Emergency readmissions - where patients are readmitted to hospital in an emergency within 30 days of discharge - are frequently used as a measure of poor patient outcomes. However, it is not this simple. Some emergency readmissions may result from potentially avoidable adverse events, but others may be due unrelated or unforeseen causes of admission. Some may relate to changes in the way that hospitals run services - for example through the increased use of frailty and ambulatory care units. And others might be a consequence of our ageing population and the increase in the number of people living with multiple chronic conditions.
Despite the complications in interpreting what this means for the quality of care, publishing data on emergency readmissions is the first step in understanding why they are happening. NHS Digital have not published data on emergency readmissions since December 2013, as they are delaying indicator updates while they review the methodology. For our recent briefing we used Hospital Episode Statistics data to look at trends in emergency readmissions to hospitals in England over time. We also focused on readmissions that we classified as being potentially preventable, to highlight areas for quality improvement.
Between 2010/11 and 2016/17, the number of 30-day emergency readmissions to hospital in England increased by 19.2%, from 1,157,570 to 1,379,790. Meanwhile, the total number of hospital admissions increased by 10.5% over the same time period, from 15,527,166 to 17,164,662 (data not shown). The emergency admissions rate increased from 7.5% in 2010/11 to 8.0% in 2016/17.
This analysis did not use risk adjustment (an analytical technique to take account of differences in the characteristics of a population which may impact on the risk of an event). As such, changes in readmission rates over time may reflect differences in the patient population, with more severely ill and older patients being more likely to be readmitted. A recent study showed that when you take account of this via risk adjustment, the rate of readmissions is broadly stable so quality of care seems to have been maintained.
However, while this aspect of quality has not deteriorated it does not appear to have improved either, so there remains a potential opportunity to target improvement efforts, by focusing on potentially preventable readmissions.
Patients who are readmitted to hospital within 30 days of discharge with pressure sores or venous thromboembolism (deep vein thrombosis and pulmonary embolism), when these conditions were not diagnosed in their previous admission, may have received suboptimal care. These are two conditions that we classified as being potentially preventable causes of readmission in our briefing.
This indicator shows that the emergency readmissions rate for pressure sores increased from 0.05% of admissions in 2010/11 to 0.13% of admissions in 2016/17. The emergency readmissions rate for venous thromboembolism increased from 0.11% to 0.13% over the same time period.
Improved identification of safety issues, changes in coding practices (how clinicians record diseases on their hospital systems) and population changes such as an ageing population and the increase in multimorbidity may have contributed to the increase.
To put these trends into context it is important to look at overall trends in diagnoses for these conditions over time. Between 2010/11 and 2016/17, we found that overall diagnoses for pressure sores and venous thromboembolism increase by 153% and 29% respectively (data not shown). However, diagnoses for these conditons on readmission to hospital increased by 188% and 36% respectively. Therefore, these potentially preventable causes of readmission increased at a faster rate than would be expected based on overall trends.
About this data
Emergency readmissions were defined as patients that were readmitted to hospital within 30 days of discharge between 2010/11 and 2016/17. Readmissions from all NHS trusts were included. Only ordinary admissions were included, i.e. overnight stays, excluding day cases, regular day or night attenders (for example chemotherapy or dialysis patients), and maternity admissions. Emergency admissions and readmissions were identified using the admission method code. The analysis is based on admissions rather than patients – so patients can be included more than once. The denominator for rates was all admissions (not just ordinary admissions), because these all represent an opportunity for a preventable issue to arise requiring readmission.
This work uses data provided by patients and collected by the NHS as part of their care and support. Read more on our website.