Background: The Intensive Care National Audit and Research Centre (ICNARC) data on COVID-19 intensive care admissions data is collected through the Case Mix Programme (CMP), an audit of patient outcomes from adult, general critical care units covering England, Wales and Northern Ireland. During the COVID-19 pandemic this data was linked to the Clinical Practice Research Datalink (CPRD) Primary Care data. This work investigates what value the ICNARC data offers over HES Admitted Patient Care Critical Care data.
Objectives: To explore the completeness of the ICNARC data including at the percentage of missing/incomplete data and possible reasons for this.
To investigate what information the ICNARC data contained that were not available in HES or Primary Care datasets.
To compare the INCARC data to the HES Critical Care data, looking at the percentage of patients found in ICNARC compared to HES Critical Care.
Methods: Variables within the ICNARC data were investigated for percentage missingness (5-10%, 10-15% and >15%). Cross-comparisons of variables using the Dataset documentation and data dictionaries were used to compare variables between the ICNARC, HES Critical Care and CPRD Primary Care datasets. CPRD linked HES Critical Care (Set 22) was merged with ICNARC data, to observe the numbers of distinct patients.
Results: The majority of variables had some missingness, however only 7 variables in the ICNARC data had >15% missingness. The ICNARC data was found to contain some information not found in HES APC Critical Care data and Primary Care. These include the date of discharge from hospital and critical care, the reason for discharge, if CPR was given in first 24 hours, if patients where sedated or paralysed and sedated for first 24 hours, APACHE II physiology scores and patient’s place of residence prior to hospital admission.
In the HES Critical Care data CPRD GOLD data, 93.9% of patients in ICNARC are also in HES Critical Care. There are 263 distinct patients in ICNARC (6.8%) that are not in HES Critical Care (0.086% of HES Critical Care).
In the data linked to CPRD Aurum data, 92.85% of patients in ICNARC are also in HES Critical Care. There are 1,266 distinct patients (7.1%) in ICNARC that are not in HES Critical care (0.69% of HES CC). There did not appear to be significant differences in the demographics between these two patient groups.
Conclusions: The ICNARC data were used in various studies such as those supporting the assessment of vaccine safety or exploring the effects of covid in patients with comorbidities. The data has some additional variables included in the data. However, there is a large overlap with HES Critical Care data in terms of both patients and information recorded.
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