Evidence
Alert

A simple test may predict the risk of hospitalisation for flare-up in patients with COPD, a common lung disease

The sit-to-stand test, which requires only a chair and a stopwatch, could identify patients with a common lung disease who are at high risk of being admitted to hospital. Researchers found that the test, which takes less than five minutes to perform, also predicted the length of their hospital stay.

The study looked at patients with a condition called chronic obstructive pulmonary disease (COPD), which means they have long-term breathing difficulties. COPD is punctuated with flare-ups – called exacerbations – during which patients experience worsening of symptoms such as breathlessness, productive cough, chest infection and wheezing. Many will need hospital treatment, and a longer hospital stay is linked with a higher risk of death.

In the sit-to-stand test, patients are simply timed as they stand up and sit back down again. The researchers found the test was almost as effective as more time-consuming and complicated assessments. They say the test could provide an easy, low cost and effective way to better identify patients with COPD with the highest risk of exacerbations. 

What’s the issue?

Figures from the NHS show that more than 128,000 patients in the UK were admitted to hospital for COPD exacerbations in 2016-17. The vast majority (97%) were unscheduled emergencies. Aside from increasing costs for the healthcare system, 4.3% of these patients died in hospital, with a further 2.8% dying within one month of discharge.     

Identifying these high-risk patients with COPD could help inform clinical decision-making and target interventions. Interventions that may reduce the risk of exacerbation include vaccination, optimisation of inhaled therapies and exercise-based therapies. 

The BODE Index, which includes the six-minute walk test (6MWT), is a physical performance assessment that can predict long-term outcomes for patients with COPD. However, the National Institute of Clinical Excellence (NICE) 2018 guidelines recommend against its use in primary care because it is time-intensive and challenging to carry out.

This study aimed to identify alternative and simpler assessments to identify COPD patients at risk of flare-ups. These include the short physical performance battery (SPPB), which is widely used to assess the health of elderly people.

What’s new?

Hospital data from 714 patients with stable COPD, who were taking part in the long-term observational ERICA study, were analysed. The researchers looked at several physical performance measurements, including the SPPB and its three individual components (walking speed, balance, and five repetitions of sit-to-stand), and the 6MWT. They estimated how well these measures predicted patients’ risk of hospitalisation due to COPD flare-up, and the length of their hospital stay.

Over five years, 291 of the 714 patients were admitted to hospital because of a flare-up. Some were admitted more than once; there were 762 of these hospitalisations in all. The researchers found that:

  • a worse SPPB performance was linked with a higher risk of hospitalisation for COPD exacerbation and an increased length of stay
  • the SPPB and sit-to-stand test were easier to carry out than the 6MWT and performed almost as well in predicting the risk of hospitalisation for COPD exacerbation
  • the SPPB, and sit-to-stand component, performed as well as the 6MWT in predicting the length of hospital stay in these patients.

Why is this important?

This study suggests that the SPPB, or its sit-to-stand component as a standalone, is a quick, simple and practical way of carrying out risk assessments of patients with COPD in primary and secondary care settings. 

These tests could provide a practical alternative to the 6MWT to aid decision-making for individual patients. The sit-to-stand component can be performed almost anywhere in less than five minutes. This would be much easier to implement in the clinic, where professionals are short of time, than the 6MWT – which takes around 30 minutes and requires access to a flat, uninterrupted 30m track. 

This simple way to assess risk could help doctors to ensure that patients with COPD receive appropriate interventions to help prevent lengthy hospital stays, potentially reducing their risk of death.

What’s next?

The authors propose that the sit-to-stand test should be adopted as a routine measure in the care pathway for patients with COPD, potentially as part of the annual COPD review. They say its use can help identify at-risk patients and facilitate better-informed resource planning.

If the results can be replicated in larger cohorts and/or different geographical populations over longer follow-up periods, the researchers hope that the current guidelines will be updated to recommend that clinicians use this approach to identify patients with COPD at greater risk of hospitalisation, enabling prompt intervention.

Research on COPD exacerbations is part of a current James Lind Alliance Priority Setting Partnership, which is prioritising further research focussing on preventing and managing COPD exacerbations.

You may be interested to read

The full paper: Fermont JM, and others. Risk assessment for hospital admission in patients with COPD; a multi-centre UK prospective observational study. PLoS One. 2020;15:e0228940

Fermont JM, and others. Short physical performance battery as a practical tool to assess mortality risk in chronic obstructive pulmonary disease. Age and Ageing. 2020. https://doi.org/10.1093/ageing/afaa138

Hopkinson NS, and others. Chronic obstructive pulmonary disease: diagnosis and management: summary of updated NICE guidance. BMJ. 2019;366:l4486

Kon SS, and others. Gait speed and readmission following hospitalisation for acute exacerbations of COPD: a prospective study. Thorax. 2015;70:1131‐1137

Conflict of interest

GSK was involved in funding this research.

Funding

This work was supported by the NIHR Biomedical Research Centres at Cambridge and Nottingham, Health Data Research UK, Health and Social Care Research and Development Division (Welsh Government), and Public Health Agency (Northern Ireland).

 

Commentaries

Study author

When we started this study, it wasn’t clear which kind of biomarker or physical performance measure would perform best. Although the 6MWT is superior in terms of its predictive ability, it is impractical and so it is not being used in clinical practice. I think that the SPPB, and particularly the sit-to-stand component, are great alternatives that are more feasible to implement. We could also look into developing simple digital platforms that can automatically calculate risk scores – making it even easier for clinicians to carry them out during routine appointments.

Jilles Fermont, Department of Medicine, University of Cambridge

Physiotherapist

A great body of evidence supports the use of physical performance tests in pulmonary rehabilitation and in research. Best practice guidelines recommend their use in these settings and there is an expectation that they will be consistently recorded. However, in other clinical care settings, these tests are not always practical and so this same expectation does not exist. This is why the findings from this paper supporting the use of a ‘slimmed down’ test are of value to clinical practice.

The information gained from these tests can be used to monitor change over time, to help judge how successful an intervention has been in order to justify its use or guide future management. By assessing and monitoring physical function, we can categorise patients, predicting who may be at risk of hospitalisation, functional decline and even mortality. This can be used to target treatments and to predict prognosis. If adopted widely, they could be used as a common language to clearly and objectively communicate the results between healthcare professionals.

Sara Buttery, Clinical Research Physiotherapist, Royal Brompton Hospital, London

Researcher

The research might prompt clinicians to consider physical function as a prognostic marker in COPD. Information from physical performance tests is not used widely in clinical practice at present, but conducting them more widely might enable conversations with patients about practical tasks, and further add to assessments of risk of hospitalisation.

Pulmonary rehabilitation might improve physical function and is already recommended in NICE guidance on COPD. These tests could help prioritise patients for pulmonary rehabilitation if resources are insufficient to offer this to all patients who are otherwise eligible.

For the sit to stand component of the SPPB to be really useful in preventing admissions, we need community COPD teams across the UK, capable of supporting all at risk patients over the long term. Services like this are patchy and in their absence, it is difficult to see it being implemented in primary care. In secondary care, it would take training and funding for multi-disciplinary clinics in which nurses or physiotherapies could test physical function.

Alice Turner, Professor of Respiratory Medicine, University of Birmingham