Patient deterioration single map Patient deterioration double map Consumer summary 
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The national patient deterioration programme is a five-year plan to reduce harm from failures to recognise or respond to acute physical deterioration in adults admitted to New Zealand hospitals. Such patients may suffer acute physical deterioration at any point during a hospital stay with many showing signs of instability for some time before events such as cardiac arrest or admission to an intensive care unit (ICU) occur. There are often opportunities to intervene to prevent serious harm if deterioration is detected early.

More information on how the Commission is working to standardise detection of physical deterioration and respond early can be found here: www.hqsc.govt.nz/our-programmes/patient-deterioration.

The patient deterioration domain of the Atlas of Healthcare Variation focuses on patients who deteriorate to the point that ICU admission is required. This is because individual data is not currently collected from the ward environment on patients who do not require ICU admission, as they are detected earlier. We acknowledge there are limitations of focusing on ICU admission.

This Atlas domain reports data from the Australian and New Zealand Intensive Care Society (ANZICS) adult patient database, which 15 district health boards (DHBs) with an ICU contribute data to. The domain presents data for DHBs whose ICU has explicitly given permission for data to be included.

The goal of this Atlas domain is to identify whether there is wide variation in rates which may highlight areas for further local investigation and improvement.

Key findings

  • Emergency admissions from the ward varied widely by DHB, from 2.4 to 18.9 per 1,000 hospital admissions in 2016.
  • The average length of stay following an emergency admission from the ward is 20 hours longer than other ICU admissions.
  • 23 percent of patients admitted to ICU as an emergency from the ward received invasive ventilation.
  • The severity of illness on admission varied 1.8-fold between DHBs.
  • There were no significant differences in mortality rates between DHBs over the three years.
  • There was wide variation between DHBs in the percentage of patients discharged after-hours, from 6 percent to 41 percent of discharges.
Emergency admissions from the ward varied widely by DHB.

Note: the denominator used to estimate rates for Auckland’s cardiovascular ICU was different to the method applied for other units. This difference means for this indicator, cardiovasular ICU should not be compared with other units. View the methodology for the full description.

  • On average, 6.0 per 1,000 hospital admissions resulted in an emergency admission to ICU from the ward. This varied widely from 2.4 to 18.9 per 1,000 admissions.
  • There were no significant differences in rates of emergency admission by ethnicity.
  • Those in the youngest and oldest age bands were significantly less likely to be admitted as an emergency, while those aged 65–74 years had the highest rate of admission.

Emergency admissions from the ward, by age and ethnicity (2016)

Age Māori Pacific peoples European/Other Total
18–44 2.5 4.3 2.1 2.4 (2.2–2.7)
45–64 8.2 7.4 6.3 6.8 (6.3–7.3)
65–74 9.4 7.8 8.2 8.3 (7.6–9.0)
75–84 8.4 7.6 6.7 6.8 (6.2–7.5)
85 and over 4.3 1.5 2.4 2.4 (1.9–3.0)
Total 5.6 (5.3–6.6) 5.9 (5.2–6.8) 5.0 (4.8–5.3) 5.2
Average length of stay following emergency admission from the ward is 20 hours longer than other ICU admissions.
  • People admitted to ICU as an emergency from the ward stayed on average 87 hours in 2016. This was 20 hours longer than other ICU admissions.
  • Some DHBs had consistently higher average length of stay over the three-year period.
  • Those aged 45–64 years stayed significantly longer than all other age groups and this varied over 2.5-fold between DHBs.
  • The European/Other ethnic group had significantly longer average length of stay than all other groups.

Average length of stay by age and ethnicity (2016)

Age Māori Pacific peoples European/Other Total
18–44 59.1 60.5 103.1 85.5 (84.4–86.5)
45–64 103.7 97.1 94.7 97.0 (96.2–97.7)
65–74 60.6 56.9 91.0 85.4 (84.6–86.2)
75–84 79.5 63.6 78.2 77.6 (76.7–78.4)
85 and over < 10 < 10 49.1 48.7 (47.2–50.2)
Total 83.1 (82.1–84.1) 74.4 (73.2–75.7) 88.3 (87.9–88.8) 86.2
23 percent of patients received invasive ventilation following emergency admission to ICU from the ward.
  • This indicator shows the percentage of patients who received invasive ventilation. This includes any form of positive pressure ventilation delivered through an artificial airway such as oral or nasal endotracheal tube or a tracheostomy.
  • On average 23 percent of people received invasive ventilation following emergency admission, with rates significantly lower in those aged 85 years and over.
  • From 2014 to 2016, there appears to have been an overall reduction in the percentage of patients invasively ventilated following emergency admission, although it was not a statistical difference.

Proportion of patients invasively ventilated following emergency admission by age and ethnicity (2014–16)

Age Māori Pacific peoples European/Other Total
18–44 25.4 22.6 22.6 23.2 (18.0–29.3)
45–64 25.2 24.6 27.2 26.5 (22.6–30.8)
65–74 15.4 17.2 23.0 21.8 (17.9–26.5)
75–84 18.5 25.0 19.1 19.3 (15.1–24.3)
85 and over <10 < 10 < 10 < 10.0
Total 22.5 (21.5–27.8) 21.5 (21.4–29.6) 22.4 (23.6–26.4) 22.4
The severity of illness on emergency admission varied between DHBs.
  • Illness severity is measured using APACHE III score. This calculates a patient’s risk of death using physiological parameters such as age. This partially explains why scores increase with age regardless of pathology.
  • In 2016, the mean score for illness severity was 62, ranging between 47 and 77.
  • The mean score increased significantly with age, peaking at 75–84 years.

Mean APACHE III score by age and ethnicity (2016)

Age Māori Pacific peoples European/Other Total
18–44 52.7 47.3 45.5 47.3 (46.6–48.1)
45–64 60.4 60.3 58.1 58.9 (58.3–59.5)
65–74 67.8 78.9 67.0 67.8 (67.1–68.5)
75–84 81.3 83.6 69.5 71.1 (70.2–71.9)
85 and over < 10 <10 68.2 68.4 (66.7–70.2)
Total 62.4 (61.5–63.3) 61.3 (60.2–62.4) 62.3 (61.9–62.7) 62.2
Around 11 percent of emergency admissions from the ward resulted in death in ICU.
  • Death rates did not vary significantly over the three-year period, nor did any DHBs have consistently significantly higher rates over the three years.
  • Mortality was significantly lower in those aged 18–44 and significantly higher in the oldest age group (75 and over).

The percent of emergency ICU admissions resulting in death (2014–16)

Age Māori Pacific European/Other Total
18–44 10.2 < 10 46.5 6.4 (4.8–8.2)
45–64 11.2 9.7 59.0 10.4 (9.0–11.9)
65–74 15.6 18.3 68.3 13.0 (11.2–15.0)
75 and over 19.1 21.6 70.7 17.2 (15.1–19.5)
Total 12.7 (10.5–15.3) 11.0 (8.3–14.3) 63.2 (63.0–63.4) 12.1

* Due to low numbers, the age bands 75–84 and 85 and over were grouped together.

The average ICU length of stay for emergency admissions did not vary depending on whether the patient died in ICU or was still alive when discharged.

The average ICU length of stay for all admissions was 68 hours.
  • On average, ICU length of stay was 68 hours. This remained consistent over the three years, with some DHBs consistently having shorter or longer stays. The variation was greater than 2.6-fold.
  • Those aged 85 years and over tended to stay for less time than those aged under 85 years.
On average 6 percent of people were re-admitted to ICU during their hospital stay.
  • The rate of re-admission varied more than three-fold between DHBs. 
  • Those aged 45–74 were significantly more likely to be re-admitted than those aged 18–44.
2.300 patients were discharged between 6 pm and 6 am in 2016.
  • There was wide variation between DHBs, with between 6 percent and 41 percent of all discharges being after-hours.
  • On average, after-hours discharges represented 17 percent of all discharges and did not significantly change over the three years.

What questions might the data prompt?

  • How do similar DHBs compare?
  • Are rates increasing or decreasing over time?
  • Why do rates vary between DHBs? How much can be explained by differences in patient population?
  • What is the impact of ICU capacity on the rate of emergency admissions?
  • How do these rates over time reflect changes in population health status?

Recommended reading

http://www.anzics.com.au/Pages/CORE/About-CORE.aspx
http://www.anzics.com.au/Pages/CORE/CORE-Reports.aspx

Method and limitations

Patients who deteriorate in smaller ('secondary') hospitals are often transferred to larger ('tertiary') hospitals with more ICU resource. As such, patients in tertiary hospital ICUs will include those who may have deteriorated in that hospital or been transferred as an emergency from a secondary hospital. The data set does not discriminate between these patient groups.

It is important to note that some ICUs have high dependency units (HDUs) attached. There will be a proportion of patients who may be suitable for HDU but not for ICU and this may affect outcome. Units that have an HDU may be able to admit patients earlier in their course of deterioration. Earlier admission may result in less severe APACHE scores than those admitted late but they may have similar outcomes. This bias is due to APACHE scoring only looking at the first 24 hours.

Although some variation between ICUs is due to factors outside the scope of the Commission’s patient deterioration programme (such as the balance between elective and emergency admissions, ICU bed availability, 'secondary' vs 'tertiary' level ICUs), the focus on patients admitted to ICU in an emergency from the ward may provide information as to when deterioration was detected and whether appropriate actions were taken in a timely manner. We were not able to find a reliable measure of ICU occupancy, which can also alter the threshold for admission; this is best explored using local data and should include staff availability. The data will not reflect patients in whom deterioration was detected early and managed appropriately and so ICU admission was never required. Similarly, patients who deteriorated but died before reaching ICU will not be represented in this data set.


References

Gantner D, Farley K, Bailey M, et al. 2014. Mortality related to after-hours discharge from intensive care in Australia and New Zealand, 2005–12. Intensive Care Med 40(10):1528–35.

Last updated 15/06/2018