# Comparison of Readmission, Discharge Location and Mortality over Three Years Post-Discharge Between Patients Diagnosed with Hospital-Acquired Malnutrition and Those Malnourished on Admission—A Retrospective Matched Case–Control Study in Five Facilities

## TL;DR

This study compares health outcomes three years after discharge for patients with hospital-acquired malnutrition versus those already malnourished upon admission.

## Contribution

The study reveals that mortality and readmission rates are similar between the two groups, except older MPOA patients had higher 30-day readmission rates.

## Key findings

- Mortality rates were similar between HAM and MPOA patients at 36 months post-discharge.
- Older MPOA patients were more likely to be readmitted within 30 days compared to older HAM patients.
- Discharge locations and readmission patterns were largely similar between the two groups over three years.

## Abstract

Background/Objectives: Increased mortality and poor post-discharge outcomes are common in malnourished inpatients. It is unknown whether post-discharge outcomes differ between patients with hospital-acquired malnutrition (HAM) or malnutrition present on admission (MPOA), which could impact nutrition processes within healthcare systems and hospital-acquired-complication policy. This retrospective matched case–control study compared mortality, discharge location and readmission at 3-, 12- and 36-months post-discharge between HAM and MPOA patients. Methods: The eligible patients were ≥18 years, malnourished and stayed in hospital for >14 days between 2015 and 2019. HAM patients were 1:1 matched with MPOA patients for age (±3 years), sex, facility and year of admission and further categorised by age group (18 < 65, ≥65 years). The data were obtained from medical records included demographics, mortality, discharge location and readmissions. Statistical tests were used to compare the groups. Results: There were 350 eligible patients (n = 175 HAM, 65 ± 18 years, 37%F, 88% moderately malnourished, 71% from hospitals with >500 beds). HAM and MPOA patients had similar post-discharge mortality (n = 51/175 (29%) vs. n = 64/175 (37%), p > 0.172) and discharge locations (n = 101/111 (81%) vs. n = 91/124 (82%) resided at home, p = 1.00) at 36 months. Of those readmitted to hospital (n= 268/350, 77%), days hospitalised post-discharge (HAM:17(6–40) vs. MPOA:19(8–39)) and number of readmissions (HAM:2(1–4) vs. MPOA:2(1–5)) were similar at 36 months (p > 0.05). However, older MPOA patients were more likely to readmit within 30 days (p = 0.007). Conclusions: Mortality was high but similar between MPOA and HAM patients up to 36 months post-discharge. Discharge location and readmissions were also similar between the groups, except that older MPOA patients were more likely to readmit to hospital within 30 days than older HAM patients. Mechanisms, such as nutrition policies and procedures, implementation of post-discharge nutrition interventions or allocation of post-discharge resources, should be explored further and should consider all long-stay malnourished patients, particularly those aged ≥ 65 years, to reduce preventable patient harm associated with malnutrition.