Social Adaptability Index: application and outcomes in a dialysis population.
BACKGROUND
Patient groups associated with disparities in health care are usually defined on the basis of race, gender or geographic location. Social Adaptability Index (SAI), calculated based on education, marital status, income, employment and substance abuse, has been strongly associated with clinical outcome in other patient populations and may be used to identify individuals at risk. We used data from the United States Renal Data System to evaluate the role of SAI in survival of patients on dialysis.


METHODS
We used Cox model analyses to study the association between SAI and patient survival in patients with ESRD on dialysis, as well as in the subgroups based on age, race, sex, comorbidites and diabetic status.


RESULTS
We analyzed 3396 patients (age of ESRD onset 56.9 ± 16.1 years, 54.2% males, 64.2% white, 30.3% African-American). Mean SAI of the entire population was 7.1 ± 2.5 (range 0-12 points). SAI was higher in whites (7.4 ± 2.4) than in African-Americans (6.5 ± 2.5) (analysis of variance, P <0.001) and greater in men (7.4 ± 2.4) than in women (6.7 ± 2.5) (t-test, P <0.001). In a Cox model adjusted for potential confounders, SAI was associated with decreased mortality [hazards ratio of 0.97 (95% confidence interval 0.95-0.99), P = 0.006]. Subgroup analysis demonstrated an association of SAI with survival in most of the subgroups. Potential limitations of the study include reverse causality, possible misclassification and retrospective design.


CONCLUSIONS
We demonstrated that SAI is significantly associated with mortality in dialysis patients. SAI could be used to identify individuals at risk for inferior clinical outcomes.
Division of Nephrology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA. gsandhu@bidmc.harvard.edu
Gurprataap Singh
GS
Sandhu
Muhammad
M
Khattak
Preeti
P
Rout
Mark E
ME
Williams
Shiva
S
Gautam
Bradley
B
Baird
Alexander S
AS
Goldfarb-Rumyantzev
D000293:Adolescent; D000328:Adult; D000368:Aged; D001900:Boston / Q000453:epidemiology; D005006:Ethnicity; D005260:Female; D005500:Follow-Up Studies; D054624:Health Status Disparities; D054625:Healthcare Disparities; D006801:Humans; D007676:Kidney Failure, Chronic / Q000453:epidemiology / Q000523:psychology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D006435:Renal Dialysis / Q000401:mortality* / Q000523:psychology; D012917:Social Adjustment; D012959:Socioeconomic Factors; D015996:Survival Rate; D055815:Young Adult