Comparative vs global self-rated health: associations with age and functional ability

Area of Science:

• Gerontology
• Public Health
• Health Services Research

Background:

• Self-rated health (SRH) is a key indicator in aging research.
• Distinctions between comparative and global SRH measures are not fully understood.
• Understanding these differences is crucial for accurate health assessments in older populations.

Purpose of the Study:

• To investigate the relationship between age, functional ability, and two types of SRH: comparative (age-referential) and global.
• To explore potential selection bias in SRH reporting among older adults.
• To clarify the distinct implications of using different SRH questions in research.

Main Methods:

• Utilized data from the Tampere Longitudinal Study on Ageing (TamELSA), wave 2.
• Included 830 participants aged 60-99 years.
• Employed multinomial regression analyses to assess associations between SRH measures, age, and functional ability.

Main Results:

• Increasing age, especially over 80, correlated with better comparative SRH, even after adjusting for covariates.
• Older age showed a weaker association with global SRH compared to comparative SRH.
• Functional ability demonstrated a stronger association with global SRH than with comparative SRH.

Conclusions:

• Comparative and global SRH measures are not interchangeable in aging research.
• Comparative SRH is significantly influenced by age calibration.
• Global SRH is recommended for survey studies and clinical settings due to its stronger link with functional ability.