Describing the demographic and clinical characteristics of patients who present to the Scottish Ambulance Service with non-traumatic back pain. A retrospective observational study

Abstract

Background Non-traumatic back pain (NTBP) is regarded as a prevalent, low-acuity condition in ambulance services within the United Kingdom. Recent evidence suggests that NTBP (dorsalgia) may be safely treated outside of the hospital, thereby avoiding the Emergency Department. There is limited published evidence on this population’s demographic and clinical characteristics, which is required for developing future clinical practice. This study sought to: i) establish the characteristics of patients presenting to SAS with back pain, the demographics for NTBP; ii) determine the positive predictive value (PPV) for ambulance clinicians’ diagnosis of true NTBP (dorsalgia); and iii) identify common pain relief measures used to treat these patients. Methodology This research comprised a retrospective observational study that used quantitative data situated within a positivist paradigm. The data were based on emergency calls made to the Scottish Ambulance Service (SAS) diagnosed as 05 NTBP by ambulance clinicians in 2018–2019. Quantitative methods were used to collect and analyse the data to address four research questions. Aims: i) to establish the patient demographic for NTBP 999 calls, including socioeconomic status (SIMD) with associated NEWS; ii) to analyse the positive predictive value (PPV) for ambulance clinicians’ diagnoses of true NTBP and whether this differed by dispatch priority; iii) to determine the sensitivity and specificity, positive predictive value (PPV) and negative predictive value (NPV) of aMPDS on objective acuity measured by NEWS for ambulance clinician coded 05 NTBP; and iv) To explore what pre-hospital clinical interventions were used by ambulance clinicians to treat these patients. Methods: A retrospective observational study was conducted to describe demographic and clinical characteristics over a 12-month period. Data extracted were age, gender, deprivation category, immediate outcome (home or hospital), recorded baseline observations, National Early Warning Scores (NEWS), pain scores, all recorded pharmacological treatments and final emergency department diagnosis. Findings: There were 8824 patients included in this study. More women (55.8%, 4927) made calls for NTBP than men (44.2%, 3897). Men made more calls for NTBP than women in only one age category 50-59 years. The median age of all patients was 60 years (range 43–77). Ten percent (882) of patients made more than one call for NTBP within the same 12-month period. Ten percent of people investigated from the SAS data made more than one 999 call for NTBP over one year. Fifty percent of patients (4303) lived in the most deprived areas of Scotland (SIMD 1 and 2). NTBP was determined to be more common amongst people living in SIMD 1. Clinically, 8542 patients had a complete first NEWS recorded: 49% (4215) with a score of 0, 35% (2940) NEWS of 1–6, and 16% (1403) with a NEWS ≥ 7. This indicated that NTBP could not always be considered a low acuity condition. The SAS data demonstrated that there were no significant differences in SIMD status and NEWS scores. This suggested that people living in higher areas of deprivation were just as likely to be unwell with NTBP as found in people living in more affluent areas. The final ED diagnosis confirmed that patients were more often recorded being symptomatic of NTBP rather than having true back pain (dorsalgia). This indicated that the 628 presentations of NTBP were small scale and were not common presentations in prehospital care. The aMPDS was demonstrated as not being effective at identifying NTBP, which is thought to be a low risk condition. The aMPDS high specificity of 97.6% suggested that patients who were triaged to be low clinical risk were true of low clinical risk (NEWS <7). The PPV for ambulance clinicians’ diagnosis of dorsalgia was 20.4%. Commonly recorded pain relief methods included Entonox 54% (2409), morphine 24% (1055), paracetamol 13% (568), and ibuprofen 6% (286). Over the counter medications used in combination (ibuprofen and paracetamol) may have been effective for some people with NTBP. Being in pain was not found to be a predictor for ambulance transport to ED. The findings suggested that there were other factors that determined conveyance requiring analysis of individual cases. Conclusion: Calls for NTBP span all age groups in the adult population, proportionately more women required SAS support. Medium to high clinical risk was reported in one-third of patients, suggesting not all NTBP were low acuity. In this study, ambulance clinicians’ ability to diagnose true NTBP (dorsalgia) was determined. This identified some priority areas for further research.