Risk factors for predicting progression from normal cognition to mild cognitive impairment: protocol for a systematic review and meta-analysis of cohort studies

Prognostic and Predictive Factors in Early Alzheimer's Disease: A Systematic Review

Background

Alzheimer's disease (AD) causes progressive decline of cognition and function. There is a lack of systematic literature reviews on prognostic and predictive factors in its early clinical stages (eAD), i.e., mild cognitive impairment due to AD and mild AD dementia.

Objective

To identify prognostic factors affecting eAD progression and predictive factors for treatment efficacy and safety of approved and/or under late-stage development disease-modifying treatments.

Methods

Databases were searched (August 2022) for studies reporting prognostic factors associated with eAD progression and predictive factors for treatment response. The Quality in Prognostic Factor Studies tool or the Cochrane risk of bias tool were used to assess risk of bias. Two reviewers independently screened the records. A single reviewer performed data extraction and quality assessment. A second performed a 20% check. Content experts reviewed and interpreted the data collected.

Results

Sixty-one studies were included. Self-reporting, diagnosis definition, and missing data led to high risk of bias. Population size ranged from 110 to 11,451. Analyses found data indicating that older age was and depression may be associated with progression. Greater baseline cognitive impairment was associated with progression. APOE4 may be a prognostic factor, a predictive factor for treatment efficacy and predicts an adverse response (ARIA). Elevated biomarkers (CSF/plasma p-tau, CSF t-tau, and plasma neurofilament light) were associated with disease progression.

Conclusions

Age was the strongest risk factor for progression. Biomarkers were associated with progression, supporting their use in trial selection and aiding diagnosis. Baseline cognitive impairment was a prognostic factor. APOE4 predicted ARIA, aligning with emerging evidence and relevant to treatment initiation/monitoring.

Effects of a Trans-Theoretical Model-Based Health Education Program on the Management of Cognitive Dysfunction in Older Adults With Mild Cognitive Impairment: Study Rationale and Protocol Design for a Randomized Controlled Trial

Introduction: Recent studies have confirmed that the management of cognitive dysfunction produces considerable positive effects in individuals with mild cognitive impairment (MCI), however, compliance with participation in various cognitive dysfunction management strategies remains scant in older adults with MCI. Health education programs can improve the level of knowledge of the disease effectively, though it remains unclear as to whether health education programs are sufficient to promote behavior changes of older adults with MCI in the community. Objective: The study aims to provide insight into the effect of a trans-theoretical Model (TTM)-based health education program on increasing knowledge about mild cognitive impairment (MCI), compliance in cognitive dysfunction management, and other cognition-related health outcomes (general cognitive function, sleep quality, depression symptoms, apathy symptoms) for older adults with MCI. Methods: This study is a single-blinded, randomized, prospective clinical trial. We will recruit 132 participants with MCI who will be randomly assigned to a TTM-based health education group and a standard health education group in a ratio of 1:1. The intervention group will receive a TTM-based health education program (1 session/week, 4-560 min/session for 8 weeks), while the control group will receive standard health education. Assessors blinded to participant allocation will conduct baseline, post-intervention, and 3-month follow-up assessments. Statistical analyses will consist of the Wilcoxon test, the Chi-square test, the T-test, and 2 (group) × 3 (time) ANOVA with a 5% cut-off for significance. Discussion: Supposing the TTM-based health education program will provide validated community-based cognitive dysfunction management strategies for older adults with MCI, this would be a feasible approach to improve the compliance of participation in cognitive dysfunction management and the cognition-related health outcomes. Clinical Trial Registration: ChiCTR1900028351. Registered on December 19, 2019. http://www.chictr.org.cn/edit.aspx?pid=47223&htm=4.