The effects of critical care on long-term outcomes

Why it matters

It’s known that people who survive critical illness often have poor long-term outcomes which can result in them using healthcare more frequently after they have been discharged from critical care. But less is understood about the ways in which way multi-morbidities (having more than two illnesses at one time) can also affect long term outcomes.

The number of people who are admitted to critical care internationally continues to steadily increase and there’s evidence that being discharged is often just the start of a challenging recovery trajectory for both patients and their caregivers. This process can involve physical, social, cognitive, and emotional problems in the years after discharge.

This study looked at whether critical care patients had different mortality rates or readmission risks compared with other hospitalised patients who do not need care in a critical care environment and examined baseline patient demographics to see how they impacted mortality and use of healthcare in the year after discharge from critical care.

Approach

The following three questions were asked using data from the UK Biobank, a large prospective health resource for research which aims to improve the prevention, diagnosis, and treatment of a range of illnesses:

• Do critical care patients have a different mortality rate or readmission risk use in comparison with hospitalised patients who do not need care in a critical care environment?
• What are the causes of death in the post-critical care period?
• What is the interplay between mental and social health issues and use of healthcare after admission to critical care?

The study then assessed the differences in outcomes between patients with a critical care encounter and patients who had been admitted to hospital but not to critical care. Long-term mortality was examined using nationally linked data, as was hospital resource use in the year after patients were discharged from hospital. The cause of death was also observed.

Project findings

The study revealed an increased resource use for critical care survivors in the year after discharge. It was also found that in line with previous research, readmissions in the year after hospital discharge were significantly higher in the critical care cohort.

Using data from the UK Biobank, it was demonstrated that the long-term mortality of patients who had been discharged from critical care was no different from that of a matched control group after adjustment. However, the research found that mortality was more than double in those participants with two or more documented comorbidities compared with those without comorbidities. In line with previous research, readmissions in the year after people had been discharged from hospital were significantly higher in the critical care cohort.

This study also reflects the previous association between lower socioeconomic status and higher short and long-term mortality after critical illness which has been described in previous research and underlines important concepts: that the social circumstances in which people live are important to recovery from critical care and should be prioritised both during and after the critical care encounter through appropriate rehabilitation and mental health services.

Multimorbidity, lifestyle factors, and socioeconomic status all appear to influence long-term outcomes and should be the focus of future research.