The Effect of Neonatal Sepsis on Risk of Autism Diagnosis.

OBJECTIVE: The study aimed to examine the association between neonatal sepsis and autism risk among children and whether the risk varied with the timing of exposure, child's sex, and race/ethnicity. STUDY DESIGN: We conducted a retrospective cohort study using electronic health records (EHR) extracted from Kaiser Permanente Southern California Health Care System. Mother-child dyads were constructed by linking records of children born to member mothers and continuing to receive care through the system during the follow-up period with those of their biological mothers (n = 469,789). Clinical health records were used to define neonatal sepsis. Diagnosis of autism was made by medical specialists. Potential confounders included maternal sociodemographic factors, obstetrical history, child's age, sex, race/ethnicity, and maternal and child medical history. Incident rates and adjusted hazard ratios (aHR) were used to estimate the associations. RESULTS: Compared with children without the diagnosis of autism, children with the condition were more likely to be from Asian/Pacific Islander descent and male sex. Exposed children showed higher rates of autism as compared with unexposed children (3.43 vs. 1.73 per 1,000 person-years, aHR: 1.67-95% confidence interval [CI]: 1.39-2.00). Both preterm (aHR: 1.47; 95% CI: 1.09-1.98) and term (aHR: 1.63; 95% CI: 1.29-2.06) births were associated with increased risk for autism. Although the magnitude of the HRs and incidence ratios for neonatal sepsis to increase autism risk varied between race ethnicities, neonatal sepsis was associated with significantly increased likelihood of autism diagnosis for all race-ethic groups except for Asian/Pacific Islanders. Although neonatal sepsis was associated with significantly increased autism risk for both boys and girls, incident rates and HR point estimates suggested that the effect may be stronger in girls. CONCLUSION: Neonatal sepsis is associated with increased risk of autism diagnosis in preterm- and term-born children. The association was significant for both girls and boys and all race ethnicities except for Asian-Pacific Islanders. KEY POINTS: · Neonatal sepsis is associated with increased risk of autism diagnosis.. · The association was significant in preterm- and term-born children.. · The association was significant for all race/ethnicities except for Asian-Pacific Islanders..

Association between menorrhagia and risk of intrauterine device-related uterine perforation and device expulsion: results from the Association of Uterine Perforation and Expulsion of Intrauterine Device study.

BACKGROUND: Intrauterine devices are effective instruments for contraception, and 1 levonorgestrel-releasing device is also indicated for the treatment of heavy menstrual bleeding (menorrhagia). OBJECTIVE: To compare the incidence of intrauterine device expulsion and uterine perforation in women with and without a diagnosis of menorrhagia within the first 12 months before device insertion STUDY DESIGN: This was a retrospective cohort study conducted in 3 integrated healthcare systems (Kaiser Permanente Northern California, Southern California, and Washington) and a healthcare information exchange (Regenstrief Institute) in the United States using electronic health records. Nonpostpartum women aged ≤50 years with intrauterine device (eg, levonorgestrel or copper) insertions from 2001 to 2018 and without a delivery in the previous 12 months were studied in this analysis. Recent menorrhagia diagnosis (ie, recorded ≤12 months before insertion) was ascertained from the International Classification of Diseases, Ninth and Tenth Revision, Clinical Modification codes. The study outcomes, viz, device expulsion and device-related uterine perforation (complete or partial), were ascertained from electronic medical records and validated in the data sources. The cumulative incidence and crude incidence rates with 95% confidence intervals were estimated. Cox proportional hazards models estimated the crude and adjusted hazard ratios using propensity score overlap weighting (13-16 variables) and 95% confidence intervals. RESULTS: Among 228,834 nonpostpartum women, the mean age was 33.1 years, 44.4% of them were White, and 31,600 (13.8%) had a recent menorrhagia diagnosis. Most women had a levonorgestrel-releasing device (96.4% of those with and 78.2% of those without a menorrhagia diagnosis). Women with a menorrhagia diagnosis were likely to be older, obese, and have dysmenorrhea or fibroids. Women with a menorrhagia diagnosis had a higher intrauterine device-expulsion rate (40.01 vs 10.92 per 1000 person-years) than those without, especially evident in the first few months after insertion. Women with a menorrhagia diagnosis had a higher cumulative incidence (95% confidence interval) of expulsion (7.00% [6.70-7.32] at 1 year and 12.03% [11.52-12.55] at 5 years) vs those without (1.77% [1.70-1.84] at 1 year and 3.69% [3.56-3.83] at 5 years). The risk of expulsion was increased for women with a menorrhagia diagnosis vs for those without (adjusted hazard ratio, 2.84 [95% confidence interval, 2.66-3.03]). The perforation rate was low overall (<1/1000 person-years) but higher in women with a diagnosis of menorrhagia vs in those without (0.98 vs 0.63 per 1000 person-years). The cumulative incidence (95% confidence interval) of uterine perforation was slightly higher for women with a menorrhagia diagnosis (0.09% [0.06-0.14] at 1 year and 0.39% [0.29-0.53] at 5 years) than those without it (0.07% [0.06-0.08] at 1 year and 0.28% [0.24-0.33] at 5 years). The risk of perforation was slightly increased in women with a menorrhagia diagnosis vs in those without (adjusted hazard ratio, 1.53; 95% confidence interval, 1.10-2.13). CONCLUSION: The risk of expulsion is significantly higher in women with a recent diagnosis of menorrhagia. Patient education and counseling regarding the potential expulsion risk is recommended at insertion. The absolute risk of perforation for women with a recent diagnosis of menorrhagia is very low. The increased expulsion and perforation rates observed are likely because of causal factors of menorrhagia.

Association between intrauterine device type and risk of perforation and device expulsion: results from the Association of Perforation and Expulsion of Intrauterine Device study.

BACKGROUND: Intrauterine devices, including levonorgestrel-releasing and copper devices, are highly effective long-acting reversible contraceptives. The potential risks associated with intrauterine devices are low and include uterine perforation and device expulsion. OBJECTIVE: This study aimed to evaluate the risk of perforation and expulsion associated with levonorgestrel-releasing devices vs copper devices in clinical practice in the United States. STUDY DESIGN: The Association of Perforation and Expulsion of Intrauterine Device study was a retrospective cohort study of women aged ≤50 years with an intrauterine device insertion during 2001 to 2018 and information on intrauterine device type and patient and medical characteristics. Of note, 4 research sites with access to electronic health records contributed data for the study: 3 Kaiser Permanente-integrated healthcare systems (Northern California, Southern California, and Washington) and 1 healthcare system using data from a healthcare information exchange in Indiana (Regenstrief Institute). Perforation was classified as any extension of the device into or through the myometrium. Expulsion was classified as complete (not visible in the uterus or abdomen or patient reported) or partial (any portion in the cervix or malpositioned). We estimated the crude incidence rates and crude cumulative incidence by intrauterine device type. The risks of perforation and expulsion associated with levonorgestrel-releasing intrauterine devices vs copper intrauterine devices were estimated using Cox proportional-hazards regression with propensity score overlap weighting to adjust for confounders. RESULTS: Among 322,898 women included in this analysis, the incidence rates of perforation per 1000 person-years were 1.64 (95% confidence interval, 1.53-1.76) for levonorgestrel-releasing intrauterine devices and 1.27 (95% confidence interval, 1.08-1.48) for copper intrauterine devices; 1-year and 5-year crude cumulative incidence was 0.22% (95% confidence interval, 0.20-0.24) and 0.63% (95% confidence interval, 0.57-0.68) for levonorgestrel-releasing intrauterine devices and 0.16% (95% confidence interval, 0.13-0.20) and 0.55% (95% confidence interval, 0.44-0.68) for copper intrauterine devices, respectively. The incidence rates of expulsion per 1000 person-years were 13.95 (95% confidence interval, 13.63-14.28) for levonorgestrel-releasing intrauterine devices and 14.08 (95% confidence interval, 13.44-14.75) for copper intrauterine devices; 1-year and 5-year crude cumulative incidence was 2.30% (95% confidence interval, 2.24-2.36) and 4.52% (95% confidence interval, 4.40-4.65) for levonorgestrel-releasing intrauterine devices and 2.30% (95% confidence interval, 2.18-2.44) and 4.82 (95% confidence interval, 4.56-5.10) for copper intrauterine devices, respectively. Comparing levonorgestrel-releasing intrauterine devices with copper intrauterine devices, the adjusted hazard ratios were 1.49 (95% confidence intervals, 1.25-1.78) for perforation and 0.69 (95% confidence intervals, 0.65-0.73) for expulsion. CONCLUSION: After adjusting for potential confounders, levonorgestrel-releasing intrauterine devices were associated with an increased risk of uterine perforation and a decreased risk of expulsion relative to copper intrauterine devices. Given that the absolute numbers of these events are low in both groups, these differences may not be clinically meaningful.

Do Inpatient Antimicrobial Stewardship Programs Help Us in the Battle Against Antimicrobial Resistance?

BACKGROUND: Antibiotic stewardship programs (ASPs) have demonstrated success at reducing costs, yet there is limited quality evidence of their effectiveness in reducing infections of high-profile drug-resistant organisms. METHODS: This retrospective, cohort study included all Kaiser Permanente Southern California (KPSC) members aged ≥18 years hospitalized in 9 KPSC hospitals from 1 January 2008 to 31 December 2016. We measured the impact of staggered ASP implementation on consumption of 18 ASP-targeted antibiotics using generalized linear mixed-effects models. We used multivariable generalized linear mixed-effects models to estimate the adjusted effect of an ASP on rates of infection with drug-resistant organisms. Analyses were adjusted for confounding by time, cluster effects, and patient- and hospital-level characteristics. RESULTS: We included 765 111 hospitalizations (288 257 pre-ASP, 476 854 post-ASP). By defined daily dose, we found a 6.1% (-7.5% to -4.7%) overall decrease antibiotic use post-ASP; by days of therapy, we detected a 4.3% (-5.4% to -3.1%) decrease in overall use of antibiotics. The number of prescriptions increased post-ASP (1.04 [1.03-1.05]). In adjusted analyses, we detected an overall increase in vancomycin-resistant enterococci infections post-ASP (1.37 [1.10-1.69]). We did not detect a change in the rates of extended-spectrum beta-lactamase, carbapenem-resistant Enterobacteriaceae, and multidrug-resistant Pseudomonas aeruginosa infections post-ASP. CONCLUSIONS: ASPs with successful reductions in consumption of targeted antibiotics may not see changes in infection rates with antibiotic-resistant organisms in the 2 to 6 years post-implementation. There are likely differing timescales for reversion to susceptibility across organisms and antibiotics, and unintended consequences from compensatory prescribing may occur.

Design of the Association of Uterine Perforation and Expulsion of Intrauterine Device study: a multisite retrospective cohort study.

BACKGROUND: Intrauterine devices are effective and safe, long-acting reversible contraceptives, but the risk of uterine perforation occurs with an estimated incidence of 1 to 2 per 1000 insertions. The European Active Surveillance Study for Intrauterine Devices, a European prospective observational study that enrolled 61,448 participants (2006-2012), found that women breastfeeding at the time of device insertion or with the device inserted at ≤36 weeks after delivery had a higher risk of uterine perforation. The Association of Uterine Perforation and Expulsion of Intrauterine Device (APEX-IUD) study was a Food and Drug Administration-mandated study designed to reflect current United States clinical practice. The aims of the APEX-IUD study were to evaluate the risk of intrauterine device-related uterine perforation and device expulsion among women who were breastfeeding or within 12 months after delivery at insertion. OBJECTIVE: We aimed to describe the APEX-IUD study design, methodology, and analytical plan and present population characteristics, size of risk factor groups, and duration of follow-up. STUDY DESIGN: APEX-IUD study was a retrospective cohort study conducted in 4 organizations with access to electronic health records: Kaiser Permanente Northern California, Kaiser Permanente Southern California, Kaiser Permanente Washington, and Regenstrief Institute in Indiana. Variables were identified through structured data (eg, diagnostic, procedural, medication codes) and unstructured data (eg, clinical notes) via natural language processing. Outcomes include uterine perforation and device expulsion; potential risk factors were breastfeeding at insertion, postpartum timing of insertion, device type, and menorrhagia diagnosis in the year before insertion. Covariates include demographic characteristics, clinical characteristics, and procedure-related variables, such as difficult insertion. The first potential date of inclusion for eligible women varies by research site (from January 1, 2001 to January 1, 2010). Follow-up begins at insertion and ends at first occurrence of an outcome of interest, a censoring event (device removal or reinsertion, pregnancy, hysterectomy, sterilization, device expiration, death, disenrollment, last clinical encounter), or end of the study period (June 30, 2018). Comparisons of levels of exposure variables were made using Cox regression models with confounding adjusted by propensity score weighting using overlap weights. RESULTS: The study population includes 326,658 women with at least 1 device insertion during the study period (Kaiser Permanente Northern California, 161,442; Kaiser Permanente Southern California, 123,214; Kaiser Permanente Washington, 20,526; Regenstrief Institute, 21,476). The median duration of continuous enrollment was 90 (site medians 74-177) months. The mean age was 32 years, and the population was racially and ethnically diverse across the 4 sites. The mean body mass index was 28.5 kg/m2, and of the women included in the study, 10.0% had menorrhagia ≤12 months before insertion, 5.3% had uterine fibroids, and 10% were recent smokers; furthermore, among these women, 79.4% had levonorgestrel-releasing devices, and 19.5% had copper devices. Across sites, 97,824 women had an intrauterine device insertion at ≤52 weeks after delivery, of which 94,817 women (97%) had breastfeeding status at insertion determined; in addition, 228,834 women had intrauterine device insertion at >52 weeks after delivery or no evidence of a delivery in their health record. CONCLUSION: Combining retrospective data from multiple sites allowed for a large and diverse study population. Collaboration with clinicians in the study design and validation of outcomes ensured that the APEX-IUD study results reflect current United States clinical practice. Results from this study will provide valuable information based on real-world evidence about risk factors for intrauterine devices perforation and expulsion for clinicians.

Distribution of SARS-CoV-2 Variants in a Large Integrated Health Care System - California, March-July 2021.

Data from observational studies demonstrate that variants of SARS-CoV-2, the virus that causes COVID-19, have evolved rapidly across many countries (1,2). The SARS-CoV-2 B.1.617.2 (Delta) variant of concern is more transmissible than previously identified variants,* and as of September 2021, is the predominant variant in the United States.† Studies characterizing the distribution and severity of illness caused by SARS-CoV-2 variants, particularly the Delta variant, are limited in the United States (3), and are subject to limitations related to study setting, specimen collection, study population, or study period (4-7). This study used whole genome sequencing (WGS) data on SARS-CoV-2-positive specimens collected across Kaiser Permanente Southern California (KPSC), a large integrated health care system, to describe the distribution and risk of hospitalization associated with SARS-CoV-2 variants during March 4-July 21, 2021, by patient vaccination status. Among 13,039 SARS-CoV-2-positive specimens identified from KPSC patients during this period, 6,798 (52%) were sequenced and included in this report. Of these, 5,994 (88%) were collected from unvaccinated persons, 648 (10%) from fully vaccinated persons, and 156 (2%) from partially vaccinated persons. Among all sequenced specimens, the weekly percentage of B.1.1.7 (Alpha) variant infections increased from 20% to 67% during March 4-May 19, 2021. During April 15-July 21, 2021, the weekly percentage of Delta variant infections increased from 0% to 95%. During March 4-July 21, 2021, the weekly percentage of variants was similar among fully vaccinated and unvaccinated persons, but the Delta variant was more commonly identified among vaccinated persons then unvaccinated persons overall, relative to other variants. The Delta variant was more prevalent among younger persons, with the highest percentage (55%) identified among persons aged 18-44 years. Infections attributed to the Delta variant were also more commonly identified among non-Hispanic Black persons, relative to other variants. These findings reinforce the importance of continued monitoring of SARS-CoV-2 variants and implementing multiple COVID-19 prevention strategies, particularly during the current period in which Delta is the predominant variant circulating in the United States.

Women with high plasma levels of PBDE-47 are at increased risk of preterm birth.

OBJECTIVES: Nearly 100% of North American women have detectable levels of flame retardants such as polybrominated diphenyl ethers (PBDEs) in their plasma. These molecules have structural homology to thyroid hormones and may function as endocrine disruptors. Thyroid dysfunction has previously been associated with increased risk for preterm birth. Therefore, we conducted a multi-center, case-cohort study to evaluate if high plasma concentrations of a common PBDE congener in the first trimester increases the risk of preterm birth and its subtypes. METHODS: Pregnant women were recruited at the onset of initiation of prenatal care at Kaiser-Permanente Southern California (KPSC)-West Los Angeles and KPSC-San Diego medical centers. Plasma samples from women whose pregnancies ended preterm and random subset of those delivering at term were assayed for PBDE-47 and thyroid-stimulating hormone (TSH) by immunoassay. Quartile cutoffs were calculated for the patients at term and used to determine if women with exposures in the 4th quartile are at increased risk for preterm birth using logistic regression. RESULTS: We found that high concentrations of PBDE-47 in the first trimester significantly increased the odds of both indicated (adjusted odds ratio, adjOR=2.35, 95% confidence interval [CI]: 1.31, 4.21) and spontaneous (adjOR=1.76, 95% CI: 1.02, 3.03) preterm birth. Regardless of pregnancy outcome, TSH concentrations did not differ between women with high and low concentrations of PBDE-47. CONCLUSIONS: These results suggest that high plasma concentrations of PBDE-47 in the first trimester, increases the risk of indicated and spontaneous preterm birth.

Autism Spectrum Disorders in Children Exposed in Utero to Hyperemesis Gravidarum.

OBJECTIVE: This study aimed to determine if hyperemesis gravidarum (HG) is associated with autism spectrum disorder (ASD) risk, and how this association is influenced by race, ethnicity, sex, exposure timing, and medication used to treat it. STUDY DESIGN: This is a retrospective cohort study using records from 469,789 mother-child pairs who delivered at Kaiser Permanente Southern California (KPSC) hospital (1991-2014). Singleton-born children were followed longitudinally from 2 to 17 years of age. Clinical records were used to determine the diagnosis of HG and specialist-confirmed diagnosis of ASD. RESULTS: Children exposed to HG in-utero had higher rates of ASD than unexposed children (2.87 vs. 1.71/1,000 person-years; adjusted hazard ratio [adj.HR]: 1.53; 95% confidence interval [CI]: 1.37-1.70). Children exposed at first and second trimester of pregnancies were more likely to develop ASD; 1.58-fold (95% CI: 1.40-1.79), and 1.36-fold (95% CI: 1.05-1.75), respectively, compared with unexposed children. HG was associated with ASD for boys (adj.HR: 1.50; 95% CI: 1.33-1.70) and girls (adj.HR: 1.62; 95% CI: 1.28-2.05). HG was significantly associated with ASD risk in white and Hispanic children. The medications used to treat HG did not contribute to ASD risk. CONCLUSION: HG diagnosis is associated with ASD risk and may be helpful in identifying at-risk children who could benefit from enhanced surveillance and earlier diagnosis and intervention.

Validation of pediatric diabetes case identification approaches for diagnosed cases by using information in the electronic health records of a large integrated managed health care organization.

We explored the utility of different algorithms for diabetes case identification by using electronic health records. Inpatient and outpatient diagnosis codes, as well as data on laboratory results and dispensing of antidiabetic medications were extracted from electronic health records of Kaiser Permanente Southern California members who were less than 20 years of age in 2009. Diabetes cases were ascertained by using the SEARCH for Diabetes in Youth Study protocol and comprised the "gold standard." Sensitivity, specificity, positive and negative predictive values, accuracy, and the area under the receiver operating characteristic curve (AUC) were compared in 1,000 bootstrapped samples. Based on data from 792,992 youth, of whom 1,568 had diabetes (77.2%, type 1 diabetes; 22.2%, type 2 diabetes; 0.6%, other), case identification accuracy was highest in 75% of bootstrapped samples for those who had 1 or more outpatient diabetes diagnoses or 1 or more insulin prescriptions (sensitivity, 95.9%; positive predictive value, 95.5%; AUC, 97.9%) and in 25% of samples for those who had 2 or more outpatient diabetes diagnoses and 1 or more antidiabetic medications (sensitivity, 92.4%; positive predictive value, 98.4%; AUC, 96.2%). Having 1 or more outpatient type 1 diabetes diagnoses (International Classification of Diseases, Ninth Revision, Clinical Modification, code 250.x1 or 250.x3) had the highest accuracy (94.4%) and AUC (94.1%) for type 1 diabetes; the absence of type 1 diabetes diagnosis had the highest accuracy (93.8%) and AUC (93.6%) for identifying type 2 diabetes. Information in the electronic health records from managed health care organizations provides an efficient and cost-effective source of data for childhood diabetes surveillance.

Real-world assessment of anaphylaxis and eosinophilic esophagitis with 12 SQ house dust mite SLIT-tablet sublingual immunotherapy.

Background: Sublingual immunotherapy (SLIT) with 12 SQ house dust mile SLIT-tablet (HDM SLIT-tablet) for dust mite-induced perennial allergic rhinitis is reported as effective and safe. Although serious allergic reactions (SARs) and eosinophilic esophagitis (EoE) have infrequently occurred under trial conditions, the safety of HDM SLIT-tablet challenge under real-world conditions is unknown. Objective: Our aim was to estimate the incidence of SARs and EoE due to HDM SLIT-tablet challenge. Methods: Through use of administrative data from Kaiser Permanente Southern California, this prospective observational study identified patients newly administered HDM SLIT-tablet with follow-up until SLIT discontinuation or end of study. Suspected cases of SARs and EoE were detected by using International Classification of Diseases, 10th Revision, diagnosis and Current Procedural Terminology procedure codes and medication dispensing records. A 3-member clinical review committee of allergists adjudicated suspected reactions. The incidence rate of confirmed SARs and EoE per 1000 person years of exposure were determined. Results: A total of 521 patients (93.9% adult and 6.1% pediatric) were exposed to HDM SLIT-tablet challenge from January 2018 through May 2023, for 440.4 person years of exposure. The patients' average age (SD) was 39.3 (14.1) years, 58.7% were female, 44.3% were non-Hispanic White, 40.3% had asthma, and 15.0% had gastroesophageal reflux disease. A SAR occurred in 1 adult patient, and during initial HDM SLIT-tablet challenge, SARs occurred in 2 pediatric adolescents, for an overall incidence of 6.8 SARs per 1000 patient years (95% CI = 2.2-21.1). EoE occurred in 1 adult patient, for an overall incidence of 2.3 cases of EoE per 1000 patient years (95% CI = 0.3-16.1). Conclusions: This real-world study demonstrated that SARs and EoE were infrequent events with HDM SLIT-tablet use, supporting the safety of HDM SLIT-tablets and need for physician supervision with initial challenge.

Real-world effectiveness of recombinant zoster vaccine in self-identified Chinese individuals aged ≥50 years in the United States.

We evaluated the vaccine effectiveness (VE) of two doses of recombinant zoster vaccine (RZV) against herpes zoster (HZ) and postherpetic neuralgia (PHN) in Chinese adults at Kaiser Permanente Southern California (KPSC). Chinese KPSC members were identified based on self-reported ethnicity or self-reported preferred spoken/written language. Those aged ≥50 years who received two doses of RZV 4 weeks to ≤ 6 months apart were matched 1:4 to RZV unvaccinated Chinese members and followed through June 2022; second doses were accrued 6/1/2018-12/31/2020. We estimated incidence and adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs) comparing outcomes (HZ and PHN). Adjusted VE (%) was calculated as (1-aHR)×100. 3978 RZV vaccinated Chinese members were matched to 15,912 RZV unvaccinated Chinese members. The incidence per 1000 person-years (95% CI) of HZ in the vaccinated group was 1.5 (0.9-2.5) and 10.9 (9.8-12.1) in the unvaccinated group; aHR (95% CI) was 0.12 (0.07-0.21). Adjusted VE (95% CI) was 87.6% (78.9-92.7) against HZ. We identified 0 PHN cases in the vaccinated group and 19 in the unvaccinated group. Among Chinese adults aged ≥50 years, two doses of RZV provided substantial protection against HZ and PHN supporting the real-world effectiveness of the vaccine in this population.

Predictors of nirmatrelvir-ritonavir receipt among COVID-19 patients in a large US health system.

A clear understanding of real-world uptake of nirmatrelvir-ritonavir for treatment of SARS-CoV-2 can inform treatment allocation strategies and improve interpretation of effectiveness studies. We used data from a large US healthcare system to describe nirmatrelvir-ritonavir dispenses among all SARS-CoV-2 positive patients aged ≥ 12 years meeting recommended National Institutes of Health treatment eligibility criteria for the study period between 1 January and 31 December, 2022. Overall, 10.9% (N = 34,791/319,900) of treatment eligible patients with SARS-CoV-2 infections received nirmatrelvir-ritonavir over the study period. Although uptake of nirmatrelvir-ritonavir increased over time, by the end of 2022, less than a quarter of treatment eligible patients with SARS-CoV-2 infections had received nirmatrelvir-ritonavir. Across patient demographics, treatment was generally consistent with tiered treatment guidelines, with dispenses concentrated among patients aged ≥ 65 years (14,706/63,921; 23.0%), and with multiple comorbidities (10,989/54,431; 20.1%). However, neighborhoods of lower socioeconomic status (upper third of neighborhood deprivation index [NDI]) had between 12% (95% CI: 7-18%) and 28% (25-32%) lower odds of treatment dispense over the time periods studied compared to the lower third of NDI distribution, even after accounting for demographic and clinical characteristics. A limited chart review (N = 40) confirmed that in some cases a decision not to treat was appropriate and aligned with national guidelines to use clinical judgement on a case-by-case basis. There is a need to enhance patient and provider awareness on the availability and benefits of nirmatrelvir-ritonavir for the treatment of COVID-19 illness.

Effectiveness and durability of mRNA-1273 BA.4/BA.5 bivalent vaccine (mRNA-1273.222) against SARS-CoV-2 BA.4/BA.5 and XBB sublineages.

Emerging SARS-CoV-2 sublineages continue to cause serious COVID-19 disease, but most individuals have not received any COVID-19 vaccine for >1 year. Assessment of long-term effectiveness of bivalent COVID-19 vaccines against circulating sublineages is important to inform the potential need for vaccination with updated vaccines. In this test-negative study at Kaiser Permanente Southern California, sequencing-confirmed BA.4/BA.5- or XBB-related SARS-CoV-2-positive cases (September 1, 2022 to June 30, 2023), were matched 1:3 to SARS-CoV-2-negative controls. We assessed mRNA-1273 bivalent relative (rVE) and absolute vaccine effectiveness (VE) compared to ≥2 or 0 doses of original monovalent vaccine, respectively. The rVE analysis included 20,966 cases and 62,898 controls. rVE (95%CI) against BA.4/BA.5 at 14-60 days and 121-180 days was 52.7% (46.9-57.8%) and 35.5% (-2.8-59.5%) for infection, and 59.3% (49.7-67.0%) and 33.2% (-28.2-68.0%) for Emergency Department/Urgent Care (ED/UC) encounters. For BA.4/BA.5-related hospitalizations, rVE was 71.3% (44.9-85.1%) and 52.0% (-1.2-77.3%) at 14-60 days and 61-120 days, respectively. rVE against XBB at 14-60 days and 121-180 days was 48.8% (33.4-60.7%) and -3.9% (-18.1-11.3%) for infection, 70.7% (52.4-82.0%) and 15.7% (-6.0-33.2%) for ED/UC encounters, and 87.9% (43.8-97.4%) and 57.1% (17.0-77.8%) for hospitalization. VE and subgroup analyses (age, immunocompromised status, previous SARS-CoV-2 infection) results were similar to rVE analyses. rVE of mRNA-1273 bivalent vaccine against BA.4/BA.5 and XBB infections, ED/UC encounters, and hospitalizations waned over time. Periodic revaccination with vaccines targeting emerging variants may be important in reducing COVID-19 morbidity and mortality.

Increased vaccine sensitivity of an emerging SARS-CoV-2 variant.

Host immune responses are a key source of selective pressure driving pathogen evolution. Emergence of many SARS-CoV-2 lineages has been associated with enhancements in their ability to evade population immunity resulting from both vaccination and infection. Here we show diverging trends of escape from vaccine-derived and infection-derived immunity for the emerging XBB/XBB.1.5 Omicron lineage. Among 31,739 patients tested in ambulatory settings in Southern California from December, 2022 to February, 2023, adjusted odds of prior receipt of 2, 3, 4, and ≥5 COVID-19 vaccine doses were 10% (95% confidence interval: 1-18%), 11% (3-19%), 13% (3-21%), and 25% (15-34%) lower, respectively, among cases infected with XBB/XBB.1.5 than among cases infected with other co-circulating lineages. Similarly, prior vaccination was associated with greater point estimates of protection against progression to hospitalization among cases with XBB/XBB.1.5 than among non-XBB/XBB.1.5 cases (70% [30-87%] and 48% [7-71%], respectively, for recipients of ≥4 doses). In contrast, cases infected with XBB/XBB.1.5 had 17% (11-24%) and 40% (19-65%) higher adjusted odds of having experienced 1 and ≥2 prior documented infections, respectively, including with pre-Omicron variants. As immunity acquired from SARS-CoV-2 infection becomes increasingly widespread, fitness costs associated with enhanced vaccine sensitivity in XBB/XBB.1.5 may be offset by increased ability to evade infection-derived host responses.

Association of SARS-CoV-2 BA.4/BA.5 Omicron lineages with immune escape and clinical outcome.

Expansion of the SARS-CoV-2 BA.4 and BA.5 Omicron subvariants in populations with prevalent immunity from prior infection and vaccination, and associated burden of severe COVID-19, has raised concerns about epidemiologic characteristics of these lineages including their association with immune escape or severe clinical outcomes. Here we show that BA.4/BA.5 cases in a large US healthcare system had at least 55% (95% confidence interval: 43-69%) higher adjusted odds of prior documented infection than time-matched BA.2 cases, as well as 15% (9-21%) and 38% (27-49%) higher adjusted odds of having received 3 and ≥4 COVID-19 vaccine doses, respectively. However, after adjusting for differences in epidemiologic characteristics among cases with each lineage, BA.4/BA.5 infection was not associated with differential risk of emergency department presentation, hospital admission, or intensive care unit admission following an initial outpatient diagnosis. This finding held in sensitivity analyses correcting for potential exposure misclassification resulting from unascertained prior infections. Our results demonstrate that the reduced severity associated with prior (BA.1 and BA.2) Omicron lineages, relative to the Delta variant, has persisted with BA.4/BA.5, despite the association of BA.4/BA.5 with increased risk of breakthrough infection among previously vaccinated or infected individuals.

BNT162b2 Against COVID-19-Associated Emergency Department and Urgent Care Visits Among Children 5-11 Years of Age: A Test Negative Design.

In a 1:1 matched test-negative design among 5- to 11-year-olds in the Kaiser Permanente Southern California health system (n = 3984), BNT162b2 effectiveness against the omicron-related emergency department or urgent care encounters was 60% [95%CI: 47-69] <3 months post-dose-two and 28% [8-43] after ≥3 months. A booster improved protection to 77% [53-88].

Effectiveness of nirmatrelvir-ritonavir against hospital admission or death: a cohort study in a large US healthcare system.

BACKGROUND: In the United States, oral nirmatrelvir-ritonavir (PaxlovidTM) is authorized for use among patients aged 12+ years with mild-to-moderate SARS-CoV-2 infection who are at risk for progression to severe COVID-19, including hospitalization. However, effectiveness under current real-world prescribing practices in outpatient settings is unclear. METHODS: We undertook a matched observational cohort study of non-hospitalized cases with SARS-CoV-2 infection to compare outcomes among those who received or did not receive nirmatrelvir-ritonavir within the Kaiser Permanente Southern California healthcare system. Cases were matched on testing date, age, sex, clinical status (including care received, presence or absence of acute COVID-19 symptoms at testing, and time from symptom onset to testing), history of vaccination, Charlson comorbidity index, prior-year healthcare utilization, and body mass index. Primary analyses evaluated effectiveness of nirmatrelvir-ritonavir in preventing hospital admission or death within 30 days after a positive test. Secondary analyses evaluated effectiveness against intensive care unit admission, mechanical ventilation, or death within 60 days after a positive test. We measured treatment effectiveness as (1-adjusted hazards ratio [aHR])*100%, estimating the aHR via Cox proportional hazards models. RESULTS: Analyses included 7,274 nirmatrelvir-ritonavir recipients and 126,152 non-recipients with positive results from SARS-CoV-2 tests undertaken in outpatient settings between 8 April and 7 October, 2022. Overall, 114,208 (85.6%) and 81,739 (61.3%) of 133,426 participants had received 2+ and 3+ COVID-19 vaccine doses, respectively. A total of 111,489 (83.6% of 133,426) cases were symptomatic at the point of testing, with 5,472 (75.2% of 7,274) treatment recipients and 84,657 (67.1% of 126,152) non-recipients testing within 0-5 days after symptom onset. Effectiveness in preventing hospital admission or death within 30 days after a positive test was 79.6% (95% confidence interval: 33.9% to 93.8%) for cases dispensed nirmatrelvir-ritonavir within 0-5 days after symptom onset; within the subgroup of cases tested 0-5 days after symptom onset and dispensed treatment on the day of their test, effectiveness was 89.6% (50.2% to 97.8%). Effectiveness declined to 43.8% (-33.3% to 81.7%) for treatment course dispensed 6+ days after symptom onset or to cases who were not experiencing acute clinical symptoms. Overall, for cases dispensed treatment at any time within their clinical course, effectiveness was 53.6% (6.6% to 77.0%). Effectiveness in preventing the secondary endpoint of intensive care unit admission, mechanical ventilation, or death within 60 days after a positive test was 89.2% (-25.0% to 99.3%) for cases dispensed treatment 0-5 days after symptom onset and 84.1% (18.8% to 96.9%) for cases dispensed treatment at any time. Subgroup analyses identified similar effectiveness estimates among cases who had received 2+ or 3+ COVID-19 vaccine doses. IMPLICATIONS: In a setting with high levels of COVID-19 vaccine and booster uptake, receipt of nirmatrelvir-ritonavir 0-5 days after symptom onset was associated with substantial reductions in risk of hospital admission or death within 30 days after a positive outpatient SARS-CoV-2 test.

Effectiveness of nirmatrelvir-ritonavir in preventing hospital admissions and deaths in people with COVID-19: a cohort study in a large US health-care system.

BACKGROUND: In the USA, oral nirmatrelvir-ritonavir is authorised for use in patients aged 12 years or older with mild-to-moderate COVID-19 who are at risk of progression to severe disease and hospitalisation. We aimed to establish the effectiveness of nirmatrelvir-ritonavir in preventing hospital admissions and death in people with COVID-19 in an outpatient prescribing context in the USA. METHODS: In this matched observational outpatient cohort study in the Kaiser Permanente Southern California (CA, USA) health-care system, data were extracted from electronic health records of non-hospitalised patients aged 12 years or older who received a positive SARS-CoV-2 PCR test result (their index test) between April 8 and Oct 7, 2022, and had not received another positive test result within the preceding 90 days. We compared outcomes between people who received nirmatrelvir-ritonavir and those who did not receive nirmatrelvir-ritonavir by matching cases by date, age, sex, clinical status (including care received, the presence or absence of acute COVID-19 symptoms at testing, and time from symptom onset to testing), vaccination history, comorbidities, health-care seeking during the previous year, and BMI. Our primary endpoint was the estimated effectiveness of nirmatrelvir-ritonavir in preventing hospital admissions or death within 30 days of a positive test for SARS-CoV-2. FINDINGS: 7274 nirmatrelvir-ritonavir recipients and 126 152 non-recipients with positive SARS-CoV-2 tests were included in our study. 5472 (75·2%) treatment recipients and 84 657 (67·1%) non-recipients were tested within 5 days of symptom onset. Nirmatrelvir-ritonavir had an overall estimated effectiveness of 53·6% (95% CI 6·6-77·0) in preventing hospital admission or death within 30 days of a positive test for SARS-CoV-2, which increased to 79·6% (33·9-93·8) when nirmatrelvir-ritonavir was dispensed within 5 days of symptom onset. Within the subgroup of patients tested within 5 days of symptom onset and whose treatment was dispensed on the day of their test, the estimated effectiveness of nirmatrelvir-ritonavir was 89·6% (50·2-97·8). INTERPRETATION: In a setting with high levels of COVID-19 vaccine uptake, nirmatrelvir-ritonavir effectively reduced the risk of hospital admission or death within 30 days of a positive outpatient SARS-CoV-2 test. FUNDING: US Centers for Disease Control and Prevention and US National Institutes of Health.

Analysis of mRNA COVID-19 Vaccine Uptake Among Immunocompromised Individuals in a Large US Health System.

Importance: Immunocompromised individuals are at increased risk for severe outcomes due to SARS-CoV-2 infection. Given the varying and complex nature of COVID-19 vaccination recommendations, it is important to understand COVID-19 vaccine uptake in this vulnerable population. Objective: To assess mRNA COVID-19 vaccine uptake and factors associated with uptake among immunocompromised individuals from December 14, 2020, through August 6, 2022. Design, Setting, and Participants: This cohort study was conducted with patients of Kaiser Permanente Southern California (KPSC), an integrated health care system in the US. The study included patients aged 18 years or older who were immunocompromised (individuals with an immunocompromising condition or patients who received immunosuppressive medications in the year prior to December 14, 2020) and still met criteria for being immunocompromised 1 year later. Exposures: Age, sex, self-identified race and ethnicity, prior positive COVID-19 test result, immunocompromising condition, immunomodulating medication, comorbidities, health care utilization, and neighborhood median income. Main Outcomes and Measures: Outcomes were the number of doses of mRNA COVID-19 vaccine received and the factors associated with receipt of at least 4 doses, estimated by hazard ratios (HRs) and 95% Wald CIs via Cox proportional hazards regression. Statistical analyses were conducted between August 9 and 23, 2022. Results: Overall, 42 697 immunocompromised individuals met the study eligibility criteria. Among these, 18 789 (44.0%) were aged 65 years or older; 20 061 (47.0%) were women and 22 635 (53.0%) were men. With regard to race and ethnicity, 4295 participants (10.1%) identified as Asian or Pacific Islander, 5174 (12.1%) as Black, 14 289 (33.5%) as Hispanic, and 17 902 (41.9%) as White. As of the end of the study period and after accounting for participant censoring due to death or disenrollment from the KPSC health plan, 78.0% of immunocompromised individuals had received a third dose of mRNA COVID-19 vaccine. Only 41.0% had received a fourth dose, which corresponds to a primary series and a monovalent booster dose for immunocompromised individuals. Uptake of a fifth dose was only 0.9% following the US Centers for Disease Control and Prevention (CDC) recommendation to receive a second monovalent booster (ie, fifth dose). Adults aged 65 years or older (HR, 3.95 [95% CI, 3.70-4.22]) were more likely to receive at least 4 doses compared with those aged 18 to 44 years or 45 to 64 years (2.52 [2.36-2.69]). Hispanic and non-Hispanic Black adults (HR, 0.77 [95% CI, 0.74-0.80] and 0.82 [0.78-0.87], respectively, compared with non-Hispanic White adults), individuals with prior documented SARS-CoV-2 infection (0.71 [0.62-0.81] compared with those without), and individuals receiving high-dose corticosteroids (0.88 [0.81-0.95] compared with those who were not) were less likely to receive at least 4 doses. Conclusions and Relevance: These findings suggest that adherence to CDC mRNA monovalent COVID-19 booster dose recommendations among immunocompromised individuals was low. Given the increased risk for severe COVID-19 in this vulnerable population and the well-established additional protection afforded by booster doses, targeted and tailored efforts to ensure that immunocompromised individuals remain up to date with COVID-19 booster dose recommendations are warranted.

Effectiveness of BNT162b2 BA.4/5 bivalent mRNA vaccine against a range of COVID-19 outcomes in a large health system in the USA: a test-negative case-control study.

BACKGROUND: XBB-related omicron sublineages have recently replaced BA.4/5 as the predominant omicron sublineages in the USA and other regions globally. Despite preliminary signs of immune evasion of XBB sublineages, few data exist describing the real-world effectiveness of bivalent COVID-19 vaccines, especially against XBB-related illness. We aimed to investigate the effectiveness of the Pfizer--BioNTech BNT162b2 BA.4/5 bivalent vaccine against both BA.4/5-related and XBB-related disease in adults aged 18 years or older. METHODS: In this test-negative case-control study, we estimated the effectiveness of the BNT162b2 BA.4/5 bivalent vaccine using data from electronic health records of Kaiser Permanente Southern California health system members aged 18 years or older who received at least two doses of the wild-type COVID-19 mRNA vaccines. Participants sought care for acute respiratory infection between Aug 31, 2022, and April 15, 2023, and were tested for SARS-CoV-2 via PCR tests. Relative vaccine effectiveness (≥2 doses of wild-type mRNA vaccine plus a BNT162b2 BA.4/5 bivalent booster vs ≥2 doses of a wild-type mRNA vaccine alone) and absolute vaccine effectiveness (vs unvaccinated individuals) was estimated against critical illness related to acute respiratory infection (intensive care unit [ICU] admission, mechanical ventilation, or inpatient death), hospital admission, emergency department or urgent care visits, and in-person outpatient encounters with odds ratios from logistic regression models adjusted for demographic and clinical factors. We stratified vaccine effectiveness estimates for hospital admission, emergency department or urgent care visits, and outpatient encounters by omicron sublineage (ie, likely BA.4/5-related vs likely XBB-related), time since bivalent booster receipt, age group, number of wild-type doses received, and immunocompromised status. This study is registered with ClinicalTrials.gov (NCT04848584). FINDINGS: Analyses were conducted for 123 419 encounters (24 246 COVID-19 cases and 99 173 test-negative controls), including 4131 episode of critical illness (a subset of hospital admissions), 14 529 hospital admissions, 63 566 emergency department or urgent care visits, and 45 324 outpatient visits. 20 555 infections were BA.4/5 related and 3691 were XBB related. In adjusted analyses, relative vaccine effectiveness for those who received the BNT162b2 BA.4/5 bivalent booster compared with those who received at least two doses of a wild-type mRNA vaccine alone was an additional 50% (95% CI 23-68) against critical illness, an additional 39% (28-49) against hospital admission, an additional 35% (30-40) against emergency department or urgent care visits, and an additional 28% (22-33) against outpatient encounters. Waning of the bivalent booster from 0-3 months to 4-7 months after vaccination was evident for outpatient outcomes but was not detected for critical illness, hospital admission, and emergency department or urgent care outcomes. The relative effectiveness of the BNT162b2 BA.4/5 bivalent booster for XBB-related infections compared with BA.4/5-related infections was 56% (95% CI 12-78) versus 40% (27-50) for hospital admission; 34% (21-45) versus 36% (30-41) against emergency department or urgent care visits; and 29% (19-38) versus 27% (20-33) for outpatient encounters. INTERPRETATION: By mid-April, 2023, individuals previously vaccinated only with wild-type vaccines had little protection against COVID-19-including hospital admission. A BNT162b2 BA.4/5 bivalent booster restored protection against a range of COVID-19 outcomes, including against XBB-related sublineages, with the most substantial protection observed against hospital admission and critical illness. FUNDING: Pfizer.