Bone Density Screening Rates Among Medicare Beneficiaries: An Analysis with a focus on Asian Americans.

PURPOSE: To report osteoporosis screening utilization rates among Asian American (AsA) populations in the USA. METHODS: We retrospectively assessed the use of dual-energy X-ray absorptiometry (DXA) screening using the Medicare 5% Research Identifiable Files. Using Current Procedural Terminology (CPT) codes indicative of a DXA scan, we identified patients recommended for DXA screening according to the ACR-SPR-SSR Practice Parameters (females ≥ 65 years, males ≥ 70 years). Sociodemographic factors and their association with screening were evaluated using chi-square tests. RESULTS: There were 80,439 eligible AsA beneficiaries, and 12,102 (15.1%) received osteoporosis screening. DXA rate for women was approximately four times greater than the rate for men (19.8% vs. 5.0%; p < 0.001). AsA beneficiaries in zip codes with higher mean household income (MHI) were more likely to have DXA than those in lower MHI areas (17.6% vs. 14.3%, p < 0.001). AsA beneficiaries aged < 80 were more likely to receive DXA (15.5%) than those aged ≥ 80 (14.1%, p < 0.001). There were 2,979,801 eligible non-AsA beneficiaries, and 496,957 (16.7%) received osteoporosis screening during the study period. Non-Hispanic white beneficiaries had the highest overall screening rate (17.5%), followed by North American Native (13.0%), Black (11.8%), and Hispanic (11.1%) beneficiaries. Comparing AsA to non-AsA populations, there were significantly lower DXA rates among AsA beneficiaries when controlling for years of Medicare eligibility, patient age, sex, location, and mean income (p < 0.001). CONCLUSION: We found lower than expected DXA screening rates for AsA patients. A better understanding of the barriers and facilitators to AsA osteoporosis screening is needed to improve patient care.

The Neiman Imaging Comorbidity Index: Development and Validation in a National Commercial Claims Database.

OBJECTIVE: To build the Neiman Imaging Comorbidity Index (NICI), based on variables available in claims datasets, which provides good discrimination of an individual's chance of receiving advanced imaging (CT, MR, PET), and thus, utility as a control variable in research. METHODS: This retrospective study used national commercial claims data from Optum's deidentified Clinformatics Data Mart database from the period January 1, 2018 to December 31, 2019. Individuals with continuous enrollment during this 2-year study period were included. Lasso (least absolute shrinkage and selection operator) regression was used to predict the chance of receiving advanced imaging in 2019 based on the presence of comorbidities in 2018. A numerical index was created in a development cohort (70% of the total dataset) using weights assigned to each comorbidity, based on regression ß coefficients. Internal validation of assigned scores was performed in the remaining 30% of claims, with comparison to the commonly used Charlson Comorbidity Index. RESULTS: The final sample (development and validation cohorts) included 10,532,734 beneficiaries, of whom 2,116,348 (20.1%) received advanced imaging. After model development, the NICI included nine comorbidities. In the internal validation set, the NICI achieved good discrimination of receipt of advanced imaging with a C statistic of 0.709 (95% confidence interval [CI] 0.708-0.709), which predicted advanced imaging better than the CCI (C 0.692, 95% CI 0.691-0.692). Controlling for age and sex yielded better discrimination (C 0.748, 95% CI 0.748-0.749). DISCUSSION: The NICI is an easily calculated measure of comorbidity burden that can be used to adjust for patients' chances of receiving advanced imaging. Future work should explore external validation of the NICI.

Ultrasound Utilization Among Medicare Beneficiaries From 2009 to 2021 by Billing Specialty and Place of Service.

Patterns of ultrasound utilization in the national Medicare population shifted from 2009 to 2021. Office ultrasound services were increasingly performed by radiologists, whereas hospital outpatient and inpatient services were increasingly performed by cardiologists/cardiac surgeons; ultrasound services in other places of service were increasingly performed by nonphysician practitioners.

Prevalence of "One-Off Events" in Radiology: Implications for Radiology in Episode-Based Alternative Payment Models.

OBJECTIVE: As reimbursement mechanisms become more value-based, there are questions about the applicability of these mechanisms for nonepisodic care, particularly care provided by nonpatient-facing specialists, for example, radiologists. Accordingly, this study examined the prevalence of nonepisodic care-one-off events-in diagnostic radiology. METHODS: We conducted a multiyear (2015-2019) retrospective study of diagnostic imaging using a large commercial payer database including commercial insurance and Medicare Advantage. Using a 12-month evaluation period starting with the day of the initial imaging study/studies, we categorized imaging studies as one-off events if there were no additional studies (beyond the first day of the evaluation period) for the next 12 months in the same body region. We also evaluated an alternative, more stringent definition of a one-off event: the only imaging study during the 12-month evaluation period. We computed the percentage of one-off events overall and by body region. RESULTS: We found that one-off events comprised 33.2%-45.8% of imaging studies depending on whether one-off events are defined as the only study in the evaluation period or imaging only on the first day of the evaluation period, respectively. This share varied widely by body region: highest for cardiac (80.9%-87.7%) and lower for chest (26.8%-35.2%). By place-of-service, the proportion was lowest for the inpatient (12.9%-29.1%) and long-term care settings (18.6%-30%). DISCUSSION: Given the sizeable share of imaging studies categorized as one-off events, much of radiologists' workload falls outside of the framework of episodic measurement tools and value-based payment models.

Dual-energy X-ray Absorptiometry Trends Among US Medicare Beneficiaries: 2005-2019.

INTRODUCTION: Bone density measured using dual-energy X-ray absorptiometry (DXA) volume, performance site and interpreters have changed in the US since 2005. The purpose of this report is to provide updated trends in DXA counts, rates, place of service and interpreter specialty for the Medicare fee-for-service population. METHODS: The 100 % Medicare Physician/Supplier Procedure Summary Limited Data Set between 2005-2019 was used. DXA counts and annual rates per 10,000 Medicare beneficiaries were calculated. Annual distributions of scan performance location, provider type and interpreter specialty were described. Place of service trends (significance assigned at p < 0.05) of the mean annual share of DXA utilization were identified using linear regression. RESULTS: Annual DXA use per 10,000 beneficiaries peaked in 2008 at 832, declined to 656 in 2015 then increased (p < 0.001) by 38 per year to 807 in 2019. From 2005 to 2019 DXA performance in office settings declined from 70.7 % to 47.2 %. Concurrently, outpatient hospital (OH) DXA increased from 28.6 % to 51.7 %. In 2005, 43.5 % of DXAs were interpreted by radiologists. This increased (p < 0.001) in the office and OH, averaging 0.3 and 2.0 percentage points per year respectively, reaching 73.5 % in 2019. Interpretation by most non-radiologist specialties declined (p < 0.001). CONCLUSIONS: From 2005-2019, total DXA use among Medicare beneficiaries declined reaching a nadir in 2015 then returned to 2005 levels by 2019. Office DXA declined since 2005 with 51.7 % of all scans now occurring in an OH setting. The proportion of DXAs interpreted by radiologists increased over time, reaching 73.5 % in 2019.

Bringing Opiates Off the Streets and Undertaking Excess Scripts: A novel opiate reclamation and prescription reduction program.

BACKGROUND: Opioid diversion and misuse continue to present problems in modern medicine. The "opioid epidemic" has claimed more than 250,000 lives since 1999, with studies pointing to prescription opioids as the culprit for future opiate misuse. Currently, there are no well-described, data-driven processes to educate surgeons on reducing opiate prescribing, informed by personal practice patterns. We designed and implemented a novel opiate reclamation and prescription reduction program for surgeons to reclaim unused medications and decrease prescribing using individual provider data. METHODS: We performed a prospective collection of all unused opiate pain medications for general surgery postoperative patients from July 15, 2020 to January 15, 2021. Patients brought their unused opiates to their routine postoperative follow-up appointment, where they were counted and disposed of in a secure drug take-back bin. Reclaimed opiates were totaled, analyzed, and reported to the providers, who used their individual reclamation rates to refine prescribing habits. RESULTS: During the reclamation period, 168 operations were performed, with a total of 12,970 morphine milligram equivalents of opiate prescribed by 5 physicians. A total of 6,077.5 morphine milligram equivalents (46.9%) were reclaimed, which is the equivalent of 800 5-mg tablets of oxycodone. A review of these data led to a 30.9% decrease in opiate prescriptions by participating surgeons in addition to the reclamation of an additional 3,150 morphine milligram equivalents over the next 6 months. CONCLUSION: Continuous monitoring of the medications returned by patients now continues to inform our providers' prescribing practices, decreases the amount of opiates in the community, and improves patient safety.

Trends in Diagnostic Imaging by Nonphysician Practitioners and Associations With Urbanicity and Scope-of-Practice Authority.

OBJECTIVE: We aimed to assess the changing share of diagnostic imaging billed by NPPs and how such changes differ by urbanicity within the context of scope-of-practice (SOP) regulations and legislation. METHODS: This retrospective cohort study used patient claims for diagnostic imaging studies spanning 2016-2020 from Optum Clinformatics Datamart datasets. Multivariable modeling determined the odds of patients receiving NPP-interpreted vs physician-interpreted imaging. Imaging rates and trends in proportions of NPP-billed claims were assessed by urbanicity and relative to other factors including SOP, imaging modality, and place of service. RESULTS: Of all identified imaging claims, 3,348,881 (3.0%) were attributed to NPPs, with the highest rates of NPP interpretations per 10,000 images occurring in rural and small-town areas. From 2016 to 2020, the rate of NPP-billed imaging increased from 257 to 331 claims per 10,000 beneficiaries (P = 0.004), observed across both metropolitan (240 to 315, P = 0.001) and micropolitan (367 to 436, P = 0.020) settings. Although rates in rural and small-town areas rose, the increase was not significant (330 to 392, P = 0.363). Rises in NPP imaging in metropolitan settings occurred in states with moderately restrictive (307 to 358, P = 0.008) and least restrictive (289 to 419, P = 0.004) SOP legislation. DISCUSSION: Rates of diagnostic imaging interpretation by NPPs are rising. Growth in recent years appears driven by metropolitan areas in states with less restrictive SOP regulations. Future work is necessary to assess the quality of and downstream costs related to increasing NPP-interpreted imaging.

Imaging Utilization Patterns in the Follow-Up of Extremity Soft Tissue Sarcomas in the United States.

This study aimed to describe patterns of imaging utilization after resection of extremity soft tissue sarcoma in the United States, assess for potential disparities, and evaluate temporal trends. A retrospective cohort study using a national database of private payer claims data was performed to determine the utilization rate of extremity and chest imaging in a 5-year postoperative follow-up period for patients with extremity soft tissue sarcoma treated between 2007 and 2019. Imaging utilization was assessed according to patient demographics (age, sex, race and ethnicity, and region of residency), calendar year of surgery, and postoperative year. Associations of demographic variables with imaging use were assessed using chi-square tests, trends in imaging use were analyzed using the Cochran-Armitage trend test or linear regression, and associations of postoperative year with imaging use were evaluated with the Pearson Correlation coefficient. A total of 3707 patients were included. Most patients received at least 1 chest (74%) and extremity (53%) imaging examination during their follow-up period. The presence of surveillance imaging was significantly associated with age (P < 0.0001) and region (P = 0.0029). Over the study period, there was an increase in use of extremity MRI (P < 0.05) and ultrasound (P < 0.01) and chest CT (P < 0.0001) and a decrease in use of chest radiographs (P < 0.0001). Imaging use declined over postoperative years (decrease by 85%-92% from year 1-5). In conclusion, the use of surveillance imaging varied according to patient demographics and has increased for extremity MRI and ultrasound and chest CT over the study period.

Urbanicity, Income, and Mammography-Use Disparities Among American Indian Women.

INTRODUCTION: Reported breast cancer screening among American Indian women is consistently below that of White women. The last claims-based trends were from 1991 to 2001. This study updates mammography trends for American Indian women and examines the impact of race, urbanicity, and income on long-term mammography use. METHODS: This was a multi-year (2005-2019), retrospective study of women aged 40-89 years using a 5% sample of Medicare fee-for-service beneficiaries residing in Arizona, California, New Mexico, Oklahoma, and Washington. This study used multivariable logistic regression to examine the impact of urbanicity and income on receiving mammography for American Indian women compared with that for White women. Analyses were conducted in 2022. RESULTS: Overall, annual age-adjusted mammography use declined from 205 per 1,000 in 2005 to 165 per 1,000 in 2019. The slope of these declines was significantly steeper (difference = -2.41, p<0.001) for White women (-3.06) than for American Indian women (-0.65). Mammography-use odds across all urbanicity categories were less for American Indian women than for White women compared with those of their respective metropolitan counterparts (e.g., rural: 0.96, 95% CI=0.77, 1.20 for American Indian women and 1.47, 99% CI=1.39, 1.57 for White women). Although residing in higher-income communities was not associated with mammography use for American Indian women, it was 31% higher for White women (OR=1.31, 99% CI=1.28, 1.34). CONCLUSIONS: The disparity in annual age-adjusted mammography use between American Indian and White women narrowed between 2005 and 2019. However, the association of urbanicity and community income on mammography use differs substantially between American Indian and White women. Policies to reduce disparities need to consider these differences.

Image-Guided Biopsy in Acute Diskitis-Osteomyelitis: A Systematic Review and Meta-Analysis.

BACKGROUND. The reported sensitivity and yield of image-guided biopsies for diskitis-osteomyelitis vary widely. OBJECTIVE. The purpose of this study was to perform a systematic review of the literature and meta-analysis of pooled sensitivity data to elucidate strategies for optimal image-guided biopsies among patients suspected to have diskitis-osteomyelitis. EVIDENCE ACQUISITION. A comprehensive literature search was performed for studies of patient populations with proven or suspected diskitis-osteomyelitis that included percutaneous image-guided biopsy as part of the workup algorithm. Type of pathogens, imaging modality used for biopsy guidance, tissue targeted, antibiotic administration at the time of biopsy, true microbiology positives, true microbiology negatives, false microbiology positives, false microbiology negatives, disease (i.e., diskitis-osteomyelitis) positives as determined by reference standard, true infection positives (i.e., positive microbiology or pathology results), and total number of biopsies performed were extracted from the studies. Microbiology sensitivity, microbiology biopsy yield, and infection sensitivity were calculated from the pooled data. These terms and the data required to calculate them were also defined in detail. EVIDENCE SYNTHESIS. Thirty-six articles satisfied inclusion criteria and were used for analysis. The pooled microbiology sensitivity, infection sensitivity, and microbiology biopsy yields were 46.6%, 70.0%, and 26.7%, respectively. Mycobacterium tuberculosis-only microbiology sensitivity was significantly higher than both pyogenic bacteria and mixed-organism microbiology sensitivity (p < .001). Staphylococcus aureus was the most common causative organism (28.6%). Pooled microbiology sensitivity was not significantly different for CT guidance and fluoroscopy guidance (p = .16). There was a statistically significant difference between pooled microbiology sensitivity of bone/end plate (45.5%) and disk/paravertebral soft-tissue (64.8%) image-guided biopsies (p < .001). There was no statistically significant difference in pooled microbiology sensitivities for patients who received antibiotics before the procedure (46.2%) and those who did not (44.6%) (p = .70). CONCLUSION. Image guidance by CT or fluoroscopy does not affect microbiology yield, disk and paravertebral soft-tissue biopsies should be considered over bone and end plate biopsies, and preprocedural antibiotic administration does not appear to impact biopsy results. CLINICAL IMPACT. Understanding and correctly applying reported statistics contribute to appropriate interpretation of the abundant literature on this topic and optimization of care for patients with diskitis-osteomyelitis.

Drivers of Ischemic Stroke Hospital Cost Trends Among Older Adults in the United States.

PURPOSE: The increased use of neuroimaging and innovations in ischemic stroke (IS) treatment have improved outcomes, but the impact on median hospital costs is not well understood. METHODS: A retrospective study was conducted using Medicare 5% claims data for 75,525 consecutive index IS hospitalizations for patients aged ≥65 years from 2012 to 2019 (values in 2019 dollars). IS episode cost was calculated in each year for trend analysis and stratified by cost components, including neuroimaging (CT angiography [CTA], CT perfusion [CTP], MRI, and MR angiography [MRA]), treatment (endovascular thrombectomy [EVT] and/or intravenous thrombolysis), and patient sociodemographic factors. Logistic regression was performed to analyze the drivers of high-cost episodes and median regression to assess drivers of median costs. RESULTS: The median IS episode cost increased by 4.9% from $9,509 in 2012 to $9,973 in 2019 (P = .0021). Treatment with EVT resulted in the greatest odds of having a high-cost (>$20,000) hospitalization (odds ratio [OR], 71.86; 95% confidence interval [CI], 54.62-94.55), as did intravenous thrombolysis treatment (OR, 3.19; 95% CI, 2.90-3.52). Controlling for other factors, neuroimaging with CTA (OR, 1.72; 95% CI, 1.58-1.87), CTP (OR, 1.32; 95% CI, 1.14-1.52), and/or MRA (OR, 1.26; 95% CI, 1.15-1.38) had greater odds of having high-cost episodes than those without CTA, CTP, and MRA. Length of stay > 4 days (OR, 4.34; 95% CI, 3.99-4.72) and in-hospital mortality (OR, 1.85; 95% CI, 1.63-2.10) were also associated with high-cost episodes. CONCLUSIONS: From 2012 to 2019, the median IS episode cost increased by 4.9%, with EVT as the main cost driver. However, the increasing treatment cost trends have been partially offset by decreases in median length of stay and in-hospital mortality.

Impact of the COVID-19 Pandemic on Breast Imaging: An Analysis of the National Mammography Database.

PURPOSE: The aim of this study was to quantify the initial decline and subsequent rebound in breast cancer screening metrics throughout the coronavirus disease 2019 (COVID-19) pandemic. METHODS: Screening and diagnostic mammographic examinations, biopsies performed, and cancer diagnoses were extracted from the ACR National Mammography Database from March 1, 2019, through May 31, 2021. Patient (race and age) and facility (regional location, community type, and facility type) demographics were collected. Three time periods were used for analysis: pre-COVID-19 (March 1, 2019, to May 31, 2019), peak COVID-19 (March 1, 2020, to May 31, 2020), and COVID-19 recovery (March 1, 2021, to May 31, 2021). Analysis was performed at the facility level and overall between time periods. RESULTS: In total, 5,633,783 screening mammographic studies, 1,282,374 diagnostic mammographic studies, 231,390 biopsies, and 69,657 cancer diagnoses were analyzed. All peak COVID-19 metrics were less than pre-COVID-19 volumes: 36.3% of pre-COVID-19 for screening mammography, 57.9% for diagnostic mammography, 47.3% for biopsies, and 48.7% for cancer diagnoses. There was some rebound during COVID-19 recovery as a percentage of pre-COVID-19 volumes: 85.3% of pre-COVID-19 for screening mammography, 97.8% for diagnostic mammography, 91.5% for biopsies, and 92.0% for cancer diagnoses. Across various metrics, there was a disproportionate negative impact on older women, Asian women, facilities in the Northeast, and facilities affiliated with academic medical centers. CONCLUSIONS: COVID-19 had the greatest impact on screening mammography volumes, which have not returned to pre-COVID-19 levels. Cancer diagnoses declined significantly in the acute phase and have not fully rebounded, emphasizing the need to increase outreach efforts directed at specific patient population and facility types.

Updated Trends, Disparities, and Clinical Impact of Neuroimaging Utilization in Ischemic Stroke in the Medicare Population: 2012 to 2019.

OBJECTIVE: The purpose of this study was to update trends, investigate sociodemographic disparities, and evaluate the impact on mortality of stroke neuroimaging across the United States from 2012 to 2019. METHODS: Retrospective cohort study using CMS Medicare 5% Research Identifiable Files, representing consecutive ischemic stroke emergency department or hospitalized patients aged ≥65 years. A total of 85,547 stroke episodes with demographic and clinical information were analyzed using Cochran-Mantel-Haenszel tests and logistic regression. Outcome measures were neuroimaging (CT angiography [CTA], CT perfusion [CTP], MRI, MR angiography [MRA]) utilization, acute treatment (endovascular thrombectomy [EVT] and intravenous thrombolysis [IVT]), and mortality while in the hospital and at 30 days and 1 year post discharge. RESULTS: Significantly increasing utilization trends for CTA (250%), CTP (428%) and MRI (18%), and a decreasing trend for MRA (-33%) were observed from 2012 to 2019 (P < .0001). Controlling for covariates in the logistic regression models, CTA and CTP were significantly associated with higher EVT and IVT utilization. Although CTA, MRI, and MRA were associated with lower mortality, CTP was associated with higher mortality post discharge. Less neuroimaging was performed in rural patients; older patients (≥80 years) had lower utilization of CTA, MRI, and MRA; female patients had lower rates of CTA; and Black patients had lower utilization of CTA and CTP. CONCLUSIONS: CTA and CTP utilization increased in the Medicare ischemic stroke population from 2012 to 2019 and both were associated with greater EVT and IVT use. However, disparities exist in neuroimaging utilization across all demographic groups, and further understanding of the root causes of these disparities will be crucial to achieving equity in stroke care.

Significant variations in preoperative fluid resuscitation volumes delivered to elderly hip fracture patients at six level 1 trauma centers: an observational descriptive study.

OBJECTIVE: To describe the variations in administration of preoperative (preop) fluids and in the volumes of fluid administered among geriatric hip fracture patients requiring surgical repair. DESIGN: Observational descriptive. SETTING: Six Level 1 trauma centers. PATIENTS: A total of 595 patients aged ≥65 with ICD-10 codes indicating hip fracture and surgical repair were identified. Of these, 87.9% (n = 525) received preop fluid. The median volume of preop fluid delivered was 1500 mL (IQR: 1000-2250 mL). INTERVENTION: None. MAIN OUTCOME MEASURES: Receipt of preop fluids; median volume of fluid received. RESULTS: Receipt of preop fluid was significantly different by inter-hospital transfer, facility, BMI, hospital length of stay, and postop fluid volume. Age, sex, time to surgery, time to ambulation, and hospital disposition were not associated with preop fluid. There were significant differences in median preop fluid volumes by facility and postop fluid volume. CONCLUSION: This descriptive study of current practices among geriatric trauma patients with isolated hip fractures revealed significant differences in the use of preop fluid resuscitation and the resuscitation volumes administered. Treating facility may be the most substantial source of variation highlighting the need for a guideline on fluid resuscitation. These observed variations may be a result of patient characteristics or provider discretion and should be evaluated further.

Six-year national study of damage control laparotomy and the effect of repeat re-exploration on rate of infectious complications.

BACKGROUND: Damage control laparotomy (DCL) is a life-saving procedure in patients with abdominal hemorrhage. After DCL, patients are sometimes left with an open abdomen (OA) so they may undergo multiple exploratory laparotomies (EXLAP), or re-explorations. Patients with OA are at increased risk of infectious complications (ICs). The association between number of re-explorations after DCL and the number of ICs is not clear. We hypothesized that each additional re-exploration increases the risk of developing IC. METHODS: This 6-year retrospective cohort study included patients aged ≥16 years from the NTDB who had DCL defined as EXLAP within 2 hours of arrival (ICD-9: 54.11, 54.12, 54.19) with at least one re-exploration. The primary outcome was IC (ie, superficial surgical site infection (SSI), organ space SSI, deep SSI, sepsis, pneumonia, or catheter-related bloodstream infection), examined dichotomously (present/absent) and ordinally as the number of ICs. Multivariate Poisson regression was used to assess the association between number of re-explorations and number of ICs. Significance was assigned at p<0.01. RESULTS: There were 7431 patients who underwent DCL; 2509 (34%) patients developed at least one IC. The rate of IC was lowest in patients who were closed during the first re-exploration (27%) and significantly increased with each re-exploration to 59% in patients who had five or more re-explorations (Cochran-Armitage trend p<0.001). After adjustment, there was 14% increased risk of an additional IC with each re-exploration (p<0.001). DISCUSSION: For patients requiring DCL, each re-exploration of the abdomen is associated with increased rate of ICs. LEVEL OF EVIDENCE: III, retrospective epidemiological study.

COVID-19 and trauma: how social distancing orders altered the patient population using trauma services during the 2020 pandemic.

BACKGROUND: Recent studies have reported changes in trauma volumes resulting from the COVID-19 pandemic and social distancing orders (SDOs) implemented by federal and state governments. However, literature is lacking on demographic, injury and outcome patterns. METHODS: This retrospective, cross-sectional study included patients aged ≥18 years at six US level 1 trauma centers. Patients not discharged by the date of data acquisition were excluded. Demographic, injury and outcome variables were assessed across four time periods: period 1 (January 1, 2019-December 31, 2019); period 1b (March 16, 2019-June 30, 2019); period 2 (January 1, 2020-March 15, 2020); and period 3 (March 16, 2020-June 30, 2020). Patients admitted in period 3 were compared with patients presenting during all other periods. Categorical data were compared with χ2 and Fisher's exact tests, and continuous data were assessed with Student's t-tests and Wilcoxon rank-sum tests. RESULTS: We identified 18 567 patients: 12 797 patients in period 1 (including 3707 in period 1b), 2488 in period 2 and 3282 in period 3. Compared with period 1, period 3 had a statistically significant decrease in mean patient volume, increase in portion of penetrating injuries, increase in higher levels of trauma activation, change in emergency department discharge disposition locations, increase in in-hospital mortality and a shorter hospital length of stay. Comparison between period 1b and period 3 demonstrated a decrease in mean patient volume, increase in penetrating injuries, increase in high acuity trauma activations and increase in in-hospital mortality rate. From period 2 to period 3, the penetrating injuries rose from 6.7% to 9.4% (p=0.004), injury severity scale ≥25 increased from 5.9% to 7.7% (p=0.002), full trauma team activations increased from 13.7% to 16.4% (p<0.001), interhospital transfers decreased from 36.7% to 31.6% (p<0.001) and the in-hospital mortality rate increased from 3.3% to 4.2% (p=0.003). DISCUSSION: Beyond altering social interactions among people, the federal SDO is associated with changes in trauma volumes, demographics and injury patterns among patients seeking care at six level 1 hospitals during the pandemic. LEVEL OF EVIDENCE: IV, prognostic and epidemiological.