Importance Therapeutic hypothermia is widely used for neuroprotection following cardiac arrest, but clinical trials have not consistently demonstrated improved neurological outcomes, and the optimal duration of cooling remains uncertain. Objective To determine the duration of therapeutic hypothermia that maximizes neurological recovery in comatose survivors of out-of-hospital cardiac arrest. Design, Setting, and Participants Multicenter, randomized, adaptive-allocation clinical trial conducted at 71 hospitals in the US. Adults with out-of-hospital cardiac arrest who remained unconscious, achieved a target temperature less than 34 °C within 4 hours of cardiac arrest, and had a definitive temperature control device started were eligible. Patients were enrolled between June 2020 and June 2025. Interventions Therapeutic hypothermia at 33 °C with adaptive randomized allocation to cooling durations of 6, 12, 18, 24, 30, 36, 42, 48, 60, and 72 hours. The first 200 patients were randomized to 12-, 24-, and 48-hour durations in a 1:1:1 ratio. Subsequently, a response-adaptive randomization algorithm allocated preferentially to the groups most likely to be optimal and to best inform the duration-response curve separately within each rhythm type. Main Outcomes and Measures The primary outcome was neurological function at 90 days, measured using a weighted modified Rankin Scale score, analyzed using a bayesian duration-response model. The primary analysis estimated the posterior probability that each duration was optimal, wherein optimal indicates the shortest duration consistent with the best outcome observed at any duration. Results A total of 1158 patients were randomized (883 with nonshockable rhythms and 275 with shockable rhythms). Participants had a median age of 61 (IQR, 50-70) years and 39.6% were female. The trial met a prespecified stopping rule at the interim analysis. For the nonshockable rhythm cohort, the posterior probability that 6 hours was the shortest duration achieving the maximal mean weighted modified Rankin Scale score was 0.51. Results were similar in the shockable rhythm cohort. No differences were observed in secondary outcomes or mortality across cooling durations. Conclusions and Relevance Among comatose survivors of out-of-hospital cardiac arrest treated with therapeutic hypothermia at 33 °C, increasing cooling duration did not improve neurological outcomes. Trial Registration ClinicalTrials.gov Identifier: NCT04217551

Introduction: PulsePoint is a mobile application that can notify volunteers about nearby out-of-hospital cardiac arrest events, allowing them to respond and provide cardiopulmonary resuscitation (CPR) and an automated external defibrillator (AED), lowering downtime prior to Emergency Medical Services (EMS) arrival. The use of PulsePoint is predominantly for public OHCA events, but the incorporation of a registered / vetted tier of volunteers can facilitate its use for residential OHCA alerts. We sought to describe system performance characteristics in the early phase of transitioning a county-level PulsePoint deployment to include registered responders capable of residential response. Hypothesis: Number of responders alerted, bystander CPR (BCPR) rates, and use of AEDs (BAED) would differ between public and private locations when the system incorporates registered volunteers. Methods: PulsePoint alert records for the City of Pittsburgh, Pennsylvania were obtained via the PulsePoint Central dashboard for the capture period of January 1, 2024, to April 30, 2025, covering all events that met dispatch determinant criterion for a PulsePoint alert (absent or agonal breathing). This criterion will trigger an alert if a PulsePoint volunteer is with a qualifying distance of the caller’s location (Public OHCA: 0.25mi; Private OHCA: 0.5mi). Each record summarized whether an alert was triggered, the type of response, number of responders notified, number of AEDs within radius, and event timing. We obtained EMS records to determine medical category, presence of BCPR, and BAED. We calculated percentage of qualifying events resulting in an alert, resultant medical categories, proportion private/public, and layperson bystander intervention rates. Results: Of a total of 1,007 qualifying PulsePoint events (30.7%Public vs 69.3%Private), 311 resulted in an alert (83.3%Public vs 16.7%Private). Most common medical categories among these were: [No Patient 32.4%] [Cardiac Arrest 13.5%] [Drug Overdose 9.6%]. Among confirmed OHCA, 26.3% were private. Overall BCPR rate for those alerts with confirmed OHCAs was 26.3%, while overall BAED use rate among the same was 5.3%. The maximum number of residential-eligible responders (60) was low relative to the number of public-eligible responders (5,107) during this early phase. Conclusions: In the early phase of incorporating residential alerts into PulsePoint deployment, event characteristics differed between private and public location events.

Introduction: Cardiac arrest is an emergency that requires action via timely administration of CPR and AED use. PulsePoint is a phone application that alerts layperson users of nearby cardiac arrest events allowing them to provide aid before first responders arrive. Hospitals already have cardiac arrest protocols and are therefore excluded from PulsePoint. However, healthcare adjacent facilities (HAFS), locations that provide medical services without being inpatient treatment centers, may or may not have cardiac arrest protocols. It is unknown whether PulsePoint layperson dispatch to HAFS would be beneficial for CPR response or AED retrieval. Hypothesis: HAFS already have internal cardiac arrest response protocols. The same facilities can make AEDs available in nearby areas. Goal: Categorize HAFS related to cardiac arrest response or AED retrieval for PulsePoint alerts. Methods: We retrieved 940 records from the Allegheny County, PA PulsePoint deployment from 2022-2023, including only events occurring in public locations classified as HAFS. Health care adjacency was manually determined by a single reviewer, using a primary criterion of providing health care services but excluding inpatient facilities. The team contacted each site via telephone to administer a standardized survey querying the facility’s cardiac arrest response procedure, presence of an AED, and whether PulsePoint responders could enter their facility in response to an emergency. Results: Of the 108 HAFS identified, 46 (42.6%) completed the phone survey and 44/46 (95.7%) have a cardiac arrest response protocol. Additionally, 39/46 (84.8%) of facilities have an AED on-site and 100% of those facilities have staff present who are trained in AED use. A total of 5/46 (10.9%) facilities were aware of or had staff who were aware of PulsePoint. Permission for PulsePoint responders to enter their facility 9/46 (19.6%) was low, but AED use in the nearby community was higher at 25/46 (54.3%). Conclusion: The majority of HAFS have existing cardiac arrest protocols and AEDs available. Dispatch of PulsePoint volunteers to HAFS may be inefficient, however, willingness to provide AEDs suggests that HAFS could play a supportive role to bystander cardiac arrest response. Future steps would best focus on exploring means to overcome low survey participation to properly characterize response protocols, investigating individualized location designation within PulsePoint, and increasing knowledge of PulsePoint.

AimTo inform screening, referral and treatment initiatives, we tested the hypothesis that emotional distress, social support, functional dependence, and cognitive impairment within 72 hours prior to discharge predict readiness for discharge in awake and alert cardiac arrest (CA) survivors.MethodsThis was a secondary analysis of prospective single-center cohort of CA survivors enrolled between 4/2021 and 9/2022. We quantified emotional distress using the Posttraumatic Stress Disorder Checklist-5 or PROMIS Emotional Distress – Anxiety and Depression Short Forms 4a; perceived social support using the ENRICHD Social Support Inventory; functional dependence using the modified Rankin Scale; and cognitive impairment using the Telephone Interview for Cognitive Status. Our primary outcome was readiness for discharge, measured using the Readiness for Hospital Discharge Scale. We used multivariable linear regression to test the independent association of each survivorship factor and readiness for discharge.ResultsWe included 110 patients (64% male, 88% white, mean age 59 [standard deviation ± 13.1 years]). Emotional distress, functional dependence, and social support were independently associated with readiness for discharge (adjusted β’s [absolute value]: 0.25-0.30, all p < 0.05).ConclusionsHospital systems should consider implementing routine in-hospital screening for emotional distress, social support, and functional dependence for CA survivors who are awake, alert and approaching hospital discharge, and prioritize brief in hospital treatment or post-discharge referrals.

Introduction: PulsePoint is a smartphone-based system that alerts layperson responders to out-of-hospital cardiac arrest (OHCA) events in non-residential locations within the United States. These locations can be classified to inform public access defibrillator (PAD) placement and focus responder training and recruitment efforts in high-frequency areas. Our objective was to manually classify the locations of PulsePoint alerts to better understand how PulsePoint performs across a variety of location types. Methods: Records were obtained for each PulsePoint alert in Allegheny County, PA, USA (pop. 1.2M) from 06/24/2016 to 10/28/2020. PulsePoint generates an alert when a potential OHCA occurs in public and is within 400m of at least one responder. Alert data contains address and location name, and the number and locations of nearby responders and PADs. We placed each location into one of the following categories: “education”, “consumer goods/services”, “restaurants/bars”, “transit hubs”, “hotels”, “entertainment venues”, “recreational facilities”, “government/municipal”, “offices”, “industrial/manufacturing”, “religious institutions”, “parks/outdoor spaces”, “sidewalk/street”, and “shelters/supportive housing”. “Unspecified/unknown” was used for locations that could not be classified due to insufficient information. We excluded all outpatient health, assisted-living, daycare, and correctional facilities. For each location category, we calculated the event count and the median number of nearby responders and PADs. Results: There were 994 included events during the capture period. The most frequent location category was “sidewalk/street”, which represented 24 percent of all alerts; the least frequent was “transit hubs”, which represented 0.7 percent of all alerts. “Shelters/supportive housing” had the highest median number of responders (7, IQR 1-14), while “industrial/manufacturing” had the lowest (1, IQR 1-3.5). “Transit hubs” had the highest median number of PADs (31, IQR 31-41), while “parks/outdoor spaces” had the lowest (0.5, IQR 0-1). Conclusion: PulsePoint alert-generating events occur across a wide variety of location types. Further research is needed to understand the accuracy of the system’s location data versus EMS dispatch records. Nonetheless, the data may have implications for system improvement by highlighting which location types have low numbers of nearby responders and PADs and may benefit from strategic PAD placements and training efforts.

Objective We hypothesized that the administration of amantadine would increase awakening of comatose patients resuscitated from cardiac arrest. Methods We performed a prospective, randomized, controlled pilot trial, randomizing subjects to amantadine 100 mg twice daily or placebo for up to 7 days. The study drug was administered between 72 and 120 hours after resuscitation and patients with absent N20 cortical responses, early cerebral edema, or ongoing malignant electroencephalography patterns were excluded. Our primary outcome was awakening, defined as following two-step commands, within 28 days of cardiac arrest. Secondary outcomes included length of stay, awakening, time to awakening, and neurologic outcome measured by Cerebral Performance Category at hospital discharge. We compared the proportion of subjects awakening and hospital survival using Fisher exact tests and time to awakening and hospital length of stay using Wilcoxon rank sum tests. Results After 2 years, we stopped the study due to slow enrollment and lapse of funding. We enrolled 14 subjects (12% of goal enrollment), seven in the amantadine group and seven in the placebo group. The proportion of patients who awakened within 28 days after cardiac arrest did not differ between amantadine (n=2, 28.6%) and placebo groups (n=3, 42.9%; P>0.99). There were no differences in secondary outcomes. Study medication was stopped in three subjects (21.4%). Adverse events included a recurrence of seizures (n=2; 14.3%), both of which occurred in the placebo group. Conclusion We could not determine the effect of amantadine on awakening in comatose survivors of cardiac arrest due to small sample size.

Hypothermia has multiple physiological effects, including decreasing metabolic rate and oxygen consumption (VO2). There are few human data about the magnitude of change in VO2 with decreases in core temperature. We aimed to quantify to magnitude of reduction in resting VO2 as we reduced core temperature in lightly sedated healthy individuals. After informed consent and physical screening, we cooled participants by rapidly infusing 20 mL/kg of cold (4°C) saline intravenously and placing surface cooling pads on the torso. We attempted to suppress shivering using a 1 mcg/kg intravenous bolus of dexmedetomidine followed by titrated infusion at 1.0 to 1.5 μg/(kg·h). We measured resting metabolic rate VO2 through indirect calorimetry at baseline (37°C) and at 36°C, 35°C, 34°C, and 33°C. Nine participants had mean age 30 (standard deviation 10) years and 7 (78%) were male. Baseline VO2 was 3.36 mL/(kg·min) (interquartile range 2.98-3.76) mL/(kg·min). VO2 was associated with core temperature and declined with each degree decrease in core temperature, unless shivering occurred. Over the entire range from 37°C to 33°C, median VO2 declined 0.7 mL/(kg·min) (20.8%) in the absence of shivering. The largest average decrease in VO2 per degree Celsius was by 0.46 mL/(kg·min) (13.7%) and occurred between 37°C and 36°C in the absence of shivering. After a participant developed shivering, core body temperature did not decrease further, and VO2 increased. In lightly sedated humans, metabolic rate decreases around 5.2% for each 1°C decrease in core temperature from 37°C to 33°C. Because the largest decrease in metabolic rate occurs between 37°C and 36°C, subclinical shivering or other homeostatic reflexes may be present at lower temperatures.

Background: Older adults are at high risk for experiencing out-of-hospital cardiac arrest, and therefore they are an important target for CPR training efforts. Physical, mental, and other barriers associated with advanced age present plausible obstacles to training/learning, and may warrant a need for tailored training programs. Hypothesis: Barriers to CPR training for older adults may be widely characterized, but efforts to resolve them are limited. Goal: This literature review’s purpose is to consolidate existing knowledge on teaching CPR to older adults and identify any gaps for future study. Methods: A complete search in both CINAHL and PubMed was conducted for the capture period 2014-2024. The terms “CPR”, “bystander CPR”, “older adult”, “training”, “development”, “out-of-hospital cardiac arrest”, “chest compressions”, and synonyms were used. The full search strategy will be shared at time of presentation. Search results not mentioning CPR, elderly people, and training of older adults were excluded. Any duplicates between the two databases were resolved. Included articles were reviewed by 2 researchers. Age, sex, and study designs were documented and summarized, with ranges, percentages or means reported where appropriate. Results: A total of 14 articles from CINAHL (n=8) and PubMed (n=6) were selected and were either qualitative surveys (n=4) or randomized control trials (n=10). In the studies reviewed, disparate knowledge or retention of CPR skills in older adults was linked to increased course duration or intricacy, physical or mental limitations (real or perceived), and lack of confidence. When analyzing the participants, the definition of older adult ranged from 55 to 65 years old and above with variable sample sizes (n=21-119, median=58). All the studies that documented sex had over 53% of older adults being female (n=53%-100%, median=64.85%). Studies identified methods to address limitations in older adults, including employing continuous chest compression delivery (versus 30:2) to improve quality/compliance, and Andrew’s Maneuver, also known as 4-hands CPR, for increasing effective compression depth while mitigating limited mobility and frailty. Conclusion: Within current literature, established best practices for teaching older adults CPR are limited, and few studies attempt to characterize the limitations of training older adults. Of those studies available in the literature, valuable foundations are available for future work.

Background: Individuals experiencing unsheltered homelessness (those living in encampments) are at greater risk of experiencing health issues, including consequences of cardiovascular disease and opioid abuse, compared to sheltered individuals. They also face more significant barriers to care, one of which may be access to emergency medical care. Many individuals in homeless encampments are concealed within urban areas, often making it challenging for Emergency Medical Services (EMS) to precisely pinpoint their location. Furthermore, the lack of phone access and delays in bystanders notifying EMS can lead to delayed response times and inadequate medical attention. Objective: We aimed to categorize EMS calls and analyze EMS unit arrival times for homeless individuals on the street versus those in shelters, focusing on events requiring life-saving skills amenable to bystander intervention. Methods: The study is a retrospective review of EMS records for incidents in Allegheny County, PA, from January to July 2023. Cases were included that had documented evidence of a homeless patient treated by EMS, occurring near or in homeless encampments, as well as cases with homeless patients occurring at known homeless shelters as defined by EMS charting. The primary outcome was the response time of 911-initiated EMS (time of dispatch to arrival). Case characteristics and chief complaints were summarized and stratified by sheltered and unsheltered homeless status. Results: 1204 cases were reviewed, with 424 (35.2%) involving unsheltered and sheltered homeless patients. Unsheltered individuals experienced more traumatic injuries and were disproportionately involved in drug overdose and intoxication incidents, with a mean overdose/intoxication of 20 with 95% CI ( 16.5, 24) compared to the mean of 10.7 with 95% CI (8.1, 14) for sheltered individuals. The mean EMS response time did not significantly differ between unsheltered and sheltered individuals, averaging 7.95 and 8.15 minutes, with a p-value of 0.79 for both groups respectively. Conclusion: In Allegheny County, although unsheltered individuals have equal timely access to EMS services, they exhibit higher rates of trauma and drug overdoses, which require timely intervention, and can benefit from trained lay people assisting prior to EMS arrival. Future training in these skills may be of benefit to this population.

Background While sudden cardiac arrest (CA) survivors are at risk for developing psychiatric disorders, little is known about the impact of preexisting mental health conditions on long-term survival or postacute healthcare utilization. We examined the prevalence of preexisting psychiatric conditions in CA patients who survived hospital discharge, characterized incidence and reason for inpatient psychiatry consultation during these patients’ acute hospitalizations, and determined the association of pre-CA depression and anxiety with hospital readmission rates and long-term survival. We hypothesized that prior depression or anxiety would be associated with higher hospital readmission rates and lower long-term survival. Methods We conducted a retrospective cohort study including patients resuscitated from in- and out-of-hospital CA who survived both admission and discharge from a single hospital between January 1, 2010, and December 31, 2017. We identified patients from our prospective registry, then performed a structured chart review to abstract past psychiatric history, prescription medications for psychiatric conditions, and identify inpatient psychiatric consultations. We used administrative data to identify readmissions within 1 year and vital status through December 31, 2020. We used multivariable Cox regressions controlling for patient demographics, medical comorbidities, discharge Cerebral Performance Category and disposition, depression, and anxiety history to predict long-term survival and hospital readmission. Results We included 684 subjects. Past depression or anxiety was noted in 24% ( n = 162) and 19% ( n = 129) of subjects. A minority of subjects ( n = 139, 20%) received a psychiatry consultation during the index hospitalization. Overall, 262 (39%) subjects had at least 1 readmission within 1 year. Past depression was associated with an increased hazard of hospital readmission (hazard ratio 1.50, 95% CI 1.11–2.04), while past anxiety was not associated with readmission. Neither depression nor anxiety were independently associated with long-term survival. Conclusions Depression is an independent risk factor for hospital readmission in CA survivors.

Background: There is a critical need to identify factors that can prevent emotional distress post-cardiac arrest (CA). CA survivors have previously described benefitting from utilizing positive psychology constructs (mindfulness, existential well-being, resilient coping, social support) to cope with distress. Here, we explored associations between positive psychology factors and emotional distress post-CA.Methods: We recruited CA survivors treated from 4/2021-9/2022 at a single academic medical center. We assessed positive psychology factors (mindfulness [Cognitive and Affective Mindfulness Scale-Revised], existential well-being [Meaning in Life Questionnaire Presence of Meaning sub -scale], resilient coping [Brief Resilient Coping Scale], perceived social support [ENRICHD Social Support Inventory]) and emotional distress (post -traumatic stress [Posttraumatic Stress Checklist-5], anxiety and depression symptoms [PROMIS Emotional Distress - Anxiety and Depression Short Forms 4a]) just before discharge from the index hospitalization. We selected covariates for inclusion in our multivariable models based on an asso-ciation with any emotional distress factor (p < 0.10). For our final, multivariable regression models, we individually tested the independent association of each positive psychology factor and emotional distress factor.Results: We included 110 survivors (mean age 59 years, 64% male, 88% non-Hispanic White, 48% low income); 36.4% of survivors scored above the cut-off for at least one measure of emotional distress. In separate adjusted models, each positive psychology factor was independently asso-ciated with emotional distress (b:-0.20 to-0.42, all p < 0.05).Conclusions: Higher levels of mindfulness, existential well-being, resilient coping, and perceived social support were each associated with less emotional distress. Future intervention development studies should consider these factors as potential treatment targets.

Introduction: Long-term cardiac arrest (CA) survivors have recounted feeling unprepared to confront the psychosocial, functional, and cognitive sequelae of CA, but this has not been assessed quantitatively. Hypothesis: Psychosocial, functional, and cognitive status are associated with readiness for discharge post-CA. Methods: We prospectively recruited CA survivors treated by the University of Pittsburgh Post-Cardiac Arrest Service (4/21-9/22) who completed study measures within 72 hours prior to hospital discharge. We used linear regression to examine unadjusted associations between potential covariates (sex, income, arrest location, Charlson Comorbidity Index, time to return of spontaneous circulation, initial rhythm), post-CA sequelae (emotional distress screen via PROMIS Depression and Anxiety Short Forms 4A or PTSD Checklist-5, functional status via modified Rankin Scale, cognitive status via Telephone Interview for Cognitive Status, and social support via ENRICHD Social Support Inventory) and our dependent variable (readiness for discharge assessed via Patient Readiness for Hospital Discharge Scale - Short Form). Covariates significant at p < 0.10 were included in a multivariable regression. Results: We included 110 grossly cognitively intact CA survivors (mean age 59 years, 64% male, 88% non-Hispanic White, 48% low income, 36.4% emotionally distressed, 21.9% functionally dependent, 24.5% cognitively impaired). Emotional distress, functional dependence, and lower social support were associated with lower readiness for discharge (β’s [absolute value]: 0.23-0.31, p < 0.01; R 2 = 0.34) after adjusting for CA location and Charlson Comorbidity Index. Cognitive status, demographic covariates, and other CA clinical characteristics were not associated with readiness for discharge. Conclusion(s): Psychosocial and functional status predict readiness for discharge in this sample of grossly cognitively intact CA survivors. Further research should focus on developing interventions targeted towards these domains prior to hospital discharge.

Introduction: Smartphone alert systems (SAS) mobilize trained volunteers to initiate CPR prior to Emergency Medical Services (EMS) arrival. Among the potential factors affecting the probability of a successful response is time; time of day, day of the week, and season each present plausible barriers to response. We sought to examine the temporal characteristics of an SAS in order to better understand this relationship between time and system performance. Methods: Operational records were obtained from the PulsePoint deployment in Allegheny County, Pennsylvania, USA for the period June 2016 to May 2023. PulsePoint sends alerts including nearby AED locations to volunteer responders within a 400m radius of public cardiac arrest events. Case data included alert time and number of responders and AEDs within range of the event. We associated each PulsePoint event with an 8-hour Timeframe (TF) {1 (00:00-07:59), 2 (08:00-15:59), and 3 (16:00-23:59)}, a day of the week, and a season. For each, we calculated the median number of associated responders and AEDs, and the total number of events. We then compared each across each time variable with a Mann-Whitney U-test or Kruskal-Wallis test. Results: There were a total of 2354 events in the capture period. Alerts were least common on Sundays (12.4%) and most common on Tuesday (15.6%). Alerts most frequently occurred in TF2 (45.6% vs TF1: 18.3, TF3: 36.1) and were similar between seasons. Weekday alerts had a higher median number of responders than weekend alerts {3 (1-5) vs 2 (1-4), p=0.004}. Responder count was lower for TF1 than TF2 and TF3 {2 (1-4) vs 3(1-5) vs 3(1-5), p < 0.001}. Count of proximal AEDs did not vary by any of the temporal characteristics. Conclusion: Both event frequency and number of notified responders were associated with day of the week and time of day. Either feature is more complicated than meets the eye, and may include associations with diurnal population movement cycles, overall patterns in emergency services utilization, and responder device configuration preferences. All could be influential in optimizing such SAS deployments.

Out of hospital cardiac arrest from shockable rhythms that is refractory to standard treatment is a unique challenge. Such patients can achieve neurological recovery even with long low-flow times if perfusion can somehow be restored to the heart and brain. Extracorporeal cardiopulmonary resuscitation is an effective treatment for refractory cardiac arrest if applied early and accurately, but often cannot be directly implemented by frontline providers and has strict inclusion/exclusion criteria. We present the case of a novel treatment strategy for out of hospital cardiac arrest due to refractory ventricular fibrillation utilizing Resuscitative Endovascular Balloon Occlusion of the Aorta-assisted cardiopulmonary resuscitation and intra-arrest left stellate ganglion blockade to achieve return of spontaneous circulation and eventual good neurological outcome after 101 minutes of downtime.

The COVID-19 pandemic has increased healthcare workers' (HCWs) risk for posttraumatic stress disorder (PTSD). Although subthreshold PTSD symptoms (PTSS) are common and increase vulnerability for health im-pairments, they have received little attention. We examined the prevalence of subthreshold PTSS and their relationship to physical health symptoms and sleep problems among HCWs during the pandemic's second wave (01/21-02/21). Participants (N = 852; 63.1% male; Mage = 38.34) completed the Short-Form PTSD Checklist (SF-PCL), the Cohen-Hoberman Inventory of Physical Symptoms, and the PROMIS Sleep-Related Impairment -Short-Form 4a. We created three groups with the SF-PCL: scores >= 11 = probable PTSD (5.5%); scores between 1 and 10 = subthreshold PTSS (55.3%); scores of 0 = no PTSS (39.2%). After controlling for demographics, occupational characteristics, and COVID-19 status, HCWs with subthreshold PTSS experienced greater physical health symptoms and sleep problems than HCWs with no PTSS. While HCWs with PTSD reported the greatest health impairment, HCWs with subthreshold PTSS reported 88% more physical health symptoms and 36% more sleep problems than HCWs with no PTSS. Subthreshold PTSS are common and increase risk for health impair-ment. Interventions addressing HCWs' mental health in response to the COVID-19 pandemic must include subthreshold PTSS to ensure their effectiveness.