Table 1.

Summary of the studies included in the meta-analysis

Study ID	Population	Playing a musical instrument	Follow-up	Dementia	Adjusted variables
The Bronx Aging Study [9]	469 participants residing in one community in the US Age: 75–85 years Women: 64.0%	Interview (frequent or rare) Music players: 3.5%	5.1 years (median)	Incidence: 26.4% Diagnosed by the Diagnostic and Statistical Manual of Mental Disorders and the revised edition	Age, sex, educational level, medical illnesses, the Blessed Information–Memory–Concentration test, and participation in other leisure activities
MoVIES project [10]	942 participants from one rural area in the US Age: ≥65 years Women: 66.5%	Self-administered questionnaire (yes or no) Music players: 5.0%	6.1 years (mean)	Incidence: 11.8% Diagnosed by score ≥ 1 based on the Clinical Dementia Rating	Age, sex, education, depressive symptoms, physical exercise, functional impairment, self-reported health, medication use, and the recruitment status
JAGES [11]	52,601 participants representing 31 municipalities in 12 Japanese prefectures Age: ≥65 years Women: 53.9%	Self-administered questionnaire (yes or no musical activities at all) Music players: 2.5%	5.8 years (median)	Incidence: 11.0% Diagnosed by level ≥ II according to the Standardized Dementia Scale of the Long-term Care Insurance System	Age, sex, area, daily walking, mutual assistance, smoking, alcohol intake, marriage, education, annual income, engaging in other leisure cognitive activities, daily activities and meeting friends, body mass index, diabetes, hypertension, hyperlipidemia, stroke, hearing loss, and depression