Page 79 - JSOM Winter 2023

Timers were positioned adjacent to each team member to handoff was compared separately across groups for both the
record the time for each patient handoff to be received. All ramp handoff and internal team handoff using a one-way
timers and the SOF medic were in direct view of the study analysis of variance (ANOVA) with alpha set at 0.05. When
coordinator to trigger the start of each scenario. When the a difference was identified between groups, methods of com-
handoff was completed and the team member received what munication were then compared using a single-tailed, paired
they perceived as all the relevant information, they signaled t test for continuous variables with a Bonferroni-adjusted al-
their time to stop, which was recorded. No further documen- pha set at 0.0125. Accuracy, as measured by the percentage
tation was allowed after the time was stopped. The patient of correct information transcribed, was compared between
handoff was performed by the medic twice in each scenario, methods of communication also using an ANOVA with alpha
once at the ramp intended for the team member positioned set at 0.05.
at the base of the ramp and once at the center of the aircraft
intended for the remainder of the medical team within the Results
aircraft. There were six different patient scenarios; each was
performed four times for a total of 24 simulated patient hand- Accuracy
offs. Each method of communication was used for each sce- All methods of communication had an average accuracy of
nario, and the scenario order and method of communication more than 90%. While the use of the Bluetooth PTT resulted
for each patient handoff were randomized. Finally, to simulate in the most accurate patient handoffs, with an average accu-
a real-world tactical patient handoff, the rotary-wing aircraft racy of 98% (range 75%–100%), there was no significant dif-
utilized its auxiliary power unit (APU) throughout the study. ference between any of the groups studied when evaluating
Decibel readings were collected using the National Institute the accuracy of the transmission received (p=.25 ANOVA)
for Occupational Safety and Health Sound Level Meter Appli- (Table 1).
cation (Version 1.2.5.63, EA Lab) on a government-approved
mobile device. 12,13
TABLE 1 Accuracy Group Comparison Statistical Analysis Method
of Communication
All casualty forms completed by team members were reviewed,
and accuracy was evaluated by determining the percentage of Method of Accuracy, %, mean Group comparison
statistical analysis,
key information transcribed. Finally, to assess the subjective communication (range) ANOVA
preference of the medical team participating in the study, each Radio push-to-talk 92.61 (70–100)
of the members was asked to rank their preferred methods of Tactical medic
communication based on clarity and ease of use after the study intercom system 95.89 (78–100)
was completed. Bluetooth push-to-talk 98.00 (75–100) p=.25
Bluetooth voice-
Statistical analysis was performed using Microsoft Ex- operated transmission 93.72 (60–100)
cel 2018 (Microsoft Corporation, Redmond, Washington; ANOVA = analysis of variance.
https://www.microsoft.com/en-us/) with the Analysis Tool-
Pak Add In. A power analysis was performed using data from Time
an initial sample of patient handoff times using radio PTT
(α = 0.05 and σ = 4.8 seconds). If the true difference in the Ramp Handoff
mean time of matched pairs is 10 seconds, which was chosen The average Bluetooth PTT resulted in the fastest patient
as being clinically relevant, a minimum of six study pairs of handoff (mean 17.81 [range 13.31–25.54] seconds), and the
patient scenarios would be required to reject the null hypoth- slowest occurred when using the TM-ICS (mean 20.13 [range
esis that this response difference is zero with a probability 16.20–30.18] seconds), but there was no significant difference
(power) of 0.95. Time required for completion of the patient between ramp handoff times (p=.86 ANOVA) (Table 2).

TABLE 2 Comparison of Handoff Times at both the Ramp and Internal Team
Handoff times (sec) ramp Group comparison statistical analysis,
Method of communication (team member 1) ANOVA
Radio PTT 19.76
TC-ICS 20.13 p=.86
Bluetooth PTT 17.81
Bluetooth VOX 18.97

Handoff times (sec)
Method of internal team
communication (team members 2 and 3) ANOVA Radio PTT TC-ICS Bluetooth PTT Bluetooth VOX
Radio PTT 31.31 p<.01* p<.03 p<.01*
TC-ICS 41.33 p<.001 p<.01* p<.001* p<.001*
Bluetooth PTT 22.44 p<.03 p<.001* p<.47
Bluetooth VOX 22.19 p<.01* p<.001* p<.47
*Denotes statistical significance (single-tailed, paired t test with Bonferroni correction; α = 0.0125).
ANOVA = analysis of variance; Bluetooth VOX = Bluetooth voice operated transmission ; PTT = push-to-talk; TC-ICS = tactical medic intercom
system.

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