Table 2. Results of Included Studies With a Higher Risk of Bias.
| Source | CEW model, exposure duration | Sample type (No.) | Study design | General study quality | Main findings | Funding source |
|---|---|---|---|---|---|---|
| Levine et al,30 2007, US | X26, 3 s (on average) | Police officers (105) | Nonrandomized trial (no control group) | Moderate | CEW exposure was associated with a significant increase in heart rate, but no other cardiac rhythm disturbances or morphologic changes were detected except for in a few participants who appeared to have changes in their ECGs; the significance of the changes was unclear. | Not reported |
| Dawes et al,31 2008, US | X26, 15 s | Law enforcement officers (21) | Nonrandomized trial (with a control group) | Low | CEW exposure was not associated with changes in core body temperature in resting, nonenvironmentally stressed adults. | Not reported |
| Ho et al,32 2008, US | X26, 10 s | Law enforcement officers (34) | Nonrandomized trial (no control group) | Moderate | CEW exposure was not associated with clinically relevant tachyarrhythmias. | Not reported |
| Sloane et al,33 2008, US | X26, 4.4 s (on average) | Law enforcement officers (66) | Nonrandomized trial (no control group) | Moderate | No abnormal serum troponin I levels were observed 6 h after exposure, suggesting no associated cardiac injuries. | Biosite Inc |
| Bozeman et al,34 2009, US | X26, 5, 3, and 1 s | Law enforcement officers (28) | Nonrandomized trial (no control group) | Moderate | CEW exposure was not associated with detectable dysrhythmias; small increases in heart rate and systolic blood pressure were observed. | Department of Emergency Medicine |
| VanMeenen et al,35 2013, US | X26, 5 s | Law enforcement trainees (23) | Nonrandomized trial (no control group) | Moderate | Cessation of normal breathing patterns (decrease in inspiratory activity) was observed during exposure. Normal breathing resumed after cessation of the exposure. There was no evidence of cardiac rhythm disruption. | National Institute of Justice |
| White et al,36 2014, US | X26, duration not reported | Police officers (21) | Nonrandomized trial (no control group) | Moderate | CEW exposure was associated with significant reductions in cognitive functioning. | National Institute of Justice |
| Havranek et al,37 2015, Czech Republic | X26, 5 s | Volunteers, type unclear (26) | Nonrandomized trial (no control group) | Moderate | CEW exposure was not associated with any clinically relevant ECG changes except for significant increase in heart rate in most participants. | Charles University, Prague |
| Gibbons et al,38 2017, US | X26, 5 s | US Air Force personnel (24) | Nonrandomized trial (no control group) | High | CEW exposure was followed by significant changes in ECGs, suggesting a risk of ventricular tachycardia. | US Air Force |
| Ho et al,39 2006, US | X26, 5 s | Taser CEW trainees (66) | Nonrandomized trial (no control group) | High | In a resting state, CEW exposure was not associated with significant changes in physiologic measures that could indicate dysrhythmias, cellular damage, hyperkalemia, or acidosis. | Axon Enterprise Inc |
| Ho et al,40 2007, US | X26, 15 s or 3 times, each for 5 s | Law enforcement officers (52) | Nonrandomized trial (no control group) | Moderate | Prolonged (continuous or intermittent) CEW exposure was not associated with significant changes in respiratory parameters. | Axon Enterprise Inc |
| Dawes et al,41 2009, US | X26, 5 s | Police officers (16) | Randomized clinical trial | Moderate | A 5-s CEW exposure did not induce a stronger physiologic stress response vs a 5-s exposure to oleoresin capsicum, a 45-s exposure of the hand and forearm in a 0 °C cold water tank, or a 1-min defensive tactics drill. | Axon Enterprise Inc |
| Ho et al,42 2009, US | X26, 15 s | Taser CEW trainees (40) | Randomized clinical trial | Moderate | The group that was only exposed to CEWs showed higher pH and lower lactate values than those who completed the exertion protocol only. There were no significant differences between the groups in combination CEW exposure and exertion and exertion followed by continued exertion. | Axon Enterprise Inc |
| Dawes et al,43 2010, US | X26, 5 s | Law enforcement officers (10) | Nonrandomized trial (no control group) | Moderate | CEW exposure did not electrically capture the human heart muscle when used with probe deployment. | Axon Enterprise Inc |
| Dawes et al,44 2010, US | C2*, 30 s | Law enforcement officers (11) | Nonrandomized trial (no control group) | Moderate | CEW exposure was associated with mild lactic acidosis; no other important physiologic effects were found. | Axon Enterprise Inc |
| Dawes et al,45 2010, US | Taser shockwave, 5 s (2-3 times) | Law enforcement officers and taser CEW trainees (16) | Nonrandomized trial (no control group) | Moderate | CEW exposure was associated with mild increases in creatine kinase and lactate levels; a nonsignificant trend toward reduced respiratory volume was observed. ECGs did not show any effects. | Axon Enterprise Inc |
| Moscati et al,46 2010, US | X26, 15 s | Law enforcement officers and medical personnel (22) | Nonrandomized trial (no control group) | Moderate | Prolonged, continuous CEW exposure of resting adults with acute alcohol intoxication was not associated with clinically significant changes in markers of metabolic acidosis. | Axon Enterprise Inc |
| Dawes et al,47 2011, US | X3, 10 s | Law enforcement officers and prison officers (56) | Nonrandomized trial (no control group) | Low | A higher number of probes deployed during exposure was associated with higher levels of creatine kinase. There were no significant changes in other vital signs. | Axon Enterprise Inc |
| Ho et al,48 2011, US | NCGEW, 10 s | Law enforcement officers, prison officers, and taser CEW trainees (45) | Nonrandomized trial (no control group) | Moderate | Exposure to NGCEW1 was associated with cardiac capture in one participant and the product was not approved for public use. Exposure to a modified version (NGCEW2) was not associated with any significant health effects. | Axon Enterprise Inc |
| Ho et al,49 2013, US | X26, 5 s |
Law enforcement officers and prison officers (8) | Randomized clinical trial | Moderate | Effects on markers of acidosis and stress following CEW exposure were comparable (equal or smaller) to an 18 m sprint. | Axon Enterprise Inc |
| Dawes et al,50 2014, US | X26, 5 s |
Law enforcement officers and prison officers (13) | Nonrandomized trial (with a control group) | Moderate | CEW exposure was associated with a decline in neurocognitive functioning. These effects were transient, of questionable clinical significance, and returned to baseline after 1 h. | Axon Enterprise Inc |
| Ho et al,51 2014, US | X2, 10 s |
Law enforcement officers and prison officers (10) | Nonrandomized trial (no control group) | Moderate | No associations between CEW exposure and changes in physiologic measurements were observed, based on various measured parameters (cardiac, respiratory, venous pH, electrolytes, and creatine kinase). | Axon Enterprise Inc |
Abbreviations: CEW, conducted electrical weapon; ECG, electrocardiogram.