Taking measurements of heart rate, blood pressure, temperature and other "vital signs" is an important part of care for nearly all patients in hospital. Staff and patients often refer to this as taking observations. Changes in observations are used to track recovery and can show when someone's condition is getting worse and needs urgent attention. When changes are spotted early, medical staff can often prevent serious deterioration, provide early treatment and avoid serious consequences including death. However, taking observations can be burdensome to patients, interfering with rest and sleep, which are also important to recovery. Frequent observations also cause more work for nursing staff. At the moment, there is little evidence to guide hospital staff on how frequently to take observations.
In the UK, the Royal College of Physicians and the National Institute for Clinical Excellence recommend that vital signs observations are combined into a single score (NEWS) that shows when the measurements are abnormal. There is now some evidence to support using the NEWS score to identify patients at increased risk of cardiac arrest, death or unexpected transfer to intensive care, so that staff can take preventative action. The guidance is also that the higher the NEWS score, the more often a patient should be observed. Although it is recommended that people with higher scores need more frequent observation, there is no direct evidence for this. We need to find out how often we need to monitor patients. Moreover, some observations could be unnecessary or too far apart to be useful in spotting deterioration.
Our study aims to address this by developing a protocol for how frequently observations should be made.
We will use records from two hospitals where vital signs are recorded in electronic systems. No personal information that identifies individual patients will be used. In total, 6 million measurements from over 200,000 hospital admissions are available. Using information from one hospital, we will calculate NEWS scores and look to see how these change over time, with the aim of identifying the earliest point possible where we might detect that a patient is deteriorating. By linking these measurements to other information (such as diagnoses, cardiac arrests, intensive care admissions), we will also be able to see the extent to which changes in vital signs affect patients' risk of poor outcomes. The results of these analyses will be used to set monitoring schedules, which will then be tested on the patient data from the second hospital. Together with the results from a study where we watch and time ward staff taking observations, we will also be able to estimate how much work will be generated by each monitoring schedule and estimate the expected staff requirements.
We aim for this study to provide the first evidenced-based protocol for patient monitoring, which will be both safe and achievable across all acute NHS hospitals.