Updated Estimate of the Number of Extreme Risk Protection Orders Needed to Prevent 1 Suicide.

Importance: Extreme risk protection orders (ERPOs)-also known as red flag, risk warrant, and gun violence restraining orders-authorize law enforcement, family members, and sometimes others to petition a court to remove firearms from and prevent the acquisition of new firearms by a person judged to pose an immediate danger to themselves or others. Previous estimates suggest that 1 suicide is prevented for every 10 ERPOs issued, a number needed to treat that depends critically on the counterfactual estimate of the proportion of suicidal acts by ERPO respondents that would have involved firearms in the absence of ERPOs. Objective: To empirically inform updated estimates of the number of ERPOs needed to prevent 1 suicide. Design, Setting, and Participants: This cohort study used data from California for method-specific suicides by handgun ownership (October 18, 2004, to December 31, 2015). Handgun-owning suicide decedents in California were identified using individual-level registry data about lawful handgun ownership linked to cause-specific mortality for a cohort of more than 25 million adults. The study also used data from Connecticut for method-specific suicides among ERPO respondents who died by suicide, extracted from published data (October 1999 to June 2013). Data analysis was performed in December 2023. Exposure: Handgun ownership. Main Outcomes and Measures: The primary outcomes were the number and distribution of suicidal acts by handgun owners in California, estimated using method-specific suicide mortality data and published case fatality ratios, and the counterfactual number and distribution of suicidal acts and deaths among ERPO respondents in Connecticut had no ERPOs been issued. Results: A total of 1216 handgun owners (mean [SD] age, 50 [18] years; 1019 male [83.8%]) died by suicide during the study period. Among male handgun owners in California, 28% of suicidal acts involved firearms, 54% involved drug poisoning, 9% involved cutting or piercing, 3% involved hanging or suffocation, 2% involved poisoning with solids and/or liquids, and the remaining 4% involved other methods. Assuming this distribution approximates the counterfactual distribution among ERPO respondents in Connecticut in the absence of ERPOs, 1 suicide death was prevented for every 22 ERPOs issued. Conclusions and Relevance: The estimates produced by this cohort study of California handgun owners suggest that ERPOs can play an important role in averting deaths among high-risk individuals.

Inappropriate Prescribing to Older Patients by Nurse Practitioners and Primary Care Physicians.

BACKGROUND: Many U.S. states have legislated to allow nurse practitioners (NPs) to independently prescribe drugs. Critics contend that these moves will adversely affect quality of care. OBJECTIVE: To compare rates of inappropriate prescribing among NPs and primary care physicians. DESIGN: Rates of inappropriate prescribing were calculated and compared for 23 669 NPs and 50 060 primary care physicians who wrote prescriptions for 100 or more patients per year, with adjustment for practice experience, patient volume and risk, clinical setting, year, and state. SETTING: 29 states that had granted NPs prescriptive authority by 2019. PATIENTS: Medicare Part D beneficiaries aged 65 years or older in 2013 to 2019. MEASUREMENTS: Inappropriate prescriptions, defined as drugs that typically should not be prescribed for adults aged 65 years or older, according to the American Geriatrics Society's Beers Criteria. RESULTS: Mean rates of inappropriate prescribing by NPs and primary care physicians were virtually identical (adjusted odds ratio, 0.99 [95% CI, 0.97 to 1.01]; crude rates, 1.63 vs. 1.69 per 100 prescriptions; adjusted rates, 1.66 vs. 1.68). However, NPs were overrepresented among clinicians with the highest and lowest rates of inappropriate prescribing. For both types of practitioners, discrepancies in inappropriate prescribing rates across states tended to be larger than discrepancies between these practitioners within states. LIMITATION: The Beers Criteria addresses the appropriateness of a selected subset of drugs and may not be valid in some clinical settings. CONCLUSION: Nurse practitioners were no more likely than physicians to prescribe inappropriately to older patients. Broad efforts to improve the performance of all clinicians who prescribe may be more effective than limiting independent prescriptive authority to physicians. PRIMARY FUNDING SOURCE: The Robert Wood Johnson Foundation and National Science Foundation.

Handgun Divestment and Risk of Suicide.

BACKGROUND: Firearm ownership is strongly related to suicide risk, yet little is known about how much risk declines when ownership ends ("divestment"). METHODS: Using data from 523,182 handgun owners, we estimated the effect of divesting and remaining divested versus never divesting on the risk of suicide and firearm-specific suicide. We used pooled logistic regression with inverse probability weighting, adjusting for demographic and area-level measures. RESULTS: The 5-year risk of suicide death was 25.6 (95% confidence interval [CI] = 15.1, 37.2) per 10,000 persons with divestment and 15.2 (95% CI = 13.2, 17.3) per 10,000 persons with no divestment, corresponding to a risk difference of 10.4 (95% CI = 0.7, 21.1) per 10,000 persons. The 5-year risk of firearm-specific suicide death was 6.3 (95% CI = 1.4, 11.9) per 10,000 persons with divestment and 12.9 (95% CI = 11.0, 14.6) per 10,000 persons with no divestment, corresponding to a risk difference of -6.6 (95% CI = -11.4, -0.1) per 10,000 persons. Comparing divestment to no divestment, risks were elevated for deaths due to other causes proposed as negative control outcomes; we incorporated these estimates into a series of bias derivations to better understand the magnitude of unmeasured confounding. CONCLUSIONS: Collectively, these estimates suggest that divestment reduces firearm suicide risk by 50% or more and likely reduces overall suicide risk as well, although future data collection is needed to fully understand the extent of biases such as unmeasured confounding.

Protection against Omicron from Vaccination and Previous Infection in a Prison System.

BACKGROUND: Information regarding the protection conferred by vaccination and previous infection against infection with the B.1.1.529 (omicron) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is limited. METHODS: We evaluated the protection conferred by mRNA vaccines and previous infection against infection with the omicron variant in two high-risk populations: residents and staff in the California state prison system. We used a retrospective cohort design to analyze the risk of infection during the omicron wave using data collected from December 24, 2021, through April 14, 2022. Weighted Cox models were used to compare the effectiveness (measured as 1 minus the hazard ratio) of vaccination and previous infection across combinations of vaccination history (stratified according to the number of mRNA doses received) and infection history (none or infection before or during the period of B.1.617.2 [delta]-variant predominance). A secondary analysis used a rolling matched-cohort design to evaluate the effectiveness of three vaccine doses as compared with two doses. RESULTS: Among 59,794 residents and 16,572 staff, the estimated effectiveness of previous infection against omicron infection among unvaccinated persons who had been infected before or during the period of delta predominance ranged from 16.3% (95% confidence interval [CI], 8.1 to 23.7) to 48.9% (95% CI, 41.6 to 55.3). Depending on previous infection status, the estimated effectiveness of vaccination (relative to being unvaccinated and without previous documented infection) ranged from 18.6% (95% CI, 7.7 to 28.1) to 83.2% (95% CI, 77.7 to 87.4) with two vaccine doses and from 40.9% (95% CI, 31.9 to 48.7) to 87.9% (95% CI, 76.0 to 93.9) with three vaccine doses. Incremental effectiveness estimates of a third (booster) dose (relative to two doses) ranged from 25.0% (95% CI, 16.6 to 32.5) to 57.9% (95% CI, 48.4 to 65.7) among persons who either had not had previous documented infection or had been infected before the period of delta predominance. CONCLUSIONS: Our findings in two high-risk populations suggest that mRNA vaccination and previous infection were effective against omicron infection, with lower estimates among those infected before the period of delta predominance. Three vaccine doses offered significantly more protection than two doses, including among previously infected persons.

Uptake of COVID-19 Vaccination Among Frontline Workers in California State Prisons.

Importance: Prisons and jails are high-risk environments for COVID-19. Vaccination levels among workers in many such settings remain markedly lower than those of residents and members of surrounding communities. The situation is troubling because prison staff are a key vector for COVID-19 transmission. Objective: To assess patterns and timing of staff vaccination in California state prisons and identify individual-level and community-level factors associated with remaining unvaccinated. Design Setting and Participants: This cohort study used data from December 22, 2020, through June 30, 2021, to quantify the fractions of staff and incarcerated residents who remained unvaccinated among 23 472 custody and 7617 health care staff who worked in roles requiring direct contact with residents at 33 of the 35 prisons operated by the California Department of Corrections and Rehabilitation. Multivariable probit regressions assessed demographic, community, and peer factors associated with staff vaccination uptake. Main Outcomes and Measures: Remaining unvaccinated throughout the study period. Results: Of 23 472 custody staff, 3751 (16%) were women, and 1454 (6%) were Asian/Pacific Islander individuals, 1571 (7%) Black individuals, 9008 (38%) Hispanic individuals, and 6666 (28%) White individuals. Of 7617 health care staff, 5434 (71%) were women, and 2148 (28%) were Asian/Pacific Islander individuals, 1201 (16%) Black individuals, 1409 (18%) Hispanic individuals, and 1771 (23%) White individuals. A total of 6103 custody staff (26%) and 3961 health care staff (52%) received 1 or more doses of a COVID-19 vaccine during the first 2 months vaccines were offered, but vaccination rates stagnated thereafter. By June 30, 2021, 14 317 custody staff (61%) and 2819 health care staff (37%) remained unvaccinated. In adjusted analyses, remaining unvaccinated was positively associated with younger age (custody staff: age, 18-29 years vs ≥60 years, 75% [95% CI, 73%-76%] vs 45% [95% CI, 42%-48%]; health care staff: 52% [95% CI, 48%-56%] vs 29% [95% CI, 27%-32%]), prior COVID-19 infection (custody staff: 67% [95% CI, 66%-68%] vs 59% [95% CI, 59%-60%]; health care staff: 44% [95% CI, 42%-47%] vs 36% [95% CI, 36%-36%]), residing in a community with relatively low rates of vaccination (custody staff: 75th vs 25th percentile:, 63% [95% CI, 62%-63%] vs 60% [95% CI, 59%-60%]; health care staff: 40% [95% CI, 39%-41%] vs 34% [95% CI, 33%-35%]), and sharing shifts with coworkers who had relatively low rates of vaccination (custody staff: 75th vs 25th percentile, 64% [95% CI, 62%-66%] vs 59% [95% CI, 57%-61%]; health care staff: 38% [95% CI, 36%-41%] vs 35% [95% CI, 31%-39%]). Conclusions and Relevance: This cohort study of California state prison custody and health care staff found that vaccination uptake plateaued at levels that posed ongoing risks of further outbreaks in the prisons and continuing transmission from prisons to surrounding communities. Prison staff decisions to forgo vaccination appear to be multifactorial, and vaccine mandates may be necessary to achieve adequate levels of immunity in this high-risk setting.

Protection against Omicron conferred by mRNA primary vaccine series, boosters, and prior infection.

B ackground: Prisons and jails are high-risk settings for Covid-19 transmission, morbidity, and mortality. We evaluate protection conferred by prior infection and vaccination against the SARS-CoV-2 Omicron variant within the California state prison system. M ethods: We employed a test-negative design to match resident and staff cases during the Omicron wave (December 24, 2021-April 14, 2022) to controls according to a case's test-week as well as demographic, clinical, and carceral characteristics. We estimated protection against infection using conditional logistic regression, with exposure status defined by vaccination, stratified by number of mRNA doses received, and prior infection, stratified by periods before or during Delta variant predominance. R esults: We matched 15,783 resident and 8,539 staff cases to 180,169 resident and 90,409 staff controls. Among cases, 29.7% and 2.2% were infected before or during the emergence of the Delta variant, respectively; 30.6% and 36.3% were vaccinated with two or three doses, respectively. Estimated protection from Omicron infection for two and three doses were 14.9% (95% Confidence Interval [CI], 12.3-19.7%) and 43.2% (42.2-47.4%) for those without known prior infections, 47.8% (95% CI, 46.6-52.8%) and 61.3% (95% CI, 60.7-64.8%) for those infected before the emergence of Delta, and 73.1% (95% CI, 69.8-80.1%) and 86.8% (95% CI, 82.1-92.7) for those infected during the period of Delta predominance. C onclusion: A third mRNA dose provided significant, additional protection over two doses, including among individuals with prior infection. Our findings suggest that vaccination should remain a priority-even in settings with high levels of transmission and prior infection.

Suicide Deaths Among Women in California Living With Handgun Owners vs Those Living With Other Adults in Handgun-Free Homes, 2004-2016.

Importance: Little is known about the extent to which secondhand exposure to household firearms is associated with risk of suicide in adults who do not own guns, most of whom are women. Objective: To evaluate changes in risk of suicide among women living in gun-free households after one of their cohabitants became a handgun owner. Design, Setting, and Participants: This cohort study observed participants for up to 12 years and 2 months from October 18, 2004, to December 31, 2016. Data were analyzed from April to November 2021. The study population included 9.5 million adult women in California who did not own guns and who entered the study while living with 1 or more adults in a handgun-free home. Exposures: Secondhand exposure to household handguns. Main Outcomes and Measures: Suicide, firearm suicide, nonfirearm suicide. Results: Of 9.5 million women living in handgun-free homes, 331 968 women (3.5% of the study population; mean [SD] age, 41.6 [18.0] years) became exposed to household handguns during the study period. In the entire study population, 294 959 women died: 2197 (1%) of these were by suicide, 337 (15%) of which were suicides by firearm. Rates of suicide by any method during follow-up were higher among cohort members residing with handgun owners compared with those residing in handgun-free homes (hazard ratio, 1.43; 95% CI, 1.11-1.84). The excess suicide rate was accounted for by higher rates of suicide by firearm (hazard ratio, 4.32; 95% CI, 2.89-6.46). Women in households with and without handguns had similar rates of suicide by nonfirearm methods (hazard ratio, 0.90; 95% CI, 0.63-1.27). Conclusions and Relevance: In this study, the rate of suicide among women was significantly higher after a cohabitant of theirs became a handgun owner compared with the rate observed while they lived in handgun-free homes.

Homicide Deaths Among Adult Cohabitants of Handgun Owners in California, 2004 to 2016 : A Cohort Study.

BACKGROUND: Although personal protection is a major motivation for purchasing firearms, existing studies suggest that people living in homes with firearms have higher risks for dying by homicide. Distribution of those risks among household members is poorly understood. OBJECTIVE: To estimate the association between living with a lawful handgun owner and risk for homicide victimization. DESIGN: This retrospective cohort study followed 17.6 million adult residents of California for up to 12 years 2 months (18 October 2004 through 31 December 2016). Cohort members did not own handguns, but some started residing with lawful handgun owners during follow-up. SETTING: California. PARTICIPANTS: 17 569 096 voter registrants aged 21 years or older. MEASUREMENTS: Homicide (overall, by firearm, and by other methods) and homicide occurring in the victim's home. RESULTS: Of 595 448 cohort members who commenced residing with handgun owners, two thirds were women. A total of 737 012 cohort members died; 2293 died by homicide. Overall rates of homicide were more than twice as high among cohabitants of handgun owners than among cohabitants of nonowners (adjusted hazard ratio, 2.33 [95% CI, 1.78 to 3.05]). These elevated rates were driven largely by higher rates of homicide by firearm (adjusted hazard ratio, 2.83 [CI, 2.05 to 3.91]). Among homicides occurring at home, cohabitants of owners had sevenfold higher rates of being fatally shot by a spouse or intimate partner (adjusted hazard ratio, 7.16 [CI, 4.04 to 12.69]); 84% of these victims were female. LIMITATIONS: Some cohort members classified as unexposed may have lived in homes with handguns. Residents of homes with and without handguns may have differed on unobserved traits associated with homicide risk. CONCLUSION: Living with a handgun owner is associated with substantially elevated risk for dying by homicide. Women are disproportionately affected. PRIMARY FUNDING SOURCE: The National Collaborative on Gun Violence Research, the Fund for a Safer Future, the Joyce Foundation, Stanford Law School, and the Stanford University School of Medicine.

Mortality among US veterans after emergency visits to Veterans Affairs and other hospitals: retrospective cohort study.

OBJECTIVE: To measure and compare mortality outcomes between dually eligible veterans transported by ambulance to a Veterans Affairs hospital and those transported to a non-Veterans Affairs hospital. DESIGN: Retrospective cohort study using data from medical charts and administrative files. SETTING: Emergency visits by ambulance to 140 Veteran Affairs and 2622 non-Veteran Affairs hospitals across 46 US states and the District of Columbia in 2001-18. PARTICIPANTS: National cohort of 583 248 veterans (aged ≥65 years) enrolled in both the Veterans Health Administration and Medicare programs, who resided within 20 miles of at least one Veterans Affairs hospital and at least one non-Veterans Affairs hospital, in areas where ambulances regularly transported patients to both types of hospitals. INTERVENTION: Emergency treatment at a Veterans Affairs hospital. MAIN OUTCOME MEASURE: Deaths in the 30 day period after the ambulance ride. Linear probability models of mortality were used, with adjustment for patients' demographic characteristics, residential zip codes, comorbid conditions, and other variables. RESULTS: Of 1 470 157 ambulance rides, 231 611 (15.8%) went to Veterans Affairs hospitals and 1 238 546 (84.2%) went to non-Veterans Affairs hospitals. The adjusted mortality rate at 30 days was 20.1% lower among patients taken to Veterans Affairs hospitals than among patients taken to non-Veterans Affairs hospitals (9.32 deaths per 100 patients (95% confidence interval 9.15 to 9.50) v 11.67 (11.58 to 11.76)). The mortality advantage associated with Veterans Affairs hospitals was particularly large for patients who were black (-25.8%), were Hispanic (-22.7%), and had received care at the same hospital in the previous year. CONCLUSIONS: These findings indicate that within a month of being treated with emergency care at Veterans Affairs hospitals, dually eligible veterans had substantially lower risk of death than those treated at non-Veterans Affairs hospitals. The nature of this mortality advantage warrants further investigation, as does its generalizability to other types of patients and care. Nonetheless, the finding is relevant to assessments of the merit of policies that encourage private healthcare alternatives for veterans.

Patterns of handgun divestment among handgun owners in California.

BACKGROUND: Little is known about voluntary divestment of firearms among US firearm owners. Here, we aim to estimate the proportion of handgun owners who divest their handguns in the years following their initial acquisition; examine the timing, duration, and dynamics of those divestments; and describe characteristics of those who divest. METHODS: We use data from the Longitudinal Study of Handgun Ownership and Transfer, a cohort of registered voters in California with detailed information on 626,756 adults who became handgun owners during the 12-year study period, 2004-2016. For the current study, persons were followed from the time of their initial handgun acquisition until divestment, loss to follow-up, death, or the end of the study period. We describe the cumulative proportion who divest overall and by personal and area-level characteristics. We also estimate the proportion who reacquired handguns among persons who divested. RESULTS: Overall, 4.5% (95% CI 4.5-4.6) of handgun owners divested within 5 years of their first acquisition, with divestment relatively more common among women and among younger adults. Among those who divested, 36.6% (95% CI 35.8-37.5) reacquired a handgun within 5 years. CONCLUSIONS: Handgun divestment is rare, with the vast majority of new handgun owners retaining them for years.

Effectiveness of Coronavirus Disease 2019 (COVID-19) Vaccines Among Incarcerated People in California State Prisons: Retrospective Cohort Study.

BACKGROUND: Prisons and jails are high-risk settings for coronavirus disease 2019 (COVID-19). Vaccines may substantially reduce these risks, but evidence is needed on COVID-19 vaccine effectiveness for incarcerated people, who are confined in large, risky congregate settings. METHODS: We conducted a retrospective cohort study to estimate effectiveness of messenger RNA (mRNA) vaccines, BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna), against confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections among incarcerated people in California prisons from 22 December 2020 through 1 March 2021. The California Department of Corrections and Rehabilitation provided daily data for all prison residents including demographic, clinical, and carceral characteristics, as well as COVID-19 testing, vaccination, and outcomes. We estimated vaccine effectiveness using multivariable Cox models with time-varying covariates, adjusted for resident characteristics and infection rates across prisons. RESULTS: Among 60 707 cohort members, 49% received at least 1 BNT162b2 or mRNA-1273 dose during the study period. Estimated vaccine effectiveness was 74% (95% confidence interval [CI], 64%-82%) from day 14 after first dose until receipt of second dose and 97% (95% CI, 88%-99%) from day 14 after second dose. Effectiveness was similar among the subset of residents who were medically vulnerable: 74% (95% CI, 62%-82%) and 92% (95% CI, 74%-98%) from 14 days after first and second doses, respectively. CONCLUSIONS: Consistent with results from randomized trials and observational studies in other populations, mRNA vaccines were highly effective in preventing SARS-CoV-2 infections among incarcerated people. Prioritizing incarcerated people for vaccination, redoubling efforts to boost vaccination, and continuing other ongoing mitigation practices are essential in preventing COVID-19 in this disproportionately affected population.

Dependence of COVID-19 Policies on End-of-Year Holiday Contacts in Mexico City Metropolitan Area: A Modeling Study.

Background. Mexico City Metropolitan Area (MCMA) has the largest number of COVID-19 (coronavirus disease 2019) cases in Mexico and is at risk of exceeding its hospital capacity in early 2021. Methods. We used the Stanford-CIDE Coronavirus Simulation Model (SC-COSMO), a dynamic transmission model of COVID-19, to evaluate the effect of policies considering increased contacts during the end-of-year holidays, intensification of physical distancing, and school reopening on projected confirmed cases and deaths, hospital demand, and hospital capacity exceedance. Model parameters were derived from primary data, literature, and calibrated. Results. Following high levels of holiday contacts even with no in-person schooling, MCMA will have 0.9 million (95% prediction interval 0.3-1.6) additional COVID-19 cases between December 7, 2020, and March 7, 2021, and hospitalizations will peak at 26,000 (8,300-54,500) on January 25, 2021, with a 97% chance of exceeding COVID-19-specific capacity (9,667 beds). If MCMA were to control holiday contacts, the city could reopen in-person schools, provided they increase physical distancing with 0.5 million (0.2-0.9) additional cases and hospitalizations peaking at 12,000 (3,700-27,000) on January 19, 2021 (60% chance of exceedance). Conclusion. MCMA must increase COVID-19 hospital capacity under all scenarios considered. MCMA's ability to reopen schools in early 2021 depends on sustaining physical distancing and on controlling contacts during the end-of-year holiday.

Effectiveness of COVID-19 Vaccines among Incarcerated People in California State Prisons: A Retrospective Cohort Study.

BACKGROUND: Prisons and jails are high-risk settings for COVID-19 transmission, morbidity, and mortality. COVID-19 vaccines may substantially reduce these risks, but evidence is needed of their effectiveness for incarcerated people, who are confined in large, risky congregate settings. METHODS: We conducted a retrospective cohort study to estimate effectiveness of mRNA vaccines, BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna), against confirmed SARS-CoV-2 infections among incarcerated people in California prisons from December 22, 2020 through March 1, 2021. The California Department of Corrections and Rehabilitation provided daily data for all prison residents including demographic, clinical, and carceral characteristics, as well as COVID-19 testing, vaccination status, and outcomes. We estimated vaccine effectiveness using multivariable Cox models with time-varying covariates that adjusted for resident characteristics and infection rates across prisons. FINDINGS: Among 60,707 residents in the cohort, 49% received at least one BNT162b2 or mRNA-1273 dose during the study period. Estimated vaccine effectiveness was 74% (95% confidence interval [CI], 64-82%) from day 14 after first dose until receipt of second dose and 97% (95% CI, 88-99%) from day 14 after second dose. Effectiveness was similar among the subset of residents who were medically vulnerable (74% [95% CI, 62-82%] and 92% [95% CI, 74-98%] from 14 days after first and second doses, respectively), as well as among the subset of residents who received the mRNA-1273 vaccine (71% [95% CI, 58-80%] and 96% [95% CI, 67-99%]). CONCLUSIONS: Consistent with results from randomized trials and observational studies in other populations, mRNA vaccines were highly effective in preventing SARS-CoV-2 infections among incarcerated people. Prioritizing incarcerated people for vaccination, redoubling efforts to boost vaccination and continuing other ongoing mitigation practices are essential in preventing COVID-19 in this disproportionately affected population. FUNDING: Horowitz Family Foundation, National Institute on Drug Abuse, Centers for Disease Control and Prevention, National Science Foundation, Open Society Foundation, Advanced Micro Devices.

Outbreaks of COVID-19 variants in US prisons: a mathematical modelling analysis of vaccination and reopening policies.

BACKGROUND: Residents of prisons have experienced disproportionate COVID-19-related health harms. To control outbreaks, many prisons in the USA restricted in-person activities, which are now resuming even as viral variants proliferate. This study aims to use mathematical modelling to assess the risks and harms of COVID-19 outbreaks in prisons under a range of policies, including resumption of activities. METHODS: We obtained daily resident-level data for all California state prisons from Jan 1, 2020, to May 15, 2021, describing prison layouts, housing status, sociodemographic and health characteristics, participation in activities, and COVID-19 testing, infection, and vaccination status. We developed a transmission-dynamic stochastic microsimulation parameterised by the California data and published literature. After an initial infection is introduced to a prison, the model evaluates the effect of various policy scenarios on infections and hospitalisations over 200 days. Scenarios vary by vaccine coverage, baseline immunity (0%, 25%, or 50%), resumption of activities, and use of non-pharmaceutical interventions (NPIs) that reduce transmission by 75%. We simulated five prison types that differ by residential layout and demographics, and estimated outcomes with and without repeated infection introductions over the 200 days. FINDINGS: If a viral variant is introduced into a prison that has resumed pre-2020 contact levels, has moderate vaccine coverage (ranging from 36% to 76% among residents, dependent on age, with 40% coverage for staff), and has no baseline immunity, 23-74% of residents are expected to be infected over 200 days. High vaccination coverage (90%) coupled with NPIs reduces cumulative infections to 2-54%. Even in prisons with low room occupancies (ie, no more than two occupants) and low levels of cumulative infections (ie, <10%), hospitalisation risks are substantial when these prisons house medically vulnerable populations. Risks of large outbreaks (>20% of residents infected) are substantially higher if infections are repeatedly introduced. INTERPRETATION: Balancing benefits of resuming activities against risks of outbreaks presents challenging trade-offs. After achieving high vaccine coverage, prisons with mostly one-to-two-person cells that have higher baseline immunity from previous outbreaks can resume in-person activities with low risk of a widespread new outbreak, provided they maintain widespread NPIs, continue testing, and take measures to protect the medically vulnerable. FUNDING: Horowitz Family Foundation, National Institute on Drug Abuse, Centers for Disease Control and Prevention, National Science Foundation, Open Society Foundation, Advanced Micro Devices.

COVID-19 in the California State Prison System: an Observational Study of Decarceration, Ongoing Risks, and Risk Factors.

BACKGROUND: Correctional institutions nationwide are seeking to mitigate COVID-19-related risks. OBJECTIVE: To quantify changes to California's prison population since the pandemic began and identify risk factors for COVID-19 infection. DESIGN: For California state prisons (March 1-October 10, 2020), we described residents' demographic characteristics, health status, COVID-19 risk scores, room occupancy, and labor participation. We used Cox proportional hazard models to estimate the association between rates of COVID-19 infection and room occupancy and out-of-room labor, respectively. PARTICIPANTS: Residents of California state prisons. MAIN MEASURES: Changes in the incarcerated population's size, composition, housing, and activities. For the risk factor analysis, the exposure variables were room type (cells vs. dormitories) and labor participation (any room occupant participating in the prior 2 weeks) and the outcome variable was incident COVID-19 case rates. KEY RESULTS: The incarcerated population decreased 19.1% (119,401 to 96,623) during the study period. On October 10, 2020, 11.5% of residents were aged ≥60, 18.3% had high COVID-19 risk scores, 31.0% participated in out-of-room labor, and 14.8% lived in rooms with ≥10 occupants. Nearly 40% of residents with high COVID-19 risk scores lived in dormitories. In 9 prisons with major outbreaks (6,928 rooms; 21,750 residents), dormitory residents had higher infection rates than cell residents (adjusted hazard ratio [AHR], 2.51 95% CI, 2.25-2.80) and residents of rooms with labor participation had higher rates than residents of other rooms (AHR, 1.56; 95% CI, 1.39-1.74). CONCLUSION: Despite reductions in room occupancy and mixing, California prisons still house many medically vulnerable residents in risky settings. Reducing risks further requires a combination of strategies, including rehousing, decarceration, and vaccination.

Public views about COVID-19 'Immunity Passports'.

IMPORTANCE: Discovery of effective vaccines and increased confidence that infection confers extended protection against coronavirus disease (COVID-19) have renewed discussion of using immunity certificates or 'passports' to selectively reduce ongoing public health restrictions. OBJECTIVE: To determine public views regarding government and private conferral of immunity privileges. DESIGN AND SETTING: National on-line survey fielded in June 2020. Participants were randomly asked about either government 'passports' or private 'certificates' for COVID-19 immunity. PARTICIPANTS: Adults from a standing panel maintained for academic research, selected to approximate national demographics. MAIN OUTCOMES/MEASURES: Level of support/opposition to immunity privileges, and whether views vary based on: government vs. private adoption; demographics; political affiliation or views; or various COVID19-related attitudes and experiences. RESULTS: Of 1315 respondents, 45.2% supported immunity privileges, with slightly more favoring private certificates than government passports (48.1% vs 42.6%, p = 0.04). Support was greater for using passports or certificates to enable returns to high-risk jobs or attendance at large recreational events than for returning to work generally. Levels of support did not vary significantly according to age groups, socioeconomic or employment status, urbanicity, political affiliation or views, or whether the respondent had chronic disease(s). However, estimates from adjusted analyses showed less support among women (odds ratio, 0.64; 95% confidence interval, 0.51 to 0.80), and among Hispanics (0.56; 0.40 to 0.78) and other minorities (0.58; 0.40 to 0.85) compared with whites, but not among blacks (0.83; 0.60 to 1.15). Support was much higher among those who personally wanted a passport or certificate (75.6% vs 24.4%) and much lower among those who believed this would harm the social fabric of their community (22.9% vs 77.1%). CONCLUSIONS AND RELEVANCE: Public views are divided on both government or private uses of immunity certificates, but, prior to any efforts to politicize the issues, these views did not vary along usual political lines or by characteristics that indicate individual vulnerability to infection. Social consensus on the desirability of an immunity privileges programs may be difficult to achieve.