||Purpose: Preference-based measures of health-related quality of life (HRQOL) or health utility, such as the EuroQol-5D5L (EQ5), cover multiple health domains and are combined into a single summary score. Preference-based scoring allows for estimates of quality-adjusted life years (QALYs) that afford comparisons among treatment options in clinical decision-making and economic analysis. Social support, financial and interpersonal difficulties are important determinants of HRQOL in patients with kidney transplant (KT). The Social Difficulties Inventory (SDI) has been developed to assess practical, financial, and interpersonal concerns in patients with cancer. The SDI score was an independent predictor of HRQOL in patients with cancer. Here we assess the association between SDI score and the EQ5 health utility score among patients with KT.
Methods: A cross-sectional, convenience sample of adults was recruited from the outpatient KT clinic of our institution. Participants completed the SD and the EQ5 questionnaires on an electronic data capture platform. Clinical characteristics were collected from medical records. Multiple imputation by chained equations was used to handle missing data, and multivariable adjusted linear regression was used to assess the independent association between SDI and EQ5 health utility score.
Results: A total of 327 participants (60% male, 25% with diabetes, mean [SD] age 52  years, eGFR 56  ml/min/1.76m2, median [IQR] time since transplant 7.5 [1.5-13.7] years) were enrolled. The median (IQR) SDI score was 3 (1-9); 23% of the sample had significant social distress (cut off=10). The median (IQR) EQ5 health utility score was 0.89 (0.81-0.95. Female (19 vs 29%, p=0.006) patients with lower income (33 vs 25 vs 18% for patients with low, mid and high income, p=0.064) and patients from minority groups (13 vs 38% for Caucasian vs other ethnicity, p<0.001) had higher risk for social distress. In multivariable adjusted (age, sex, marital status, ethnicity, income, education, comorbidity, eGFR, serum albumin, hemoglobin and depression and anxiety scores) linear regression, the SDI score was significantly associated with the EQ5 health utility score (coeff=-0.007; 95%CI:-0.01, -0.003; p=0.003).
Conclusion: Social distress is an independent predictor of the EQ5 health utility score in KT recipients. Future research should assess the impact of interventions providing targeted social support on quality of life in this patient population.