What do changes in readmission rates tell us about quality of care in the NHS?

This past winter we have been bombarded with evidence of the rising pressures faced by the NHS. As a result, many of us are concerned whether these pressures translate into poor quality of care for patients. Undoubtedly, hospitals are experiencing a high demand for services, clearly illustrated by the increasing number of hospital admissions. However, what this means for quality is unclear.

Are readmission rates a useful quality indicator?

The Health Foundation has just published research that sheds light on this question by assessing quality of care through readmission rates, describing the proportion of patients returning to hospital unexpectedly following an initial hospital stay, commonly measured within 30 days from discharge.

There are several reasons why 30-day readmission rates are a useful quality indicator and a focus for improvement. Readmissions are often undesirable for patients, and they can be a burden for resource-stretched NHS hospitals. Importantly, readmissions have also been shown to be associated with the quality of care provided to patients at several stages along the clinical pathway including during initial hospital stays, transitional care services and post-discharge support.

Readmission rates are, however, an imperfect measure with substantial limitations. Not all reasons for readmission are under the control of the health care service or hospital, and they also are not a measure of patient preference or experience. This is important to bear in mind when trying to derive meaningful interpretations from observed changes in readmission rates and their relationship with the quality of care provided to patients.

How have readmission rates changed over the last 10 years?

In our research article, we investigated readmission rates over a 10-year period from 2006. Similar to a report published by HealthWatch at the end of last year, we found evidence to suggest that the number of patients readmitted to hospital had increased substantially. The total annual number of readmissions to any non-specialist NHS trust has increased by 33.7%, from 338,277 readmissions in 2006/07 to 452,546 readmissions in 2015/16. Importantly though, the number of initial admissions to hospital has increased too. When the number of readmissions is expressed as a percentage of admissions, readmission rates increased from 6.50% in 2006/07 to 6.73% in 2015/16.

Some of this increase in readmission rates is due to changes in the characteristics of patients admitted. If we compare a person admitted today with a person with the same characteristics admitted a decade ago, their readmission rates are very similar. Specifically, when adjusting for the characteristics of the patients admitted, we found that readmission rates have increased only from 6.56% to 6.64%.

We then examined whether this trend was the same in nine different patient subgroups from different clinical specialties. The choice of patient groups was guided by the hypothesis that changes in readmission rates might vary depending on the nature of the patient’s health condition. We thought this variation might tell us something about what is happening to quality for people with acute needs versus long-term conditions.

We found that readmission rates following any elective admission (ie patients attending for a planned intervention) showed small decreases (–0.27%), while readmission rates for patients with any initial hospitalisation classified as an emergency (ie those coming via the A&E department) showed small increases (+1.27%). Trends in readmission rates within clinical subgroups were very heterogeneous. Some patient groups showed substantial decreases in readmissions (e.g. –1.29% for hip and knee replacements), with some remaining stable (eg –0.04% for acute myocardial infarction), and others showing substantial increases (eg +7.09% for diabetes).

Interpreting our findings

There are several possible explanations of our findings. It is possible that the enhanced focus on reducing readmission rates in the past – through the introduction of financial penalties for hospitals with high readmission rates or other initiatives targeting quality more widely (eg ‘Right Care Programme’ and ‘Getting it Right First Time’) – resulted in stabilising trends in readmission rates. It could also be that some of the observed rises in readmission rates, particularly those following acute emergency admissions, are a consequence of improved survival rates, rather than poorer quality of care.

On the other hand, the increase in readmission rates for diabetes patients – a long-term condition that is commonly managed within the community and by patients themselves – is more difficult to explain. While the literature points to the significant reduction in mortality from diabetes, and to side effects of certain diabetic drugs, it is possible that the increase in readmission rates for this patient group suggests shortcomings in quality of care. However, it is also possible that the observed increase was due to improved coding practices over time, or due to a change in severity of diabetes amongst admitted patients – both issues that were not accounted for in our analysis.

While overall there seems to be little change in the quality of care as measured through readmission rates over the past years, our work shows that more needs to be done to understand the variation in readmission trends across patient groups. This will help to identify areas that require greater policy attention, specifically in reducing the ‘quality gap’ and helping to achieve high quality care for all patients using the NHS.

Rocco Friebel (@r_friebel) is a Senior Data Analyst at the Health Foundation (@healthfdn)