Abstract:
|
For chronic dialysis patients, a unique population requiring continuous medical care, methodologies to monitor patient outcomes, such as hospitalizations, over time, after initiation of dialysis, are of particular interest. Contributing to patient hospitalizations is a number of multilevel covariates such as demographics and comorbidities at the patient level and staffing composition at the dialysis facility level. We propose a varying coefficient model for multilevel risk factors (VCM?MR) to study the time?varying effects of covariates on patient hospitalization risk as a function of time on dialysis. The proposed VCM?MR also includes subject?specific random effects to account for within?subject correlation and dialysis facility?specific fixed effect varying coefficient functions to allow for the modeling of flexible time?varying facility?specific risk trajectories. The proposed modeling allows for comparisons between time-varying effects of multilevel risk factors as well as testing of facility-specific fixed effects. The method is applied to model hospitalization risk using the rich hierarchical data available on dialysis patients from the United States Renal Data System.
|