, and aspects of investigation using logistic regression. We found that a relatively low proportion of cases (18%) were substantiated overall. Compared to cases that were not substantiated, cases that were substantiated were more likely to feature nursing home residents, older victims, female victims, and allegations of physical contact between the alleged perpetrator and victim. Despite the high proportion of alleged perpetrators who were facility staff (51%) compared to resident perpetrators (25%), cases with resident-to-resident allegations of abuse were much more likely to be substantiated, accounting for 63% of substantiated cases. In light of these findings, we believe it is important that investigators are trained to handle sexual abuse cases appropriately and that they are able to investigate the case thoroughly, promptly, and with as much information as possible. It is also critical that investigators make substantiation decisions using the appropriate standard for confirmation (e.g., preponderance of the evidence, beyond a reasonable doubt, clear and convincing evidence) as state law dictates