The financial toxicity of ageing: a longitudinal analysis of the health and functional determinants of household OOP spending in rural South Africa.

Hypertension was associated with a 26% increase in the likelihood of incurring any out-of-pocket health expenditure.

• Adjusted odds ratio (AOR) of 1.26 with 95% CI 1.14–1.40 for hypertension and market entry into OOP spending.
• Socioeconomic status and NCD diagnoses were identified as the primary drivers of market entry.
• Analysis used Generalised Estimating Equations (GEE) on longitudinal data from HAALSI Waves 1–3 (2015–2022).
• Analytic sample included 4,371 adults aged ≥40 years comprising 13,437 person-wave observations.

Physical frailty, measured by weaker grip strength, was associated with greater magnitude of OOP spending among those already incurring costs.

• The association between grip strength and spending magnitude was statistically significant (p = 0.012).
• This finding applied specifically to the sub-sample of individuals who were already incurring OOP expenditure, not to market entry.
• Grip strength was used as an objective measure of physical frailty alongside gait speed in the model.

Each additional Activity of Daily Living (ADL) limitation was associated with a 16% decrease in the odds of incurring any OOP health expenditure.

• AOR 0.84 per additional ADL limitation, p < 0.001.
• This indicates that severe functional disability paradoxically predicts lower likelihood of entering the OOP payment system.
• The authors describe this as severe vulnerability unexpectedly predicting lower spending, suggesting exclusion from rather than engagement with formal health services.

Depression was associated with significantly lower OOP expenditure intensity among those incurring costs.

• The association between depression and lower expenditure intensity was statistically significant (p < 0.001).
• Depression was included as a cognitive/mental status predictor alongside delayed recall.
• This finding parallels the ADL result, suggesting that mental health decline also acts as a barrier to accessing and spending on formal health care.

HIV-positive status was protective against high OOP health costs.

• HIV was included as one of three chronic diagnoses alongside hypertension and diabetes.
• The protective effect of HIV-positive status against high OOP costs is likely attributable to established HIV treatment programs providing subsidised or free care in South Africa.
• This contrasts with the effect of hypertension, which increased the likelihood of OOP spending.

The study identified a 'dual burden of exclusion' in the financial toxicity of ageing, where NCD diagnoses drive spending while severe functional and mental decline excludes the most vulnerable from the formal health economy.

• NCD diagnoses (particularly hypertension) were associated with increased market entry into OOP spending.
• Severe ADL limitations and depression were associated with reduced OOP spending, interpreted as exclusion from formal care rather than reduced need.
• The authors argue that financial risk protection mechanisms must be expanded beyond disease-specific models to cover geriatric frailty and disability explicitly.
• The study used data from the Health and Ageing in Africa: A Longitudinal Study (HAALSI) in rural South Africa, Waves 1–3 (2015–2022).

The epidemiological transition in sub-Saharan Africa has created a double burden of chronic disease and functional decline, motivating examination of OOP spending beyond NCD diagnosis alone.

• Prior literature had established the relationship between NCDs and OOP expenditure but less was known about the financial burden of physical frailty and cognitive decline.
• The study aimed to distinguish between the costs of disease diagnosis and those of functional disability.
• The HAALSI cohort in rural South Africa was used to study adults aged ≥40 years across three waves from 2015 to 2022.