Regional and Socioeconomic Disparities in Frailty Across Tasmania: Evidence From Island Study Linking Ageing and Neurodegenerative Disease.

Frailty index scores in the ISLAND cohort followed a gamma distribution with a mean score of 0.16.

• The analytical sample comprised 5740 participants from the Island Study Linking Ageing and Neurodegenerative Disease (ISLAND).
• Mean frailty index score was 0.16 (SD = 0.09).
• A 33-item frailty index was constructed using cohort data.
• The mean age of the analytical sample was 69.3 years (SD = 8.0) and most participants were women (72%).

Frailty index scores increased with age and were highest in central and western areas of Tasmania.

• Spatial mapping was used to examine frailty distribution across Tasmania.
• The geographic pattern showed elevated frailty concentrated in central and western regions.
• Frailty increased with age across the cohort.

After adjustment for confounders, frailty index scores were significantly higher in rural towns and remote communities compared to regional centres.

• Participants in rural towns had significantly higher frailty index scores than those in regional centres (β = 0.011 [95% CI = 0.005, 0.016]).
• Participants in remote communities had significantly higher frailty index scores than those in regional centres (β = 0.023 [95% CI = 0.009, 0.038]).
• Models were adjusted for age, gender, education, retirement and migrant status.
• Geographic remoteness was classified using the Modified Monash Model.

After full adjustment, frailty was significantly higher in areas of middle or low socioeconomic advantage compared with areas of highest socioeconomic advantage.

• Participants in areas of middle socioeconomic advantage had higher frailty index scores than those in the highest advantage areas (β = 0.013 [95% CI = 0.007, 0.018]).
• Participants in areas of low socioeconomic advantage had higher frailty index scores than those in the highest advantage areas (β = 0.024 [95% CI = 0.018, 0.030]).
• Socioeconomic status was measured using the Index of Relative Socioeconomic Advantage and Disadvantage, linked via participant postcodes.
• Models were adjusted for age, gender, education, retirement and migrant status.

The ISLAND study used a web-based longitudinal cohort design to examine frailty in adults aged 50 years and over in Tasmania, Australia.

• The study linked participant postcodes to Modified Monash Model remoteness classifications and the Index of Relative Socioeconomic Advantage and Disadvantage.
• Analyses included descriptive statistics, spatial mapping, and multivariable linear regression models.
• The cohort was a web-based longitudinal study of adults aged 50 years and over.