Spinal Cord Stimulator Inequities Within the US Military Health System.

OBJECTIVES: Although studies have described inequities in spinal cord stimulation (SCS) receipt, there is a lack of information to inform system-level changes to support health care equity. This study evaluated whether Black patients exhaust more treatment options than do White patients, before receiving SCS. MATERIALS AND METHODS: This retrospective cohort study included claims data of Black and non-Latinx White patients who were active-duty service members or military retirees who received a persistent spinal pain syndrome (PSPS) diagnosis associated with back surgery within the US Military Health System, January 2017 to January 2020 (N = 8753). A generalized linear model examined predictors of SCS receipt within two years of diagnosis, including the interaction between race and number of pain-treatment types received. RESULTS: In the generalized linear model, Black patients (10.3% [8.7%, 12.0%]) were less likely to receive SCS than were White patients (13.6% [12.7%, 14.6%]) The interaction term was significant; White patients who received zero to three different types of treatments were more likely to receive SCS than were Black patients who received zero to three treatments, whereas Black and White patients who received >three treatments had similar likelihoods of receiving a SCS. CONCLUSIONS: In a health care system with intended universal access, White patients diagnosed with PSPS tried fewer treatment types before receiving SCS, whereas the number of treatment types tried was not significantly related to SCS receipt in Black patients. Overall, Black patients received SCS less often than did White patients. Findings indicate the need for structured referral pathways, provider evaluation on equity metrics, and top-down support.

Racialized Inequities in Knee Arthroplasty Receipt After Osteoarthritis Diagnosis in the US Military Health System.

OBJECTIVE: The goal was to evaluate institutional inequities in the US Military Health System in knee arthroplasty receipt within three years of knee osteoarthritis diagnosis when accounting for other treatments received (eg, physical therapy, medications). METHODS: In this retrospective observational cohort study, medical record data of patients (n = 29,734) who received a primary osteoarthritis diagnosis in the US Military Health System between January 2016 and January 2020 were analyzed. Data included receipt of physical therapy one year before diagnosis and up to three years after diagnosis, prediagnosis opioid and nonopioid prescription receipt, health-related factors associated with levels of racism, and the primary outcome, knee arthroplasty receipt within three years after diagnosis. RESULTS: In a generalized additive model with time-varying covariates, Asian and Pacific Islander (incidence rate ratio [IRR] 0.58, 95% confidence interval [CI] 0.45-0.74), Black (IRR 0.52, 95%CI 0.46-0.59), and Latine (IRR 0.66, 95%CI 0.52-0.85) patients experienced racialized inequities in knee arthroplasty receipt, relative to white patients (all P < 0.001). CONCLUSIONS: In the present sample, Asian and Pacific Islander, Black, and Latine patients were significantly less likely to receive a knee arthroplasty, relative to white patients. Taken together, system-level resources are needed to identify and address mechanisms underlying institutional inequities in knee arthroplasty receipt, such as factors related to systemic and structural, institutional, and personally mediated racism.

Opioid Prescribing Variation After Laparoscopic Cholecystectomy in the US Military Health System.

INTRODUCTION: After laparoscopic cholecystectomy (LC), there is a wide variation in opioid prescription miligram morphine equivalent dose (MED) and refills across US medical institutions. Given wide variation and opioid prescription guidelines, it is essential to conduct thorough health services research across medical, surgical, and patient-level factors that can be implemented to improve system-wide prescribing practices. Therefore, this study describes discharge MED variation and opioid refill probability after emergent and nonemergent LC. MATERIALS AND METHODS: This retrospective cohort study included medical record data of adult patients (N = 20,025) undergoing LC from January 2016 to June 2021 in the US Military Health System. Data visualizations and bivariate analyses examined prescription patterns across hospitals and evaluated the relationship between patient-level, care-level, and system-level factors and each outcome: discharge MED and opioid refill probability. Two generalized additive mixed models evaluated the relationship between predictors and each outcome. RESULTS: There was a significant variation in opioid and nonopioid pain medication prescribing practices across hospitals. While several factors were associated with discharge MED and opioid refill probability, the strongest effects were related to time period (before versus after a June 2018 Defense Health Agency policy release) and receipt of an opioid/nonopioid combination medication. Despite decreases in MED, the MED remained almost twice the recommended dose per prior research. CONCLUSIONS: Variation by hospital suggests the need for system-level changes that target genuine practice change and opioid stewardship. Inclusion of patient-reported outcomes, electronic health record decision support tools, and academic detailing programs may support system-level improvements.

Appendectomy Pain Medication Prescribing Variation in the U.S. Military Health System.

INTRODUCTION: Post-appendectomy opioid prescription practices may vary widely across and within health care systems. Although guidelines encourage conservative opioid prescribing and prescribing of non-opioid pain medications, the variation of prescribing practices and the probability of opioid refill remain unknown in the U.S. Military Health System. MATERIALS AND METHODS: This retrospective observational cohort study evaluated medical data of 11,713 patients who received an appendectomy in the Military Health System between January 2016 and June 2021. Linear-mixed and generalized linear-mixed models evaluated the relationships between patient-, care-, and system-level factors and the two primary outcomes; the morphine equivalent dose (MED) at hospital discharge; and the probability of 30-day opioid prescription refill. Sensitivity analyses repeated the generalized linear-mixed model predicting the probability of opioid (re)fill after an appendectomy, but with inclusion of the full sample, including patients who had not received a discharge opioid prescription (e.g., 0 mg MED). RESULTS: Discharge MED was twice the recommended guidance and was not associated with opioid refill. Higher discharge MED was associated with opioid/non-opioid combination prescription (+38 mg) relative to opioid-only, lack of non-opioid prescribing at discharge (+6 mg), care received before a Defense Health Agency opioid safety policy was released (+61 mg), documented nicotine dependence (+8 mg), and pre-appendectomy opioid prescription (+5 mg) (all P < .01). Opioid refill was more likely for patients with complicated appendicitis (OR = 1.34; P < .01); patients assigned female (OR = 1.25, P < .01); those with a documented mental health diagnosis (OR = 1.32, P = .03), an antidepressant prescription (OR = 1.84, P < .001), or both (OR = 1.54, P < .001); and patients with documented nicotine dependence (OR = 1.53, P < .001). Opioid refill was less likely for patients who received care after the Defense Health Agency policy was released (OR = 0.71, P < .001), were opioid naive (OR = 0.54, P < .001), or were Asian or Pacific Islander (relative to white patients, OR = 0.68, P = .04). Results from the sensitivity analyses were similar to the main analysis, aside from two exceptions. The probability of refill no longer differed by race and ethnicity or mental health condition only. CONCLUSIONS: Individual prescriber practices shifted with new guidelines, but potentially unwarranted variation in opioid prescribing dose remained. Future studies may benefit from evaluating patients' experiences with pain management, satisfaction, and patient-centered education after appendectomy within the context of opioid prescribing practices, amount of medications used, and refill probability. Such could pave a way for standardized patient-centered procedures that both decrease unwarranted prescribing pattern variability and optimize pain management regimens.

Post-lumbar surgery prescription variation and opioid-related outcomes in a large US healthcare system: an observational study.

BACKGROUND CONTEXT: Spinal decompression and fusion procedures are one of the most common procedures performed in the United States (US) and remain associated with high postsurgical opioid burden. Despite guidelines emphasizing nonopioid pharmacotherapy strategies for postsurgical pain management, prescribing practices are likely variable and guideline-incongruent. PURPOSE: The purpose of this study was to characterize patient-, care-, and system-level factors associated with opioid, nonopioid pain medication, and benzodiazepine prescribing variation in the US Military Health System (MHS). STUDY DESIGN/SETTING: Retrospective study analyzing medical records from the US MHS Data Repository. PATIENT SAMPLE: Adult patients (N=6,625) undergoing lumbar decompression and spinal fusion procedures from 2016 to 2021 in the MHS enrolled in TRICARE at least a year prior to their procedure and had at least one encounter beyond the 90-day postprocedure period, without recent trauma, malignancy, cauda equina syndrome, and co-occurring procedures. OUTCOME MEASURES: Patient-, care-, and system-level factors influencing outcomes of discharge morphine equivalent dose (MED), 30-day opioid refill, and persistent opioid use (POU). POU was defined as dispensing of opioid prescriptions monthly for the first 3 months after surgery and then at least once between 90 and 180 days after surgery. METHODS: (Generalized) linear mixed models evaluated multilevel factors associated with discharge MED, opioid refill, and POU. RESULTS: The median discharge MED was 375 mg (IQR 225, 580) and days' supply was 7 days (IQR 4, 10); 36% received an opioid refill and 5%, overall, met criteria for POU. Discharge MED was associated with fusion procedures (+151-198 mg), multilevel procedures (+26 mg), policy release (-184 mg), opioid naïvty (-31 mg), race (Black -21 mg, another race and ethnicity -47 mg), benzodiazepine receipt (+100 mg), opioid-only medications (+86 mg), gabapentinoid receipt (-20 mg), and nonopioid pain medications receipt (-60 mg). Longer symptom duration, fusion procedures, beneficiary category, mental healthcare, nicotine dependence, benzodiazepine receipt, and opioid naivety were associated with both opioid refill and POU. Multilevel procedures, elevated comorbidity score, policy period, antidepressant receipt, and gabapentinoid receipt, and presurgical physical therapy were also associated with opioid refill. POU increased with increasing discharge MED. CONCLUSIONS: Significant variation in discharge prescribing practices require systems-level, evidence-based intervention.

Hysterectomy inequities between black and white patients in the US military health system: A retrospective cohort study.

OBJECTIVE: To evaluate multicomponent aspects of hysterectomy-related care in the US Military Health System including the probability of open hysterectomy (versus vaginal or laparoscopic hysterectomy), probability of having a length of stay > 1 day, and discharge milligram morphine equivalent dose (MED). Analyses sought to identify the presence and strength of healthcare inequities between Black and white patients. METHODS: In this retrospective cohort study, records of patients (N = 11,067) ages 18-65 years enrolled in TRICARE who underwent a hysterectomy between January 2017 to January 2021 in US military treatment facilities (direct care) or civilian facilities (purchased care) were included. Graphic representations illustrated provider and facility variation. Generalized additive mixed models (GAMMs) evaluated inequities across outcomes. Sensitivity analyses included only direct care receipt and added a random effect for the facility. RESULTS: There was significant variation in provider use of open versus vaginal or laparoscopic hysterectomies, as well as provider and facility discharge MED. The GAMMs indicated Black patients were more likely to receive an open hysterectomy [log(OR) -0.54, (95 %CI -0.65, -0.43), p < 0.001] and have a length of stay > 1 day [log(OR) 0.18, (95 %CI 0.07, 0.30), p = 0.002], but had similar discharge MED [-2 mg (95% CI -7 mg, 3 mg), p = 0.51], relative to white patients. Patients receiving care in purchased care, relative to direct care, were more likely to receive a vaginal or laparoscopic hysterectomy [log(OR) 0.28, (95 %CI 0.17, 0.38), p = 0.002] and received approximately 21 mg lower discharge MED (95 %CI 16-26 mg less, p < 0.001), but were more likely to have a hospital stay > 1 day [log(OR) 0.95, (95 %CI 0.83, 0.1.10), p < 0.001]. Additional gynecological conditions (e.g., uterine fibroids) and prescription receipt were associated with some, but not all outcomes. CONCLUSION: Improving timely care receipt, especially for uterine fibroids, increasing access to vaginal and laparoscopic hysterectomies, and reducing unwarranted variation in discharge MED could improve care quality and equity in the US Military Health System.

Post-total joint arthroplasty opioid prescribing practices vary widely and are not associated with opioid refill: an observational cohort study.

INTRODUCTION: Optimized health system approaches to improving guideline-congruent care require evaluation of multilevel factors associated with prescribing practices and outcomes after total knee and hip arthroplasty. MATERIALS AND METHODS: Electronic health data from patients who underwent a total knee or hip arthroplasty between January 2016-January 2020 in the Military Health System Data were retrospectively analyzed. A generalized linear mixed-effects model (GLMM) examined the relationship between fixed covariates, random effects, and the primary outcome (30-day opioid prescription refill). RESULTS: In the sample (N = 9151, 65% knee, 35% hip), the median discharge morphine equivalent dose was 660 mg [450, 892] and varied across hospitals and several factors (e.g., joint, race and ethnicity, mental and chronic pain conditions, etc.). Probability of an opioid refill was higher in patients who underwent total knee arthroplasty, were white, had a chronic pain or mental health condition, had a lower age, and received a presurgical opioid prescription (all p < 0.01). Sex assigned in the medical record, hospital duration, discharge non-opioid prescription receipt, discharge morphine equivalent dose, and receipt of an opioid-only discharge prescription were not significantly associated with opioid refill. CONCLUSION: In the present study, several patient-, care-, and hospital-level factors were associated with an increased probability of an opioid prescription refill within 30 days after arthroplasty. Future work is needed to identify optimal approaches to reduce unwarranted and inequitable healthcare variation within a patient-centered framework.

Variation by default: cesarean section discharge opioid prescription patterns and outcomes in Military Health System hospitals: a retrospective longitudinal cohort study.

BACKGROUND: To examine factors associated with post-Cesarean section analgesic prescription variation at hospital discharge in patients who are opioid naïve; and examine relationships between pre-Cesarean section patient and care-level factors and discharge morphine equivalent dose (MED) on outcomes (e.g., probability of opioid refill within 30 days) across a large healthcare system. METHODS: The Walter Reed Institutional Review Board provided an exempt determination, waiver of consent, and waiver of HIPAA authorization for research use in the present retrospective longitudinal cohort study. Patient records were included in analyses if: sex assigned in the medical record was "female," age was 18 years of age or older, the Cesarean section occurred between January 2016 to December 2019 in the Military Health System, the listed TRICARE sponsor was an active duty service member, hospitalization began no more than three days prior to the Cesarean section, and the patient was discharged to home < 4 days after the Cesarean section. RESULTS: Across 57 facilities, 32,757 adult patients had a single documented Cesarean section procedure in the study period; 24,538 met inclusion criteria and were used in analyses. Post-Cesarean section discharge MED varied by facility, with a median MED of 225 mg and median 5-day supply. Age, active duty status, hospitalization duration, mental health diagnosis, pain diagnosis, substance use disorder, alcohol use disorder, gestational diabetes, discharge opioid type (combined vs. opioid-only medication), concurrent tubal ligation procedure, single (vs. multiple) births, and discharge morphine equivalent dose were associated with the probability of an opioid prescription refill in bivariate analyses, and therefore were included as covariates in a generalized additive mixed model (GAMM). Generalized additive mixed model results indicated that non-active duty beneficiaries, those with mental health and pain conditions, those who received an opioid/non-opioid combination medication, those with multiple births, and older patients were more likely to obtain an opioid refill, relative to their counterparts. CONCLUSION: Significant variation in discharge pain medication prescriptions, as well as the lack of association between discharge opioid MED and probability of refill, indicates that efforts are needed to optimize opioid prescribing and reduce unnecessary healthcare variation.

Procedural Benzodiazepine and Post-Vasectomy Opioid and Nonopioid Prescribing Variation in a Large Health Care System.

INTRODUCTION: Our goal was to describe variation in procedural benzodiazepine and post-vasectomy nonopioid pain and opioid prescription dispense events, and multilevel factors associated with the probability of an opioid refill. METHODS: Patients (40,584) undergoing vasectomies in the U.S. Military Health System between January 2016-January 2020 were included in this observational retrospective study. The main outcome was the probability of being dispensed an opioid prescription refill within 30 days post-vasectomy. Bivariate analyses examined the relationships between patient- and care-level characteristics, prescription dispense and 30-day opioid prescription refill. A generalized additive mixed-effects model and sensitivity analyses examined factors associated with opioid refill. RESULTS: There was wide variation in procedural benzodiazepine (32%) and post-vasectomy nonopioid (71%) and opioid (73%) prescription dispense patterns across facilities. Only 5% of the patients dispensed opioids received a refill. Probability of an opioid refill was associated with race (White), younger age, opioid dispense history, documented mental health or pain condition, lack of post-vasectomy nonopioid pain medication dispense events and higher dispensed post-vasectomy opioid prescription dose; albeit the effect of dose did not replicate in sensitivity analyses. CONCLUSIONS: Despite the wide variation in vasectomy-related pharmacological pathways across a large health care system, most patients do not require an opioid refill. Significant variation in prescribing practices indicated racial inequities. Given the low rates of opioid prescription refill, combined with the wide variation in opioid prescription dispense events and American Urological Association recommendations for conservative opioid prescribing after vasectomy, intervention to address excessive opioid prescribing is warranted.

Sex differences in cued fear responses and parvalbumin cell density in the hippocampus following repetitive concussive brain injuries in C57BL/6J mice.

There is strong evidence to suggest a link between repeated head trauma and cognitive and emotional disorders, and Repetitive concussive brain injuries (rCBI) may also be a risk factor for depression and anxiety disorders. Animal models of brain injury afford the opportunity for controlled study of the effects of injury on functional outcomes. In this study, male and cycling female C57BL/6J mice sustained rCBI (3x) at 24-hr intervals and were tested in a context and cued fear conditioning paradigm, open field (OF), elevated zero maze and tail suspension test. All mice with rCBI showed less freezing behavior than sham control mice during the fear conditioning context test. Injured male, but not female mice also froze less in response to the auditory cue (tone). Injured mice were hyperactive in an OF environment and spent more time in the open quadrants of the elevated zero maze, suggesting decreased anxiety, but there were no differences between injured mice and sham-controls in depressive-like activity on the tail suspension test. Pathologically, injured mice showed increased astrogliosis in the injured cortex and white matter tracts (optic tracts and corpus callosum). There were no changes in the number of parvalbumin-positive interneurons in the cortex or amygdala, but injured male mice had fewer parvalbumin-positive neurons in the hippocampus. Parvalbumin-reactive interneurons of the hippocampus have been previously demonstrated to be involved in hippocampal-cortical interactions required for memory consolidation, and it is possible memory changes in the fear-conditioning paradigm following rCBI are the result of more subtle imbalances in excitation and inhibition both within the amygdala and hippocampus, and between more widespread brain regions that are injured following a diffuse brain injury.

Chronic Neurobehavioral Sex Differences in a Murine Model of Repetitive Concussive Brain Injury.

Traumatic brain injury (TBI) resulting from repeated head trauma is frequently characterized by diffuse axonal injury and long-term motor, cognitive and neuropsychiatric symptoms. Given the delay, often decades, between repeated head traumas and the presentation of symptoms in TBI patients, animal models of repeated injuries should be studied longitudinally to properly assess the longer-term effects of multiple concussive injuries on functional outcomes. In this study, male and cycling female C57BL/6J mice underwent repeated (three) concussive brain injuries (rCBI) delivered via a Leica ImpactOne cortical impact device and were assessed chronically on motor (open field and rotarod), cognitive (y-maze and active place avoidance), and neuropsychiatric (marble-burying, elevated zero maze and tail suspension) tests. Motor deficits were significant on the rotarod on the day following the injuries, and slight impairment remained for up to 6 months. All mice that sustained rCBI had significant cognitive deficits on the active place avoidance test and showed greater agitation (less immobility) in the tail suspension test. Only injured male mice were significantly hyperactive in the open field, and had increased time spent in the open quadrants of the elevated zero maze. One year after the injuries, mice of both sexes exhibited persistent pathological changes by the presence of Prussian blue staining (indication of prior microbleeds), primarily in the cortex at the site of the injury, and increased GFAP staining in the perilesional cortex and axonal tracts (corpus callosum and optic tracts). These data demonstrate that a pathological phenotype with motor, cognitive, and neuropsychiatric symptoms can be observed in an animal model of rCBI for at least one year post-injury, providing a pre-clinical setting for the study of the link between multiple brain injuries and neurodegenerative disorders. Furthermore, this is the first study to include both sexes in a pre-clinical long-term rCBI model, and female mice are less impaired functionally than males.

Applications of the Morris water maze in translational traumatic brain injury research.

Acquired traumatic brain injury (TBI) is frequently accompanied by persistent cognitive symptoms, including executive function disruptions and memory deficits. The Morris Water Maze (MWM) is the most widely-employed laboratory behavioral test for assessing cognitive deficits in rodents after experimental TBI. Numerous protocols exist for performing the test, which has shown great robustness in detecting learning and memory deficits in rodents after infliction of TBI. We review applications of the MWM for the study of cognitive deficits following TBI in pre-clinical studies, describing multiple ways in which the test can be employed to examine specific aspects of learning and memory. Emphasis is placed on dependent measures that are available and important controls that must be considered in the context of TBI. Finally, caution is given regarding interpretation of deficits as being indicative of dysfunction of a single brain region (hippocampus), as experimental models of TBI most often result in more diffuse damage that disrupts multiple neural pathways and larger functional networks that participate in complex behaviors required in MWM performance.

Cognitive performance of male and female C57BL/6J mice after repetitive concussive brain injuries.

In contact sports, repetitive concussive brain injury (rCBI) is the prevalent form of head injury seen in athletes. The need for effective treatment is urgent as rCBI has been associated with a host of cognitive, behavioral and neurological complaints. There has been a growing trend in the use of female animals in pre-clinical research, but few studies have investigated possible sex differences following rCBI. The goal of the current study was to determine any differences between male and female C57BL/6J mice on assessments of learning and memory after repetitive concussive injury. Following rCBI by impact to the scalp, male mice exhibited longer righting reflexes during acute recovery. In both sexes, there were no evident histopathological changes observed in the underlying cerebral cortex or hippocampus. Reactive astrogliosis was elevated in the corpus callosum and optic tract, and astrogliosis was slightly less in the optic tract of female mice. rCBI mice exhibited impairment during the learning phase of the Morris water maze (MWM), but female mice, in comparison to male mice, were observed to have superior spatial memory during standard MWM probe trials. Female mice were overall more active, evidenced by greater distances traveled in the y-maze and greater swim speeds in the MWM. The results of this study demonstrate sex differences in cognitive performance following rCBI and support previous research suggesting the neuroprotective role of sex in brain injury.