US Integrated Healthcare System Research Articles

Health Care Utilization and Clinical Management of All-Cause and Norovirus-Associated Acute Gastroenteritis Within a US Integrated Health Care System.

Norovirus-associated acute gastroenteritis (AGE) exacts a substantial disease burden, yet the health care utilization for and clinical management of norovirus-associated AGE are not well characterized. We describe the health care encounters and therapeutics used for patients with all-cause and norovirus-associated AGE in the Kaiser Permanente Northwest health system from 1 April 2014 through 30 September 2016. Medical encounters for patients with AGE were extracted from electronic health records, and encounters within 30 days of one another were grouped into single episodes. An age-stratified random sample of patients completed surveys and provided stool samples for norovirus testing. In total, 40 348 individuals had 52 509 AGE episodes; 460 (14%) of 3310 participants in the substudy tested positive for norovirus. An overall 35% of all-cause AGE episodes and 29% of norovirus-associated AGE episodes had ≥2 encounters. While 80% of norovirus-associated AGE episodes had at least 1 encounter in the outpatient setting, all levels of the health care system were affected: 10%, 22%, 10%, and 2% of norovirus-associated AGE episodes had at least 1 encounter in virtual, urgent care, emergency department, and inpatient settings, respectively. Corresponding proportions of therapeutic use between norovirus-positive and norovirus-negative episodes were 13% and 10% for intravenous hydration (P = .07), 65% and 50% for oral rehydration (P < .001), 7% and 14% for empiric antibiotic therapy (P < .001), and 33% and 18% for antiemetics (P < .001). Increased health care utilization and therapeutics are likely needed for norovirus-associated AGE episodes during peak norovirus winter seasons, and these data illustrate that effective norovirus vaccines will likely result in less health care utilization.

Latent Tuberculosis Infection Testing Practices in a Large US Integrated Healthcare System.

Tuberculosis (TB) is a public health threat, with >80% of active TB in the United States occurring due to reactivation of latent TB infection (LTBI). We may be underscreening those with high risk for LTBI and overtesting those at lower risk. A better understanding of gaps in current LTBI testing practices in relation to LTBI test positivity is needed. This study, conducted between 1 January 2008 and 31 December 2019 at Kaiser Permanente Southern California, included individuals aged ≥18 years without a history of active TB. We examined factors associated with LTBI testing and LTBI positivity. Among 3 816 884 adults (52% female, 37% White, 37% Hispanic, mean age 43.5 years [standard deviation, 16.1]), 706 367 (19%) were tested for LTBI, among whom 60 393 (9%) had ≥1 positive result. Among 1 211 971 individuals who met ≥1 screening criteria for LTBI, 210 025 (17%) were tested for LTBI. Factors associated with higher adjusted odds of testing positive included male sex (1.32; 95% confidence interval, 1.30-1.35), Asian/Pacific Islander (2.78, 2.68-2.88), current smoking (1.24, 1.20-1.28), diabetes (1.13, 1.09-1.16), hepatitis B (1.45, 1.34-1.57), hepatitis C (1.54, 1.44-1.66), and birth in a country with an elevated TB rate (3.40, 3.31-3.49). Despite being risk factors for testing positive for LTBI, none of these factors were associated with higher odds of LTBI testing. Current LTBI testing practices may be missing individuals at high risk of LTBI. Additional work is needed to refine and implement screening guidelines that appropriately target testing for those at highest risk for LTBI.

Risk factors for reoperation following inguinal hernia repair: results from a cohort of patients from an integrated healthcare system.

Inguinal hernia repair is one of the most common operations performed globally. Identification of risk factors that contribute to hernia recurrence following an index inguinal hernia repair, especially those that are modifiable, is of paramount importance. Therefore, we sought to investigate risk factors for reoperation following index inguinal hernia repair. 125,133 patients aged ≥ 18years who underwent their first inguinal hernia repair with mesh within a large US integrated healthcare system were identified for a cohort study (2010-2020). Laparoscopic, robotic, and open procedures were included. The system's integrated electronic health record was used to obtain data on demographics, patient characteristics, surgical characteristics, and reoperations. The association of these characteristics with ipsilateral reoperation during follow-up was modeled using Cox proportional-hazards regression. Risk factors were selected into the final model by stepwise regression with Akaike Information Criteria, which quantifies the amount of information lost if a factor is left out of the model. Factors associated with reoperation with p < 0.05 were considered statistically significant. The cumulative incidence of reoperation at 5-year follow-up was 2.4% (95% CI 2.3-2.5). Increasing age, female gender, increasing body mass index, White race, chronic pulmonary disease, diabetes, drug abuse, peripheral vascular disease, and bilateral procedures all associated with a higher risk for reoperation during follow-up. This study identifies several risk factors associated with reoperation following inguinal hernia repair. These risk factors may serve as targets for optimization protocols prior to elective inguinal hernia repair, with the goal of reducing reoperation risk.

Abstract 18357: Racial Disparities in Direct Oral Anticoagulant Orders in Patients With Nonvalvular Atrial Fibrillation Within A Large Integrated Health System

Introduction: Anticoagulant (OAC) use for stroke prevention in non-valvular atrial fibrillation (NVAF), specifically direct oral anticoagulants (DOAC) use, is suboptimal in racial/ethnic (RE) minorities. Hypothesis: We hypothesized differences in OAC and DOAC orders among RE groups over time in patients newly diagnosed with NVAF from 2012-2022 within a large US integrated healthcare system. Methods: We conducted a retrospective cohort study using Kaiser Permanente Southern California electronic medical record data on adults with NVAF between 2012-2022. We compared the proportion of OAC and DOAC orders within 60 days from the first NVAF diagnosis among those with a CHA 2 DS 2 -VASc score ≥2 across self-reported RE groups over time using chi-squared tests. Multivariable logistic regression was used to compare OAC and DOAC orders in RE groups compared with non-Hispanic White (NHW) adjusting for age, sex, and CHA 2 DS 2 -VASc score. Results: Of 59,340 OAC eligible patients from 2012-2022, 52% of patients received an OAC order and 33% received a DOAC order. DOAC orders across all RE groups increased over time, with DOAC orders comprising 95% of all OAC orders for new NVAF patients in 2022. The percentages of OAC and DOAC orders were highest among NHW patients in most years. In 2022, OACs were ordered at higher rates for NHW (67.1%) than Asian (67.0%) (OR=0.84, 95% CI=0.67-1.05), Hispanic (65.6%) (OR=0.63, 95% CI=0.54-0.74), or non-Hispanic Black (62.0%) (OR=0.54, 95% CI=0.43-0.68) patients. In 2022, DOACs were ordered at higher rates for NHW (65.3%) than Asian (64.2%) (OR=0.78, 95% CI=0.63-0.98), Hispanic (64.1%) (OR=0.64, 95% CI=0.55-0.75), or non-Hispanic Black (60.7%) (OR=0.55, 95% CI=0.44-0.69) patients ( Figures 1a/1b ). Conclusions: Although DOAC orders have been increasing over time across all RE groups, minority groups were still less likely to receive OAC or DOAC orders than NHW patients.

OR24-04 High Prevalence Of Elevated ALT In Adolescent Females With Obesity And PCOS

Abstract Disclosure: S. Zhang: None. J.A. Darbinian: None. L.C. Greenspan: None. J.B. Schwimmer: Grant Recipient; Self; Intercept, Seraphina. J.C. Lo: None. Background: We recently observed that US Asian/Pacific Islander (PI) adolescents have two-fold higher odds of polycystic ovary syndrome (PCOS) compared to non-Hispanic White adolescents, with prevalence strongly associated with higher BMI. Moreover, similar to Hispanic/Latina adolescents, Asian/PI adolescents with obesity have much higher odds of elevated alanine aminotransferase (ALT), a biochemical marker for suspected non-alcoholic fatty liver disease (NAFLD). In a pilot study, we observed that PCOS was an independent predictor of elevated ALT in adolescent females with obesity. In this study, we characterized the association of PCOS and elevated ALT in a much larger population of adolescent females and further examined the burden of elevated ALT within the PCOS subset. Methods: We used data from 15,683 females aged 13-17 years who were members of a US integrated healthcare system, had a well-child visit in 2012-2018, met BMI criteria for obesity (BMI ≥95th percentile), and had ALT measured within 1 year of the visit. Elevated ALT was defined as ≥44 U/L (NASPHGAN criteria). PCOS was identified based on clinical diagnosis within 1 year of the visit. Class I, II, III obesity were defined by BMI percent of the 95th percentile from 100 to &amp;lt;120%, 120% to &amp;lt;140%, and ≥140%, respectively. Differences between PCOS and non-PCOS groups were compared using the Chi-square test. Multivariable logistic regression was used to examine the association of PCOS and elevated ALT. Results: Among 15,683 adolescent females with obesity and measured ALT (23.5% White, 14.1% Black, 11.0% Asian/PI, 46.8% Hispanic, and 4.7% other/unknown race and ethnicity), 5.5% had diagnosed PCOS and 39.5% had severe (class II-III) obesity. The prevalence of elevated ALT was 5.1% overall and was substantially higher among those with PCOS (10.6%) compared to those without PCOS (4.7%, p&amp;lt;0.001). In multivariable analyses, PCOS was associated with a 1.8-fold (CI 1.4-2.2) higher odds of elevated ALT, adjusting for age, race/ethnicity, and level of obesity. Similar to our prior report, greater obesity severity, Asian/PI race, and Hispanic ethnicity were significant predictors of elevated ALT. Among the subset of 865 adolescents with obesity and PCOS (40.9% class I, 34.9% class II, 24.2% class III obesity), the prevalence of elevated ALT varied by race and ethnicity, ranging from 15.8% among Asian/PI, 12.8% among Hispanic/Latina, 8.5% among White, and 2.0% among Black females. Conclusion: Our findings confirm a strong independent association of PCOS and elevated ALT among adolescent females with obesity. Among those with both obesity and PCOS, about 1 in 10 had elevated ALT, increasing to 1 in 8 among Hispanic/Latina females and nearly 1 in 6 among Asian/PI females. These findings support recommendations for NAFLD screening in adolescents with PCOS and consideration of screening in young adult women with PCOS, especially high-risk subsets. Presentation: Saturday, June 17, 2023

Female sex and ipsilateral reoperation risk following mesh-based inguinal hernia repair: a cohort study including 131,626 repairs in adults from an integrated healthcare system over a 10-year period.

We sought to compare females and males for the risk of reoperation following different inguinal hernia repair approaches (open, laparoscopic, and robotic). We conducted a retrospective cohort study including all patients aged ≥ 18 who underwent first inguinal hernia repair with mesh within a US integrated healthcare system (2010-2020). Data were obtained from the system's integrated electronic health record. Multiple Cox proportional-hazards regression was used to evaluate the association between sex and risk for ipsilateral reoperation during follow-up. Analysis was stratified by surgical approach (open, laparoscopic, and robotic). The study cohort was comprised of 110,805 patients who underwent 131,626 inguinal hernia repairs with mesh, 10,079 (7.7%) repairs were in females. After adjustment for confounders, females had a higher risk of reoperation than males following open groin hernia repair (hazard ratio [HR] = 1.98, 95% CI 1.74-2.25), but a lower reoperation risk following laparoscopic repair (HR = 0.70, 95% CI 0.51-0.97). The crude 5-year cumulative reoperation probability following robotic repair was 2.8% in males and no reoperations were observed for females. Of females who had a reoperation, 10.3% (39/378) were for a femoral hernia, while only 0.6% (18/3110) were for femoral hernias in males. In a large multi-center cohort of mesh-based inguinal hernia repair patients, we found a higher risk for reoperation in females after an open repair approach compared to males. Lower risk was observed for females through a minimally invasive approach (laparoscopic or robotic) and may be due to the ability to identify an occult femoral hernia through these approaches.

Similar rates of revision surgery following primary anatomic compared to reverse shoulder arthroplasty in patients ≥70 years old with glenohumeral osteoarthritis: A cohort study of 3,791 patients.

Reverse total shoulder arthroplasty (RTSA), initially indicated for cuff tear arthropathy, is increasingly used for elderly patients with primary glenohumeral osteoarthritis (GHOA) and an intact rotator cuff. This is often done to avoid revision surgery in elderly patients for rotator cuff failure with anatomic total shoulder arthroplasty (TSA) despite traditionally good outcomes of TSA. We sought to determine whether there was a difference in outcomes for patients ≥70 years who receive RTSA compared to TSA for GHOA. A retrospective cohort study was conducted using data from a US integrated health care system's Shoulder Arthroplasty Registry. Patients ≥70 years who underwent primary shoulder arthroplasty for GHOA with an intact rotator cuff were included (2012-2021). RTSA was compared to TSA. Multivariable Cox proportional hazard regression was used to evaluate all-cause revision risk during follow-up, while multivariable logistic regression was used to evaluate 90-day emergency department (ED) visit, and 90-day readmission. The final study sample comprised 685 RTSA and 3,106 TSA. Mean age was 75.8 years (standard deviation 4.6) and 43.4% were male. After accounting for confounders, no significant difference in all-cause revision risk was observed for RTSA compared to TSA (hazard ratio=0.79, 95% confidence interval [CI]=0.39-1.58). The most common reason for revision following RTSA was glenoid component loosening (40.0%). Over half (54.0%) of revisions following TSA were for rotator cuff tear. No difference between procedure type was observed in likelihood for 90-day ED visits (odds ratio [OR]=0.94, 95% CI=0.71-1.26) and 90-day readmission (OR=1.32, 95% CI=0.83-2.09). RTSA and TSA for GHOA with an intact rotator cuff in patients ≥70 years had a similar revision risk, as well as likelihood for 90-day ED visits and readmissions. While revision risk was similar, the most common causes for revision were different with rotator cuff tears for TSA and glenoid component loosening for RTSA.

Utilization of Total Joint Arthroplasty by Rural-Urban Designation in Patients With Osteoarthritis in a Universal Coverage System

BackgroundUtilization of total joint arthroplasty (TJA) is affected by differences linked to sex, race, and socioeconomic status; there is little information about how geographic variation contributes to these differences. We sought to determine whether discrepancies in TJA utilization exist in patients diagnosed with osteoarthritis (OA) based upon urban-rural designation in a universal coverage system. MethodsWe conducted a cohort study using data from a US-integrated healthcare system (2015 to 2019). Patients aged ≥50 years who had a diagnosis of hip or knee OA were included. Total hip arthroplasty and total knee arthroplasty utilization (in respective OA cohorts) was evaluated by urban-rural designation (urban, mid, and rural). Incidence rate ratios (IRRs) for urban-rural regions were modeled using multivariable Poisson regressions. ResultsThe study cohort included 93,642 patients who have hip OA and 275,967 patients who had knee OA. In adjusted analysis, utilization of primary total hip arthroplasty was lower in patients living in urban areas (IRR = 0.87, 95% confidence interval = 0.81 to 0.94) compared to patients in rural regions. Similarly, total knee arthroplasty was used at a lower rate in urban areas (IRR = 0.88, 95% confidence interval = 0.82 to 0.95) compared with rural regions. We found no differences in the hip and knee groups within the mid-region. ConclusionsIn hip and knee OA patients enrolled in a universal coverage system, we found patients living in urban areas had lower TJA utilization compared to patients living in rural areas. Further research is needed to determine how patient location contributes to differences in elective TJA utilization. Level of EvidenceIII.

Validation of ICD-10 hospital discharge diagnosis codes to identify incident and recurrent ischemic stroke from a US integrated healthcare system.

This study validated incident and recurrent ischemic stroke identified by International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10) hospital discharge diagnosis codes. Using electronic health records (EHR) of adults (≥18 years) receiving care from Kaiser Permanente Southern California with ICD-10 hospital discharge diagnosis codes of ischemic stroke (I63.x, G46.3, and G46.4) between October 2015 and September 2020, we identified 75 patients with both incident and recurrent stroke events (total 150 cases). Two neurologists independently evaluated validity of ICD-10 codes through chart reviews. The positive predictive value (PPV, 95% CI) for incident stroke was 93% (95% CI: 88%, 99%) and the PPV for recurrent stroke was 72% (95% CI: 62%, 82%). The PPV for recurrent stroke improved after applying a gap of 20 days (PPV of 75%; 95% CI: 63%, 87%) or removing hospital admissions related to stroke-related procedures (PPV of 78%; 95% CI: 68%, 88%). The ICD-10 hospital discharge diagnosis codes for ischemic stroke showed a high PPV for incident cases, while the PPV for recurrent cases were less optimal. Algorithms to improve the accuracy of ICD-10 codes for recurrent ischemic stroke may be necessary.

EE222 Healthcare Costs Associated with Initial Combination Therapy Versus Monotherapy for Patients with Hypertension

Initiation of antihypertensive medication with combination therapy requires less treatment modifications which may result in lower healthcare costs compared with initiation of antihypertensive monotherapy. We compared direct medical costs for patients with hypertension who initiated antihypertensive medication with combination therapy versus monotherapy in a US integrated healthcare system.

Failed rotator cuff surgery that resulted in reverse total shoulder arthroplasty within 5 years or less: a descriptive analysis of 42 shoulders from a US integrated healthcare system

BackgroundAlthough reverse total shoulder arthroplasty (RTSA) has become an effective treatment for patients after failed rotator cuff surgery, minimizing these failed surgeries by identifying patients who are likely to fail would improve resource utilization and decrease patient morbidity. MethodsFrom an integrated healthcare system’s Shoulder Arthroplasty Registry, of 570 RTSA performed between 2010 and 2015, we identified 42 shoulders (in 39 patients) that underwent RTSA after any prior rotator cuff surgery (repair or non-repair) within the previous five years. The medical records and imaging studies available were reviewed before and after the index rotator cuff surgery and the RTSA. Patient clinical and radiographic characteristics were analyzed statistically to identify patterns. ResultsThose 42 shoulders that underwent RTSA after a prior rotator cuff surgery were younger (mean ± standard deviation: 70.2 ± 6.5 vs. 74.0 ± 7.4, P < .01) with a higher prevalence of female sex (81.0% vs. 66.1%, P < .01) than those that did not have prior cuff surgery within five years in the Shoulder Arthroplasty Registry. 64.2% of index rotator cuff surgeries were reconstructive, while 35.7% were symptomatic. The median time from index surgery to RTSA was 15.5 months (range: 4-55 months). At the time of the index rotator cuff surgery, 50.0% exhibited pseudoparalysis. Most rotator cuff tears at their index surgery (75.7%) were retracted to near or beyond the glenoid rim, and 70.2% showed advanced fatty infiltration (Goutallier grade 3 or 4). Two-tendon tears accounted for 45.9% of patients (24.3% supraspinatus/subscapularis, 21.6% supraspinatus/infraspinatus). Isolated supraspinatus tears accounted for 43.2% of patients (34.2% full thickness and 10.8% partial thickness). Three or more tendon tear involvement only accounted for 10.8% of patients (4 patients). ConclusionRotator cuff tear retraction, fatty infiltration, pseudoparalysis, age near 70 years, and female sex are prevalent in patients who fail rotator cuff surgery and require conversion to RTSA. Therefore, repeated attempts at rotator cuff repair may be unwarranted in the presence of these unfavorable characteristics, and these patients may be better suited for initial management with RTSA.

Association Between Graft Type and Risk of Repeat Revision Anterior Cruciate Ligament Reconstruction: A Cohort Study of 1747 Patients

Background: With an increasing number of primary anterior cruciate ligament reconstructions (ACLRs), the burden of revision ACLR (rACLR) has also increased. Graft choice for rACLR is complicated by patient factors and the remaining available graft options. Purpose: To examine the association between graft type at the time of rACLR and the risk of repeat rACLR (rrACLR) in a large US integrated health care system registry while accounting for patient and surgical factors at the time of revision surgery. Study Design: Cohort study; Level of evidence, 3. Methods: Data from the Kaiser Permanente ACLR registry were used to identify patients who underwent a primary isolated ACLR between 2005 and 2020 and then went on to have rACLR. Graft type used at rACLR, classified as autograft versus allograft, was the exposure of interest. Multivariable Cox proportional hazard regression was used to evaluate the risk of rrACLR, with ipsilateral and contralateral reoperation as secondary outcomes. Models included factors at the time of the rACLR (age, sex, body mass index, smoking status, staged revision, femoral fixation, tibial fixation, femoral tunnel method, lateral meniscal injury, medial meniscal injury, and cartilage injury) and a factor from the primary ACLR (activity at injury) as covariates. Results: A total of 1747 rACLR procedures were included. The crude cumulative rrACLR incidence at 8-year follow-up was 13.9% for allograft and 6.0% for autograft. Cumulative ipsilateral reoperation incidence at 8-year follow-up was 18.3% for allograft and 18.9% for autograft; contralateral reoperation cumulative incidence was 4.3% for allograft and 6.8% for autograft. With adjustment for covariates, a 70% lower risk for rrACLR was observed for autograft compared with allograft (hazard ratio [HR], 0.30; 95% CI, 0.18-0.50; P < .0001). No differences were observed for ipsilateral reoperation (HR, 1.05; 95% CI, 0.73-1.51; P = .78) or contralateral reoperation (HR, 1.33; 95% CI, 0.60-2.97; P = .48). Conclusion: The use of autograft at rACLR was associated with a 70% lower risk of rrACLR compared with allograft in this cohort from the Kaiser Permanente ACLR registry. When accounting for all reoperations outside of rrACLR after rACLR, the authors found no significant difference in risk between autograft and allograft. To minimize the risk of rrACLR, surgeons should consider using autograft for rACLR when possible.

Investigating Disparities in Telehealth Among CKD Patients in a US Integrated Healthcare System

Investigating Disparities in Telehealth Among CKD Patients in a US Integrated Healthcare System

Female Gender and Risk of Ipsilateral Reoperation After Inguinal Hernia Repair: A Cohort Study Including 131,626 Patients in An Integrated Healthcare System Over A 10-Year Period

Introduction: The objective of this study is to compare the male and female patients for the risk of reoperation after different repair approaches (open, laparoscopic, and robotic). Methods: We conducted a cohort study of patients ≥18 years who underwent first inguinal hernia repair within a US integrated healthcare system (2010-2020). Multiple Cox proportional-hazards regression was used to evaluate the association between gender and risk for ipsilateral reoperation during follow-up. Analysis stratified by surgical approach (open, laparoscopic, and robotic) with covariate adjustment for potential confounders. Results: The study cohort comprised 131,626 patients who underwent inguinal hernia repair, 10,079 (7.7%) were women. After adjustment for confounders, females had a higher risk of reoperation than males after open repair (hazard ratio [HR]=1.98, 95% CI =1.74-2.25, P < 0.001), but a lower reoperation risk after laparoscopic repair (HR=0.70, 95% CI=0.51-0.97, P = 0.031). The crude 5-year cumulative reoperation probability after robotic repair was 2.8% (95% CI=0.7-4.8) in men and no reoperations were observed for women during follow-up. 0.3% of reoperations in women were for a femoral hernia while only 0.6% were for femoral hernias in men. Conclusion: In a large multi-center cohort of inguinal hernia repair patients, we found a higher risk for reoperation in women after an open repair compared with men which may be due to missed diagnoses of ipsilateral femoral hernias. Lower risk was observed for women through a minimally invasive approach (laparoscopic or robotic) and may be due to the ability to identify an occult femoral hernia through these approaches.

Association Between Race/Ethnicity and Total Joint Arthroplasty Utilization in a Universally Insured Population.

Previous studies have documented racial and ethnic disparities in total joint arthroplasty (TJA) utilization in the United States. A potential mediator of healthcare disparities is unequal access to care, and studies have suggested that disparities may be ameliorated in systems of universal access. The purpose of this study was to assess whether racial/ethnic disparities in TJA utilization persist in a universally insured population of patients enrolled in a managed healthcare system. This retrospective cohort study used data from a US integrated healthcare system (2015 to 2019). Patients aged 50 years and older with a diagnosis of hip or knee osteoarthritis were included. The outcome of interest was utilization of primary total hip arthroplasty and/or total knee arthroplasty, and the exposure of interest was race/ethnicity. Incidence rate ratios (IRRs) were modeled using multivariable Poisson regression controlling for confounders. There were 99,548 patients in the hip analysis and 290,324 in the knee analysis. Overall, 10.2% of the patients were Black, 20.5% were Hispanic, 9.6% were Asian, and 59.7% were White. In the multivariable analysis, utilization of primary total hip arthroplasty was significantly lower for all minority groups including Black (IRR, 0.55, 95% confidence interval [CI], 0.52-0.57, P < 0.0001), Hispanic (IRR, 0.63, 95% CI, 0.60-0.66, P < 0.0001), and Asian (IRR, 0.64, 95% CI, 0.61-0.68, P < 0.0001). Similarly, utilization of primary total knee arthroplasty was significantly lower for all minority groups including Black (IRR, 0.52, 95% CI, 0.49-0.54, P < 0.0001), Hispanic (IRR, 0.72, 95% CI, 0.70-0.75, P < 0.0001), and Asian (IRR, 0.60, 95% CI, 0.57-0.63, P < 0.0001) (all in comparison with White as reference). In this study of TJA utilization in a universally insured population of patients enrolled in a managed healthcare system, disparities on the basis of race and ethnicity persisted. Additional research is required to determine the reasons for this finding and to identify interventions which could ameliorate these disparities.

Poster 251: Autograft Associated with Lower Risk of Repeat Revision Anterior Cruciate Ligament Reconstruction than Allograft: Results from a Large Integrated Healthcare System

Objectives:With the rising utilization of primary anterior cruciate ligament reconstruction (ACLR), the burden of revision ACLR (rACLR) has also increased. Graft choice for rACLR is complicated by patient factors and the remaining available graft options. This study examines the relationship between graft type at the time of rACLR and the risk of repeat rACLR (rrACLR).Methods:We conducted a cohort study from a US integrated healthcare system’s ACLR registry. The study population included patients with a primary isolated ACLR, between 2005-2020, who then went on to have an aseptic rACLR. Graft type used at revision surgery, classified as autograft versus allograft, was the exposure of interest. Multivariable Cox proportional hazard regression was used to evaluate the risk of aseptic rrACLR with ipsilateral and contralateral reoperation as secondary outcomes. Models included factors at the time of the revision procedure (age, gender, body mass index, smoking status, staged revision, femoral fixation, tibial fixation, femoral tunnel method, lateral meniscus injury, medial meniscus injury, and cartilage injury) and a factor from the primary ACLR (activity at injury) as covariates.Results:1747 rACLR procedures were included. The crude cumulative aseptic rrACLR incidence at 8-years follow-up was 13.9% for allograft and 6.0% for autografts (Figure 1). Cumulative ipsilateral reoperation incidence at 8-years follow-up was 18.3% for allograft and 18.9% for autograft; contralateral reoperation cumulative incidence was 4.3% for allograft and 6.8% for autograft. With adjustment for covariates, a lower aseptic rrACLR risk was observed for autografts compared with allografts (HR=0.30, 95% CI=0.18-0.50, p <0.0001). No differences were observed for ipsilateral reoperation (HR=1.05, 95% CI=0.73-1.51, p=0.78) nor for contralateral reoperation (HR=1.33, 0.60-2.97, p=0.48) for autografts compared with allografts.Conclusions:The use of autograft at rACLR was associated with a 70% reduced risk of rrACLR compared to allograft in this large integrated health care system registry. When accounting for all reoperations after rACLR, we found no significant difference in risk between autograft and allograft. In order to minimize the risk of rrACLR, surgeons should consider using autograft for rACLR when possible.Figure 1.Cumulative Incidence of Asceptic Re-revision by Graft Type.

Radial head arthroplasty: a descriptive study of 970 patients in an integrated health care system.

Radial head arthroplasty (RHA) is commonly performed for isolated comminuted radial head fractures and in conjunction with traumatic elbow instability. However, there is a paucity of literature directly describing the characteristics and outcomes of patients who undergo RHA in a community-based setting. We describe a cohort of 970 RHA performed in the California regions of a US integrated health care system over a 9-year period. Patient demographics, implant selection, 90-day acute postoperative events, and cumulative reoperation/revision rates are included. Patients aged ≥18 years who underwent primary RHA were identified (2009-2017). Patient characteristics and demographics, including age, body mass index, gender, diabetes status, American Society of Anesthesiologists (ASA) classification, primary diagnosis, and concomitant procedures were described. Crude cumulative revision and reoperation probabilities were calculated as 1 minus the Kaplan-Meier estimator, with follow-up time calculated as the time from the index RHA to revision/reoperation date for those with the outcome of interest and time from index RHA to censoring date (eg, date of death, health care termination, study end date [March 31, 2018]) for those without the outcome. Ninety-day postoperative incidence of emergency department (ED) visit, readmission, and mortality was calculated as the number of patients with the event of interest over the number of patients at risk. A total of 970 patients underwent primary unilateral RHA by 205 surgeons during the study period. Annual procedure volume increased from 53 procedures in 2009 to 157 procedures in 2017. More patients were female, without diabetes, and had an ASA classification of 1 or 2. Fracture was the predominant indication for RHA (98.4%) and more than half (54.3%) had concomitant procedures performed. Most implants were press fit (63.2%) over loose fit, and >90% were monopolar. Three-year cumulative revision and reoperation probabilities following RHA were 6.5% (95% confidence interval [CI]=5.0%-8.5%) and 8.2% (95% CI=6.5%-10.3%), respectively. Revisions and reoperations tended to occur within the first postoperative year. Of the 970 RHA patients, 83 (8.5%) had a 90-day ED visit, 58 (6.0%) had a 90-day readmission, and 1 (0.1%) died within a 90-day postoperative period. This large cohort of RHA patients provides information about the practice of RHA at large and in the community. Surgeons are performing more RHA over time and choosing press fit stems more often. Revisions and reoperations tended to occur early. Readmission and ED visits were low but not negligible, with pain being the most common reason for ED visit.

Risk of hospitalization and mortality associated with uncontrolled blood pressure in patients with hypertension and COVID-19

ObjectiveThe role of uncontrolled blood pressure (BP) in COVID-19 severity among patients with hypertension is unclear. We evaluated the association between uncontrolled BP and the risk of hospitalization and/or mortality in patients with hypertension from a large US integrated healthcare system. MethodsWe identified patients with hypertension and a positive RT-PCR test result or a diagnosis of COVID-19 between March 1 – September 1, 2020 from Kaiser Permanente Southern California. BP categories was defined using the most recent outpatient BP measurement during 12 months prior to COVID-19 infection. The primary outcome of interest was all-cause hospitalization or mortality within 30 days from COVID-19 infection. ResultsAmong 12,548 patients with hypertension and COVID-19 (mean age = 60 years, 47% male), 63% had uncontrolled BP (≥130/80 mm Hg) prior to COVID-19. Twenty-one percent were hospitalized or died within 30 days of COVID-19 infection. Uncontrolled BP was not associated with higher hospitalization or mortality (adjusted rate ratios for BP ≥ 160/100 mm Hg vs < 130/80 mm Hg = 1.00 [95% CI: 0.87, 1.14]; BP 140–159/90-99 mm Hg vs < 130/80 mm Hg = 1.02 [95% CI: 0.93, 1.11]). These findings were consistent across different age groups, treatment for antihypertensive medications, as well as atherosclerotic cardiovascular disease risk. ConclusionAmong patients with hypertension, uncontrolled BP prior to COVID-19 infection did not appear to be an important risk factor for 30-day mortality or hospitalization.

Long-Term Medication Adherence Trajectories to Direct Oral Anticoagulants and Clinical Outcomes in Patients With Atrial Fibrillation.

BackgroundDirect oral anticoagulants (DOACs) are widely used in patients with nonvalvular atrial fibrillation for stroke prevention. However, long‐term adherence to DOACs and clinical outcomes in real‐world clinical practice is not well understood. This study evaluated long‐term medication adherence patterns to DOAC therapy and clinical outcomes in a large US integrated health care system.Methods and ResultsWe included adult patients with nonvalvular atrial fibrillation who newly initiated DOACs between 2012 and 2018 in Kaiser Permanente Southern California. Long‐term (3.5 years) adherence trajectories to DOAC were investigated using monthly proportion of days covered and group‐based trajectory models. Factors associated with long‐term adherence trajectories were investigated. Multivariable Poisson regression analyses were used to investigate thromboembolism and major bleeding events associated with long‐term adherence trajectories. Of 18 920 patients newly initiating DOACs, we identified 3 DOAC adherence trajectories: consistently adherent (85.2%), early discontinuation within 6 months (10.6%), and gradually declining adherence (4.2%). Predictors such as lower CHA2DS2‐VASc (0–1 versus ≥5) and previous injurious falls were associated with both early discontinuation and gradually declining adherence trajectories. Early discontinuation of DOAC therapy was associated with a higher risk of thromboembolism (rate ratio, 1.40; 95% CI, 1.05–1.86) especially after 12 months from DOAC initiation but a lower risk of major bleed compared with consistent adherence (rate ratio, 0.48; 95% CI, 0.30–0.75), specifically during the first 12 months following DOAC initiation. A gradual decline in adherence to DOACs was not statistically significantly associated with thromboembolism outcomes compared with consistent adherence.ConclusionsAlthough a large proportion of patients with nonvalvular atrial fibrillation were adherent to DOAC therapy over 3.5 years, early discontinuation of DOAC was associated a higher risk of thromboembolic events. Future tailored interventions for early discontinuers may improve clinical outcomes.

Clinical Outcomes Following Regionalization of Gastric Cancer Care in a US Integrated Health Care System.

In 2016, Kaiser Permanente Northern California regionalized gastric cancer care, introducing a regional comprehensive multidisciplinary care team, standardizing staging and chemotherapy, and implementing laparoscopic gastrectomy and D2 lymphadenectomy for patients eligible for curative-intent surgery. This study evaluated the effect of regionalization on outcomes. The retrospective cohort study included gastric cancer cases diagnosed from January 2010 to May 2018. Information was obtained from the electronic medical record, cancer registry, state vital statistics, and chart review. Overall survival was compared in patients with all stages of disease, stage I-III disease, and curative-intent gastrectomy patients using annual inception cohorts. For the latter, the surgical approach and surgical outcomes were also compared. Among 1,429 eligible patients with gastric cancer with all stages of disease, one third were treated after regionalization, 650 had stage I-III disease, and 394 underwent curative-intent surgery. Among surgical patients, neoadjuvant chemotherapy utilization increased from 35% to 66% (P < .0001), laparoscopic gastrectomy increased from 18% to 92% (P < .0001), and D2 lymphadenectomy increased from 2% to 80% (P < .0001). Dissection of ≥ 15 lymph nodes increased from 61% to 95% (P < .0001). Surgical complication rates did not appear to increase after regionalization. Length of hospitalization decreased from 7 to 3 days (P < .001). Overall survival at 2 years was as follows: all stages, 32.8% pre and 37.3% post (P = .20); stage I-III cases with or without surgery, 55.6% and 61.1%, respectively (P = .25); and among surgery patients, 72.7% and 85.5%, respectively (P < .03). Regionalization of gastric cancer care within an integrated system allowed comprehensive multidisciplinary care, conversion to laparoscopic gastrectomy and D2 lymphadenectomy, increased overall survival among surgery patients, and no increase in surgical complications.