Risk factors for hospital readmission in older adults within 30 days of discharge - a comparative retrospective study

The area of hospital readmission in older adults within 30 days of discharge is extensively researched but few studies look at the whole process. In this study we investigated risk factors related, not only to patient characteristics prior to and events during initial hospitalisation, but also to the processes of discharge, transition of care and follow-up. We aimed to identify patients at most risk of being readmitted as well as processes in greatest need of improvement, the goal being to find tools to help reduce early readmissions in this population.

This comparative retrospective study included 720 patients in total. Medical records were reviewed and variables concerning patient characteristics prior to and events during initial hospital stay, as well as those related to the processes of discharge, transition of care and follow-up, were collected in a standardised manner. Either a Student's t-test, χ²-test or Fishers' exact test was used for comparisons between groups. A multiple logistic regression analysis was conducted to identify variables associated with readmission.

The final model showed increased odds of readmission in patients with a higher Charlson Co-morbidity Index (OR 1.12, p-value 0.002), excessive polypharmacy (OR 1.66, p-value 0.007) and living in the community with home care (OR 1.61, p-value 0.025). The odds of being readmitted within 30 days increased if the length of stay was 5 days or longer (OR 1.72, p-value 0.005) as well as if being discharged on a Friday (OR 1.88, p-value 0.003) or from a surgical unit (OR 2.09, p-value 0.001).

Patients of poor health, using 10 medications or more regularly and living in the community with home care, are at greater risk of being readmitted to hospital within 30 days of discharge. Readmissions occur more often after being discharged on a Friday or from a surgical unit. Our findings indicate patients at most risk of being readmitted as well as discharging routines in most need of improvement thus laying the ground for further studies as well as targeted actions to take in order to reduce hospital readmissions within 30 days in this population.