Ever since we began discussing the ability of early warning systems like MEWS to detect clinical deterioration early we have commented on the need to add clinical impression (by a nurse or physician) to the prediction score.
In our March 2012 What’s New in the Patient Safety World column “Value of an Expanded Early Warning System Score” we noted a study (Smith 2012) from the Netherlands that showed a positive impact of a modification of the MEWS that added some new parameters, including a more subjective parameter: the nurse’s level of concern about the patient’s condition.
In our July 15, 2014 Patient Safety Tip of the Week “Barriers to Success of Early Warning Systems” we discussed an excellent study in the nursing literature (Watson 2014) that provided great insight into the barriers that impact implementation of an early warning system. One of those barriers was that there was a general perception by RN’s that the EWS was no better at predicting deterioration than their own clinical impression. They recommended adding RN or family concerns to the EWS score.
Now a new study has addressed the role of physicians’ clinical judgment in detecting early clinical deterioration (Patel 2015). Patel and colleagues utilized the Patient Acuity Rating (PAR) (Edelson 2011) as a clinical tool to predict clinical deterioration. The PAR has an interesting history. It was originally proposed as a way to summarize a patient’s risk of deterioration by a score that could simply be added to the signout/handoff to a covering physician. It simply consists of the response on a 7-point Lickert scale to the question “How likely is this patient to suffer a cardiac arrest or require emergent transfer to the ICU in the next 24 hours?” (a score of 7 being extremely likely and a score of 1 being very unlikely). When Edelson and colleagues tested the PAR on medical attendings, interns, residents and physician extenders on non-ICU medical patients they found it had reasonable inter-rater reliability and good ability to predict which patients would likely have a cardiac arrest or require urgent transfer to an ICU within 24 hours. A PAR of 4 or higher corresponded to a sensitivity of 82% and a specificity of 68% for predicting cardiac arrest or ICU transfer in the next 24 hours.
In the new study Patel and colleagues (Patel 2015) assessed PAR scores and MEWS (Modified Early Warning Scores) scores on over 3000 medical inpatients. Outcome measures were cardiac arrest, ICU transfer, RRT (rapid response team) activation, or a composite of the three. They found poor correlation between the MEWS and PAR scores and there was a median 84 minute gap between the PAR and MEWS scores. However, the combined PAR plus MEWS score was more accurate for the composite outcome than either the MEWS or PAR scores individually.
But be careful – there is a possibility that the PAR is a self-fulfilling prophecy. That is, the clinician doing the PAR might also be the one who may make the decision to transfer the patient to the ICU or might influence the receiving physician to do so. So using transfer to the ICU as an outcome variable may be somewhat biased.
As we refine some of the hi-tech collection and background analysis of physiological variables as noted in our November 11, 2014 Patient Safety Tip of the Week “Early Detection of Clinical Deterioration” it will be of interest to see how scores for predicting clinical deterioration might make better use of the clinician’s clinical judgment.
Some of our other columns on MEWS or recognition of clinical deterioration:
Smith T, Den Hartog D, Moerman T, et al. Accuracy of an expanded early warning score for patients in general and trauma surgery wards. British Journal of Surgery 2012; 99: 192-197
Watson A, Skipper C, Steury R, et al. Inpatient Nursing Care and Early Warning Scores: A Workflow Mismatch. J Nurs Care Qual 2014; 29(3): 215-222
Patel AR, Zadravecz FJ, Young RS, et al. The Value of Clinical Judgment in the Detection of Clinical Deterioration. JAMA Intern Med 2015; Published online January 05, 2015
Edelson DP, Retzer E,Weidman EK, et al. Patient acuity rating: quantifying
clinical judgment regarding inpatient stability. J Hosp Med 2011; 6(8): 475-479
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