Browsing Publications - North West Ambulance Service by Author "Harley, Clare"
How accurate is the prehospital diagnosis of hyperventilation syndrome?Wilson, Caitlin; Harley, Clare; Steels, Stephanie (2020-11-09)Background: The literature suggests that hyperventilation syndrome (HVS) should be diagnosed and treated prehospitally. Aim: To determine diagnostic accuracy of HVS by paramedics and emergency medical technicians using hospital doctors' diagnosis as the reference standard. Methods: A retrospective audit was carried out of routine data using linked prehospital and in-hospital patient records of adult patients (≥18 years) transported via emergency ambulance to two emergency departments in the UK from 1 January 2012–31 December 2013. Accuracy was measured using sensitivity, specificity, positive and negative predictive values (NPV/PPVs) and likelihood ratios (LRs) with 95% confidence intervals. Results: A total of 19 386 records were included in the analysis. Prehospital clinicians had a sensitivity of 88% (95% CI [82–92%]) and a specificity of 99% (95% CI [99–99%]) for diagnosing HVS, with PPV 0.42 (0.37, 0.47), NPV 1.00 (1.00, 1.00), LR+ 75.2 (65.3, 86.5) and LR− 0.12 (0.08, 0.18). Conclusions: Paramedics and emergency medical technicians are able to diagnose HVS prehospitally with almost perfect specificity and good sensitivity. Abstract published with permission.
Pre-hospital diagnostic accuracy for hyperventilation syndromeWilson, Caitlin; Harley, Clare; Steels, Stephanie (2017-10)Background Hyperventilation syndrome (HVS) encompasses a wide variety of symptoms and is diagnosed by excluding organic causes for patients’ symptoms. Literature suggests that HVS should be diagnosed and treated pre-hospitally to avoid costly attendances at Accident and Emergency departments. The study aim was to determine diagnostic accuracy for HVS of paramedics and emergency medical technicians (index test) in comparison to hospital doctors (reference standard). Methods A retrospective cross-sectional audit of routine data utilising linked pre-hospital and in-hospital patient records of adult patients (age ≥18 years) transported via emergency ambulance to two Accident and Emergency departments in the United Kingdom from January 2012 – December 2013. Agreement between pre-hospital and in-hospital HVS diagnoses was calculated using percent agreement, Cohen’s kappa and prevalence-adjusted bias-adjusted kappa. Accuracy was measured using sensitivity, specificity, predictive values and likelihood ratios with 95% confidence intervals. Results A total of 19 386 records were included in the analysis. Percent agreement between pre-hospital clinicians and hospital doctors was 98.73%, producing kappa of κ=0.57 and adjusted kappa of PABAK=0.97. Pre-hospital clinicians had a sensitivity 0.88 (0.82, 0.92) and specificity 0.99 (0.99, 0.99) for diagnosing HVS, with PPV 0.42 (0.37, 0.47), NPV 1.00 (1.00, 1.00), LR +75.2 (65.3, 86.5) and LR- 0.12 (0.08, 0.18). Subgroup analyses for sensitivity were statistically non-significant but for positive predictive values were statistically significant (p<0.001) for the number of pre-hospital diagnoses and patient age. Conclusions Paramedics and emergency medical technicians were able to diagnose HVS pre-hospitally with almost perfect specificity and good sensitivity. Pre-hospital diagnostic accuracy was highest for patients less than 30 years of age and if HVS was the sole diagnosis documented. Following this study, a review of the local ambulance service policy excluding adult HVS patients from referrals to Primary Care Services is anticipated. https://emj.bmj.com/content/34/10/e3.3 This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/ http://dx.doi.org/10.1136/emermed-2017-207114.9
Systematic review and meta-analysis of pre-hospital diagnostic accuracy studiesWilson, Caitlin; Harley, Clare; Steels, Stephanie (2018-12)https://emj.bmj.com/content/35/12/757.long. Introduction Paramedics are involved in examining, treating and diagnosing patients. The accuracy of these diagnoses is evaluated using diagnostic accuracy studies. We undertook a systematic review of published literature to provide an overview of how accurately paramedics diagnose patients compared with hospital doctors. A bivariate meta-analysis was incorporated to examine the range of diagnostic sensitivity and specificity. Methods We searched MEDLINE, CINAHL, Embase, AMED and the Cochrane Database from 1946 to 7 May 2016 for studies where patients had been given a diagnosis by paramedics and hospital doctors. Keywords focused on study type (’diagnostic accuracy’), outcomes (sensitivity, specificity, likelihood ratio?, predictive value?) and setting (paramedic*, pre-hospital, ambulance, ’emergency service?’, ’emergency medical service?’, ’emergency technician?’). Results 2941 references were screened by title and/ or abstract. Eleven studies encompassing 384 985 patients were included after full-text review. The types of diagnoses in one of the studies encompassed all possible diagnoses and in the other studies focused on sepsis, stroke and myocardial infarction. Sensitivity estimates ranged from 32% to 100%and specificity estimates from 14% to 100%. Eight of the studies were deemed to have a low risk of bias and were incorporated into a metaanalysis which showed a pooled sensitivity of 0.74 (0.62 to 0.82) and a pooled specificity of 0.94 (0.87 to 0.97). Discussion Current published research suggests that diagnoses made by paramedics have high sensitivity and even higher specificity. However, the paucity and varying quality of studies indicates that further prehospital diagnostic accuracy studies are warranted especially in the field of non-life-threatening conditions. https://emj.bmj.com/content/emermed/35/12/757.full.pdf This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/ http://dx.doi.org/10.1136/emermed-2018-207588