Neighborhood Poverty and 9-1-1 Ambulance Contacts

Background: Neighborhood poverty is positively associated with frequency of 9-1-1 ambulance utilization, but it is unclear whether this association remains significant when accounting for variations in the severities and types of ambulance contacts. Methods: We merged EMS ambulance contact records in a single California county (n = 88,027) with data from the American Community Survey at the census tract level (n = 300). Using tract as a proxy for neighborhood and negative binomial regression as an analytical tool, we predicted 16 outcomes: any ambulance contacts, ambulance contacts stratified by three intervention severities, and ambulance contacts varied by 12 primary impression categories. For each model, we estimated the incident rate ratios for 10 percentage point increases in tract-level poverty while controlling for geographic patterns in race, citizenship, gender, age, emergency department proximity, population density, and population size. Results: Our study produced three major findings. First, tract-level poverty was positively associated with ambulance contacts (incident rate ratio [IRR] 1.45; 95% confidence interval [CI] 1.34 to 1.57). Second, poverty was positively associated with low severity contacts (IRR 1.48; 95% CI 1.35 to 1.61), medium severity contacts (IRR 1.38; 95% CI 1.28 to 1.49), and high severity contacts (IRR 1.40; 95% CI 1.30 to 1.51). Third, poverty was positively associated with 12 primary impression categories: abdominal (IRR 1.48; 95% CI 1.36 to 1.61), altered level of consciousness (IRR 1.37; 95% CI 1.25 to 1.50), cardiac (IRR 1.28; 95% CI 1.14 to 1.42), overdose/intoxication (IRR 1.59; 95% CI 1.40 to 1.81), pain (IRR 1.56; 95% CI 1.41 to 1.73), psych/behavioral (IRR 1.50; 95% CI 1.34 to 1.67), respiratory (IRR 1.42; 95% CI 1.29 to 1.56) seizure (IRR 1.52; 95% CI 1.38 to 1.68), stroke (IRR 1.14; 95% CI 1.01 to 1.28), syncope/near syncope (IRR 1.23; 95% CI 1.12 to 1.36), trauma (IRR 1.44; 95% CI 1.31 to 1.58), and general weakness (IRR 1.31; 95% CI 1.20 to 1.42). Conclusion: Our study suggests poverty is a positive, strong, and enduring predictor of ambulance contacts at the neighborhood level. The relationship between neighborhood poverty and ambulance utilization should be considered at multiple levels of EMS decision making     

Neighborhood Poverty and 9-1-1 Ambulance Response Time

Background: Are 9-1-1 ambulances relatively late to poorer neighborhoods? Studies suggesting so often rely on weak measures of neighborhood (e.g., postal zip code), limit the analysis to particular ambulance encounters (e.g., cardiac arrest responses), and do little to account for variations in dispatch priority or intervention severity. Methods: We merged EMS ambulance contact records in a single California county (n = 87,554) with tract-level data from the American Community Survey (n = 300). After calculating tract-level median ambulance response time (MART), we used ordinary least squares (OLS) regression to estimate a conditional average relationship between neighborhood poverty and MART and quantile regression to condition this relationship on 25th, 50th, and 75th percentiles of MART. We also specified each of these outcomes by five dispatch priorities and by three intervention severities. For each model, we estimated the associated changes in MART per 10 percentage point increase in tract-level poverty while adjusting for emergency department proximity, population density, and population size. Results: Our study produced three major findings. First, most of our tests suggested tract-level poverty was negatively associated with MART. Our baseline OLS model estimates that a 10 percentage point increase in tract-level poverty is associated with almost a 24 s decrease in MART (?23.55 s, 95% confidence interval [CI] ?33.13 to ?13.98). Results from our quantile regression models provided further evidence for this association. Second, we did not find evidence that ambulances are relatively late to poorer neighborhoods when specifying MART by dispatch priority. Third, we were also unable to identify a positive association between tract-level poverty and MART when we specified our outcomes by three intervention severities. Across each of our 36 models, tract-level poverty was either not significantly associated with MART or was negatively associated with MART by a magnitude smaller than a full minute per estimated 10 percentage point increase in poverty concentration. Conclusion: Our study challenges the commonly held assumption that ambulances are later to poor neighborhoods. We scrutinize our findings before cautiously considering their relevance for ambulance response time research and for ongoing conversations on the relationship between neighborhood poverty and prehospital care.     

9-1-1: Rapid identification and treatment of acute myocardial infarction

The sooner a person who is experiencing symptoms and signs of an acute myocardial infarction (AMI) (including out-of-hospital cardiac arrest) receives medical treatment, the greater his or her chances of survival and limitation of infarct size. A universal 9-1-1 emergency telephone system makes it possible for AMI patients or those around them to easily and quickly call for help and for emergency medical services (EMS) personnel to rapidly and accurately locate the patient. This article by the Access to Care Subcommittee of the National Heart Attack Alert Program (NHAAP) Coordinating Committee describes the history of 9-1-1, its key elements, its current implementation status, and existing State legislation and standards. Currently, approximately 78% of the United States population, mainly in urban areas, has access to a 9-1-1 system. Approximately 195 United States cities with a population of greater than 100,000 people have access to enhanced 9-1-1. It is the contention of the NHAAP that 9-1-1 services should be universally available to all Americans to ensure seamless access to EMS and, potentially, early detection, evaluation, and treatment for AMI. This article reports several key recommendations for achieving this goal.     

Follow-up of elderly patients who refuse transport after accessing 9-1-1

Objective. To obtain medical follow-up and determine reasons why elderly patients access paramedics via 9-1-1 and then refuse transport. Methods. A telephone survey of patients aged 65 years and older who refused transport and signed out against medical advice (AMA) after accessing paramedics via 9-1-1 was performed to obtain information about the patients' experiences, reasons why they refused, medical follow-up, and patient outcomes. Results. One hundred of 121 (83%) patients who were contacted by telephone participated in the survey. Patients stated that financial concerns were a major determinant in refusing to be transported. Overall, 70% of the patients reported receiving follow-up medical care. Care was obtained at an emergency department (ED) via a second 9-1-1 call in 16% of cases, at an ED via private vehicle in 13%, at an urgent care clinic by a private vehicle in 35%, and with a family physician via private car in 38% of cases. Of the patients who obtained follow-up, there was a 32% hospital admission rate, with 39% of those admitted to an intensive care unit setting. Finally, 80% of the sample studied did not speak to a physician online, with 49% stating that they would have changed their minds if a physician had suggested transport. Conclusion. The majority of patients who were 65 years of age and older and refused transport received follow-up care, with a significant number requiring admission to the hospital at the time of their follow-up. PREHOSPITAL EMERGENCY CARE 2002;6:391-395     

The lay public's expectations of prearrival instructions when dialing 9-1-1

Objective. To determine whether the lay public expects public safety answering points (PSAPs) to provide prearrival instructions. Methods. Two thousand telephone numbers were randomly generated from all listed residential numbers in a county containing urban, suburban, and rural communities served by 26 enhanced 9-1-1 PSAPs. Only a minority of the PSAPs provided prearrival instructions. Research assistants made two attempts to contact an individual at each telephone number. A survey was administered to any person who answered the telephone provided the person was at least 18 years of age and gave verbal consent. The respondents were asked their age, level of education, and gender. They were also asked what number they would call for first aid or an ambulance and whether they would expect telephone instructions from the dispatcher if a close relative was choking, not breathing, bleeding, or giving birth. Results. One thousand twenty-four individuals were successfully contacted; and 524 (51%) were at least 18 years of age and agreed to participate. The respondents' mean age was 50 (standard deviation 19 years). Sixty-five percent of the respondents were female; and 90% had at least a high school diploma. Only 37% had previously called 9-1-1 (nine-one-one) for an emergency. Ninety-seven percent said they would dial either 9-1-1 (85%) or 9-11 (nine-eleven) (12%) in an emergency. Seventy-six percent (95% CI: 73%-80%) expected prearrival instructions for all four medical conditions. Specifically, prearrival instructions were expected by: 88% for choking (95% CI: 85%-90%), 87% for not breathing (95% CI: 84%-90%), 89% for bleeding (95% CI: 86%-91%), and 88% for childbirth (95% CI: 86%-91%). Ninety-nine of 117 respondents (81%) served by a PSAP that did not provide prearrival instructions expected to receive phone instructions for all four emergencies. Logistic regression revealed that knowing to dial 9-1-1 or 9-11 in an emergency was the only significant predictor of prearrival instruction expectation [p < 0.03, odds ratio 3.4 (95% CI: 1.16-9.78)]. Age, gender, service by a PSAP providing prearrival instructions, and level of education were not predictive. Conclusion. The lay public expects prearrival instructions when calling 9-1-1, although they may not currently receive this service. PREHOSPITAL EMERGENCY CARE 2000;4:234-237     

Prevalence of Aspirin Use among Patients Calling 9-1-1 for Chest Pain

Abstract. Objective: Early aspirin administration during an acute myocardial infarction (AMI) decreases morbidity and mortality. This investigation examined the extent to which patients with a complaint of chest pain, the symptom most identified with AMI by the general population, self-administer aspirin before the arrival of emergency medical services (EMS) personnel.
Methods: In this prospective, cross-sectional prevalence study, data were derived through the analysis of EMS incident reports for patients with a complaint of chest pain from June 1, 1997, to August 31,1997.
Results: The study included 694 subjects. One hundred two (15%) took aspirin for their chest pain before the arrival of EMS personnel. Of the 322 subjects who reported taking aspirin on a regular basis, 82 (26%) took additional aspirin for their acute chest pain. Only 20 (5%) of the 370 patients who were not using regular aspirin therapy self-administered aspirin acutely (p < 0.001). In addition, patients with lower intensity of chest pain (p = 0.03) were more likely to take aspirin for their chest pain.
Conclusion: Only a relatively small fraction of individuals calling 9-1-1 with acute chest pain take aspirin prior to the arrival of EMS personnel. These individuals are more likely to self-administer aspirin if they are already taking it on a regular basis. It is also possible that they are less likely to take aspirin if their chest pain is more severe.     

Emergency Medical Dispatchers Can Obtain Accurate Pediatric Weights from 9-1-1 Callers

Background: Prehospital pediatric drug dosing errors affect 56,000 U.S. children annually. An accurate weight is the first step in accurate dosing. To date, the accuracy of Emergency Medical Dispatcher (EMD) obtained weights has not been evaluated. We hypothesized that EMD could obtain accurate pediatric weights. Methods: We used a convenience sample of patients 12 years and younger that were transported by EMS to one children's hospital. EMD obtained patient weight (DW) from the 9-1-1 caller. Paramedics reported their estimate of the patient's weight on arrival to the hospital (PW). The DW and PW were compared to the hospital scale weight (HW) for accuracy. Results: A total of 197 patients were included. Parent/guardians were the most frequent 9-1-1 callers (74%). The most frequent method utilized by paramedics to obtain patient weight was to ask a family member. For 0–2 year olds, the mean differences between HW and DW/PW were 0.239kg (SD 3.117)/ -0.374 (SD 2.528). For 3–7 year olds, the mean differences between HW and DW/PW were 0.041kg (SD 4.684)/1.007 (SD 2.466). For 8–11 year olds the mean difference between HW and DW/PW was 2.768 kg (SD 10.926)/ 1.919 (SD 6.909). Conclusion: EMD were able to obtain pediatric patient weights with relative accuracy for patients 0–7 year old. Using this EMD-obtained weight to carry out a drug dose calculation would be unlikely to result in a clinically significant dose error in the vast majority of cases. Communicating an EMD-obtained weight to EMS crews en route to a pediatric patient offers additional preparation time for drug calculations, which could improve accuracy.     

Cardiac arrest diagnostic accuracy of 9-1-1 dispatchers: A prospective multi-center study

IntroductionWe sought to determine the ability of 9-1-1 dispatchers to accurately determine the presence of out-of-hospital cardiac arrest (OOHCA) over the telephone, and to determine the frequency with which CPR instructions are initiated and chest compressions delivered in patients not in cardiac arrest.MethodsWe conducted a multi-center, prospective cohort study of adult OOHCA patients not witnessed by EMS for which resuscitation was attempted. Dispatchers were not health care professionals and received 6 weeks of training followed by a 6-month preceptorship. We reviewed 9-1-1 call digital recordings for all unconscious patients for which the possibility of cardiac arrest was considered using a piloted standardized data collection sheet.ResultsWe reviewed 2260 recordings occurring between January 2008 and October 2009. Among those, 1536 were confirmed OOHCA, and 724 were not. Among the 1536 confirmed OOHCA cases, 1012 were recognized by dispatchers and 524 were not. Among the 724 cases not in cardiac arrest, dispatchers suspected cardiac arrest was present in 490 and absent in 234. OOHCA diagnostic accuracy characteristics were: sensitivity 65.9% (95%CI 63.5–68.2%), specificity 32.3% (95%CI 29.0–35.9%), PPV 67.4%, and NPV 30.9%. Dispatchers believed that OOHCA was present in 490/2260 (21.7%) cases when it was not, resulting in 54/490 (11.0%) patients inappropriately receiving chest compressions, or 54/2260 (2.4%) of the whole cohort.ConclusionsDispatchers had a fair sensitivity and modest specificity for the recognition of OOHCA. We found a very small number of patients receiving CPR when not in cardiac arrest, supporting the current use of dispatch-assisted CPR instructions.     

Predictors of Stroke During 9-1-1 Calls: Opportunities for Improving EMS Response

Objective. Only 31%–52% of stroke calls are accurately identified by 9-1-1 dispatchers according to prior studies. Recognizing the time-dependent nature of acute stroke, better identification of stroke patients at the time of their 9-1-1 calls may allow an improved prehospital response. We sought to identify any words/phrases that 9-1-1 dispatchers could use to identify more stroke calls. Methods. Potential stroke calls were identified from emergency medical services run sheets, andthe discharge diagnosis for each of these patients was obtained. The emergency medical services tapes were independently reviewed by two listeners who were blinded to the final diagnosis. Words/phrases previously associated with 9-1-1 stroke calls mentioned by the caller were recorded. Other pertinent words/phrases were also recorded. Using the final diagnosis of stroke as the gold standard, the sensitivity, specificity, andpositive likelihood ratio of each word andphrase were calculated. Cohen's κ was calculated to assess interrater agreement. Data were collected for runs from October 2003 to July 2004. Results. A total of 176 tapes were reviewed (40 strokes, 136 nonstrokes). The presence of at least one of four criteria predicted 80% of all stroke calls: the word “stroke,” facial droop, weakness/fall, andimpaired communication. All criterion elements had very good interrater agreement (κ > 0.7). The word “stroke” was highly predictive of actual stroke (positive likelihood ratio, 2.27). Conclusions. The majority of stroke patients in this study could be identified by 9-1-1 dispatchers if the caller reported any one of the following four complaints: stroke, facial droop, weakness/fall, or impaired communication.     

Effect of Dial-Out Prefix Change on 9-1-1 Calls at a Large State University

Background: Accessing the emergency medical services system via 9–1-1 operators is an effective way for patients to seek urgent health care; however, technological advances and telecommunication practices inundate the 9–1-1 and emergency services infrastructure with unintentional calls that delay response efforts to legitimate medical emergencies. Objective: To determine whether the change in university-wide dial-out prefix from “9” to “7” reduced unnecessary calls to a 9–1-1 call center. Methods: This is a retrospective study conducted utilizing information obtained from the University of North Carolina at Chapel Hill (UNC) Department of Public Safety (DPS) call center. Call center calls received during pre-change, intervening, and post-change periods were included in the study. The cost savings, defined in time and money, resulting from the prefix change were also examined. Results: A total of 33,646 calls were made during the study period (January 11, 2010 through December 31, 2012) and included in the analysis. The prefix change was found to reduce the rate of invalid calls to the call center by 319 calls per month, resulting in a 43% reduction in total calls to the call center while preserving the rate of valid calls. The largest decrease occurred in hang-up calls (a decrease of 232 calls per month), especially those originating from the university. The prefix change was found to save the UNC DPS telecommunications division approximately $798.82 per month and the police officer division approximately $3,874.95 per month. Conclusion: A prefix change was not only beneficial to the UNC community but it also has potentially wide-reaching effects. A reduction of invalid 9–1-1 calls translates to telecommunicators having more time available to handle true emergencies, phone lines remaining available for true emergencies, and police officers dedicating more time and effort to matters that necessitate officer assistance. Based on the call decrease seen with the prefix change, this study may be used as evidence to advocate for a change of dial-out codes beginning with “9.”