Methods
Course development
Two American national registry-certified emergency medical technicians and a National Association of EMS Educators-certified emergency medical responder instructor developed the lay first responder course, building on prior experience studying, developing, and launching lay first responder programs in Chad and Uganda.17 The final curriculum was revised in collaboration with two local Guatemalan physicians from Jocotenango Municipal Clinic (located in Antigua Guatemala), given their experience and knowledge of local trauma and injury mechanisms. The curriculum was informed by the WHO’s guidelines, the Red Cross, and the American College of Surgeons Prehospital Trauma Life Support Course and “Stop The Bleed” Initiative. The 5-hour course was taught in Spanish in a lecture format, interspersed with five hands-on breakout sessions, administered in a 44 slide-slideshow using graphics for learning objective reinforcement.18
Participant learning objectives began by first focusing on the principles, definitions, and responsibilities of competent first aid providers and the goals of providing rapid care. The curriculum’s seven categories then consisted of “Scene Safety,” “Triage,” “Airway and Breathing,” “Resuscitation,” “Hemorrhage Control,” “Fracture Management,” and “Transport,” with the latter five objectives as the subject of each breakout session. To maximize practicality for participants, each course lasted 5 hours in total and was taught during a single day to accommodate participant work schedules and maximize convenience. The number of participants per session varied between 10 and 40 as participant availability fluctuated, and investigators attempted to iteratively analyze a target course size, which was decided to be 25, based on trainer feedback. Two instructors led each course, with an additional assistant present during hands-on breakout sessions. For the practical sessions, participants were divided into groups of two to four (depending on course size). Trainees practiced skills using supplies similar to those included in the first aid kits provided to each participant at the end of the course: gauze (hemorrhage control), bandages (hemorrhage control), cardboard splints (fracture management), pens and fabric strips for improvised tourniquets (hemorrhage control), and tourniquets (hemorrhage control). During the cardiopulmonary resuscitation and choking component, mannequins were used by instructors to demonstrate skills and allow participants to practice and receive instructor feedback.
Study design
Investigators collaborated with local and international stakeholders, including municipal and volunteer firefighter departments (bomberos municipales and bomberos voluntarios), “LFR International,” an American non-governmental, not-for-profit organization committed to EMS development, police divisions including the Division of Nature Protection (División de Protección a la Naturaleza—DIPRONA), which operates within rural and remote regions of Guatemala, and the Division of Tourism Security (División de Seguridad Turística—DISETUR), which focuses on protecting tourists. Participants were verbally recruited 3 weeks before course dates from law enforcement and firefighting organizations, which are the first to respond to common trauma-causing events in Guatemala. Fourteen 1-day sessions were organized during May and June 2019 across Chimaltenango, Escuintla, and Sacatepéquez. Courses were administered exclusively to each organization’s members in a venue provided by the participating organization. Although a certificate and first aid kit were awarded to each participant on course completion, no food or monetary incentives were provided to participants.
Participants provided verbal consent at the beginning of the course for study inclusion. On signing in, participants were asked to complete a criterion-referenced test that had been based on one previously validated by Boeck et al to assess the knowledge of participants in a layperson trauma first responder pilot course in La Paz, Bolivia.19 The test was administered before and after the course by investigators to measure baseline knowledge and subsequent improvement. Some pre-existing questions were lightly edited, whereas various new questions were created by PGD, JF, and ZJE to accurately reflect course content not included in the previous test. The final version of the test comprised 23 multiple choice and 3 true-false questions to examine participant first aid knowledge. On the post-test, the same questions were used with both the question and answer orders scrambled randomly. Matched questions are listed first with a question’s pretest number followed by its corresponding post-test number, written as pre(post) [#(#)]. The survey test was initially written in English and was later translated to Spanish by a bilingual, native Spanish-speaking author (JAF). The validity of the translation was then confirmed by EH, a local Guatemalan physician, who ensured question appropriateness for the local setting. Participants were excluded from the study if they did not consent or if they only took either the pretest or post-test.
The reliability of the testing instrument was assessed using Cronbach’s alpha (r) to assess internal consistency, and the SE of measurement (SEM) was calculated, lying between zero to the SD of each sample.20 Significance was recorded with each statistical test, determining any value p<0.05 to be statistically significant.21
Study setting
The departments of Chimaltenango, Escuintla, and Sacatepéquez were selected as they lie adjacent and are proximate to Guatemala City, increasing convenience to conduct the study, and are located in Guatemala’s southern region (figure 1). Chimaltenango has a population of 741 176 residents, Escuintla has 803 488 residents, and Sacatepéquez has 362 539 residents, comprising 10.9% of the country’s population.22 Poverty in Guatemala is localized to rural areas and socioeconomically, the incidence of poverty in Chimaltenango, Escuintla, and Sacatepéquez ranges between 13.7% and 23.2%, compared with 29.1% nationally.23 Guatemala’s literacy rate was 81.29% in 2014, and for persons between the ages 15 and 24, it was 94.35% in 2014.24 Between July 1, 2017 and June 30, 2018, the 528 homicides across Chimaltenango, Escuintla, and Sacatepéquez amounted to a homicide rate of 27.68 per 100 000 people.22 Additionally, 1570 people have been killed and 6235 more injured in road traffic incidents between 2014 and 2018 across the three departments (65.38 per 100 000 people injured and 16.46 per 100 000 killed).25
Figure 1Map of Chimaltenango, Escuintla, and Sacatepequez Departments of Guatemala.
Data analysis
Data were compiled in Microsoft Excel (Microsoft, Redwood, Washington, USA) and analyzed in R (R Foundation for Statistical Computing, Vienna, Austria). In a binary fashion, correct answers were assigned a score of one point, whereas incorrect, blank, or multiple answers were assigned a score of zero points. The primary outcome of interest was demonstrated by participant knowledge acquisition and was quantified as the difference between pretest and post-test scores. The secondary outcome of interest included an analysis of participant knowledge acquisition with respect to occupational demographics, and psychometric analyses replicating those employed by Boeck et al were used to evaluate and validate the assessment questions.19
To assess participant knowledge acquisition, the interquartile mean score and SD were determined for both the pretest and post-test. Distributions of total scores for the pretest and post-test were compiled and compared using a Wilcoxon signed-rank test for nonparametric analysis. Occupational affiliation of each participant was then mapped to their corresponding total score and analyzed using a Wilcoxon Rank-Sum (Mann-Whitney) test for between-group differences.
Each individual question from the pretest was mapped to its corresponding post-test analog and was compared using McNemar’s χ² test to examine knowledge acquisition on a by-question basis. Item difficulty indices were then assigned to each question via frequency-of-distribution tests and item discrimination indices were assigned via point biserial correlation, to analyze whether or not each individual question is able to differentiate between a high-scoring and low-scoring participant. Participants were then divided into quartiles by total score to determine the proportion of each question correctly answered per quartile, with well-discriminating items showing a sequential increase in correct answers. The proportion of questions that improved, worsened, or remained static was then recorded.
To assess participant knowledge acquisition in terms of discrete topics in first aid, questions were then grouped according to which course topic was tested. The seven categories consisted of “Scene Safety,” “Triage,” “Airway and Breathing,” “Resuscitation,” “Hemorrhage Control,” “Fracture Management,” and “Transport.” The proportion of correct answers on both the preassessment and postassessment were recorded, and each category was assessed for significance using McNemar’s test.