BACKGROUND: More data are needed to guide evidence-based, inpatient registered dietitian nutritionist (RDN) staffing models. OBJECTIVE: Identify relationships between: 1) patient malnutrition risk or intervention categories and estimated total RDN care time ("care time")
and 2) care time and emergency department (ED) visits. DESIGN: This study was a prospective cohort study with data collection via RDN surveys, patient interviews, and medical record review. PARTICIPANTS/SETTING: Adult (n = 550) and pediatric (n = 345) patients enrolled at 32 adult and 27 pediatric US hospitals from August 2019 to January 2023. MAIN OUTCOME MEASURES: Care time and ED visits within 90 days of hospital discharge were measured. STATISTICAL ANALYSIS: Multilevel, generalized linear, and negative binomial regression models were used to evaluate relationships between patient characteristics and Box-Cox-transformed care time and the relationship between Box-Cox-transformed care time and total ED visits. RESULTS: After adjusting for patient characteristics, adult patients classified as at malnutrition risk vs not at risk required a mean of 8% (95% CI 5% to 11%) more care time. Pediatric patients at medium or high compared with low malnutrition risk needed a mean of 21% (95% CI 4% to 40%) and 31% (95% CI 12% to 54%) more care time, respectively. Number of initial RDN interventions categories per patient (0 to 1 vs 2 to 3 or 4+) was associated with a mean of 10% (95% CI 7% to 14%) or 8% (95% CI 2% to 15%) more care time for adults and 17% (95% CI 5% to 32%) and 39% (95% CI 21% to 61%) more care time for children, respectively. More estimated total RDN care time was associated with significantly higher incidence rate ratios of ED visits (adults: incidence rate ratio 2.8
95% CI 1.1 to 7.2
children: incidence rate ratio 1.7
95% CI 1.02 to 2.8). CONCLUSIONS: Patient malnutrition risk or breadth of nutrition interventions required can inform nutrition department staffing. Intervention studies may better define relationships between care time and medical outcomes.