Association between multimorbidity and mortality in a cohort of patients admitted to hospital with COVID-19 in Scotland

October 2021: Research published in the Journal of the Royal Society of Medicine looks at the risk of death after being admitted to hospital with COVID-19. We look at patients who were shielding or living with multiple long term conditions, during the first wave of the pandemic in Scotland.

Summary in Plain English

Research has shown that there are risk factors linked to hospital admission and death from COVID-19. These include being in older age groups, male, or having a history of some long term conditions such as high blood pressure, diabetes, and kidney disease.

Based on data available at the time, the UK Government created a Shielded Patient List of people living with particular conditions or having certain medical treatments. In the first wave of the pandemic, this group was advised to avoid or reduce contact with others. This is because they were thought to be at high risk of serious complications if they became ill with COVID-19.

However, there was limited research on people living with more than one long term illness, so no special recommendations were provided by policy-makers for this group.

Why did we carry out this research?

Understanding how living with multiple long term conditions might impact the health of patients admitted to hospital with COVID-19 is very important. It can help policy makers develop public health measures, hospital staff with providing care, and patients and healthcare professionals with making shared decisions.

We wanted to provide evidence on three key areas:

1. How many people admitted to hospital with COVID-19 had multiple long term conditions
2. Whether there was a higher risk of dying of COVID-19 for people with multiple long term conditions
3. Whether there was an increased risk of dying of COVID-19 for people who were both included on the Shielded Patient List, and living with multiple long term conditions.

What data did we use?

A total of 6512 people were admitted to hospital for the first time with COVID-19 in Scotland from 28 February to 22 September 2020. They were either admitted within 14 days of a positive COVID-19 (PCR) test or had COVID-19 recorded as the reason for admission.

We selected the 4684 people whose information could be linked to their health records to make up our study group, or cohort. Their data, with personal identifiable information removed, are held securely in the National Data Safe Haven platform.

Find out more about the National Data Safe Haven

We defined COVID-19 deaths as any patient who died within 28 days of a positive COVID-19 test, or with COVID-19 reported as a cause of death on their death certificate.

What conditions did we look at?

We looked at 8 of the nine medical situations – excluding pregnancy – on the Shielded Patient List (SPL), as well as 31 other common co-existing treatments or conditions. Although some pregnant women were advised to shield, we weren’t able to identify them in the data available at the time.

Find out more about our ongoing COVID-19 and pregnancy research

We grouped patients as having: 0-1 recorded conditions; 2 or more conditions; or 4 or more conditions.

You can find a list of the conditions we used at the bottom of this page.

What did we find?

Describing the group

In this group of 4684 people admitted to hospital with COVID-19, 58% of people had at least two long term conditions, of whom nearly half had four or more conditions.

1330 people died of COVID-19. Among those who died, seven in ten had more than one condition and four in ten had four or more.

The number of patients with more than one condition increased with age, but there was no real difference between men and women in terms of the number of conditions. People living in deprived areas were more likely to have more than one condition.

There were 1759 people in the shielding group. More people in this group had multiple long term conditions (82%) than in the group who weren’t advised to shield (44%). In the shielding group, 45% had four or more conditions.

COVID-19 deaths in the group

Across the whole group, we found a higher risk of dying from COVID-19 for people who are:

• Living with multiple long term conditions (37%, compared to 17% with one or fewer)
• Older (increased from 4% in under 50s, to 46% in over 80s)
• Male (32% compared to 24% in women)
• On the Shielded Patient List (37%, compared to 23% non-shielding)

Taking into account people’s age, sex, shielding status and location, we calculated the risk of death from COVID-19 in different groups of people.

We found that those over 80 were at 15-times higher risk of dying from COVID-19 than those aged 50 or under.

Being on the Shielded Patient List and having more than one condition both put people at higher risk of dying from COVID-19.

We wanted to see if people who had multiple conditions and were on the shielding list had a higher risk because they were in both groups. Our analysis showed that there was no extra risk to people in both groups.

What is next?

This work has shown that over half of people admitted to hospital with COVID-19 have multiple long term conditions, which puts them at a greater risk of dying.  We have communicated these findings to key decision-makers in Scotland.  Better knowledge of these risks will, we hope, allow policy makers and people living with multiple long term conditions to make more informed choices on how best to minimise their ongoing risk of infection.

Note

This plain English summary was created with the support and feedback of the EAVE II Public Advisory Group (PAG). This summary in particular was reviewed by Lynn L and Emily L.

To learn more about the PAG, see: Our EAVE II Public Advisory Group (PAG) | The University of Edinburgh

Conditions studied

The following is a list of the conditions included in the study.

Shielded Patient List conditions we used are listed in bold:

• Chemotherapy for treating cancer
• Diseases of the spleen, which filters and controls blood cell numbers in the body
• Down’s Syndrome
• Late-stage (Stage 5) long term kidney disease
• Organ transplants
• Rare or inherited conditions affecting metabolism (e.g. SCID*, sickle cell disease)
• Severe breathing conditions (e.g. cystic fibrosis, asthma, COPD*)
• Treatments that suppress the immune system enough to increase infection risk
• AIDS* and HIV*
• Alcohol and drug abuse
• Being overweight (obesity)
• Cancer of the lymph nodes and lymph system (lymphoma)
• Cancerous tumours or spreading (metastatic) cancer
• Circulation problems caused by narrowing blood vessels outside the heart and brain (peripheral vascular disorders)
• Depression
• Diabetes (complicated and uncomplicated)
• Heart failure
• Heart valve or rhythm (cardiac arrhythmia) problems
• High blood pressure (hypertension, complicated and uncomplicated)
• Kidney disorders (fluid and electrolyte processing)
• Kidney failure
• Liver disease
• Long term lung disease (chronic pulmonary disease)
• Low number of, or faulty, red blood cells (blood loss or deficiency anaemia)
• Paralysis and other nervous system conditions (neurological disorders)
• Peptic ulcers, excluding bleeding
• Problems circulating oxygen via the lungs (pulmonary circulation disorders)
• Problems with forming blood clots (coagulopathy)
• Psychosis, a type of mental health disease
• Rheumatoid arthritis
• Underactive thyroid (hypothyroidism)
• Weight loss

*Acronyms:

COPD: Chronic obstructive pulmonary disease

SCID: Severe combined immunodeficiency

AIDS: Acquired immune deficiency syndrome

HIV: Human immunodeficiency virus