Sex differences in frailty: A systematic review and meta-analysis.

Area of Science:

• Gerontology
• Epidemiology
• Biostatistics

Background:

• Females exhibit increased longevity but higher comorbidity and disability.
• This presents a paradox: females are simultaneously more frail (poorer health) and less frail (lower mortality risk).
• The Frailty Index (FI) is a key metric for assessing health status in aging populations.

Purpose of the Study:

• To investigate the 'male-female health-survival paradox' using the Frailty Index (FI).
• To determine if sex differences in frailty and mortality persist across different age groups in older adults.
• To synthesize evidence from observational studies on frailty and mortality in community-dwelling individuals aged 65 and above.

Main Methods:

• Systematic review and meta-analysis of observational studies.
• Searched Medline, EMBASE, and CINAHL databases for relevant literature.
• Analyzed sex differences in mean Frailty Index (FI) scores and mortality rates in five-year age groups.

Main Results:

• Seven studies (37,426 participants) met inclusion criteria.
• Females consistently exhibited higher FI scores than males across all age groups (MD range=0.02-0.06, p<0.001).
• Male mortality rates exceeded female rates until age 94, with males showing higher mortality risk at all FI levels.

Conclusions:

• The study confirms the 'male-female health-survival paradox' in older adults.
• Sex differences in frailty and mortality are consistent across populations.
• Higher frailty scores in females do not translate to higher mortality risk compared to males.