COVID-19 Death Determination Methods, Minnesota, USA, 2020-20221.

Accurate and timely mortality surveillance is crucial for elucidating risk factors, particularly for emerging diseases. We compared use of COVID-19 keywords on death certificates alone to identify COVID-19 deaths in Minnesota, USA, during 2020-2022, with use of a standardized mortality definition incorporating additional clinical data. For analyses, we used likelihood ratio χ2 and median 1-way tests. Death certificates alone identified 96% of COVID-19 deaths confirmed by the standardized definition and an additional 3% of deaths that had been classified as non-COVID-19 deaths by the standardized definition. Agreement between methods was >90% for most groups except children, although agreement among adults varied by demographics and location at death. Overall median time from death to filing of death certificate was 3 days; decedent characteristics and whether autopsy was performed varied. Death certificates are an efficient and timely source of COVID-19 mortality data when paired with SARS-CoV-2 testing data.

Acute Meningoencephalitis Associated with Borrelia miyamotoi, Minnesota, USA.

Borrelia miyamotoi is an emerging tickborne pathogen that has been associated with central nervous system infections in immunocompromised patients, albeit infrequently. We describe a case-patient in Minnesota, USA, who had meningeal symptoms of 1 month duration. B. miyamotoi infection was diagnosed by Gram staining on cerebrospinal fluid and confirmed by sequencing.

Advanced Heart Failure Characteristics and Outcomes in Women and Men.

BACKGROUND: The epidemiology and pathophysiology of heart failure (HF) differ in women and men. Whether these differences extend to the subgroup of patients with advanced HF is not well defined. METHODS AND RESULTS: This is a retrospective cohort study of all adult Olmsted County, Minnesota residents with advanced HF (European Society of Cardiology criteria) from 2007 to 2017. Differences in survival and hospitalization risks in women and men following advanced HF development were examined using Cox proportional hazard regression and Andersen-Gill models, respectively. Of 936 individuals with advanced HF, 417 (44.6%) were women and 519 (55.4%) were men (self-reported sex). Time from development of HF to advanced HF was similar in women and men (median 3.2 versus 3.6 years). Women were older at diagnosis (mean age 79 versus 75 years), less often had coronary disease and hyperlipidemia, but more often had hypertension and depression (P<0.05 for each). Advanced HF with preserved ejection fraction was more prevalent in women than men (60% versus 30%, p<0.001). There were no differences in adjusted risks of all-cause mortality (hazard ratio [HR], 0.89 [95% CI, 0.77-1.03]), cardiovascular mortality (HR, 0.85 [95% CI, 0.70-1.02]), all-cause hospitalizations (HR, 1.04 [95% CI, 0.90-1.20]), or HF hospitalizations (HR, 0.91 [95% CI, 0.75-1.11]) between women and men. However, adjusted cardiovascular mortality was lower in women versus men with advanced HF with reduced ejection fraction (HR, 0.72 [95% CI, 0.56-0.93]). CONCLUSIONS: Women more often present with advanced HF with preserved ejection fraction and men with atherosclerotic disease and advanced HF with reduced ejection fraction. Despite these differences, survival and hospitalization risks are largely comparable in women and men with advanced HF.

Outbreak of Human Trichinellosis - Arizona, Minnesota, and South Dakota, 2022.

Trichinellosis is a parasitic zoonotic disease transmitted through the consumption of meat from animals infected with Trichinella spp. nematodes. In North America, human trichinellosis is rare and is most commonly acquired through consumption of wild game meat. In July 2022, a hospitalized patient with suspected trichinellosis was reported to the Minnesota Department of Health. One week before symptom onset, the patient and eight other persons shared a meal that included bear meat that had been frozen for 45 days before being grilled and served rare with vegetables that had been cooked with the meat. Investigation identified six trichinellosis cases, including two in persons who consumed only the vegetables. Motile Trichinella larvae were found in remaining bear meat that had been frozen for >15 weeks. Molecular testing identified larvae from the bear meat as Trichinella nativa, a freeze-resistant species. Persons who consume meat from wild game animals should be aware that that adequate cooking is the only reliable way to kill Trichinella parasites and that infected meat can cross-contaminate other foods.

Community and household-level incarceration and its association with mental health in a racially/ethnically diverse sample of families.

This study examines the association between community incarceration rates, household incarceration, and the mental health of parents and children. Participant families had children ages 5-9 (n = 1307) from the African American, Latinx, Hmong, Somali/Ethiopian, Native American, and White communities in the Twin Cities, Minnesota. Linear mixed models were used to estimate associations between parent and child mental health, household incarceration exposure, and census tract race, ethnicity and gender-specific incarceration rates matched to the family's home address and race/ethnicity. Findings indicated that living in census tracts with elevated incarceration rates of men from your same racial or ethnic group was significantly associated with psychological distress in parents and externalizing behaviors in boys, regardless of household exposure to incarceration. The association between incarceration rates and externalizing behaviors was only observed among girls with exposure to household incarceration. Policies that deconstruct pervasive racism in penal systems are needed to improve population mental health.

The incidence of pediatric dacryocystitis among a population-based cohort of infants with congenital nasolacrimal duct obstruction.

PURPOSE: To report the incidence, clinical characteristics, and outcomes of acute dacryocystitis among a large, population-based cohort of children born with congenital nasolacrimal duct obstruction (CNLDO) over a 10-year period. METHODS: This multicenter retrospective, population-based cohort study included all patients diagnosed with acute dacryocystitis in a cohort of patients diagnosed with CNLDO before age 5 years in Olmsted County, Minnesota, United States of America from January 1, 1995, through December 31, 2004. RESULTS: Of 1,998 patients with CNLDO, there were 70 cases (36 female [(51%)]) of acute dacryocystitis during the study, yielding an incidence rate of 243 per 100,000 children (95% CI, 170-316). Mean age at diagnosis was 9.0 months. Patients who developed dacryocystitis were significantly less likely to be born via C-section (OR = 0.29, P = 0.009). Less than half of patients with dacryocystitis were treated with oral/intravenous antibiotics (46%), but whose who were had a significantly higher odds of requiring probing (OR = 8.50, P = 0.004). Spontaneous CNLDO resolution was significantly less likely to occur in patients diagnosed with acute dacryocystitis compared with those without (OR = 2.46, P = 0.001). The median age of spontaneous resolution in the dacryocystitis group (6.0 months) was significantly older than the uncomplicated CNLDO group (P = 0.012). CONCLUSIONS: Pediatric acute dacryocystitis is an uncommon complication of CNLDO and is associated with both a lower likelihood of and older age at spontaneous resolution of CNLDO symptoms.

Corticosteroid Injections and Risk of Fracture.

Importance: Corticosteroid injections (CSIs) are an important tool for pain relief in many musculoskeletal conditions, but the longitudinal effects of these treatments on bone health and fracture risk are unknown. Objective: To determine whether cumulative doses of corticosteroid injections are associated with higher risk of subsequent osteoporotic and nonosteoporotic fractures. Design, Setting, and Participants: This cohort study included adult patients receiving any CSI from May 1, 2018, through July 1, 2022. Eligible patients resided in Olmsted County, Minnesota, and were empaneled to receive primary care within the Mayo Clinic. Cox proportional hazards regression models were used to evaluate risk of fracture based on cumulative injected corticosteroid dose. Exposure: Receipt of any CSI during the study period. Main Outcomes and Measures: The primary outcome was risk of fracture by total triamcinolone equivalents received. Secondary outcomes consisted of risks of fracture based on triamcinolone equivalents received in subgroups of patients not at high risk for fracture and patients with osteoporosis. Results: A total of 7197 patients were included in the study (mean [SD] age, 64.4 [14.6] years; 4435 [61.6%] women; 183 [2.5%] Black and 6667 [92.6%] White), and 346 (4.8%) had a new fracture during the study period. Of these fractures, 149 (43.1%) were considered osteoporotic. In the adjusted Cox proportional hazards regression model, there was no association of higher fracture risk based on cumulative CSI dose (adjusted hazard ratio [HR], 1.04 [95% CI, 0.96-1.11]). There was also no associated higher risk of fracture in the non-high-risk (adjusted HR, 1.11 [95% CI, 0.98-1.26]) or osteoporosis (adjusted HR, 1.01 [95% CI, 0.90-1.11]) subgroups. Age, Charleson Comorbidity Index, and previous fracture were the only factors that were associated with higher fracture risk. Conclusions and Relevance: In this cohort study of cumulative injected corticosteroid dose and risk of subsequent fracture, no association was observed, including in patients with a preexisting diagnosis of osteoporosis. Treatment of painful conditions with CSI should not be withheld or delayed owing to concern about fracture risk.

Surveillance for highly pathogenic avian influenza A (H5N1) in a raptor rehabilitation center-2022.

An ongoing, severe outbreak of highly pathogenic avian influenza virus (HPAI) A H5N1 clade 2.3.4.4b has been circulating in wild and domestic bird populations throughout the world, reaching North America in 2021. This HPAI outbreak has exhibited unique characteristics when compared to previous outbreaks. The global distribution of disease, prolonged duration, extensive number of species and individual wild birds affected, and the large impact on the global poultry industry have all exceeded historical impacts of previous outbreaks in North America. In this study, we describe the results of HPAI surveillance conducted at The Raptor Center, a wildlife rehabilitation hospital at University of Minnesota (Saint Paul, MN, U.S.A.), from March 28th-December 31, 2022. All wild raptors admitted to the facility were tested for avian influenza viruses using polymerase chain reaction (PCR) testing. All non-negative samples were submitted to the United States Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) National Veterinary Services Laboratories for confirmatory HPAI testing and genetic sequencing. During the study period, 996 individual birds representing 20 different species were tested for avian influenza, and 213 birds were confirmed HPAI positive. Highly pathogenic avian influenza surveillance conducted at The Raptor Center contributed 75% of the HPAI positive raptor detections within the state of Minnesota, located within the Mississippi flyway, significantly augmenting state wildlife surveillance efforts. The viral genotypes observed in birds sampled at The Raptor Center were representative of what was seen in wild bird surveillance within the Mississippi flyway during the same time frame. Wildlife rehabilitation centers provide an opportune situation to augment disease surveillance at the human, wildlife and domestic animal interface during ongoing infectious disease outbreaks.

Development and Evaluation of Surveillance System for Identifying Jail-Associated COVID-19 Cases in Minnesota, USA, 2022.

Confinement facilities are high-risk settings for the spread of infectious disease, necessitating timely surveillance to inform public health action. To identify jail-associated COVID-19 cases from electronic laboratory reports maintained in the Minnesota Electronic Disease Surveillance System (MEDSS), Minnesota, USA, the Minnesota Department of Health developed a surveillance system that used keyword and address matching (KAM). The KAM system used a SAS program (SAS Institute Inc., https://www.sas.com) and an automated program within MEDSS to identify confinement keywords and addresses. To evaluate KAM, we matched jail booking data from the Minnesota Statewide Supervision System by full name and birthdate to the MEDSS records of adults with COVID-19 for 2022. The KAM system identified 2,212 cases in persons detained in jail; sensitivity was 92.40% and specificity was 99.95%. The success of KAM demonstrates its potential to be applied to other diseases and congregate-living settings for real-time surveillance without added reporting burden.

COVID-19 vaccine uptake among non-US-born populations in the United States, 2020-2022.

BACKGROUND: In the United States (US), COVID-19 vaccination rates among non-US-born individuals (i.e., refugees, immigrants, and migrants [RIM]) are variable. Understanding baseline COVID-19 vaccine coverage among these populations and determining if disparities exist is essential for quality improvement initiatives and public health interventions. METHODS: Baseline COVID-19 vaccination rates for both primary series and booster doses were calculated at four health systems located in Minnesota, Colorado, and Pennsylvania participating in the Minnesota Department of Health's Center of Excellence in Newcomer Health. Patients aged ≥5 years as of 1/1/22, seen for ≥1 primary care visit during 7/1/2019-6/30/22 were included. Descriptive statistics were calculated for three measures of COVID-19 vaccine coverage during 12/14/2020-6/30/2022: 1) initiation of primary series; 2) completion of primary series; 3) completion of first booster. We calculated vaccine coverage rates for the entire population and stratified by subgroup including country of origin, refugee status, and primary language preference. RESULTS: We included 1,624,573 patients eligible for COVID-19 primary series vaccine and 907,749 eligible for COVID-19 booster vaccination. The percent of eligible patients who completed a COVID-19 primary series (63.4 %) and booster dose (66.2 %) were similar. Completion of the primary series was higher for non-US-born persons (72.7 %) compared with US born persons (65.4 %), similar among refugees (63.5 %) and non-refugees (63.4 %), and lower in patients with language preference other than English (62.7 %) compared with English preferring patients (63.6 %). Booster completion was lower for non-US-born persons (61.8 %), refugees (46.7 %), and patients with language preference other than English (55.3 %) compared with US-born (70 %), non-refugees (66.3 %), and English preferring patients (67.3 %) respectively. CONCLUSIONS: This evaluation identified disparities in COVID-19 vaccination rates among non-US-born persons and persons with a language preference other than English living in the US. Targeted outreach efforts may be beneficial in reaching these populations.

Ocular Manifestations of Multiple Sclerosis: A Population-Based Study.

BACKGROUND: To evaluate the population-based frequency and severity of multiple sclerosis (MS)-related ocular diseases. METHODS: Retrospective, population-based study examining patients with MS between January 1, 1998 and December 31, 2011. Patients were identified using the Rochester Epidemiology Project, which is a record-linkage system of medical records for all patient-physician encounters among Olmsted County, Minnesota residents. Diagnosis of MS was confirmed based on neuroimaging, cerebrospinal fluid studies, and serum studies for each patient according to the 2017 McDonald criteria. Patient data were obtained using the medical records and followed through April 1, 2018. RESULTS: Of the 116 patients with MS, 66% were female and the median age of onset was 36 years (interquartile range 27.5-43.5 years). About half (61/116, 53%) had MS-related neuro-ophthalmic manifestations during their disease course, and about one-fourth (33/116, 28%) had visual symptoms as their presenting symptom of MS, most commonly as optic neuritis (26/116, 22%). Optic neuritis was the leading MS-related ocular condition (37%), followed by internuclear ophthalmoplegia (16%) and nystagmus (13%). Optic neuritis was mostly unilateral (40/43, 93%), with 16% (6/43) having a visual acuity of 20/200 or worse at nadir but ultimately 95% (35/37) improving to a visual acuity of 20/40 or better. CONCLUSIONS: This study provides the population-based frequency of MS-related ocular disease, which demonstrates a high frequency of ocular manifestations in MS both at disease onset and during the disease course, emphasizing the utility of neuro-ophthalmologists, or collaboration between neurologists and ophthalmologists, in the care of patients with MS.

Long-term outcomes with abandoning versus extracting sterile leads: A 10-year population-based study.

BACKGROUND: Long-term outcomes of sterile lead management strategies of lead abandonment (LA) or transvenous lead extraction (TLE) remain unclear. METHODS: We performed a retrospective study of a population residing in southeastern Minnesota with follow-up at the Mayo Clinic and its health systems. Patients who underwent LA or TLE of sterile leads from January 1, 2000, to January 1, 2011, and had follow-up for at least 10 years or until their death were included. RESULTS: A total of 172 patients were included in the study with 153 patients who underwent LA and 19 who underwent TLE for sterile leads. Indications for subsequent lead extraction arose in 9.1% (n = 14) of patients with initial LA and 5.3% (n = 1) in patients with initial TLE, after an average of 7 years. Moreover, 28.6% of patients in the LA cohort who required subsequent extraction did not proceed with the extraction, and among those who proceeded, 60% had clinical success and 40% had a clinical failure. Subsequent device upgrades or revisions were performed in 18.3% of patients in the LA group and 31.6% in the TLE group, with no significant differences in procedural challenges (5.2% vs. 5.3%). There was no difference in 10-year survival probability among the LA group and the TLE group (p = .64). CONCLUSION: An initial lead abandonment strategy was associated with more complicated subsequent extraction procedures compared to patients with an initial transvenous lead extraction strategy. However, there was no difference in 10-year survival probability between both lead management approaches.

Disparities in Influenza, Pneumococcal, COVID-19 Vaccine Coverage in High-Risk Adults Aged 19 to 64 Years in Southeastern Minnesota, 2010-2021.

BACKGROUND: Despite effective vaccines against influenza, pneumococcus, and COVID-19, uptake has been suboptimal. RESEARCH QUESTION: Although disparities in vaccination by race and ethnicity have been observed, what is the role of other sociodemographic factors in US vaccine uptake? STUDY DESIGN AND METHODS: We conducted a population-based study using the Rochester Epidemiology Project (REP), a comprehensive medical records linkage system, to assess effects of sociodemographic factors including race, ethnicity, individual-level socioeconomic status (SES) via the housing-based socioeconomic status index, education, population density (urban or nonurban), and marital status with uptake of influenza, pneumococcal, and COVID-19 vaccination in high-risk adults. Adults at high risk of invasive pneumococcal disease residing in four counties in southeastern Minnesota who were aged 19 to 64 years were identified. Vaccination data were obtained from the Minnesota Immunization Information Connection and REP from January 1, 2010, through December 31, 2021. RESULTS: We identified 45,755 residents. Most were White (82%), non-Hispanic (94%), married (56%), and living in an urban setting (81%), with three-quarters obtaining at least some college education (74%). Although 45.1% were up to date on pneumococcal vaccines, 60.1% had completed the primary COVID-19 series. For influenza and COVID-19, higher SES, living in an urban setting, older age, and higher education positively correlated with vaccination. Magnitude of differences in race, education, and SES widened with booster vaccines. INTERPRETATION: This high-risk population is undervaccinated against preventable respiratory diseases, especially influenza and pneumococcus. Although national data reported improvement of disparities in COVID-19 vaccination uptake observed early in the pandemic, our data demonstrated gaps related to race, education level, SES, and age that widened with booster vaccines. Communities with high social vulnerabilities often show increased risk of severe disease outcomes, yet demonstrate lower uptake of preventive services. This highlights the need to understand better vaccine compliance and access in rural, lower SES, less-educated, Black, Hispanic, and younger populations, each of which were associated independently with decreased vaccination.

Older Tissue Age Derived From Abdominal Computed Tomography Biomarkers of Muscle, Fat, and Bone Is Associated With Chronic Conditions and Higher Mortality.

OBJECTIVE: To determine whether body composition derived from medical imaging may be useful for assessing biologic age at the tissue level because people of the same chronologic age may vary with respect to their biologic age. METHODS: We identified an age- and sex-stratified cohort of 4900 persons with an abdominal computed tomography scan from January 1, 2010, to December 31, 2020, who were 20 to 89 years old and representative of the general population in Southeast Minnesota and West Central Wisconsin. We constructed a model for estimating tissue age that included 6 body composition biomarkers calculated from abdominal computed tomography using a previously validated deep learning model. RESULTS: Older tissue age associated with intermediate subcutaneous fat area, higher visceral fat area, lower muscle area, lower muscle density, higher bone area, and lower bone density. A tissue age older than chronologic age was associated with chronic conditions that result in reduced physical fitness (including chronic obstructive pulmonary disease, arthritis, cardiovascular disease, and behavioral disorders). Furthermore, a tissue age older than chronologic age was associated with an increased risk of death (hazard ratio, 1.56; 95% CI, 1.33 to 1.84) that was independent of demographic characteristics, county of residency, education, body mass index, and baseline chronic conditions. CONCLUSION: Imaging-based body composition measures may be useful in understanding the biologic processes underlying accelerated aging.

Re-evaluating the Incidence and Prevalence of Clinical Hypertrophic Cardiomyopathy: An Epidemiological Study of Olmsted County, Minnesota.

OBJECTIVE: To contemporaneously reappraise the incidence-rate, prevalence, and natural history of hypertrophic cardiomyopathy (HCM) in Olmsted County, Minnesota, from 1984 to 2015. PATIENTS AND METHODS: A validated medical-record linkage system collecting information for residents of Olmsted County was used to identify all cases of HCM between January 1, 1984, and December 31, 2015. After adjudication of records from Mayo Clinic and Olmsted Medical Center, data relating to diagnoses and outcomes were abstracted. The calculated incidence rate and prevalence were standardized to the US 1980 White population (age- and sex-adjusted) and compared with a prior study examining the years 1975-1984. RESULTS: Two hundred seventy subjects with HCM were identified. The age- and sex-adjusted incidence rate was 6.6 per 100,000 person-years, and the point prevalence of HCM on January 1, 2016, was 89 per 100,000 population. The incidence rate and point prevalence of HCM on January 1, 2016, standardized to the US 1980 White population (age- and sex-adjusted), were 6.7 (95% CI, 7.1 to 8.8) per 100,000 person-years and 81.5 per 100,000 population, respectively. The incidence rate of HCM increased each decade since the index study. Individuals with HCM had a higher overall standardized mortality rate than the general population with an observed to expected HR of 1.44 (95% CI, 1.21 to 1.71; P<.001) which improved by each decade. CONCLUSION: The incidence and prevalence of HCM are higher than rates reported from a prior study in the same community examining the years 1975-1984, but lower than other study cohorts. The risk of mortality in HCM remains higher than expected, albeit with improvement in rates of mortality observed each decade during the study period.

Predictors of Adolescent Intimate Partner Sexual Violence Victimization: Patterns of Intersectional Social Positions in a Statewide, School-based Sample.

Intimate partner sexual violence (IPSV) is a substantial public health issue faced by youth, with disparities along lines of race, gender, and sexual orientation. Using an intersectional framework, the current study describes the prevalence of self-reported IPSV victimization across intersecting social positions among adolescents. High school students who completed the 2019 Minnesota Student Survey were asked whether they had ever experienced IPSV. Using exhaustive Chi-Square Automatic Interaction Detection (eCHAID), responses were modeled using five indicators: racial/ethnic identity, transgender/genderqueer/genderfluid identity, sex assigned at birth, sexual orientation, and school location. The prevalence of IPSV victimization within each end group identified by the eCHAID varied from 2.6% to 32.0%. The highest prevalence of IPSV among all students was observed in subgroups defined by multiple marginalized social positions; for example, 32.0% among lesbian, gay, bisexual, queer, pansexual, or questioning (LGBQ+) students of color who were transgender, genderqueer, genderfluid or unsure of their gender, and assigned male at birth; 22.8% among LGBQ+ students assigned female at birth and enrolled in a Greater Minnesota (outside of the Twin Cities) school; and 22.2% among Native+ or missing race LGBQ+ students assigned female at birth and enrolled in a metropolitan school. Within the eCHAID decision tree, several subsamples of students were split into two more subsamples with a twofold or greater statistically significant difference in IPSV victimization prevalence between them. Findings from this study highlight notable disparities in the prevalence of IPSV victimization among Minnesota youth and demonstrate the importance of detailing the distribution of interpersonal violence outcomes across youth with multiple marginalized identities. Findings suggest that disparities reported along one categorical axis only may miss important nuances in how risk for IPSV is distributed. Population health researchers should utilize methods that allow for the explication of complex intersections that characterize individuals' social positions in estimating the prevalence of sexual violence.

Outbreak of Anthrax in Livestock with Human Occupational Exposures - Minnesota, 2023.

In July 2023, the Minnesota Department of Health (MDH) was notified of possible occupational exposures to anthrax during an outbreak in animals. In consultation with the Centers for Disease Control and Prevention, MDH epidemiologists created a questionnaire that assessed exposure risks and helped determine individual illness monitoring and antibiotic post-exposure prophylaxis needs. This investigation and the resources developed for it could be useful in future scenarios where there are occupational exposures to naturally occurring anthrax.

Severe aortic stenosis: secular trends of incidence and outcomes.

BACKGROUND AND AIMS: Severe aortic stenosis (AS) is the guideline-based indication for aortic valve replacement (AVR), which has markedly increased with transcatheter approaches, suggesting possible increasing AS incidence. However, reported secular trends of AS incidence remain contradictory and lack quantitative Doppler echocardiographic ascertainment. METHODS: All adults residents in Olmsted County (MN, USA) diagnosed over 20 years (1997-2016) with incident severe AS (first diagnosis) based on quantitatively defined measures (aortic valve area ≤ 1 cm2, aortic valve area index ≤ 0.6 cm2/m2, mean gradient ≥ 40 mmHg, peak velocity ≥ 4 m/s, Doppler velocity index ≤ 0.25) were counted to define trends in incidence, presentation, treatment, and outcome. RESULTS: Incident severe AS was diagnosed in 1069 community residents. The incidence rate was 52.5 [49.4-55.8] per 100 000 patient-year, slightly higher in males vs. females and was almost unchanged after age and sex adjustment for the US population 53.8 [50.6-57.0] per 100 000 residents/year. Over 20 years, severe AS incidence remained stable (P = .2) but absolute burden of incident cases markedly increased (P = .0004) due to population growth. Incidence trend differed by sex, stable in men (incidence rate ratio 0.99, P = .7) but declining in women (incidence rate ratio 0.93, P = .02). Over the study, AS clinical characteristics remained remarkably stable and AVR performance grew and was more prompt (from 1.3 [0.1-3.3] years in 1997-2000 to 0.5 [0.2-2.1] years in 2013-16, P = .001) but undertreatment remained prominent (>40%). Early AVR was associated with survival benefit (adjusted hazard ratio 0.55 [0.42-0.71], P < .0001). Despite these improvements, overall mortality (3-month 8% and 3-year 36%), was swift, considerable and unabated (all P ≥ .4) throughout the study. CONCLUSIONS: Over 20 years, the population incidence of severe AS remained stable with increased absolute case burden related to population growth. Despite stable severe AS presentation, AVR performance grew notably, but while declining, undertreatment remained substantial and disease lethality did not yet decline. These population-based findings have important implications for improving AS management pathways.