Minimum income for healthy living and frailty in adults over 65 years old in the English Longitudinal Study of Ageing: a population-based cohort study

OBJECTIVE: To test whether minimum income for healthy living of a person aged 65 years or older (MIHL(65)) is associated with frailty in older adults. DESIGN AND SETTING: Secondary analysis of the English Longitudinal Study of Ageing, a multiwave prospective cohort study in England, UK. PARTICIPANTS: A subset (n=1342) of English Longitudinal Study of Ageing participants, who at wave 1 in 2002 were aged 65 years or older, without any limiting long-standing illnesses, and who had the information required to calculate MIHL(65) in 2002, 2004 and 2006 and two measures of frailty in 2008. MAIN OUTCOME MEASURES: Frailty defined using Fried’s phenotype criteria and Rockwood’s Index of deficits. RESULTS: The odds of frailty in 2008 were significantly higher for participants living below MIHL(65) in 2002, both on Fried’s phenotype criteria (OR 2.56, 95% CI 1.57 to 4.19) and Rockwood’s Index (OR 2.83, 95% CI 1.74 to 4.60). These associations remained after adjustment for age and gender for both Fried’s phenotype (OR 1.85, 95% CI 1.18 to 2.90) and Rockwood’s Index (OR 2.15, 95% CI 1.38 to 3.35). Compared with those whose income during 2002–2006 was always above MIHL(65), the odds of frailty in 2008 for those below MIHL(65) were two-to-three times higher, with a tendency for the ORs to increase in line with the length of time spent below MIHL(65) (ORs (95% CIs) were: Fried’s phenotype, below MIHL(65) once: 2.02 (1.23 to 3.34); twice: 2.52 (1.37 to 4.62); thrice: 3.53 (1.65 to 7.55). Rockwood’s Index: once: 2.34 (1.41 to 3.86); twice: 3.06 (1.64 to 5.71); thrice: 2.56 (1.22 to 5.34)). These associations remained after adjustment for age and gender on Rockwood’s Index, but not Fried’s phenotype. CONCLUSIONS: These results provide some support for the idea that frailty at older ages is associated with not having sufficient income to lead a healthy life.