Comparison of approaches to control for intracranial volume in research on the association of brain volumes with cognitive outcomes.

Most neuroimaging studies linking regional brain volumes with cognition correct for total intracranial volume (ICV), but methods used for this correction differ across studies. It is unknown whether different ICV correction methods yield consistent results. Using a brain-wide association approach in the MRI substudy of UK Biobank (N = 41,964; mean age = 64.5 years), we used regression models to estimate the associations of 58 regional brain volumetric measures with eight cognitive outcomes, comparing no correction and four ICV correction approaches. Approaches evaluated included: no correction; dividing regional volumes by ICV (proportional approach); including ICV as a covariate in the regression (adjustment approach); and regressing the regional volumes against ICV in different normative samples and using calculated residuals to determine associations (residual approach). We used Spearman-rank correlations and two consistency measures to quantify the extent to which associations were inconsistent across ICV correction approaches for each possible brain region and cognitive outcome pair across 2320 regression models. When the association between brain volume and cognitive performance was close to null, all approaches produced similar estimates close to the null. When associations between a regional volume and cognitive test were not null, the adjustment and residual approaches typically produced similar estimates, but these estimates were inconsistent with results from the crude and proportional approaches. For example, when using the crude approach, an increase of 0.114 (95% confidence interval [CI]: 0.103-0.125) in fluid intelligence was associated with each unit increase in hippocampal volume. However, when using the adjustment approach, the increase was 0.055 (95% CI: 0.043-0.068), while the proportional approach showed a decrease of -0.025 (95% CI: -0.035 to -0.014). Different commonly used methods to correct for ICV yielded inconsistent results. The proportional method diverges notably from other methods and results were sometimes biologically implausible. A simple regression adjustment for ICV produced biologically plausible associations.

Mind the gaps: prescription coverage and HIV incidence among patients receiving pre-exposure prophylaxis from a large federally qualified health center in Los Angeles, California : Mind the Gaps: Cobertura de recetas e incidencia de VIH entre pacientes recibiendo profilaxis pre-exposición de un centro de salud grande y federalmente calificado en Los Ángeles, CA.

We conducted a records-based cohort study of patients who initiated pre-exposure prophylaxis (PrEP) at a large federally qualified health center in Los Angeles, CA to characterize patterns of PrEP use, identify correlates of PrEP discontinuation, and calculate HIV incidence. Of 3121 individuals initiating PrEP between 2014 and 2017, 42% (n = 1314) were active (i.e., had a current PrEP prescription) in April 2018. HIV incidence was 0.1/100 person-years among active PrEP patients, compared to 2.1/100 person-years among patients who discontinued. Compared to patients accessing PrEP through government programs with no prescription copay, risk of discontinuation was higher among those with private insurance (ARR = 1.4, 95% CI 1.2, 1.7), or no insurance (ARR = 4.5, 95% CI 3.2, 6.4). Sixty-three percent of active PrEP patients had gaps between PrEP prescriptions, averaging one gap per year (median length = 65 days). Increasing access to free or low-cost PrEP can improve PrEP continuity.

Does HIV pre-exposure prophylaxis use lead to a higher incidence of sexually transmitted infections? A case-crossover study of men who have sex with men in Los Angeles, California.

BACKGROUND: Pre-exposure prophylaxis (PrEP) is an effective method for reducing HIV incidence among at-risk populations. However, concerns exist over the potential for an increase in STIs following PrEP initiation. The objective of this study is to compare the STI incidence before and after PrEP initiation within subjects among a cohort of men who have sex with men in Los Angeles, California. METHODS: The present study used data from patients who initiated PrEP services at the Los Angeles LGBT Center between October 2015 and October 2016 (n=275). A generalised linear mixed model was used with a case-crossover design to determine if there was a significant difference in STIs within subjects 365 days before (before-PrEP period) and 365 days after PrEP initiation (after-PrEP period). RESULTS: In a generalised linear mixed model, there were no significant differences in urethral gonorrhoea (P=0.95), rectal gonorrhoea (P=0.33), pharyngeal gonorrhoea (P=0.65) or urethral chlamydia (P=0.71) between periods. There were modest increases in rectal chlamydia (rate ratio (RR) 1.83; 95% CI 1.13 to 2.98; P=0.01) and syphilis diagnoses (RR 2.97; 95% CI 1.23 to 7.18; P=0.02). CONCLUSIONS: There were significant increases in rectal chlamydia and syphilis diagnoses when comparing the periods directly before and after PrEP initiation. However, only 28% of individuals had an increase in STIs between periods. Although risk compensation appears to be present for a segment of PrEP users, the majority of individuals either maintain or decrease their sexual risk following PrEP initiation.

App-Based Sexual Partner Seeking and Sexually Transmitted Infection Outcomes: A Cross-Sectional Study of HIV-Negative Men Who Have Sex With Men Attending a Sexually Transmitted Infection Clinic in Los Angeles, California.

BACKGROUND: Gay, bisexual, and other men who have sex with men (MSM) face higher rates of sexually transmitted infections (STIs) compared with the general population. The association between venues where sexual partners are met and STI transmission is dynamic and poorly understood, especially among those who use geosocial networking (GSN) apps. This study aimed to determine whether there is a difference in STI incidence between MSM who met their last sexual partner through a GSN app and MSM who met their last partner via other venues. METHODS: Data were analyzed from HIV-negative MSM attending the Los Angeles LBGT Center between August 2015 and July 2016 (n = 9499). Logistic regression models were used to investigate the relationship between STI incidence and whether or not an individual met his last partner through a GSN app. RESULTS: No relationship was detected between STI incidence and whether one's last sexual partner was met via GSN app. However, an association was detected between STI incidence and having used GSN apps to meet sexual partners in the past 3 months. A dose-response relationship was observed between the number of venues used to meet partners and testing positive for any STI (adjusted odds ratio, 1.08; 95% confidence interval, 1.02-1.14). CONCLUSIONS: The relationship between how people meet sexual partners and STI acquisition is much more nuanced than previously thought. Geosocial networking apps do not inherently expose users to high-risk reservoirs of STIs, but further understanding of the complexity of sexual networks and networking methods is warranted, given increasing rates of STIs.

Using Sexual Orientation and Gender Identity to Monitor Disparities in HIV, Sexually Transmitted Infections, and Viral Hepatitis.

OBJECTIVES: To quantify sexual orientation and gender identity (SOGI) disparities in incidence of HIV, other sexually transmitted infections (STIs), and viral hepatitis. METHODS: We performed a records-based study of 19 933 patients visiting a federally qualified health center in Los Angeles, California, between November 2016 and October 2017 that examined HIV, STIs, and viral hepatitis incidence proportions. We created multivariable logistic regression models to examine the association between incidence proportions and SOGI among people living with HIV and HIV-negative patients. RESULTS: Among those who were HIV-negative at baseline (n = 16 757), 29% tested positive for any STI during the study period, compared with 38% of people living with HIV. Stratified by birth sex, STI positivity was 32% among men and 11% among women. By SOGI, STI positivity was 35% among gay and bisexual cisgender men, 15% among heterosexual cisgender men, 11% among cisgender women, 25% among transgender women, 13% among gay and bisexual transgender men, 3% among heterosexual transgender men, and 26% among nonbinary people. CONCLUSIONS: Stratifying by SOGI highlighted disparities that are obscured when stratifying by birth sex. Public Health Implications. To monitor and reduce disparities, health jurisdictions should include SOGI data with infectious disease reporting.

Excess Mortality With Alzheimer Disease and Related Dementias as an Underlying or Contributing Cause During the COVID-19 Pandemic in the US.

Importance: Adults with Alzheimer disease and related dementias (ADRD) are particularly vulnerable to the direct and indirect effects of the COVID-19 pandemic. Deaths associated with ADRD increased substantially in pandemic year 1. It is unclear whether mortality associated with ADRD declined when better prevention strategies, testing, and vaccines became widely available in year 2. Objective: To compare pandemic-era excess deaths associated with ADRD between year 1 and year 2 overall and by age, sex, race and ethnicity, and place of death. Design, Setting, and Participants: This time series analysis used all death certificates of US decedents 65 years and older with ADRD as an underlying or contributing cause of death from January 2014 through February 2022. Exposure: COVID-19 pandemic era. Main Outcomes and Measures: Pandemic-era excess deaths associated with ADRD were defined as the difference between deaths with ADRD as an underlying or contributing cause observed from March 2020 to February 2021 (year 1) and March 2021 to February 2022 (year 2) compared with expected deaths during this period. Expected deaths were estimated using data from January 2014 to February 2020 fitted with autoregressive integrated moving average models. Results: Overall, 2 334 101 death certificates were analyzed. A total of 94 688 (95% prediction interval [PI], 84 192-104 890) pandemic-era excess deaths with ADRD were estimated in year 1 and 21 586 (95% PI, 10 631-32 450) in year 2. Declines in ADRD-related deaths in year 2 were substantial for every age, sex, and racial and ethnic group evaluated. Pandemic-era ADRD-related excess deaths declined among nursing home/long-term care residents (from 34 259 [95% PI, 25 819-42 677] in year 1 to -22 050 [95% PI, -30 765 to -13 273] in year 2), but excess deaths at home remained high (from 34 487 [95% PI, 32 815-36 142] in year 1 to 28 804 [95% PI, 27 067-30 571] in year 2). Conclusions and Relevance: This study found that large increases in mortality with ADRD as an underlying or contributing cause of death occurred in COVID-19 pandemic year 1 but were largely mitigated in pandemic year 2. The most pronounced declines were observed for deaths in nursing home/long-term care settings. Conversely, excess deaths at home and in medical facilities remained high in year 2.

Cancer Risk Behaviors, Cancer Beliefs, and Health Information Seeking Among Under-Represented Populations in San Francisco: Differences by Sexual Orientation and Gender Identity.

Purpose: Sexual and gender minority (SGM) individuals in the United States are at increased risk of cancer compared to the non-SGM population. Understanding how SGM persons perceive cancer risk and their practices and preferences for accessing health information is key for improving the preventive and health care services they receive. Methods: In this cross-sectional study, we analyzed data from the San Francisco Health Information National Trends Survey. SGM individuals were identified by self-report. Differences in cancer risk factors, cancer beliefs, and health information seeking were evaluated by SGM status using multivariable logistic regression models. Results: Out of 1027 participants, 130 (13%) reported being SGM individuals. Current smoking (odds ratio [OR]=1.93, 95% confidence interval [CI]=1.24-3.01) and alcohol use (OR=1.69, 95% CI=1.10-2.59) were more common among SGM persons than among non-SGM persons. No differences by SGM status were observed in health information seeking behaviors, preferences, and cancer beliefs, but SGM participants reported significantly higher odds of feeling frustrated (OR=1.78, 95% CI=1.20-2.64) and having concerns about the quality of the information (OR=1.54, 95% CI=1.03-2.31) during their most recent health information search. Conclusions: Intervention efforts aimed at SGM individuals with current use of tobacco and/or alcohol should be expanded. SGM communities also need improved access to consistent, reliable, and accurate sources of health information. Their increased frustration when seeking health information and concerns about the quality of the information they find have important implications for SGM health and care, and the drivers of these differences merit further evaluation.

Excess Mortality in California by Education During the COVID-19 Pandemic.

INTRODUCTION: Understanding educational patterns in excess mortality during the coronavirus disease 2019 (COVID-19) pandemic may help to identify strategies to reduce disparities. It is unclear whether educational inequalities in COVID-19 mortality have persisted throughout the pandemic, spanned the full range of educational attainment, or varied by other demographic indicators of COVID-19 risks, such as age or occupation. METHODS: This study analyzed individual-level California Department of Public Health data on deaths occurring between January 2016 and February 2021 among individuals aged ≥25 years (1,502,202 deaths). Authors applied ARIMA (autoregressive integrated moving average) models to subgroups defined by the highest level of education and other demographics (age, sex, race/ethnicity, U.S. nativity, occupational sector, and urbanicity). Authors estimated excess deaths (the number of observed deaths minus the number of deaths expected to occur under the counterfactual of no pandemic) and excess deaths per 100,000 individuals. RESULTS: Educational inequalities in excess mortality emerged early in the pandemic and persisted throughout the first year. The greatest per-capita excess occurred among people without high-school diplomas (533 excess deaths/100,000), followed by those with a high-school diploma but no college (466/100,000), some college (156/100,000), and bachelor's degrees (120/100,000), and smallest among people with graduate/professional degrees (101/100,000). Educational inequalities occurred within every subgroup examined. For example, per-capita excess mortality among Latinos with no college experience was 3.7 times higher than among Latinos with at least some college experience. CONCLUSIONS: Pervasive educational inequalities in excess mortality during the pandemic suggest multiple potential intervention points to reduce disparities.

Structural, Dosing, and Risk Change Factors Affecting Discontinuation of Pre-exposure Prophylaxis (PrEP) in a Large Urban Clinic.

Understanding why clients stop taking pre-exposure prophylaxis (PrEP) is critical to improve PrEP delivery and ultimately reduce HIV incidence. We analyzed data from a programmatic evaluation conducted at the Los Angeles LGBT Center from February to May 2018. Of 180 respondents to the emailed survey, 91 had stopped taking PrEP and 11 never started. Among former PrEP users, most common reasons for stopping were entering a monogamous relationship (43%) and side effects (40%). Ten of 11 who never started PrEP reported access barriers (e.g., cost, insurance problems). A quarter of inactive clients re-engaged with PrEP services following the survey and 15% restarted PrEP by October 2018. Improving PrEP retention may require multifaceted interventions-e.g., tailored discussions about stopping and restarting PrEP safely as HIV risk changes, ensuring consistent access to affordable PrEP, and alternative dosing strategies. An emailed survey may be a simple, effective strategy to reengage some PrEP clients.

Salivary Osmolality, Function, and Hydration Habits in Community-Dwelling Older Adults.

The aim of this study was to examine the relationship between hydration status as measured by salivary osmolality and personal hydration habits, selected demographic characteristics, and performance on a walking and balance test in older community-dwelling adults. This study used a descriptive observational design in a convenience sample of multiethnic, community-dwelling older adults (N = 53). We collected saliva for analysis on 3 days both in the morning and early afternoon, along with a hydration habit questionnaire, get up and go test and demographic information. An exploratory factor analysis of the hydration habit questionnaire revealed a two-factor solution including physical barriers and psychological barriers to drinking fluids. A linear mixed-model approach revealed that time of day (p < .01), race (p = .015), mobility (p < .01), and cognitive barriers (p = .023) are all significant predictors of salivary osmolality among noninstitutionalized seniors. There is also a significant interaction between psychological barriers to drinking fluids and time of day (p < .01). Average salivary osmolality was higher in this group of older adults than has been reported in younger adults. Controlling for all other variables, salivary osmolality is higher in the morning than in the afternoon, lower among Black or African American seniors than among White or Caucasian seniors, and higher among seniors with decreased mobility. An interaction between psychological barriers and salivary osmolality showed that those participants with more psychological barriers to drinking had higher salivary osmolality in the morning and an inverse relationship in the afternoon.