All patients should undergo nutrition screening on admission to hospital because malnutrition is an overlooked factor in driving readmissions, South Australian researchers say.

Patients who screen positive for malnutrition have an almost 40% higher risk of early readmission (odds ratio 1.39), a retrospective study of more than 26,000 admissions at two tertiary hospitals throughout 2016 has found.

Other factors that predicted early readmissions (0-7 days after discharge) included comorbidities, length of initial hospital stay, low socioeconomic status and being single or divorced. Indigenous patients were twice as likely to be readmitted early, which the authors of the study said might be related to high rates of early discharge against medical advice.

The study, published in BMJ Open, showed that 11% of discharged patients had an early readmission and 34% had a late (up to 6 months) readmission.

The prevalence of impaired nutrition – as measured by the malnutrition universal screening tool (MUST) – was 31%, and malnutrition was also a factor in late readmissions, increasing the risk by 23%. However, only 16% of  patients underwent nutrition screening during hospital admission, the study authors led by Dr Yogesh Sharma, a general physician at Flinders Medical Centre, Adelaide, noted.

“This highlights that a significant proportion of malnourished patients are missed,” they wrote.

“Targeted nutrition intervention may prevent unplanned hospital readmissions, … There is a window of opportunity to target malnutrition among hospitalised patients and future intervention studies should target patients of all age groups to see if it helps reduce readmissions,” they suggested

Interestingly, the study also found that weekend discharge was associated with a lower rate of readmissions. This might have been due to less medically complicated patients being selected for weekend discharge, since patients tended to have had a shorter length of hospital stay, had fewer complications during admission and were more likely to be discharged home.

“These findings suggest that hospitals need not worry that weekend discharges will adversely affect their readmission statistics,” Dr Sharma and colleagues noted.