Do nonpharmacological interventions prevent cognitive decline? a systematic review and meta-analysis

Area of Science:

• Gerontology
• Neuroscience
• Public Health

Background:

• Cognitive decline is a growing concern with limited effective pharmacological treatments.
• Nonpharmacological interventions are desirable for preventing cognitive decline due to potential adverse effects of medications.
• No previous meta-analyses have synthesized evidence on nonpharmacological interventions for cognitive decline prevention.

Purpose of the Study:

• To investigate the effectiveness of nonpharmacological interventions in preventing cognitive decline among older adults.
• To synthesize evidence from randomized controlled trials (RCTs) on nonpharmacological approaches for cognitive decline prevention.

Main Methods:

• Systematic search of multiple databases (MEDLINE, EMBASE, CENTRAL, ClinicalTrials) up to March 31, 2019.
• Inclusion of RCTs with participants >60 years at risk of cognitive decline, receiving nonpharmacological interventions.
• Data extraction, quality assessment (GRADE), heterogeneity analysis (I²), subgroup/meta-regression, and outlier/bias assessment.

Main Results:

• Nonpharmacological interventions were associated with a reduced incidence of mild cognitive impairment (MCI) or dementia (RR, 0.73; moderate-certainty evidence).
• Significant improvements were observed in activities of daily living (ADL) and Mini-Mental State Examination (MMSE) scores.
• While initial analysis suggested potential moderators, further meta-regression indicated no significant association with decreased MCI incidence.

Conclusions:

• Nonpharmacological therapies may play a role in reducing the incidence of MCI or dementia.
• Moderate-certainty evidence supports the use of nonpharmacological interventions for cognitive decline prevention.
• Further high-quality, preregistered trials are necessary to confirm these findings and explore moderating factors.