BivRec: an R package for the nonparametric and semiparametric analysis of bivariate alternating recurrent events.

BACKGROUND: Bivariate alternating recurrent event data can arise in longitudinal studies where patients with chronic diseases go through two states that occur repeatedly, e.g., care periods and break periods. However, there was no statistical software that provided tools for the analysis of such data. To meet this software need, we developed BivRec, a package for R that contains a set of tools for exploratory, nonparametric and semiparametric regression analysis of bivariate alternating recurrent events. RESULTS: The BivRec package provides functions for nonparametric estimations for the joint distribution of bivariate gap times (bivrecNP) and semiparametric regression methods for evaluating covariate effects on the two types of gap times under the accelerated failure time model framework (bivrecReg). The package also provides exploratory data analysis tools such as a visualization of the gap times by groups. We utilize a subset of the South Verona Psychiatric Case Register (PCR) data to illustrate the use of the BivRec package for the reviewed methods. CONCLUSIONS: We demonstrate BivRec's capability for data visualization, nonparametric and regression based analysis, as well as data simulation. The package has default methods with satisfactory performance despite the complexity of calculations and fills a gap in software for statistical analysis of bivariate alternating recurrent events. BivRec is accessible under the GPL-3 General Public License through CRAN, facilitating its installation.

Deeply Tailored Adaptive Interventions to Reduce College Student Drinking: a Real-World Application of Q-Learning for SMART Studies.

M-bridge was a sequential multiple assignment randomized trial (SMART) that aimed to develop a resource-efficient adaptive preventive intervention (API) to reduce binge drinking in first-year college students. The main results of M-bridge suggested no difference, on average, in binge drinking between students randomized to APIs versus assessment-only control, but certain elements of the API were beneficial for at-risk subgroups. This paper extends the main results of M-bridge through an exploratory analysis using Q-learning, a novel algorithm from the computer science literature. Specifically, we sought to further tailor the two aspects of the M-bridge APIs to an individual and test whether deep tailoring offers a benefit over assessment-only control. Q-learning is a method to estimate decision rules that assign optimal treatment (i.e., to minimize binge drinking) based on student characteristics. For the first aspect of the M-bridge API (when to offer), we identified the optimal tailoring characteristic post hoc from a set of 20 candidate variables. For the second (how to bridge), we used a known effect modifier from the trial. The results of our analysis are two rules that optimize (1) the timing of universal intervention for each student based on their motives for drinking and (2) the bridging strategy to indicated interventions (i.e., among those who continue to drink heavily mid-semester) based on mid-semester binge drinking frequency. We estimate that this newly tailored API, if offered to all first-year students, would reduce binge drinking by 1 occasion per 2.5 months (95% CI: decrease of 1.45 to 0.28 occasions, p < 0.01) on average. Our analyses demonstrate a real-world implementation of Q-learning for a substantive purpose, and, if replicable in future trials, our results have practical implications for college campuses aiming to reduce student binge drinking.

The effect of cooperator recognition on competition among clones in spatially structured microbial communities.

In spatially structured microbial communities, clonal growth of stationary cells passively generates clusters of related individuals. This can lead to stable cooperation without the need for recognition mechanisms. However, recent research suggests that some biofilm-forming microbes may have mechanisms of kin recognition. To explore this unexpected observation, we studied the effects of different types of cooperation in a microbial colony using spatially explicit, agent-based simulations of two interacting strains. We found scenarios that favor a form of kin recognition in spatially structured microbial communities. In the presence of a "cheater" strain, a strain with greenbeard cooperation was able to increase in frequency more than a strain with obligate cooperation. This effect was most noticeable in high density colonies and when the cooperators were not as abundant as the cheaters. We also studied whether a polychromatic greenbeard, in which cells only cooperate with their own type, could provide a numerical benefit beyond a simple, binary greenbeard. We found the greatest benefit to a polychromatic greenbeard when cooperation is highly effective. These results suggest that in some ecological scenarios, recognition mechanisms may be beneficial even in spatially structured communities.

A Microsimulation of Well-Being and Literacy Interventions to Reduce Scam Susceptibility in Older Adults.

Poor financial and health literacy and poor psychological well-being are significant correlates of scam susceptibility in older adults; yet, no research has examined whether interventions that target these factors may effectively reduce susceptibility. Using longitudinal data from older adults in the Rush Memory and Aging Project (MAP) (N = 1,231), we used microsimulations to estimate the causal effect of hypothetical well-being and literacy interventions on scam susceptibility over six years. Microsimulations can simulate a randomized trial to estimate intervention effects using observational data. We simulated hypotheticalinterventions that improved well-being or literacy scores by either 10% or 30% from baseline, or to the maximum scores, for an older adult population and for income and education subgroups. Simulations suggest thathypotheticalinterventions that increase well-being or literacy cause statistically significant reductions in scam susceptibility of older adults over time, but improving well-being caused a greater-albeit not significantly different-reduction compared to improving literacy.

Examining engagement effects in an adaptive preventive intervention for college student drinking.

OBJECTIVE: This study determined the characteristics of engagement and whether engagement in an adaptive preventive intervention (API) was associated with reduced binge drinking and alcohol-related consequences. METHOD: Incoming students were recruited for a sequential multiple assignment randomized trial (SMART; N = 891, 62.4% female, 76.8% non-Hispanic White) with an assessment-only control group. The API occurred during the first semester of college, with outcomes assessed at the end of the semester. The API involved two stages. Stage 1 included universal intervention components (personalized normative feedback [PNF] and self-monitoring). Stage 2 bridged heavy drinkers to access additional resources. We estimated the effect of engagement in Stage 1 only and in the whole API (Stages 1 and 2) among the intervention group, and the effect of the API versus control had all students assigned an API engaged, on alcohol-related outcomes. RESULTS: Precollege binge drinking, intention to pledge a fraternity/sorority, and higher conformity motives were most associated with lower odds of Stage 1 engagement. Action (readiness to change) and PNF engagement were associated with Stage 2 engagement. API engagement was associated with significant reductions in alcohol-related consequences among heavy drinkers. Compared to the control, we estimated the API would reduce the relative increase in alcohol-related consequences from baseline to follow-up by 25%, had all API students engaged. CONCLUSIONS: Even partial engagement in each component of the "light-touch" API rendered benefits. Analyses suggested that had all students in the intervention group engaged, the API would significantly reduce the change in alcohol-related consequences over the first semester in college. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Evaluating Human Papillomavirus eHealth in Hmong Adolescents to Promote Vaccinations: Pilot Feasibility Study.

BACKGROUND: Human papillomavirus (HPV) is a common sexually transmitted infection, causing multiple cancers, including cervical, penile, and anal. Infection and subsequent health risks caused by HPV can be diminished by HPV vaccination. Unfortunately, vaccination rates among Hmong Americans are substantially lower than those among other racial and ethnic groups, despite having higher cervical cancer rates than non-Hispanic White women. Such disparities and sparse literature highlight the need for innovative and culturally appropriate educational interventions to improve HPV vaccine rates in Hmong Americans. OBJECTIVE: We aimed to develop and evaluate the effectiveness and usability of an innovative web-based eHealth educational website, the Hmong Promoting Vaccines website (HmongHPV website), for Hmong-American parents and adolescents to improve their knowledge, self-efficacy, and decision-making capacities to obtain HPV vaccinations. METHODS: Through social cognitive theory and community-based participatory action research process, we created a theory-driven and culturally and linguistically appropriate website for Hmong parents and adolescents. We conducted a pre-post intervention pilot study to assess the website's effectiveness and usability. Overall, 30 Hmong-American parent and adolescent dyads responded to questions about HPV and HPV vaccine knowledge, self-efficacy, and decision-making at preintervention, 1 week after intervention, and at the 5-week follow-up. Participants responded to survey questions about website content and processes at 1 and 5 weeks, and a subset of 20 dyad participants participated in telephone interviews 6 weeks later. We used paired t tests (2-tailed) to measure the change in knowledge, self-efficacy, and decision-making processes, and used template analysis to identify a priori themes for website usability. RESULTS: Participants' HPV and HPV vaccine knowledge improved significantly from pre- to postintervention stage and follow-up. Knowledge scores increased from preintervention to 1 week after intervention for both parents (HPV knowledge, P=.01; vaccine knowledge, P=.01) and children (HPV knowledge, P=.01; vaccine knowledge, P<.001), which were sustained at the 5-week follow-up. Parents' average self-efficacy score increased from 21.6 at baseline to 23.9 (P=.007) at post intervention and 23.5 (P=.054) at follow-up. Similar improvements were observed in the teenagers' self-efficacy scores (from 30.3 at baseline to 35.6, P=.009, at post intervention and 35.9, P=.006, at follow-up). Collaborative decision-making between parents and adolescents improved immediately after using the website (P=.002) and at follow-up (P=.02). The interview data also revealed that the website's content was informative and engaging; in particular, participants enjoyed the web-based quizzes and vaccine reminders. CONCLUSIONS: This theory-driven, community-based participatory action research-designed and culturally and linguistically appropriate educational website was well received. It improved Hmong parents' and adolescents' knowledge, self-efficacy, and decision-making processes regarding HPV vaccination. Future studies should examine the website's impact on HPV vaccine uptake and its potential for broader use across various settings (eg, clinics and schools).