Income and survival in chronic dialysis patients

Area of Science:

• Nephrology
• Public Health
• Socioeconomic Determinants of Health

Background:

• Chronic dialysis patients face varying survival rates influenced by numerous factors.
• Socioeconomic status, particularly income, is a potential determinant of health outcomes in end-stage renal disease (ESRD).

Purpose of the Study:

• To examine the relationship between income and survival rates among chronic dialysis patients in Michigan.
• To determine if income level affects the relative risk (RR) of mortality in ESRD patients, adjusting for key demographic and clinical variables.

Main Methods:

• A Cox survival regression model was employed to analyze data from new dialysis patients in Michigan (1980-1987).
• Income was assessed using average household income from census data for patients' ZIP Codes.
• Survival was tracked from day 180 of ESRD until death, transplant, or study end (12/31/87).

Main Results:

• For Black patients, each $1,000 increase in income was associated with a 3.3% decrease in the adjusted RR of dying (p < 0.01).
• No statistically significant trend between income and mortality was found for white patients (p > 0.10).
• The differential impact of income on survival between Black and white patients was significant (p < 0.01), despite white patients having higher overall death rates.

Conclusions:

• Income level demonstrates a significant, positive association with survival among Black patients with chronic kidney disease on dialysis.
• Socioeconomic status, indicated by area income, disproportionately affects survival outcomes for Black ESRD patients compared to white patients.
• Further investigation is warranted to understand the underlying mechanisms driving the income-survival relationship in this population, particularly for Black patients.