Understanding Factors that Influence Inpatient Readmission After Step-Down


Understanding Factors that Influence Inpatient Readmission After Step-Down
September 1, 2023 MHO

Inpatient readmission is complex, influenced by a combination of socio-demographic, clinical and service-related variables, and can have adverse effects on patients’ well-being, their families, and in psychiatric units (Owusu et al, 2022). Additionally, readmission within a year of inpatient discharge is a metric indicating how well prior treatment and post-discharge support worked (Hermann et al., 2006). MHO’s readmission data are limited to readmissions to the same hospital, however research suggests the national inpatient readmission rate is 33.1% (Mills et al, 2023)1.

One post-discharge support offered to many patients is continued treatment via partial hospitalization (PHP) or intensive outpatient (IOP) programs, hereinafter referred to as Step-Down. Interestingly, analysis of MHO’s Step-Down data found that patients who Step-Down are more likely to readmit to the same hospital within the next year than those who don’t Step-Down (20.2% vs 16.3%; Figure 1). Furthermore, one in three step-down patients readmitted to inpatient within 30 days of completing Step-Down treatment.

Figure 1. Flow of all inpatients: those who step down are 25% more likely to readmit within a year

These observations prompted us to look for key determinants of readmissions in the context of Step-Down treatment, with existing research on most influential factors serving as a basis for investigating differences between Step-Down patients who do and don’t readmit to inpatient at the same hospital within one year of inpatient discharge.

Primary Diagnosis

Step-Down patients with Psychoactive Substance Use Disorders as well as Schizophrenia & Other Psychotic Disorders were more likely to be readmitted, consistent with Owusu et al (2022).  In contrast with previous studies (Owusu et al, 2022), those with Mood Disorders were less likely to be readmitted. (Figure 2).

Figure 2. Percent of Readmission Status Groups with Specified Primary Diagnostic Category

Number of Co-occurring Diagnoses

Inconsistent with prior research (e.g., Owusu et al., 2022), our data indicate step-down patients with an inpatient readmission have no meaningful difference in number of comorbidities compared to those who did not readmit (2.78 vs 2.72).

 Length of Stay in the Inpatient Visit Preceding Step-Down

When symptom severity and diagnosis are accounted for, length of stay is not meaningfully different between patients who did and did not readmit within a year. This finding aligns with Thompson et al. (2003) and contrasts Owusu et al. (2022).

Symptom Severity in the Inpatient Visit Preceding Step-Down

Analysis of BASIS-32™, 2 admission and discharge scores in the inpatient stay prior to Step-Down found that patients who later readmitted to inpatient had higher symptom severity upon inpatient admission (small differences) and no meaningful difference at inpatient discharge.

Figure 3. BASIS-32™ Severity at Admission and Discharge, by Readmission Status


Concluding Thoughts

Our analysis demonstrates that readmission risks are elevated for individuals diagnosed with Substance Use Disorder, and Schizophrenia & Other Psychotic Disorders. Furthermore, higher symptom severity upon admission to the inpatient setting immediately before the Step-Down is also associated with increased readmission risk. While the inpatient length of stay did not have large variation between the groups, given that patients who readmit after Step-Down display elevated severity, extending the length of stay during their inpatient visit could potentially prove advantageous. For additional insight into readmission prevention, check out this recent blog post by Horizon Health.

It’s important to note that additional factors such as prior inpatient admissions, treatment adherence, medication compliance, as well as post-discharge family and community support (Thompson et al., 2003; Owusu et al., 2022), likely also play a pivotal role in readmission trends following Step-Down.


1 Psychiatric 30-day readmission rate reported by CMS in 2020.

2 BASIS-32: The Behavior and Symptom Identification Scale is a self-report measure of a patient’s functioning, rated on a scale of 0 ‘No difficulties’ to 4 ‘Extreme difficulties’. BASIS-32 © McLean Hospital, Used by licensee with permission from McLean Hospital.

Mills, C., Gaiser, M., Saunders, R., & Scholle, S. (2020). Impact of Hospital Readmissions Reduction Initiatives on Vulnerable Populations , 1–60.

Owusu, E., Oluwasina, F., Nkire, N., Lawal, M. A., & Agyapong, V. I. (2022). Readmission of patients to acute psychiatric hospitals: Influential factors and interventions to reduce psychiatric readmission rates. Healthcare, 10(9), 1808. https://doi.org/10.3390/healthcare10091808

Thompson, E. E., Neighbors, H. W., Munday, C., & Trierweiler, S. (2003). Length of stay, referral to aftercare, and rehospitalization among psychiatric inpatients. Psychiatric Services, 54(9), 1271–1276. https://doi.org/10.1176/appi.ps.54.9.1271