Studies reporting on the outcome of exertion-related mortality
| Study . | Design . | Study population . | Primary outcome(s) investigated . | Method of SCT diagnosis . | Described perimortem physical activity or triggers . | Method used to ascertain the primary outcome . | Are compared populations representative? . | Are covariates considered in the analysis? . | Is the distribution of potential covariates similar in compared populations?1 . | Key findings (narrative) . | Reported associations . | Is the reported association adjusted for covariates? . |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Nelson et al22 | Case-control | Active-duty Black soldiers in the US Army, 2011-2014 Universal precautions to prevent heat injury were implemented during this time frame | Any death Battle-related death Non–battle-related death Exertional rhabdomyolysis | Laboratory | Not described | Laboratory | Yes | Duration of service, physical conditioning, BMI, self-reported tobacco use | Yes | Similar rates of any death, battle-related death, and non–battle-related deaths, among Black soldiers with and without SCT Increased rate of exertional rhabdomyolysis among Black recruits with vs those without SCT | Any death: HR, 0.99 (95% CI, 0.46-2.13) Battle-related death: HR, 0.96 (95% CI, 0.13-7.3) Non–battle-related death: HR, 0.99 (95% CI, 0.43-2.27) Exertional rhabdomyolysis: HR, 1.54 (95% CI, 1.12-2.12) | Yes |
| Kark et al7 | Case-control | Enlisted US Armed Forces recruits during basic training (1977- 1981) | Exertion-related sudden death | History | Exercise | Autopsy and clinical records | No, only confirmed deaths were tested for SCT. All other participants’ SCT status inferred. | Race and age | Not presented | 13 total sudden deaths reported in Black recruits with SCT Increased relative risk of cardiac and heat-related sudden death in SCT vs non-SCT Cardiac and heat-related sudden death: RR 34.9 (95% CI, 6-38) in Black recruits and 33.7 (95% CI, 11-478) in all recruits | Any sudden death: RR, 39.8 (95% CI, 19.1-82.7) Sudden death among Black recruits: RR, 27.6 (95% CI, 10.2-75.1) | Stratified analysis by race and age |
| Kark et al21 | Case-control | Enlisted US Armed Forces recruits during basic training (1968- 1986) | Exertion-related sudden death | History | Exercise | Autopsy and clinical records | No, only confirmed deaths were tested for SCT. All other participants’ SCT status inferred. | Race and age | Not presented | 24 Deaths with SCT and 31 without SCT Stratified analysis by age group showing that the risk of death increases with age | Any sudden death: RR, 39.8 (95% CI, 17-90) Sudden death among Black recruits: RR, 28 (95% CI, 9-100) | Stratified analysis by race and age |
| Study . | Design . | Study population . | Primary outcome(s) investigated . | Method of SCT diagnosis . | Described perimortem physical activity or triggers . | Method used to ascertain the primary outcome . | Are compared populations representative? . | Are covariates considered in the analysis? . | Is the distribution of potential covariates similar in compared populations?1 . | Key findings (narrative) . | Reported associations . | Is the reported association adjusted for covariates? . |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Nelson et al22 | Case-control | Active-duty Black soldiers in the US Army, 2011-2014 Universal precautions to prevent heat injury were implemented during this time frame | Any death Battle-related death Non–battle-related death Exertional rhabdomyolysis | Laboratory | Not described | Laboratory | Yes | Duration of service, physical conditioning, BMI, self-reported tobacco use | Yes | Similar rates of any death, battle-related death, and non–battle-related deaths, among Black soldiers with and without SCT Increased rate of exertional rhabdomyolysis among Black recruits with vs those without SCT | Any death: HR, 0.99 (95% CI, 0.46-2.13) Battle-related death: HR, 0.96 (95% CI, 0.13-7.3) Non–battle-related death: HR, 0.99 (95% CI, 0.43-2.27) Exertional rhabdomyolysis: HR, 1.54 (95% CI, 1.12-2.12) | Yes |
| Kark et al7 | Case-control | Enlisted US Armed Forces recruits during basic training (1977- 1981) | Exertion-related sudden death | History | Exercise | Autopsy and clinical records | No, only confirmed deaths were tested for SCT. All other participants’ SCT status inferred. | Race and age | Not presented | 13 total sudden deaths reported in Black recruits with SCT Increased relative risk of cardiac and heat-related sudden death in SCT vs non-SCT Cardiac and heat-related sudden death: RR 34.9 (95% CI, 6-38) in Black recruits and 33.7 (95% CI, 11-478) in all recruits | Any sudden death: RR, 39.8 (95% CI, 19.1-82.7) Sudden death among Black recruits: RR, 27.6 (95% CI, 10.2-75.1) | Stratified analysis by race and age |
| Kark et al21 | Case-control | Enlisted US Armed Forces recruits during basic training (1968- 1986) | Exertion-related sudden death | History | Exercise | Autopsy and clinical records | No, only confirmed deaths were tested for SCT. All other participants’ SCT status inferred. | Race and age | Not presented | 24 Deaths with SCT and 31 without SCT Stratified analysis by age group showing that the risk of death increases with age | Any sudden death: RR, 39.8 (95% CI, 17-90) Sudden death among Black recruits: RR, 28 (95% CI, 9-100) | Stratified analysis by race and age |
BMI, body mass index; HR, hazard ratio; RR, risk ratio.