Predictors of Health Utility among 60-Day Survivors of Acute Kidney Injury in the Veterans Affairs/National Institutes of Health Acute Renal Failure Trial Network Study

Background and objectives: Health-related quality of life (HRQOL) after acute kidney injury (AKI) is an area of great importance to patients. It was hypothesized that HRQOL after AKI would relate to intensity of dialysis during AKI and dialysis dependence at follow-up.Design, setting, participants, & measurements: The Veterans Affairs/National Institutes of Health Acute Renal Failure Trial Network Study was a multicenter, prospective, randomized trial of intensive versus less intensive renal replacement therapy in critically ill patients with AKI. Of 1124 participants, 415 survived at least 60 days and completed the Health Utilities Index (HUI), which measures 8 health attributes and calculates an overall HRQOL score, also called a utility score. How strongly pre–intensive care unit (ICU) health, severity of illness, hospital course, intensity of dialysis, and outcome were associated with 60-day HUI scores was assessed, after adjustment for demographics.Results: The overall HUI score was 0.40 ± 0.37, indicating severely compromised health utility and was associated with only admission from home and hospital and ICU length of stay (LOS). Ambulation was better among those with a shorter hospital and ICU LOS. Better cognition was associated with dialysis independence and with fewer comorbid chronic illnesses. Emotion was associated with only hospital LOS. Pain was associated with ICU LOS.Conclusions: Health utility was low in this cohort of patients after AKI, and intensity of dialysis did not affect subsequent health utility. The effects of a lengthy hospitalization generally outweighed the effects of delayed recovery of kidney function on HRQOL after AKI.A cute kidney injury (AKI) is common among hospitalized patients and is particularly prevalent among patients cared for in the intensive care unit (ICU) setting (1–3). AKI has been associated with increased morbidity, mortality, and costs (1–4). It remains unclear to what extent treatment of or recovery from AKI influences health-related quality of life in survivors of AKI. There have been several reports of health-related quality of life (HRQOL) among survivors of AKI in the ICU (5–10). However, many of these studies are limited by small sample size and low response rate. In addition, follow-up times are variable among and sometimes within studies, ranging from 3 months to several years. Several measures of HRQOL have been used, including the Medical Outcomes Study Short Form 36-item health survey (SF-36) (9), EuroQol (EQ-5D) (5), and Nottingham Health Profile (6,8,10), and also health utilities by time trade-off (7) or visual analog scale (5) and Activities of Daily Living (7,8). Perhaps because of this variability, results are mixed. On balance, limitations in mobility were fairly common, ranging from 29 to 60% (6,8). However, patients generally reported a favorable health status, with 62 to 77% of patients reporting “good” or “excellent” health status (7,10). Health utility on the EQ-5D index was 0.68 compared with an age- and sex-matched norm of 0.86 (5), but in the same study utility by visual analog scale was not different from the general population. Health utility by the time trade-off method was reported by Hamel et al. to be 0.84, but no normative data were presented (7).The availability of HRQOL data in a large cohort of survivors of AKI requiring renal replacement therapy (RRT) provides a unique opportunity to study HRQOL and its potential determinants in this population. The Veterans Affairs/National Institutes of Health (VA/NIH) Acute Renal Failure Trial Network (ATN) study (ClinicalTrials.gov, {"type":"clinical-trial","attrs":{"text":"NCT00076219","term_id":"NCT00076219"}}NCT00076219) was a multicenter randomized trial of intensive versus less intensive renal replacement therapy in critically ill patients with acute kidney injury conducted between November 2003 and July 2007 at 27 VA and university-affiliated medical centers (11,12). Although the major goals of the ATN study were to assess the effects of treatment assignment on 60-day mortality, in-hospital mortality, and recovery of renal function, HRQOL was also assessed at 60 days among survivors with the intention of establishing the effect of dialysis intensity on HRQOL and of assigning health utilities to facilitate performance of cost-effectiveness analysis.We hypothesized that study treatment assignment and ongoing dialysis dependence at 60 days would be potential determinants of HRQOL. Although intensive dialysis did not lead to shorter hospital stays or more rapid recovery of renal function (12), both of which might have contributed to improved HRQOL at 60 days, we postulated that better control of uremia could have direct effects on HRQOL. In addition, given that patients receiving maintenance dialysis routinely report impaired HRQOL (13–15), we also hypothesized that ongoing need for dialysis would be an important determinant of HRQOL at 60 days.