Community early warning systems



Early warning systems (EWS) have become part of regular and mainstream clinical practice in secondary care. Although there are varying models for different clinical settings,1-2 essentially these tools score different physiological parameters to calculate a score.

This score is used by the clinician/healthcare professional to guide ongoing management. This may vary from immediately informing senior doctor to repeating observations in eight hours.

Systematic reviews have reported that EWS perform well for prediction of acute deterioration, cardiac arrest and death within 48 hours.1-2 There were other data that suggested a positive trend towards better clinical outcomes following the introduction of the EWS chart, sometimes coupled with an outreach service. However, both systematic reviews commented upon methodological limitations of EWS clinical trials that made comparing different models and assessing the impact of EWS on other markers of health very difficult.1-2

Community early warning systems

There have been recent moves to attempt to utilise early warning scoring systems in the community to identify patient at risk of deteriorating and prioritise those requiring clinical review. This is a commendable approach. Many services in the community can be mainly nurse or allied health professional led (ranging from district nursing patient care to community hospital beds), with medical cover mainly provided over the phone unless specifically asked to review patients or as part of structured community hospital ward round.

A community EWS aims to detect physiological changes and requesting early medical intervention prior to any deterioration. A structured approach in terms of stratifying risk and associated communication with GPs (such as the Situation Background Assessment Recommendation) is appealing.

One of the main challenges for managers and clinicians about community EWS is who should be started onto a EWS chart. Requesting all patients seen in the community be started on a EWS is not going to be welcomed by doctors and nurses alike. All patients admitted to hospital, electively or otherwise, are at increased risk of deterioration and as such the yield of early recognition of acute illness is greater. In-patients are also a captive audience so repeating observations at a set time is less of a logistical challenge. Following Kings Fund Report3 findings that district nursing numbers are declining (in particular senior district nursing posts), we need to ensure that any additional documentation and request for clinical assessment from nursing colleagues is only implemented when it is going to improve clinical care for patients.

There has been work in Sunderland, which adapted an early warning system for patients in the community who were being seen by the urgent care team (UCT).4 The UCT is primarily concerned with complex multi-morbid patients who require more medical/nursing input than can be provided by GP services alone for a short-period to avoid hospital admission (over the age of 18).

This appears similar in remit to other Hospital @ Home services, although without an age limit. EWS are often continued for a short-time after discharge from UCT to GP to ensure continuing resolution of acute illness. This latter approach has been well received by primary care teams. This approach to patient selection seems very reasonable, as their GP/healthcare specialist has assessed this group of patients as high risk of deterioration as they have been referred to the UCT in the first place.

After auditing their own patient cohort and EWS,4 they made some adjustments to the parameters (in particular with oxygen saturations and respiratory rate given the high number of patients with brittle COPD). Although the parameters they use are not consistent with other EWS tools in use in acute care, the modification has reduced over-sensitivity in community-supported exacerbations of extremely complex patients with long-term conditions.

In other areas, such as Liverpool, there have been other attempts to try and utilise EWS within the community for the majority of patients seen by community teams.5 Such approaches will require clear inclusion criteria for patients having observations charted, as the action plans for patients based upon their scores could become onerous for district nurses and GPs alike.

The Wirral NHS Trust suggests excluding patients who are palliative and those receiving a single or intermittent service for single issue. Clearly, any early warning system is not a comprehensive assessment tool and cannot replace clinical judgment, but the argument is that having objective measures of physiology will help prioritise clinical reviews rather than being added on to home visit lists for GPs. There has been no published data about how this approach in Liverpool has impacted GP and nursing work-load, and whether this approach has had an effect upon important markers such as hospital admission.

A further challenge to the EWS approach in the community is the practical. If a patient scores highly enough to merit clinical review and have observations repeated in 1-2 hours, it is unclear how this is performed practically. If the GP assesses the patient and starts treatment at home, is the district nurse expected to arrange repeat observations into her/his daily work-load until directed otherwise by the GP? Staffing and work-load challenges may be considerable.

Finally, as with many other examples of service delivery reforms these changes have no strong evidence base. The extrapolation of EWS performance in acute care to community is limited at best. There is no randomised controlled trial, or gold standard direct comparison trial looking at hospital admission or mortality.


There are clear benefits to trialling EWS in the community, but there are implications for service delivery and practical challenges. In essence, patient selection for enhanced observation should be the important factor looking at examples to date in England. This should ensure manageable work-load and prioritisation of at-risk patients, and getting the best from enhanced structured observation. Alongside this, communication between healthcare staff remains crucial to ensure that information is transferred effectively between teams and acted upon.

As community EWS are developed and implemented, we really need to ensure that we are auditing and reviewing their efficacy in particular the impact on markers such as hospital admission, healthcare contacts, and cost-effectiveness. It would be advisable to trialling one standardised score to facilitate comparison between different areas. The heterogeneity of secondary care EWS have been commented upon as a issue when trying to examine their clinical impact.1-2


Dr Lloyd D Hughes, GP Registrar, Kelty Medical Practice, NHS Fife

Conflict of interest: none declared.



  1. Smith ME, Chiovaro JC, O’Neil M, et al. Early warning system scores for clinical deterioration in hospitalised patients: a systematic review. Ann Am Thorac Soc 2014. 11(9): 1454–65
  2. Alam N, Hobbelink EL, van Tienhoven AJ, et al. The impact of the use of the Early Warning Score (EWS) on patient outcomes: A systematic review. Resuscitation 2014; 85(5): 587–94
  3. Quality of district nursing care under threat. The Kings Fund. 2016. London. Available from: Last Accessed 2nd January 2017
  4. Mann S, Bowler, M. (2008). Using an early warning score tool in community nursing. The Nursing Times. Available from: Last Accessed 2nd January 2017
  5. Clinical Protocol Modified Early Warning Score (MEWS) Observation Chart. Wirrill Community NHS Trust. Available from: Last Accessed 2nd January 2017