As a go-between unit, an intermediate care unit (IMCU) fulfills several roles in a hospital system. It can take less acute patients who would normally be in an intensive care unit (ICU) bed. They can also help keep a closer eye on patients too critical for the general ward.
But are there proven benefits to patients when IMCUs are available? Additionally, are there cost savings to be had for the patient and health system by using these intermediary units?
Today’s article looks at some of the research surrounding IMCUs and their potential benefits to patients and health systems.
What is an Intermediate Care Unit?
Intermediate care units (IMCU) are areas in the hospital meant to be an in-between space for the general ward and the ICU.
Patients who were previously in the ICU who have improved or only require a portion of ICU levels of care can ‘step down’ to the IMCU. Inversely, patients in the general ward who require more careful monitoring and care but don’t necessarily qualify for an ICU bed can ‘step up’ to the IMCU.1
Because of this stepwise method, IMCUs are also called step down units (SDU) in many hospitals.
IMCUs can be a general medical or surgical unit or specific to certain specialties like cardiology or pulmonary and focus only on patients with those conditions.1 Other uses of an IMCU include admitting patients directly from post-surgical recovery or the emergency room.1
What Are Staffing Ratios for Intermediate Care Units?
A nurse working on a general ward may have an average of six patients per shift. In the ICU, this ratio drops substantially to one to two patients for every nurse. Some guidelines state the ratio in the ICU should be 1:1 for ventilated patients and 1:2 for non-ventilated patients.2
In the IMCU the ratios fall in the middle with 2.5 to four patients for every nurse. This follows with the role of the IMCU where patients have a higher acuity than the general ward but not quite as high as in the ICU.
Are There Clinical Benefits of Using an IMCU?
IMCUs are often seen as a safe ‘bridge’ and buffer for ICU patients who are transitioning away from intensive care.3 Several studies have been done over the years trying to determine the specific benefits beyond this of using an IMCU.
One study looking at data from ten hospitals found a benefit of utilizing an IMCU for patients with a higher illness severity. A significant reduction in mortality, ICU readmission (but not hospital readmission), and hospital length of stay was seen with these patients. Although patients with a higher illness severity did not have a reduction in hospital readmission, patients with a lower acuity did have a reduction in hospital readmission when an IMCU was in place.3
Researchers from this study concluded IMCUs have the potential to decrease hospital bed utilization and staffing costs.3
One challenge in determining benefits of IMCUs or SDUs is the difficulty in determining patient severity or acuity. ICUs use validated scoring tools to measure severity, but these are not always applied in the IMCU. This discrepancy makes it hard to compare IMCU outcomes to ICU outcomes.
Are There Financial Benefits for Patients When IMCUs Are Utilized?
A study looking at patients who had percutaneous coronary intervention found patients managed in the IMCU had a significantly lower inpatient cost, even if patient characteristics were similar to those in the ICU.
Another study looking at patients undergoing neurological procedures found patients admitted to the IMCU did not have more complications compared to those admitted to the neurological ICU and overall cost per patient was reduced if they went to the SDU.
Three studies looking at pulmonary ICU patients did not find the use of an IMCU to be cost-effective, however one study looking at patients with chronic obstructive pulmonary disease found costs to be reduced.
Are There Financial Benefits for Health Systems When IMCUs Are Utilized?
Although a night in the IMCU is less expensive than the ICU (1,307€ vs 2,224€), it may not reduce health system costs overall. One study found when a hospital has an IMCU, length of stay in the ICU increased and overall cost of care increased.4
This was thought to be because the hospital could admit more patients with higher illness severity to the ICU while the lower severity patients could be in the IMCU.4
While there is a lower staffing requirement for IMCUs, if the ICUs are just as full or more full with sicker patients – the cost savings may be minimal, but the overall profitability for the hospital could potentially increase.
Secondary Benefits of IMCUs
The benefits of IMCU could be more abstract and holistic to the health system. A study looking at 167 ICUs across 17 European countries found a significant reduction in mortality in hospitals who have an IMCU.
However, less than 25% of those ICU patients spent time in the IMCU. Researchers concluded IMCUs must somehow improve care for patients in the ICU that never get admitted to the IMCU.7 While the reason for this improvement was not expounded upon in this study, optimizing hospital resources may be one factor.
Another benefit of an IMCU is that they have been associated with an increased ability to perform elective surgical procedures. This in turn can reduce costs and improve outcomes by reducing delays in elective surgery which are known to increase admission costs and postoperative risk.4
It's clear more research is needed to discover and define benefits of IMCUs/SDUs. These units help alleviate the strain on ICU capacity limits but may not reduce overall hospital strain by simply reallocating patients to a new unit.
- Intermediate care units (IMCUs), also known as stepdown units (SDU), serve as an in-between space for patients too sick for the general ward but not sick enough for ICU care
- Patient outcomes may improve for certain populations when using IMCU, such as patients with a higher severity of illness
- Staffing for IMCUs is higher than the general ward, but still less than the ICU which may help save on staffing costs
- Patient costs may be reduced, but more research is needed to determine health system cost savings utilizing IMCUs
- There are secondary benefits to the health system and patients by having IMCUs in place, such as reduction in mortality and an increased ability to perform elective surgical procedures
 Sharma, S. & Rani, R. (2020). Nurse-to-patient ratio and nurse staffing norms for hospitals in India: a critical analysis of national benchmarks. J Family Med Prim Care, 9(6): 2631-2637
 Suparerk, L et al. (2020). The impact of step-down unit care on patient outcomes after ICU discharge. Critical Care Explorations, 2(5):p e0114.
 Chou, Y et al. (2020). Step-down units are cost-effective alternatives to coronary care units with non-inferior outcomes in the management of ST-elevation myocardial infarction patients after successful primary percutaneous coronary intervention. Intern Emerg Med, 15(1):59-66.
 Richards, B et al. (2011). Safety and cost effectiveness of step-down unit admission following elective neurointerventional procedures. J Neurointerv Surg, 4(5):390-2.
 Vincent, JL & Rubenfeld, G. (2015). Does intermediate care improve patient outcomes or reduce costs? Critical Care, 19(89).
 Plate JDJ, Peelen LM, Leenen LPH, Hietbrink F. The intermediate care unit as a cost-reducing critical care facility in tertiary referral hospitals: a single-centre observational study. BMJ Open. 2019 Jun 4;9(6):e026359. doi: 10.1136/bmjopen-2018-026359. PMID: 31167865; PMCID: PMC6561455.