Development of a tool to assess HIV prevention readiness of adolescent girls and young women in HPTN 082 study.

BACKGROUND: African adolescent girls and young women (AGYW) represent a large proportion of new HIV infections, a priority population for pre-exposure prophylaxis (PrEP), but adherence remains a challenge. A reliable, valid readiness tool would help identify AGYW motivated to take PrEP who need adherence support. METHODS: In the HPTN 082 open-label PrEP study (2016-2019), South African and Zimbabwean women ages 16-25 were administered an HIV prevention readiness measure (HPRM). The 25 items in the HPRM included medication beliefs, connection with care, disclosure of PrEP use, social support, and housing stability using a 5-point Likert scale. Exploratory factor analysis (EFA) using polychoric correlations, scale reliability, and predictive validity were performed on data from 315 participants who responded to all items. We assessed the predictive value of HPRM scores with PrEP adherence, defined as tenofovir-diphosphate (TFV-DP) concentrations in dried blood spots, as a continuous measure and dichotomized as high PrEP adherence (≥700 fmol/punch). RESULTS: EFA yielded 23 items with three subscales: self-efficacy (16 items), PrEP disclosure (4 items), and social support (3 items). Cronbach's α ranged from 0.71 to 0.92 for the overall scale and the subscales. The average overall scale and the subscales were predictive of 3-month PrEP adherence for TFV-DP concentrations: for each unit increase of the HPRM score, TFV-DP concentration increased by 103 fmol/punch (95% CI: 16, 189, p = 0.02); the highest HPRM score equated with 608 fmol/punch on average. For the self-efficacy subscale, TFV-DP increased by 90 fmol/punch (95% CI: 7, 172, p = 0.03); PrEP disclosure, 68 fmol/punch (95% CI: 19, 117 p = 0.01); and social support, 58fmol/punch (95% CI: 2, 113, p = 0.04). Higher PrEP disclosure suggests high adherence (OR 1.36, 95% CI: 1.00, 1.86, p = 0.05) and predicted persistent high adherence at both months three and six (OR: 1.50, 95% CI: 1.03, 2.21, p = 0.04). CONCLUSIONS: The HPRM scale overall and the subscales individually demonstrated good internal consistency among African young women. PrEP disclosure subscale exhibiting significant association with persistent high PrEP adherence is an important finding for PrEP adherence support programs. Future work will assess replicability and expand self-efficacy and social-support subscales after item revision. TRIAL REGISTRATION: ClinicalTrials.gov NCT02732730.

Patterns of Gender-Based Violence and Associations with Mental Health and HIV Risk Behavior Among Female Sex Workers in Mombasa, Kenya: A Latent Class Analysis.

Gender-based violence (GBV) is common among female sex workers (FSWs) and is associated with multiple HIV risk factors, including poor mental health, high-risk sexual behavior, and sexually transmitted infections (STIs). Prior studies have focused on GBV of one type (e.g. physical or sexual) or from one kind of perpetrator (e.g., clients or regular partners), but many FSWs experience overlapping types of violence from multiple perpetrators, with varying frequency and severity. We examined the association between lifetime patterns of GBV and HIV risk factors in 283 FSWs in Mombasa, Kenya. Patterns of GBV were identified with latent class analysis based on physical, sexual, or emotional violence from multiple perpetrators. Cross-sectional outcomes included depressive symptoms, post-traumatic stress disorder (PTSD) symptoms, disordered alcohol and other drug use, number of sex partners, self-reported unprotected sex, prostate-specific antigen (PSA) in vaginal secretions, and a combined unprotected sex indicator based on self-report or PSA detection. We also measured HIV/STI incidence over 12 months following GBV assessment. Associations between GBV patterns and each outcome were modeled separately using linear regression for mental health outcomes and Poisson regression for sexual risk outcomes. Lifetime prevalence of GBV was 87%. We identified 4 GBV patterns, labeled Low (21% prevalence), Sexual (23%), Physical/Moderate Emotional (18%), and Severe (39%). Compared to women with Low GBV, those with Severe GBV had higher scores for depressive symptoms, PTSD symptoms, and disordered alcohol use, and had more sex partners. Women with Sexual GBV had higher scores for disordered alcohol use than women with Low GBV, but similar sexual risk behavior. Women with Physical/Moderate Emotional GBV had more sex partners and a higher prevalence of unprotected sex than women with Low GBV, but no differences in mental health. HIV/STI incidence did not differ significantly by GBV pattern. The prevalence of GBV was extremely high in this sample of Kenyan FSWs, and different GBV patterns were associated with distinct mental health and sexual risk outcomes. Increased understanding of how health consequences vary by GBV type and severity could lead to more effective programs to reduce HIV risk in this vulnerable population.

Latino Cigarette Smoking Patterns by Gender in a US-National Sample.

BACKGROUND: Latino smokers are a rising public health concern who experience elevated tobacco-related health disparities. PURPOSE: Additional information on Latino smoking is needed to inform screening and treatment. ANALYSIS: Latent class analysis using smoking frequency, cigarette preferences, onset, smoking duration, cigarettes per day, and minutes to first cigarette was used to create multivariate latent smoking profiles for Latino men and women. RESULTS: Final models found seven classes for Latinas and nine classes for Latinos. Despite a common finding in the literature that Latino smokers are more likely to be low-risk intermittent smokers, the majority of classes for both males and females described patterns of high-risk daily smoking. Gender variations in smoking classes were noted. CONCLUSIONS: Several markers of smoking risk were identified among both male and female Latino smokers, including long durations of smoking, daily smoking, and preference for specialty cigarettes, all factors associated with long-term health consequences.

The natural history of college smoking: trajectories of daily smoking during the freshman year.

Although the initiation of cigarette use typically occurs prior to age 18, there is evidence for considerable change in smoking behavior after this age. College may be a particularly important period to study smoking because it is a time when adolescents transition into a new social context where substance use is normative. Using a longitudinal design, daily assessments of smoking were collected during the entire first year of college for a large cohort of freshman (N=496). Findings suggested a weekly cycle of smoking such that the probability of smoking was much higher on weekends (Friday and Saturday) than on remaining days of the week. In addition to this weekly cycle, there was an overall trend for smoking to decline over the course of the year. Substantial individual variability in levels of smoking was observed. These findings provide new insights into college smoking, and have implications for assessment, policy, intervention, and future directions for research.

Most smokeless tobacco use does not cause cigarette smoking: results from the 2000 National Household Survey on Drug Abuse.

Those who either never progress from smokeless tobacco (SLT) to smoking or smoked before using SLT logically cannot have smoking caused by SLT use. The prevalence of such use permits strong inferences about the overall importance of the potential causal effects of SLT on cigarette smoking. We found that the majority of SLT ever users (66%) in the 2000 National Household Survey on Drug Abuse (NHSDA) were noncausal users. For these individuals, SLT use cannot have caused them to smoke. We also compared our results in 2000 with a similar sample in 1987, using current SLT users only. Potentially, the causal uses of SLT were in the minority and had not increased significantly over time (24% in 1987 to 29% in 2000, P>.05). Logistic models showed that, when noncausal users were removed, SLT was a minor predictor of current smoking. This is likely due to linked experimentation. We argue that that the majority of SLT use cannot cause smoking, such that SLT effects on smoking initiation are minimal at best. Policy implications of these findings are discussed.

Regular smokeless tobacco use is not a reliable predictor of smoking onset when psychosocial predictors are included in the model.

Tomar analyzed the CDC's Teenage Attitudes and Practices Survey (TAPS) and reported smokeless tobacco may act as a starter product for or gateway to cigarettes. Regular smokeless tobacco users at baseline were said to be 3.45 times more likely than never users of smokeless tobacco to become cigarette smokers after 4 years (95% CI=1.84-6.47). However, this analysis did not take into account well-known psychosocial predictors of smoking initiation. We reanalyzed TAPS to assess whether including psychosocial predictors of smoking affected the smokeless tobacco gateway effect. Experimenting with smoking, OR=2.09 (95% CI=1.51-2.90); below average school performance, OR=9.32 (95% CI=4.18-20.77); household members smoking, OR=1.49 (95% CI=1.13-1.95); frequent depressive symptoms, OR=2.19 (95% CI=1.25-3.84); fighting, OR=1.48 (95% CI=1.08-2.03); and motorcycle riding, OR=1.42 (95% CI=1.06-1.91) diminished the effect of both regular, OR=1.68 (95% CI=.83-3.41), and never regular smokeless tobacco use, OR=1.41 (95% CI=.96-2.05), to be statistically unreliable. Analyzing results from a sample of true never smokers (never a single puff) showed a similar pattern of results. Our results indicate that complex multivariate models are needed to evaluate recruitment to smoking and single factors that are important in that process. Tomar's analysis should not be used as reliable evidence that smokeless tobacco may be a starter product for cigarettes.

Most smokeless tobacco use is not a causal gateway to cigarettes: using order of product use to evaluate causation in a national US sample.

AIMS: To evaluate non-causal and causal patterns of smokeless tobacco (SLT) and cigarette use; to assess the prevalence of 'non-gateway' and possible 'gateway' patterns of SLT use. DESIGN AND SETTING: Data from the Cancer Control Supplement to the 1987 National Health Interview Survey, a representative survey of non-institutionalized adults in the United States. From reported age at first use, participants were categorized by type and sequence of tobacco product use. SUDAAN 8.0.1 was used for statistical analyses. PARTICIPANTS: Males aged 18-34 (n = 3454), weighted to provide estimates of the US population. A subsample of males aged 23-34 (n = 2614) was analyzed to minimize the possibility of future product switching. MEASUREMENTS: Smoking status, smokeless tobacco (snuff, chewing tobacco, both) use status, age at regular use of cigarettes, age at first use of smokeless tobacco. FINDINGS: Of those 23-34-year-olds who had ever used SLT with or without cigarettes, 77.2% (95% CI: 71.3, 83.3) were classifiable as non-gateway users in that 35.0% (95% CI: 29.9, 40.1) had only used SLT and 42.2% (95% CI: 36.8, 47.7) had used cigarettes first. Cigarette use in younger cohorts was less common, despite increased SLT use. Those who used cigarettes before moist snuff were 2.1 times more likely to have quit smoking (95% CI 1.21,6.39) than cigarette-only users. CONCLUSIONS: The large majority of SLT users are non-gateway users. Causal gateway effects should be of minor concern for policy. SLT may be more likely to prevent smoking than cause it.

Assessing reliability of categorical substance use measures with latent class analysis.

This article illustrates the use of the latent class model to identify classes of individuals and to assess the psychometric reliability of categorical items. The latent class model is a categorical latent variable model used to identify homogeneous classes of respondents such that class membership accounts for item responses. The assessment of measurement reliability comes directly from the estimates of the model. Although not based on classical test theory, the reliability assessment procedures described here answer the same question-that is, how consistent or dependable is measurement? The goal is to identify reliable indicators of a characteristic by examining measurement error and the inter-relatedness of the items. Methods for estimating the reliability of individual items as well as sets of items are presented. These methods are illustrated with data on cigarette smoking from a national sample of adolescents. By using the procedures described here, researchers are able to determine: (1). which classes of people are measured well and which are not; (2). which items perform well and which do not; and (3). whether items need to be altered or added in order to measure and identify particular classes better.