Mei-Chen Hu

Epidemiology and Correlates of Daily Smoking and Nicotine Dependence Among Young Adults in the United States.

OBJECTIVES We describe the epidemiology of smoking behaviors in a national young adult sample and identify common and unique demographic, social, and psychological correlates of daily smoking and lifetime and current nicotine dependence by race/ethnicity. METHODS Data are from the National Longitudinal Survey of Adolescent Health, wave III. Dependence was measured by the Revised Fagerström Test for Nicotine Dependence. Logistic regressions were estimated. RESULTS Hispanic ethnicity, low education, parental and peer smoking, novelty seeking, early age of smoking onset, and pleasurable initial smoking experiences are significantly correlated with daily smoking and lifetime nicotine dependence. Depressive symptoms are uniquely associated with lifetime and current dependence. Few factors are highly associated with current dependence. Initial sensitivity to smoking has a significantly greater impact on daily smoking than on dependence. Correlates of smoking behaviors are mostly common across racial/ethnic groups, although parental and peer smoking are significant for Whites and Hispanics but not for African Americans. CONCLUSIONS There are more common than unique correlates of each smoking stage and across racial/ethnic groups. Primary prevention and interventions addressing the factors tested could be uniform for most chronic smokers irrespective of dependence status and race/ethnicity.

Racial/Ethnic Differences in Cigarette Smoking Initiation and Progression to Daily Smoking: A Multilevel Analysis

OBJECTIVES We sought to identify individual and contextual predictors of adolescent smoking initiation and progression to daily smoking by race/ethnicity. METHODS We used data from the National Longitudinal Study of Adolescent Health to estimate the effects of individual (adolescent, family, peer) and contextual (school and state) factors on smoking onset among nonsmokers (n = 5374) and progression to daily smoking among smokers (n = 4474) with multilevel regression models. RESULTS Individual factors were more important predictors of smoking behaviors than were contextual factors. Predictors of smoking behaviors were mostly common across racial/ethnic groups. CONCLUSIONS The few identified racial/ethnic differences in predictors of smoking behavior suggest that universal prevention and intervention efforts could reach most adolescents regardless of race/ethnicity. With 2 exceptions, important contextual factors remain to be identified.

Do Treatment Improvements in PTSD Severity Affect Substance Use Outcomes? A Secondary Analysis From a Randomized Clinical Trial in NIDA's Clinical Trials Network

OBJECTIVE The purpose of the analysis was to examine the temporal course of improvement in symptoms of posttraumatic stress disorder (PTSD) and substance use disorder among women in outpatient substance abuse treatment. METHOD Participants were 353 women randomly assigned to 12 sessions of either trauma-focused or health education group treatment. PTSD and substance use assessments were conducted during treatment and posttreatment at 1 week and after 3, 6, and 12 months. A continuous Markov model was fit on four defined response categories (nonresponse, substance use response, PTSD response, or global response [improvement in both PTSD and substance use]) to investigate the temporal association between improvement in PTSD and substance use symptom severity during the studys treatment phase. A generalized linear model was applied to test this relationship over the follow-up period. RESULTS Subjects exhibiting nonresponse, substance use response, or global response tended to maintain original classification; subjects exhibiting PTSD response were significantly more likely to transition to global response over time, indicating maintained PTSD improvement was associated with subsequent substance use improvement. Trauma-focused treatment was significantly more effective than health education in achieving substance use improvement, but only among those who were heavy substance users at baseline and had achieved significant PTSD reductions. CONCLUSIONS PTSD severity reductions were more likely to be associated with substance use improvement, with minimal evidence of substance use symptom reduction improving PTSD symptoms. Results support the self-medication model of coping with PTSD symptoms and an empirical basis for integrated interventions for improved substance use outcomes in patients with severe symptoms.

Zero-Inflated and Hurdle Models of Count Data with Extra Zeros: Examples from an HIV-Risk Reduction Intervention Trial

Background: In clinical trials of behavioral health interventions, outcome variables often take the form of counts, such as days using substances or episodes of unprotected sex. Classically, count data follow a Poisson distribution; however, in practice such data often display greater heterogeneity in the form of excess zeros (zero-inflation) or greater spread in the values (overdispersion) or both. Greater sample heterogeneity may be especially common in community-based effectiveness trials, where broad eligibility criteria are implemented to achieve a generalizable sample. Objectives: This article reviews the characteristics of Poisson model and the related models that have been developed to handle overdispersion (negative binomial (NB) model) or zero-inflation (zero-inflated Poisson (ZIP) and Poisson hurdle (PH) models) or both (zero-inflated negative binomial (ZINB) and negative binomial hurdle (NBH) models). Methods: All six models were used to model the effect of an HIV-risk reduction intervention on the count of unprotected sexual occasions (USOs), using data from a previously completed clinical trial among female patients (N = 515) participating in community-based substance abuse treatment (Tross et al. Effectiveness of HIV/AIDS sexual risk reduction groups for women in substance abuse treatment programs: Results of NIDA Clinical Trials Network Trial. J Acquir Immune Defic Syndr 2008; 48(5):581–589). Goodness of fit and the estimates of treatment effect derived from each model were compared. Results: The ZINB model provided the best fit, yielding a medium-sized effect of intervention. Conclusions and Scientific Significance: This article illustrates the consequences of applying models with different distribution assumptions on the data. If a model used does not closely fit the shape of the data distribution, the estimate of the effect of the intervention may be biased, either over- or underestimating the intervention effect.

Effectiveness of HIV/STD Sexual Risk Reduction Groups for Women in Substance Abuse Treatment Programs : Results of NIDA Clinical Trials Network Trial

Context:Because drug-involved women are among the fastest growing groups with AIDS, sexual risk reduction intervention for them is a public health imperative. Objective:To test effectiveness of HIV/STD safer sex skills building (SSB) groups for women in community drug treatment. Design:Randomized trial of SSB versus standard HIV/STD Education (HE); assessments at baseline, 3 and 6 months. Participants:Women recruited from 12 methadone or psychosocial treatment programs in Clinical Trials Network of National Institute on Drug Abuse. Five hundred fifteen women with ≥1 unprotected vaginal or anal sex occasion (USO) with a male partner in the past 6 months were randomized. Interventions:In SSB, five 90-minute groups used problem solving and skills rehearsal to increase HIV/STD risk awareness, condom use, and partner negotiation skills. In HE, one 60-minute group covered HIV/STD disease, testing, treatment, and prevention information. Main Outcome:Number of USOs at follow-up. Results:A significant difference in mean USOs was obtained between SSB and HE over time (F = 67.2, P < 0.0001). At 3 months, significant decrements were observed in both conditions. At 6 months, SSB maintained the decrease and HE returned to baseline (P < 0.0377). Women in SSB had 29% fewer USOs than those in HE. Conclusions:Skills building interventions can produce ongoing sexual risk reduction in women in community drug treatment.

Salivary cotinine concentration versus self-reported cigarette smoking: Three patterns of inconsistency in adolescence.

The present study examined the extent and sources of discrepancies between self-reported cigarette smoking and salivary cotinine concentration among adolescents. The data are from household interviews with a cohort of 1,024 adolescents from an urban school system. Histories of tobacco use in the last 7 days and saliva samples were obtained. Logistic regressions identified correlates of three inconsistent patterns: (a) Pattern 1-self-reported nonsmoking among adolescents with cotinine concentration above the 11.4 ng/mg cutpoint (n = 176), (b) Pattern 2-low cotinine concentration (below cutpoint) among adolescents reporting having smoked within the last 3 days (n = 155), and (c) Pattern 3-high cotinine concentration (above cutpoint) among adolescents reporting not having smoked within the last 3 days (n = 869). Rates of inconsistency were high among smokers defined by cotinine levels or self-reports (Pattern 1 = 49.1%; Pattern 2 = 42.0%). Controlling for other covariates, we found that reports of nonsmoking among those with high cotinine (Pattern 1) were associated with younger age, having few friends smoking, little recent exposure to smokers, and being interviewed by the same interviewer as the parent and on the same day. Low cotinine concentration among self-reported smokers (Pattern 2) was negatively associated with older age, being African American, number of cigarettes smoked, depth of inhalation, and exposure to passive smoke but positively associated with less recent smoking and depressive symptoms. High cotinine concentrations among self-reported nonsmokers was positively associated with exposure to passive smoke (Pattern 3). The data are consonant with laboratory findings regarding ethnic differences in nicotine metabolism rate. The inverse relationship of cotinine concentration with depressive symptoms has not previously been reported. Depressed adolescent smokers may take in smaller doses of nicotine than nondepressed smokers; alternatively, depressed adolescents may metabolize nicotine more rapidly.

Developmental trajectories of criteria of nicotine dependence in adolescence

We describe the nature and predictors of developmental trajectories of symptoms of DSM-IV nicotine dependence in adolescence following smoking initiation. Data are from a longitudinal cohort of 324 new smokers from grades 6-10 in the Chicago Public Schools, interviewed 5 times at 6-month intervals. Monthly data on DSM-IV symptoms of nicotine dependence were available for 36 months. Growth mixture modeling was applied to the monthly histories to identify trajectories of DSM-IV criteria of nicotine dependence. A four-class solution best fitted the data: no DSM criterion (47.7%); early onset/chronic course (19.8%); early onset/remission (17.3%); late onset (15.2%). Blunt use prior to cigarette use was associated with the three symptomatic trajectories. Conduct disorder and prior heavy smoking were associated with Class 2 (chronic). Conduct disorder differentiated Class 2 from Class 4 (late onset), while pleasant initial sensitivity to the first tobacco experience was associated with Classes 2 and 3 (remit) and differentiated Class 2 from Class 4. Novelty seeking characterized Class 3. Parental dependence differentiated chronicity (Class 2) from remission (Class 3) among those who developed symptoms early. Being Hispanic reduced membership in Classes 3 and 4, and being male for Class 3. The data highlight the importance of parental nicotine dependence as a risk factor for early and sustained nicotine dependence by the offspring, pleasant initial sensitivity and conduct disorder for early onset of dependence, and blunt use prior to smoking for all trajectories. The factors important for onset of dependence are not necessarily the same as those for sustained course.

The role of alcohol misuse in PTSD outcomes for women in community treatment: A secondary analysis of NIDA's Women and Trauma Study

BACKGROUND Individuals with comorbid substance use and posttraumatic stress disorder may differentially benefit from integrated trauma-focused interventions based on specific presenting characteristics such as substance use type and PTSD severity. The current study is a secondary analysis of a NIDA Clinical Trials Network study exploring the effectiveness of two interventions for women with comorbid PTSD and substance use disorders. METHOD Generalized estimating equations were used to examine the association of baseline alcohol misuse with PTSD outcome measures over time for all randomized participants. RESULTS Women entering treatment with baseline alcohol misuse had higher Post Traumatic Stress Disorder Symptom Scale (PSS-SR) total scores (t=2.43, p<.05), cluster C (avoidance/numbing) scores (t=2.63, p<.01), and cluster D (hyper-arousal) scores (t=2.31, p<.05). For women with alcohol misuse, after treatment week 1, PSS-SR scores were significantly lower in the Seeking Safety intervention during treatment (chi(2)(1)=4.00, p<.05) and follow-up (chi(2)(1)=4.87, p<.05) compared to those in the health education intervention. Alcohol misusers in the Seeking Safety group who had higher baseline hyper-arousal severity improved more quickly than those with lower baseline hyper-arousal severity during treatment (chi(2)(1)=4.06, p<.05). CONCLUSIONS These findings suggest that the type of substance abuse at treatment entry may inform treatment selection, predict treatment response among those with co-occurring PTSD and substance use disorders, and indicate a more severe clinical picture.

Relationship Power and Sexual Risk among Women in Community-Based Substance Abuse Treatment

Relationship power has been highlighted as a major factor influencing women’s safer sex practices. Little research, however, has specifically examined relationship power in drug-involved women, a population with increased risk for HIV transmission. Using baseline data from a National Institute on Drug Abuse Clinical Trials Network multisite trial of a women’s HIV prevention intervention in community-based drug treatment programs, this paper examined the association between sexual relationship power and unprotected vaginal or anal sex. The Sexual Relationship Power Scale, a measure of relationship control and decision-making dominance, was used to assess the association between power and unprotected sex in relationships with primary male partners. It was hypothesized that increased relationship power would be associated with decreased unprotected sexual occasions, after controlling for relevant empirical and theoretical covariates. Findings show a more complex picture of the association between power and sexual risk in this population, with a main effect in the hypothesized direction for decision-making dominance but not for relationship control. Possible explanations for these findings are discussed, and future research directions for examining power constructs and developing interventions targeting relationship power among drug-involved women are suggested.

Training substance abuse clinicians in motivational interviewing using live supervision via teleconferencing.

OBJECTIVE Training through traditional workshops is relatively ineffective for changing counseling practices. Teleconferencing supervision (TCS) was developed to provide remote, live supervision for training motivational interviewing (MI). METHOD Ninety-seven drug treatment counselors completed a 2-day MI workshop and were randomized to live supervision via teleconferencing (TCS; n = 32), standard tape-based supervision (tape; n = 32), or workshop alone (workshop; n = 33). Supervision conditions received 5 weekly supervision sessions at their sites using actors as standard patients. Sessions with clients were rated for MI skill with the Motivational Interviewing Treatment Integrity (MITI) Coding System pre-workshop and 1, 8, and 20 weeks post-workshop. Mixed-effects linear models were used to test training condition on MI skill at 8 and 20 weeks. RESULTS TCS scored better than workshop on the MITI for spirit (mean difference = 0.76; p < .0001; d = 1.01) and empathy (mean difference = 0.68; p < .001; d = 0.74). TCS was superior to workshop in reducing MI non-adherence and was superior to workshop and tape in increasing reflection to question ratio. Tape was superior to TCS in increasing complex reflections. Percentage of counselors meeting proficiency differed significantly between training conditions for the most stringent threshold (spirit and empathy scores ≥ 6). CONCLUSIONS TCS shows promise for promoting new counseling behaviors following participation in workshop training. However, further work is needed to improve supervision methods to bring more clinicians to high levels of proficiency and facilitate dissemination of evidence-based practices.