Discrete-time Survival Analysis Research Articles

BMI Trajectories and the Influence of Missing Data

Abstract Introduction Body Mass Index (BMI) trajectories have been estimated in various ways. These estimates are important to understand how BMI develops over time and for use in cost-effectiveness analysis. However, missing data is often stated as a limitation in studies that analyse BMI over time and there is little research into how missing data can influence these BMI trajectories. The aim of this study is to determine how much influence missing data can have when estimating BMI trajectories and to explore the effects this has on subsequent analysis. Methods This study uses data from the English Longitudinal Study of Aging. First, a growth mixture model is used to estimate distinct BMI trajectories in adults over the age of 50. Next, methods that assume data is missing at random (MAR) are used: complete case analysis and multiple imputation. Finally, Diggle Kenward and Roy methods that assume data is missing not at random (MNAR) are implemented. Estimated trajectories from each method are then used to predict the risk of developing type 2 diabetes (T2DM) using discrete-time survival analysis. Results Four distinct trajectories are identified using each of the methods to account for missing data: stable overweight, elevated BMI, increasing BMI, and decreasing BMI. However, the likelihoods of individuals following the different trajectories differs between the different methods. Results show that the influence of BMI trajectory on T2DM is reduced after accounting for missing data. More work is needed to understand which methods for missing data are most appropriate and give the most reliable results. Conclusions Missing data can significantly influence estimations of BMI trajectories. When using BMI trajectories to inform cost-effectiveness analysis or policymaking, missing data should be considered. More research is needed to examine the extent to which accounting for missing data might influence the cost-effectiveness of policies, e.g. weight management interventions. Key messages • Missing data is important when modelling BMI trajectories. • More research is needed to examine the extent to which accounting for missing data might influence the cost-effectiveness of policies, e.g. weight management interventions.

Undetected suicide attempts among U.S. soldiers: results from the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS).

While previous studies have reported high rates of documented suicide attempts (SAs) in the U.S. Army, the extent to which soldiers make SAs that are not identified in the healthcare system is unknown. Understanding undetected suicidal behavior is important in broadening prevention and intervention efforts. Representative survey of U.S. Regular Army enlisted soldiers (n = 24 475). Reported SAs during service were compared with SAs documented in administrative medical records. Logistic regression analyses examined sociodemographic characteristics differentiating soldiers with an undetected SA v. documented SA. Among those with an undetected SA, chi-square tests examined characteristics associated with receiving a mental health diagnosis (MH-Dx) prior to SA. Discrete-time survival analysis estimated risk of undetected SA by time in service. Prevalence of undetected SA (unweighted n = 259) was 1.3%. Annual incidence was 255.6 per 100 000 soldiers, suggesting one in three SAs are undetected. In multivariable analysis, rank ⩾E5 (OR = 3.1[95%CI 1.6-5.7]) was associated with increased odds of undetected v. documented SA. Females were more likely to have a MH-Dx prior to their undetected SA (Rao-Scott χ21 = 6.1, p = .01). Over one-fifth of undetected SAs resulted in at least moderate injury. Risk of undetected SA was greater during the first four years of service. Findings suggest that substantially more soldiers make SAs than indicated by estimates based on documented attempts. A sizable minority of undetected SAs result in significant injury. Soldiers reporting an undetected SA tend to be higher ranking than those with documented SAs. Undetected SAs require additional approaches to identifying individuals at risk.

Gestational urinary concentrations of glyphosate and aminomethylphosphonic acid in relation to preterm birth: the MIREC study.

Few high-quality studies have evaluated associations between urinary glyphosate or its environmental degradate (aminomethylphosphonic acid (AMPA)] and preterm birth (PTB). To quantify associations between urinary glyphosate and AMPA and preterm birth in the pan-Canadian Maternal-Infant Research on Environmental Chemicals (MIREC) study and determine if associations differ by fetal sex. We measured first trimester urinary glyphosate and AMPA concentrations in MIREC participants who were recruited between 2008-2011 from 10 Canadian cities. Of the 1880 participants whose first trimester urine samples were analyzed for glyphosate or AMPA, 1765 delivered a singleton, live birth. Our primary outcome was preterm birth (PTB) defined as births occurring between 20 and <37 weeks. Secondary outcomes were spontaneous preterm births (sPTB) and gestational age. We modelled the hazard of PTB and sPTB using discrete time survival analysis with multivariable logistic regression to calculate odds ratios (OR). We used multivariable linear regression models to quantify associations between analytes and gestational age. To assess effect modification by fetal sex, we stratified all models and calculated interaction terms. In the logistic regressions models we additionally calculated the relative excess risk due to interaction. Six percent (n = 106) of the study population delivered preterm, and 4.7% (n = 83) had a spontaneous preterm birth. Median specific-gravity standardized concentrations of glyphosate and AMPA were 0.25 and 0.21 µg/L. Associations between both glyphosate or AMPA and PTB, sPTB, and gestational age centered around the null value. The adjusted ORs of PTB for each doubling of glyphosate and AMPA concentrations were 0.98 (95% CI: 0.94, 1.03) and 0.99 (95% CI: 0.92, 1.06) respectively. We observed no evidence of differences by fetal sex. In this Canadian pregnancy cohort, neither glyphosate nor AMPA urinary concentrations was associated with PTB or reduced gestational length.

Predictors of Cigar, Cigarillo, and Little Cigar Initiation Among Hip Hop-Identifying Youth

Background: We explored predictors of cigar product initiation among Hip Hop-identifying U.S. youth using data from the U.S. Food and Drug Administration’s Fresh Empire evaluation. Participants were Hip Hop-identifying youth living in evaluation markets who had not initiated cigar product use at their first survey. Objectives: We modeled cigar product initiation odds using discrete time survival analysis logistic regression models as a function of factors related to one’s large social, physical, social/normative, and intrapersonal environment, and other tobacco use. Results: In the unique sample, 26.2% initiated cigar product use. Factors associated with higher cigar product initiation odds included: current/former (vs. non-susceptible never) cigarette smoking (odds ratio [OR]=5.35; p=.008); cigarette experimentation (vs. non-susceptible never smoking) (OR=3.26; p<.001); current (vs. never) e-cigarette use (OR=2.06; p<.001) and hookah use (OR=1.83; p=.011); having at least one friend who uses marijuana (OR=1.43; p=.008); high music use (OR=1.32; p=.035); household tobacco use (OR=1.26; p =.042); increased age (OR=1.18; p< .001); and higher sensation seeking (OR=1.16; p=.018). Youth reporting higher perceived smoking risks had lower cigar product initiation odds (OR=0.86; p=.029) as did Hispanic (OR=0.53; p<.001) and non-Hispanic Other youth (OR= 0.68; p=.023) (vs. non-Hispanic Black youth). Conclusions: The finding that high music use predicted cigar product initiation should be considered in light of cigar brand sponsorship of musical artists and events and indicates a potential opportunity for counter messaging. Peer crowd segmentation in this study identified unique and differing factors that influence tobacco use risk among Hip Hop-identifying youth that are not found in the general population.

Antipsychotic Discontinuation and New Trazodone Use in Ontario Nursing Homes: Evidence of Medication Substitution

ObjectivesAn unintended consequence of efforts to reduce antipsychotic medications in nursing homes is the increase in use of other psychotropic medications; however, evidence of substitution remains limited. Our objective was to measure individual-level prescribing patterns consistent with substitution of trazodone for antipsychotics. DesignRetrospective cohort study. Setting and ParticipantsResidents of Ontario nursing homes aged 66–105 years with an admission assessment between April 1, 2010, and March 31, 2019, who were receiving an antipsychotic and had no antidepressant medication use at admission to the nursing home. MethodsWe used linked health administrative data to examine changes in medication use over three quarterly assessments following admission. Antipsychotic and trazodone use were measured at each assessment. The rate of trazodone initiation was compared between residents no longer dispensed an antipsychotic (discontinued) and those with an ongoing antipsychotic (continued) using discrete time survival analysis, controlling for baseline resident characteristics. ResultsWe identified 13,306 residents dispensed an antipsychotic with no antidepressant use at admission (mean age 84 years, 61.5% women, 82.8% with dementia). As of the first quarterly assessment, nearly 20% of residents no longer received an antipsychotic and 9% received a new trazodone medication. Over time, residents who discontinued antipsychotics had a rate of trazodone initiation that was 82% higher compared to residents who continued (adjusted hazard ratio 1.82, 95% CI 1.66–2.00). Conclusions and ImplicationsResidents admitted to a nursing home with antipsychotic use had a higher rate of trazodone initiation if they discontinued (vs continued) an antipsychotic. These findings suggest antipsychotic substitution with trazodone after entering a nursing home.

Patients May Return to Work Sooner After Laminoplasty: Occupational Outcomes of the Cervical Spondylotic Myelopathy Surgical Trial.

Return-to-work (RTW) is an important outcome for employed patients considering surgery for cervical spondylotic myelopathy (CSM). We conducted a post hoc analysis of patients as-treated in the Cervical Spondylotic Myelopathy Surgical Trial, a prospective, randomized trial comparing surgical approaches for CSM to evaluate factors associated with RTW. In the trial, patients were randomized (2:3) to either anterior surgery (anterior cervical decompression/fusion [ACDF]) or posterior surgery (laminoplasty [LP], or posterior cervical decompression/fusion [PCDF], at surgeon's discretion). Work status was recorded at 1, 3, 6, and 12 months postoperatively. For patients working full-time or part-time on enrollment, time to RTW was compared across as-treated surgical groups using discrete-time survival analysis. Multivariate logistic regression was used to assess predictors of RTW. Clinical outcomes were compared using a linear mixed-effects model. A total of 68 (42%) of 163 patients were working preoperatively and were analyzed. In total, 27 patients underwent ACDF, 29 underwent PCDF, and 12 underwent LP. 45 (66%) of 68 patients returned to work by 12 months. Median time to RTW differed by surgical approach (LP = 1 month, ACDF = 3 months, PCDF = 6 months; P = .02). Patients with longer length-of-stay were less likely to be working at 1 month (odds ratio 0.51; 95% CI, 0.29-0.91; P = .022) and 3 months (odds ratio 0.39; 95% CI, 0.16-0.96; P = .04). At 3 months, PCDF was associated with lower Short-Form 36 physical component summary scores than ACDF (estimated mean difference [EMD]: 6.42; 95% CI, 1.4-11.4; P = .007) and LP (EMD: 7.98; 95% CI, 2.7-13.3; P = .003), and higher Neck Disability Index scores than ACDF (EMD: 12.48; 95% CI, 2.3-22.7; P = .01) and LP (EMD: 15.22; 95% CI, 2.3-28.1; P = .014), indicating worse perceived physical functioning and greater disability, respectively. Most employed patients returned to work within 1 year. LP patients resumed employment earliest, while PCDF patients returned to work latest, with greater disability at follow-up, suggesting that choice of surgical intervention may influence occupational outcomes.

Factors associated with PrEP-era HIV seroconversion in a 4-year U.S. national cohort of n = 6059 sexual and gender minority individuals who have sex with men, 2017-2022.

Community-based cohort studies of HIV seroconversion can identify important avenues for enhancing HIV prevention efforts in the era of pre-exposure prophylaxis (PrEP). Within individuals, one can assess exposure and outcome variables repeatedly and with increased certainty regarding temporal ordering. This cohort study examined the association of several risk factors with subsequent HIV seroconversion. We report data from a 4-year study (2017-2022) of 6059 HIV seronegative sexual and gender minority individuals who have sex with men who had indications for-, but were not using-, PrEP at enrolment. Participants completed repeat exposure assessments and self-collection of biospecimens for HIV testing. We examined the roles of race and ethnicity, socio-economic status, methamphetamine use and PrEP uptake over the course of follow-up in relation to HIV seroconversion. Over 4 years, 303 of the participants seroconverted across 18,421 person-years (incidence rate = 1.64 [95% CI: 1.59-1.70] per 100 person-years). In multivariable discrete-time survival analysis, factors independently associated with elevated HIV seroconversion risk included being Black/African American (adjusted risk ratio [aRR]: 2.44, 1.79-3.28), Hispanic/Latinx (1.53, 1.19-1.96), housing instability (1.58, 1.22-2.05) and past year methamphetamine use (3.82, 2.74-5.33). Conversely, time since study enrolment (24 vs. 12 months, 0.67, 0.51-0.87; 36 months, 0.60, 0.45-0.80; 48 months, 0.48, 0.35-0.66) and higher education (master's degree or higher vs. less than or equal to high school, 0.36, 0.17-0.66) were associated with reduced seroconversion risk. Compared to non-PrEP users in the past 2 years without a current clinical indication, those who started PrEP but then discontinued had higher seroconversion risk, irrespective of clinical indication (3.23, 1.74-6.46) or lack thereof (4.30, 1.85-9.88). However, those who initiated PrEP in the past year (0.14, 0.04-0.39) or persistently used PrEP in the past 2 years (0.33, 0.14-0.74) had a lower risk of seroconversion. Of all HIV seroconversions observed during follow-up assessments (12, 24, 36 and 48 months), methamphetamine was reported in the 12 months prior 128 (42.2%) times (overall). Interventions that acknowledge race and ethnicity, economic variables such as education and housing instability, and methamphetamine use are critically needed. Not only are interventions to engage individuals in PrEP care needed, but those that retain them, and re-engage those who may fall out of care are essential, given the exceptionally high risk of seroconversion in these groups.

Estimating Gender Differences in the Association between Cognitive Resilience and Mild Cognitive Impairment Incidence

Introduction: Recent evidence suggests that the influence of verbal intelligence and education on the onset of subjective cognitive decline may be modulated by gender, where education contributes less to cognitive resilience (CR) in women than in men. This study aimed to examine gender differences in the association between CR and mild cognitive impairment (MCI) incidence in an Australian population-based cohort. Methods: We included 1,806 participants who had completed at least the first two waves and up to four waves of assessments in the Personality and Total Health (PATH) Through Life study (baseline: 49% female, male = 62.5, SD = 1.5, age range = 60–66 years). CR proxies included measures of educational attainment, occupation skill, verbal intelligence, and leisure activity. Discrete-time survival analyses were conducted to examine gender differences in the association between CR proxies and MCI risk, adjusting for age and apolipoprotein E4 status. Results: Gender differences were only found in the association between occupation and MCI risk, where lower occupation skill was more strongly associated with higher risk in men than in women (odds ratio [OR] = 1.30, 95% confidence interval [CI] [1.07, 1.57]). In both genders, after adjusting for education and occupation, one SD increase in leisure activity was associated with lower MCI risk by 32% (OR = 0.76, 95% CI [0.65, 0.89]). Higher scores in verbal intelligence assessment were associated with reduced risk of MCI by 28% (OR = 0.78, 95% CI [0.69, 0.89]). Conclusion: Occupational experience may contribute to CR differently between genders. Life course cognitive engagement and verbal intelligence may be more protective against MCI than education and occupation for both men and women.

Climate Change and Child Marriage: Evidence from Bangladesh

This paper examines the effects of environmental vulnerability on the risk of child marriage in Bangladesh. Community vulnerability measures are constructed for 240 rural communities in eight districts according to the presence of three indicators of environmental vulnerability—history of cyclones, flooding, and waterlogging. Community data are linked to individual-level adolescent survey data from a representative sample of 15,000 adolescent girls in those communities. Types of environmental vulnerability and the effect on adolescent girls’ marriage outcomes have been explored using discrete time survival analysis. Results show that coastal communities with prolonged waterlogging and salinity have significantly higher child marriage rates, and there is no evidence of higher risks of child marriage in flood-affected areas. The paper concludes that slow and rapid onset events vary in their impact on child marriage. It is important to distinguish between rapid onset factors, such as floods and cyclones, and slow and less dramatically visible factors, such as waterlogging, that affect marriage through longer-term impacts on lives and livelihoods. Programs need to cast a wider net to safeguard girls living in the communities not only where immediate and sudden environmental emergencies have occurred but also in the areas where climate-induced disasters may not seem very visible but have slow, cascading effects and pose a risk for child marriage.

Predicting the onset of myopia in children by age, sex, and ethnicity: Results from the CLEERE Study.

Clinicians and researchers would benefit from being able to predict the onset of myopia for an individual child. This report provides a model for calculating the probability of myopia onset, year-by-year and cumulatively, based on results from the largest, most ethnically diverse study of myopia onset in the United States. This study aimed to model the probability of the onset of myopia in previously nonmyopic school-aged children. Children aged 6 years to less than 14 years of age at baseline participating in the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study who were nonmyopic and less hyperopic than +3.00 D (spherical equivalent) were followed up for 1 to 7 years through eighth grade. Annual measurements included cycloplegic autorefraction, keratometry, ultrasound axial dimensions, and parental report of children's near work and time spent in outdoor and/or sports activities. The onset of myopia was defined as the first visit with at least -0.75 D of myopia in each principal meridian. The predictive model was built using discrete time survival analysis and evaluated with C statistics. The model of the probability of the onset of myopia included cycloplegic spherical equivalent refractive error, the horizontal/vertical component of astigmatism (J0), age, sex, and race/ethnicity. Onset of myopia was more likely with lower amounts of hyperopia and less positive/more negative values of J0. Younger Asian American females had the highest eventual probability of onset, whereas older White males had the lowest. Model performance increased with older baseline age, with C statistics ranging from 0.83 at 6 years of age to 0.92 at 13 years. The probability of the onset of myopia can be estimated for children in the major racial/ethnic groups within the United States on a year-by-year and cumulative basis up to age 14 years based on a simple set of refractive error and demographic variables.

Reviving Decades-Old Wisdom: Longitudinal Analysis of Renin-Angiotensin System Inhibitors and Its Effects on Acute Ischemic Stroke to Improve Outcomes.

While renin-angiotensin system (RAS) inhibitors have a longstanding history in blood pressure control, their suitability as first-line in-patient treatment may be limited due to prolonged half-life and kidney failure concerns. Using a cohort design, we assessed the impact of RAS inhibitors, either alone or in combination with beta-blockers, on mortality, while exploring interactions, including those related to end-stage renal disease and serum creatinine levels. Eligible subjects were Acute Ischemic Stroke (AIS) patients aged 18 or older with specific subtypes who received in-patient antihypertensive treatment. The primary outcome was mortality rates. Statistical analyses included cross-sectional and longitudinal approaches, employing generalized linear models, G-computation, and discrete-time survival analysis over a 20-day follow-up period. In our study of 3,058 AIS patients, those using RAS inhibitors had significantly lower in-hospital mortality (2.2%) compared to non-users (12.1%), resulting in a relative risk (RR) of 0.18 (95% CI: 0.12-0.26). Further analysis using G-computation revealed a marked reduction in mortality risk associated with RAS inhibitors (0.0281 vs. 0.0913, risk difference [RD] of 6.31% or 0.0631, 95% CI: 0.046-0.079). Subgroup analysis demonstrated notable benefits, with individuals having creatinine levels below and above 1.3 mg/dl exhibiting statistically significant RD (RD -0.0510 vs. -0.0895), and a significant difference in paired comparison (-0.0385 or 3.85%, CI 0.023-0.054). Additionally, longitudinal analysis confirmed a consistent daily reduction of 0.93% in mortality risk associated with the intake of RAS inhibitors. RAS inhibitors are associated with a significant reduction in in-hospital mortality in AIS patients, suggesting potential clinical benefits in improving patient outcomes.

The retention and attrition of early-career music teachers: a survival analysis

Over 30 states have experienced a shortage of music teachers in the past decade. The attrition of early-career teachers is one of the largest contributing factors to the rising demand for teachers nationally, but there is a lack of rigorous empirical research examining characteristics associated with attrition of music teachers. I leveraged data from the Maryland Longitudinal Data System to examine early-career music teachers’ retention and attrition patterns between 2013 and 2020 using descriptive statistics and discrete-time survival analysis (N = 6430). On average, 74% of early-career music teachers retained their current position each year, 8% moved to a different school in Maryland, and 18% of left public school music teaching in Maryland. Survival analysis indicated that half of all music teachers left public-school music teaching in Maryland within their first five years of teaching. Attrition risk was greatest in years two and three. Other factors associated with attrition risk included sex, race, ethnicity, school grade level, aspects of school culture, the student body, school and district urbanicity, and the number of teachers employed by the school district. Discussed policy recommendations include mentorship programs, teacher compensation, school resources, comprehensive family leave, and music teacher recruitment.

Risk of Primary Incident Hepatitis C Infection Following Bacterial Sexually Transmissible Infections Among Gay and Bisexual Men in Australia From 2016 to 2020.

In Australia, the incidence of hepatitis C virus (HCV) has declined among gay and bisexual men (GBM) with human immunodeficiency virus (HIV) since 2015 and is low among GBM using HIV preexposure prophylaxis (PrEP). However, ongoing HCV testing and treatment remains necessary to sustain this. To assess the potential utility of sexually transmissible infections (STIs) to inform HCV testing among GBM with HIV and GBM using PrEP, we examined the association between bacterial STI diagnoses and subsequent primary HCV infection. Data were from a national network of 46 clinics participating in the Australian Collaboration for Coordinated Enhanced Sentinel Surveillance. GBM included had ≥1 HCV antibody negative test result and ≥1 subsequent HCV antibody and/or RNA test. Discrete time survival analysis was used to estimate the association between a positive syphilis, rectal chlamydia, and rectal gonorrhea diagnosis in the previous 2 years and a primary HCV diagnosis, defined as a positive HCV antibody or RNA test result. Among 6529 GBM with HIV, 92 (1.4%) had an incident HCV infection. A prior positive syphilis diagnosis was associated with an incident HCV diagnosis (adjusted hazard ratio, 1.99 [95% confidence interval, 1.11-3.58]). Among 13 061 GBM prescribed PrEP, 48 (0.4%) had an incident HCV diagnosis. Prior rectal chlamydia (adjusted hazard ratio, 2.75 [95% confidence interval, 1.42-5.32]) and rectal gonorrhea (2.54 [1.28-5.05]) diagnoses were associated with incident HCV. Diagnoses of bacterial STIs in the past 2 years was associated with HCV incidence. These findings suggest that STIs might be useful for informing HCV testing decisions and guidelines for GBM with HIV and GBM using PrEP.

Non-completion of teacher education students. Educational and occupational pathways of persons who withdraw from a teacher education program in Germany

The study examines non-completion events among over 5,500 teacher education students in Germany and their paths after non-completion. Most students switch programs within teacher education or to a non-teaching program after leaving. Fewer students enter the labor market or vocational training. We use discrete-time survival analyses to study predictors of higher education dropout and study program switch. A match of self-perception and future goals with the teacher education program decreases the likelihood of switching the program or dropping out. Perceived academic performance and the match between performance goals and actual performance are exclusively predictive of the decision to drop out.

Type-switching of short-acting nicotine replacement therapy products and its implications for treatment

IntroductionThe frequency with which people change from one medical treatment to another partly reflects satisfaction with the initial intervention. In this secondary analysis of observational data, we explore switch rates for short-acting nicotine replacement therapy (NRT) products, which differ in mode of use, rapidity of action, and adverse effect profiles. MethodsWe analyzed data from 46,882 participants in the Smoking Treatment for Ontario Patients program who received short-acting NRT (gum, lozenge, oral spray, or inhaler) at their initial visit. We used discrete-time survival analysis to model the time elapsing before a change was made to another product and included time-by-product interactions to explore differences over time and product-by-previous-quit-attempts interactions to examine the importance of potential previous exposure to NRT. We adjusted both models for a range of sociodemographic and tobacco use variables. ResultsOverall, 37.9% (95% CI = 37.5%, 38.4%) of participants switched to a different product at their first follow-up visit. Time-averaged and adjusted switch probabilities were 21.1% for gum, 23.8% for lozenge, 26.0% for inhaler, and 28.8% for oral spray. Switch rates were highest for people without past quit attempts, for women, and for people also using the nicotine patch. ConclusionsPeople frequently switch from one type of short-acting NRT to another. We did not assess reasons for switching, but they may include adverse effects, impracticality, and perceived ineffectiveness. Given the superior effectiveness of combination treatment, making multiple products available may improve outcomes by allowing some people to continue with short-acting products for longer.

Physical Activity, Social Participation, and Pain Outcomes Among Community-Dwelling Older Adults

BackgroundLittle is known regarding the effect of social participation (SP) and physical activity (PA) on pain outcomes among community-dwelling older adults in the United States. AimsTo determine whether SP and PA are associated with pain outcomes (bothersome pain and number of pain sites). DesignGuided by the biopsychosocial model of chronic pain for older adults, we analyzed data from 7,187 community dwelling participants in the National Health and Aging Trends Study. In cross-sectional analyses, we utilized logistic and negative binomial regressions. MethodsWe prospectively assessed the association between SP/ PA and new or worsening pain from baseline (2011) to 2021 using a discrete time survival analysis by logistic regression, controlling for sociodemographic and health characteristics. ResultsAt baseline, participation in 5 SP activities per month versus no activities, and performing any PA compared with no PA were significantly associated with lower likelihood of bothersome pain. Although SP and PA were associated with reporting fewer pain sites at baseline, SP was not associated with developing new or worsening pain, prospectively. However, walking and vigorous exercise compared with no PA was significantly associated with a 10% lower risk of developing new or worsening pain (adj odds ratio 0.90, 95% confidence interval [CI] 0.82-0.98). ConclusionsPhysical activity but not social participation may protect against development of new or worsening pain. More research is needed to determine whether social activity can be beneficial for pain prevention and management. Efforts to promote physical activity among older adults may reduce risk of new or worsening pain.

Parenting, Peers, and Alcohol Use Initiation Among Black, White, and Black-White Adolescents: Evidence Using Discrete-Time Survival Analysis

ABSTRACT Alcohol use among Biracial adolescents remains understudied. This study examined how parenting and peer factors relate to age of alcohol use onset among Black, White, and Biracial Black-White adolescents and emerging adults. We used Add Health data to produce a final analytic sample of 13,528 adolescents who self-identified as White, Black, or Biracial Black-White. Discrete-time survival analysis implemented within logistic regression indicated Black adolescents showed the lowest probability of alcohol use onset by age 18, followed by Biracial adolescents, and White adolescents. The probability of alcohol use onset increased for Monoracial Black and White adolescents at ages 16, 18, and 21. Descriptively our model suggest that Biracial adolescents exhibit a sharp decline in their probability of alcohol use onset at age 16 and a sharp increase at age 21. However, this trend did not differ significantly from the other racial groups. Consistent with social control and learning theories, low parental acceptance, high parental control, and peer substance use were associated with alcohol use onset. Alcohol use onset trajectories differed for Monoracial and Biracial adolescents with Biracial individuals reporting greater alcohol onset in adulthood. Prevention efforts should continue to target parental acceptance, parental control, and peer substance use.

Marijuana and E-cigarette Initiation Among Adolescents: A Survival Analysis

PurposePrior literature suggests marijuana and e-cigarette initiation among adolescents is surpassing combustible cigarette uptake. Marijuana and nicotine co-use is also a concern as these products grow in popularity. Initiation trajectories for marijuana and e-cigarette products are not well understood, let alone how the use of one product may impact initiation susceptibility for the other. MethodsWe used national longitudinal data from the Population Assessment of Tobacco and Health study from 2013 to 2018. Eighth graders in Wave 1 made up the analytic sample (N = 2,270). We employed discrete time survival analyses to determine the likelihood of initiating marijuana and e-cigarettes between Waves 2 and 5. We used survival analyses to estimate the relationships between prior cigarette and marijuana use and subsequent e-cigarette initiation, as well as prior cigarette and e-cigarette use and subsequent marijuana initiation. ResultsPrevious marijuana initiation was associated with later e-cigarette initiation (odds ratio = 6.88, 95% confidence interval [4.89, 9.67]). Previous e-cigarette initiation was associated with later marijuana initiation (odds ratio = 9.28, 95% confidence interval [6.86, 12.56]). By wave 5, adolescents were more than 42% likely to initiate marijuana and e-cigarettes. DiscussionSusceptibility to marijuana and e-cigarette products starts as early as eighth grade and increases over time. The use of one product is significantly related to later initiation for the other. Rather than addressing marijuana and nicotine as separate concerns, interventions may benefit by recognizing the closely related nature of these products.

Timing matters: The contribution of running during different periods of the light/dark cycle to susceptibility to activity-based anorexia in rats

Individuals with anorexia nervosa (AN) exhibit dangerous weight loss due to restricted eating and hyperactivity. Those with AN are predominantly women and most cases have an age of onset during adolescence. Activity-based anorexia (ABA) is a rodent behavioral paradigm that recapitulates many of the features of AN including restricted food intake and hyperactivity, resulting in precipitous weight loss. In addition, there is enhanced sensitivity to the paradigm during adolescence. In ABA, animals are given time-restricted access to food and unlimited access to a running wheel. Under these conditions, most animals increase their running and decrease their food intake resulting in precipitous weight loss until they either die or researchers discontinue the paradigm. Some animals learn to balance their food intake and energy expenditure and are able to stabilize and eventually reverse their weight loss. For these studies, adolescent (postnatal day 33–42), female Sprague Dawley (n = 68) rats were placed under ABA conditions (unlimited access to a running wheel and 1.5 hrs access to food) until they either reached 25% body weight loss or for 7 days. 70.6% of subjects reached 25% body weight loss before 7 days and were designated susceptible to ABA while 29.4% animals were resistant to the paradigm and did not achieve the weight loss criterion. We used discrete time survival analysis to investigate the contribution of food intake and running behavior during distinct time periods both prior to and during ABA to the likelihood of reaching the weight loss criterion and dropping out of ABA. Our analyses revealed risk factors, including total running and dark cycle running, that increased the likelihood of dropping out of the paradigm, as well as protective factors, including age at the start of ABA, the percent of total running exhibited as food anticipatory activity (FAA), and food intake, that reduced the likelihood of dropping out. These measures had predictive value whether taken before or during exposure to ABA conditions. Our findings suggest that certain running and food intake behaviors may be indicative of a phenotype that predisposes animals to susceptibility to ABA. They also provide evidence that running during distinct time periods may reflect functioning of distinct neural circuitry and differentially influence susceptibility and resistance to the paradigm.

Prospective association of attachment style with suicide attempts among US Army soldiers.

Insecure attachment styles are associated with retrospectively reported suicide attempts (SAs). It is not known if attachment styles are prospectively associated with medically documented SAs. A representative sample of US Army soldiers entering service (n = 21 772) was surveyed and followed via administrative records for their first 48 months of service. Attachment style (secure, preoccupied, fearful, dismissing) was assessed at baseline. Administrative medical records identified SAs. Discrete-time survival analysis examined associations of attachment style with future SA during service, adjusting for time in service, socio-demographics, service-related variables, and mental health diagnosis (MH-Dx). We examined whether associations of attachment style with SA differed based on sex and MH-Dx. In total, 253 respondents attempted suicide. Endorsed attachment styles included secure (46.8%), preoccupied (9.1%), fearful (15.7%), and dismissing (19.2%). Examined separately, insecure attachment styles were associated with increased odds of SA: preoccupied [OR 2.5 (95% CI 1.7-3.4)], fearful [OR 1.6 (95% CI 1.1-2.3)], dismissing [OR 1.8 (95% CI 1.3-2.6)]. Examining attachment styles simultaneously along with other covariates, preoccupied [OR 1.9 (95% CI 1.4-2.7)] and dismissing [OR 1.7 (95% CI 1.2-2.4)] remained significant. The dismissing attachment and MH-Dx interaction was significant. In stratified analyses, dismissing attachment was associated with SA only among soldiers without MH-Dx. Other interactions were non-significant. Soldiers endorsing any insecure attachment style had elevated SA risk across the first 48 months in service, particularly during the first 12 months. Insecure attachment styles, particularly preoccupied and dismissing, are associated with increased future SA risk among soldiers. Elevated risk is most substantial during first year of service but persists through the first 48 months. Dismissing attachment may indicate risk specifically among soldiers not identified by the mental healthcare system.