Biomedical subjects

David J Klein

Publications and source records attributed to David J Klein.

At least 19 recordsLinked to original sources

PubMed2007

Outpatient mental health utilization among commercially insured individuals: in- and out-of-network care.

OBJECTIVE: This study examined the rates and correlates of out-of-network outpatient mental health specialty care. RESEARCH DESIGN: Using administrative data from a large insurer, we examine the frequency of out-of-network utilization, analyze demographic and clinical characteristics of individuals receiving out-of-network care, and examine the types of service provided out-of-network. RESULTS: Out-of-network outpatient mental health care was received by 15.4% of adults who used outpatient mental health services, with 11.8% of adult outpatient mental health users receiving only out-of-network care and 3.6% receiving both in-network and out-of-network care. Out-of-network users received significantly more outpatient mental health care than individuals receiving only in-network mental health care. Rates of out-of-network psychotherapy services were substantially greater than for other commonly provided mental health services. CONCLUSION: A significant number of patients covered under this insurer received their outpatient mental health care out-of-network. This is most pronounced for individuals receiving psychotherapy. Further information is needed to improve our understanding of who seeks care from out-of-network providers and why as well as the effect of such care on clinical outcomes.

Adolescent↗

PubMed2006

Are drug experimenters better adjusted than abstainers and users?: a longitudinal study of adolescent marijuana use.

PURPOSE: Experimentation with substance use is normative during adolescence and prior research suggests that adolescents who refrain from experimentation may be psychologically maladjusted. This longitudinal study compared lifetime marijuana abstainers (n = 1177), experimenters (n = 873), and frequent users (n = 205) at grade 12 on psychosocial functioning during late adolescence and young adulthood. METHODS: Participants were recruited from middle schools in 1985 (grade 7) and assessed repeatedly, including in 1990 (grade 12) and 1995 (age 23). Self-report surveys assessed lifetime substance use at grade 12, and psychosocial functioning at grade 12 and age 23. Group differences after controlling for key demographics were estimated using multivariate logistic regression and analysis of covariance. RESULTS: Adolescent abstainers from marijuana often fared better (and in no case worse) than experimenters and frequent users both concurrently and later in life on school engagement, family and peer relations, mental health, and deviant behavior. Similar results were found in ancillary analyses using a definition of adolescent "abstainer" that also accounted for cigarette and alcohol use. CONCLUSIONS: Results refute the idea that adolescents who abstain from substance use are maladjusted, and suggest instead that they function better than experimenters later in life, during the transition to young adulthood.

Adolescent↗

PubMed2006

Stimulus-invariant processing and spectrotemporal reverse correlation in primary auditory cortex.

The spectrotemporal receptive field (STRF) provides a versatile and integrated, spectral and temporal, functional characterization of single cells in primary auditory cortex (AI). In this paper, we explore the origin of, and relationship between, different ways of measuring and analyzing an STRF. We demonstrate that STRFs measured using a spectrotemporally diverse array of broadband stimuli-such as dynamic ripples, spectrotemporally white noise, and temporally orthogonal ripple combinations (TORCs)-are very similar, confirming earlier findings that the STRF is a robust linear descriptor of the cell. We also present a new deterministic analysis framework that employs the Fourier series to describe the spectrotemporal modulations contained in the stimuli and responses. Additional insights into the STRF measurements, including the nature and interpretation of measurement errors, is presented using the Fourier transform, coupled to singular-value decomposition (SVD), and variability analyses including bootstrap. The results promote the utility of the STRF as a core functional descriptor of neurons in AI.

Acoustic Stimulation↗

PubMed2006

Affective and behavioral responses to health-related social control.

Social control has the potential to encourage engagement in a healthy lifestyle, but its effectiveness may depend on the nature of the influence attempt. Participants (N = 282) described a situation in which someone attempted to influence their health-related behavior. Experiencing positive social control was associated with a greater tendency to change the behavior and less ignoring/doing nothing, whereas negative social control was associated with a lesser tendency to change the behavior and more hiding of unhealthy behavior. These associations could be accounted for by affective responses to the social control attempts. Results emphasize the need to better understand the regulatory influence of relationships on health behavior and the conditions under which social control is most likely to have health-promoting effects.

Adult↗

PubMed2006

Does solitary substance use increase adolescents' risk for poor psychosocial and behavioral outcomes? A 9-year longitudinal study comparing solitary and social users.

This longitudinal study compared Grade 8 solitary cigarette smokers (n = 541), drinkers (n = 577), and marijuana users (n = 148) with adolescents who restricted their use of these substances to social settings (ns = 562, 1,426, and 388, respectively) on adolescent functioning and young adult outcomes. In Grade 8, solitary users held more positive beliefs about the consequences of substance use, earned poorer grades, engaged in more deviant behavior, and devoted less time to school and more time to social activities. By age 23, these solitary users had lower educational attainment, poorer self-rated health, and greater substance use problems. Results indicate the importance of better understanding and addressing the needs of this understudied group of high-risk youth.

Adaptation, Psychological↗

PubMed2006

Impact of instructional practices on student satisfaction with attendings' teaching in the inpatient component of internal medicine clerkships.

OBJECTIVE: To determine the prevalence and influence of specific attending teaching practices on student evaluations of the quality of attendings' teaching in the inpatient component of Internal Medicine clerkships. DESIGN: Nationwide survey using a simple random sample. SETTING: One hundred and twenty-one allopathic 4-year medical schools in the United States. PARTICIPANTS: A total of 2,250 fourth-year medical students. MEASUREMENTS AND MAIN RESULTS: In the spring of 2002, student satisfaction with the overall quality of teaching by attendings in the inpatient component of Internal Medicine clerkships was measured on a 5-point scale from very satisfied to very dissatisfied (survey response rate, 68.3%). Logistic regression was used to determine the association of specific teaching practices with student evaluations of the quality of their attendings' teaching. Attending physicians' teaching practices such as engaging students in substantive discussions (odds ratio (OR)=3.0), giving spontaneous talks and prepared presentations (OR=1.6 and 1.8), and seeing new patients with the team (OR=1.2) were strongly associated with higher student satisfaction, whereas seeming rushed and eager to finish rounds was associated with lower satisfaction (OR=0.6). CONCLUSION: Findings suggest that student satisfaction with attendings' teaching is high overall but there is room for improvement. Specific teaching behaviors used by attendings affect student satisfaction. These specific behaviors could be taught and modified for use by attendings and clerkship directors to enhance student experiences during clerkships.

Adult↗

PubMed2006

A randomized, double-blind, placebo-controlled trial of metformin treatment of weight gain associated with initiation of atypical antipsychotic therapy in children and adolescents.

OBJECTIVE: Second-generation, or atypical, antipsychotics effectively treat psychiatric illness in children and adolescents. However, weight gain and abnormalities in insulin sensitivity, including diabetes, complicate this therapy. METHOD: A 16-week double-blind, placebo-controlled trial was conducted to evaluate the effectiveness of metformin in managing weight gain in 39 subjects, ages 10-17, whose weight had increased by more than 10% during less than 1 year of olanzapine, risperidone, or quetiapine therapy. Body weight, body mass index (kilograms per square meter of height), and waist circumference were measured regularly, as were fasting insulin and glucose levels. RESULTS: Weight was stabilized in subjects receiving metformin, while those receiving placebo continued to gain weight (0.31 kg/week). Because the study was conducted with growing children, metformin treatment resulted in reduction in z scores for both weight and body mass index. The homeostasis model assessment, a surrogate indicator of insulin sensitivity, decreased in treated subjects. Overt diabetes was diagnosed in two subjects before treatment (elevated baseline fasting glucose and insulin values) and in two placebo-treated subjects (one at week 12 and the other after study completion). One subject taking placebo developed impaired fasting glucose. Placebo treatment was associated with the need to perform oral glucose tolerance testing upon study completion, by which three additional subjects were identified with impaired glucose tolerance. No serious adverse events resulted from metformin treatment. CONCLUSIONS: Metformin therapy is safe and effective in abrogating weight gain, decreased insulin sensitivity, and abnormal glucose metabolism resulting from treatment of children and adolescents with atypicals.

Adolescent↗

PubMed2006

Social control of health behavior: associations with conscientiousness and neuroticism.

Despite considerable research demonstrating associations of conscientiousness and neuroticism with health-related behavior, our understanding of how and why these traits are related to lifestyle is limited. This study examined the social regulation of health behavior in a probability sample of 509 household residents who completed a Random Digit Dial (RDD) telephone survey. Results suggest that the social regulation of health behavior experienced by highly conscientious individuals has more to do with their own internalized notions of responsibility and obligation to others than to specific actions by others aimed at influencing their health habits. In contrast, individuals with higher neuroticism experience more overt attempts by others to influence their health habits but have more negative affective and behavioral responses to these social influence attempts. Findings suggest that elucidating the distinct social influence processes that operate for conscientiousness and neuroticism may further understanding of how these traits are related to health behaviors and status.

Adult↗

PubMed2006

Exploring the link between substance abuse and abortion: the roles of unconventionality and unplanned pregnancy.

CONTEXT: Several studies have found a relationship between abortion and prior substance use, suggesting that a reduction in substance use might help decrease abortion rates. However, such a conclusion requires a greater understanding of the processes linking abortion and prior substance use. METHOD: Path analysis of longitudinal data from 1,224 women was used to simultaneously test two pathways from adolescent substance use to abortion by age 29, one mediated by higher rates of unplanned pregnancy and the other independent of unplanned pregnancy rates. The model was then expanded to examine how these pathways change when unconventional attitudes and behaviors (such as rebelliousness and low religiosity) are taken into consideration. RESULTS: In the analysis that did not control for unconventionality, women who reported smoking cigarettes or using marijuana or hard drugs at age 18 had an increased likelihood of subsequent unplanned pregnancy and, as a result, higher rates of abortion. In addition, women who had used marijuana had an increased likelihood of abortion independent of unplanned pregnancy rates. In the final model, unconventionality strongly predicted both abortion and unplanned pregnancy. Moreover, it explained the associations between the use of hard drugs or marijuana and abortion that were due to higher unplanned pregnancy rates. CONCLUSIONS: Unconventionality mediates certain associations between substance use and abortion, perhaps because unconventional women are more likely both to use substances and to engage in behaviors that increase their risk of unplanned pregnancy. Hence, it seems unlikely that reducing substance use will result in substantially fewer abortions.

Abortion, Legal↗

PubMed2005

Isolating the nexus of substance use, violence and sexual risk for HIV infection among young adults in the United States.

Adults aged 18 to 29 are at significant sexual risk for HIV infection. Substance use and violence are known to be associated with sexual risk in certain groups, but few studies have examined these relationships in the general population of young adults. No studies have tested whether the contributions of substance use and violence to sexual risk are independent, and few have looked at whether drug use associations with risk are specific to certain substances. Using structural modeling techniques, we examined data for 3,437 adults aged 23-24, testing for associations between three measures of sexual risk for HIV, various forms of substance use, victimization and partner violence. Alcohol use and victimization predicted high risk sex in independent samples of single and married/cohabiting adults. Marijuana use, problem drug use, and partner violence were inconsistently related to sexual risk across measures and subsamples. HIV-prevention interventions designed for young adults in the general population should target individuals who use alcohol frequently and who are victims of violence, and should address both factors, in addition to sexual risk behavior.

Adolescent↗

PubMed2005

Scope of HIV risk and co-occurring psychosocial health problems among young adults: violence, victimization, and substance use.

PURPOSE: This study examines the co-occurrence of sexual risk with violence, victimization, risky substance use, and drug-related problems among young adults. METHODS: Data were collected from 3392 young adults drawn from California and Oregon as youth, as part of the RAND adolescent panel study. Logistic regression analyses were used to test differences in psychosocial health problems for participants at high, moderate, and low sexual risk, overall, and by gender. RESULTS: Nearly 80% of young adults exhibited some degree of sexual risk. Both moderate (56%) and high (22%) HIV risks were associated with multiple forms of drug use, drug-related problems, violence and victimization. Males and females had similar relative risk profiles, but females reported higher rates of victimization in the form of partner abuse and sexual coercion. Over 80% of those at high sexual risk exhibited psychosocial health problems in at least 2 other areas. CONCLUSIONS: Sexual risk-taking is widespread among young adults and typically co-occurs with other psychosocial health problems. Interventions designed for young adults at high sexual risk should take into account their additional psychosocial problems; broad media campaigns may be useful for those at moderate risk.

Adolescent↗

PubMed2005

Predictors of attempted quitting and cessation among young adult smokers.

BACKGROUND: This study compared young adult nonsmokers (n = 1216), light smokers (n = 406), and regular smokers (n = 360) on demographic, psychosocial, and behavioral characteristics, as well as identified predictors of attempted quitting and 6-month cessation among regular smokers. METHOD: Participants were recruited from middle schools in 1985 (age 13) and assessed repeatedly through 2001 (age 29). Mail surveys were used to obtain information on smoking status and hypothesized predictors of cessation at age 23, and quit attempts and cessation occurring between ages 23-39 among regular smokers. Logistic regression analysis was used to identify predictors of quit attempts and 6-month cessation. RESULTS: Among initial smokers, 76% attempted to quit and 26% quit for 6 months or longer between ages 23-29. Higher rates of substance use, illegal activity, poor mental health, and victimization were found among regular smokers than nonsmokers and lighter smokers at age 23. However, multivariate analyses indicated that these problems were less relevant to quitting than social transitions and interpersonal factors, demographics (e.g., race/ethnicity), and health status. CONCLUSIONS: Different risk and protective factors are relevant to understanding why smokers attempt to quit versus why they are able to quit for 6 months or longer. We discuss implications of these findings for cessation interventions and programs for young adults.

Adolescent↗

PubMed2005

Concurrent use of alcohol and cigarettes from adolescence to young adulthood: an examination of developmental trajectories and outcomes.

Concurrent use of alcohol and tobacco is common among adolescents, yet little is known about the developmental patterns of concurrent use, or the consequences associated with such patterns during young adulthood. Using data collected at six time points during 1985-1995 as part of an evaluation of a school-based substance abuse prevention program in California and Oregon, this study used latent growth mixture modeling to identify five distinct developmental trajectories of concurrent use of alcohol and tobacco from ages 13-23 in a cohort of 5873 individuals and compared these distinct groups with respect to demographic characteristics and young adult outcomes (at age 23 and age 29). Results suggest that while it is common during adolescence to drink but not smoke, it is very unusual to smoke and not drink. Compared to young people who smoked and drank consistently throughout their teens and early twenties, those who drank consistently but smoked only occasionally or dramatically decreased their smoking over time had lower rates of deviant behavior and predatory violence at age 23 and were less likely to have a history of arrest and substance use problems by age 29. This close examination of concurrent use of alcohol and cigarette use from ages 13-23 further accentuates the importance of curbing smoking behavior among adolescents before it becomes habitual.

Adolescent↗

PubMed2005

Marijuana use and later problems: when frequency of recent use explains age of initiation effects (and when it does not).

Tobacco, alcohol, and marijuana are among the most commonly used drugs during adolescence. Initiation of marijuana use typically peaks at age 15, with risk of initiation continuing throughout adolescence. The goal of the current study was to prospectively examine the influence of age of marijuana initiation on four outcomes: physical health, mental health, illicit drug use other than marijuana, and marijuana-use related consequences at age 18. We controlled for several important predictors of adolescent drug use and its associated consequences, including demographics, social bonding variables, personality variables, and recent use of marijuana. Baseline survey data were collected in 1984 at grade 7 and follow up surveys were conducted at grades 8, 9, 10, and 12 (N = 2079). This initiates-only sample was 47% female, 66% White, 11% African American, 13% Hispanic, 5% Asian, and 5% other race or ethnicity. Findings indicated that age of initiation predicted marijuana consequences and other illicit drug use after controlling for demographic, social, and behavioral factors. However, once frequency of recent marijuana use was included in the models, age of initiation was only associated with other illicit drug use. Both primary and secondary prevention are needed to curb marijuana use and its associated harms.

Adolescent↗

PubMed2005

Effects of early and later marriage on women's alcohol use in young adulthood: a prospective analysis.

OBJECTIVE: Previous research shows that marriage leads to reductions in alcohol use, especially for women. Because marriage prior to age 20 (early marriage) is a marker for deviance, the protective effects of marriage may not extend to those who marry in adolescence. We compared the effects of marriage in adolescence versus young adulthood on alcohol consumption, negative alcohol-related consequences and heavy episodic drinking at age 29. METHOD: We analyzed data from 1,138 women in a longitudinal cohort followed from ages 18 to 29. The original sample was recruited from 30 California and Oregon middle schools and first surveyed at age 13. RESULTS: Women who had not married, had married early or had married between ages 20 and 29 did not differ on alcohol use at age 18. Women who married as young adults were less likely than singles to engage in any alcohol use, heavy episodic drinking or experience negative consequences and reported less alcohol use at age 29. Women who married in adolescence reported fewer negative consequences at age 29 than did singles and (if they had not divorced) were less likely to engage in heavy episodic drinking or experience any negative consequences, reported fewer consequences and consumed less alcohol. The protective effects of marriage in young adulthood were observed whether or not women divorced. Parenthood and college attendance before age 23 did not explain the marriage effect. CONCLUSIONS: Results support role theory, which posits that individuals who marry are socialized into conventional adult roles that discourage deviant behavior.

Adolescent↗

PubMed2005

Processes linking adolescent problems to substance-use problems in late young adulthood.

OBJECTIVE: The current study explores three avenues in early young adulthood through which adolescent problems may be linked to later substance use problems: problematic substance use, failure to assume adult roles and responsibilities, and exposure to pro-drug social influences. METHOD: Participants (N = 1,986; 49% female) filled out surveys at ages 18, 23 and 29. Participants were 67% white, 9% black, 10% Hispanic and 8% Asian. Deviance, poor mental health, substance use, alcohol and other drug (AOD) problems, and school dropout were measured at age 18. AOD problems were also measured at age 23, as were role changes (e.g., marriage) and pro-drug social influences (e.g., friends use drugs). Indicators of substance abuse and dependence were measured at age 29. Demographics and family history of AOD were covariates. RESULTS: Reporting more deviant behavior and heavier drinking at age 18 was associated with a higher likelihood of abuse and dependence at age 29. Alcohol use and pro-drug social influences at age 23 appeared to mediate the effects of adolescent substance use; lack of role assumption did not. The effect of poor mental health at age 18 was not mediated by any set of variables but instead appeared to directly predict dependence at age 29. CONCLUSIONS: Findings highlight the importance of early young adult drinking and substance-using peers in continuing patterns of heavy substance use developed during adolescence and also underscore the long-term impact of poor mental health during adolescence on substance use problems in late young adulthood.

Adolescent↗

PubMed2005

Development of the metabolic syndrome in black and white adolescent girls: a longitudinal assessment.

BACKGROUND: The metabolic syndrome, associated with increased risk of type 2 diabetes mellitus and cardiovascular disease, begins to develop during adolescence. OBJECTIVE: We sought to identify early predictors of the presence of the syndrome at the ages of 18 and 19 years in black and white girls. METHODS: Using longitudinal data on participants from 2 centers in the National Heart, Lung, and Blood Institute Growth and Health Study, a 10-year cohort study, we applied cutoffs from the Adult Treatment Panel III to document changes in the prevalence of abnormal syndrome elements and the syndrome in girls aged 9 and 10 years, when cases were rare, and those aged 18 and 19 years, when prevalence had reached 3%. Longitudinal regression models identified early predictors for the presence of the syndrome. RESULTS: Only 1 girl of each race had > or =3 factors at ages 9 and 10 (0.2%), but 20 black girls (3.5%) and 12 white girls (2.3%) had the syndrome 10 years later. Low high-density lipoprotein cholesterol was prevalent throughout the period in both black and white girls. The prevalence of other variables was low at enrollment but increased during follow-up, except for abnormal triglyceride levels in black girls, which remained low throughout follow-up. In multivariate models, early measures of waist circumference and triglyceride level were significant predictors for development of the syndrome. CONCLUSION: The strong association of central adiposity with the development of the metabolic syndrome suggests that early interventions aimed at managing preteen obesity could reduce risk of developing the syndrome.

Adolescent↗

PubMed2004

Dynamics of precise spike timing in primary auditory cortex.

Although single units in primary auditory cortex (A1) exhibit accurate timing in their phasic response to the onset of sound (precision of a few milliseconds), paradoxically, they are unable to sustain synchronized responses to repeated stimuli at rates much beyond 20 Hz. To explore the relationship between these two aspects of cortical response, we designed a broadband stimulus with a slowly modulated spectrotemporal envelope riding on top of a rapidly modulated waveform (or fine structure). Using this stimulus, we quantified the ability of cortical cells to encode independently and simultaneously the stimulus envelope and fine structure. Specifically, by reverse-correlating unit responses with these two stimulus dimensions, we measured the spectrotemporal response fields (STRFs) associated with the processing of the envelope, the fine structure, and the complete stimulus. A1 cells respond well to the slow spectrotemporal envelopes and produce a wide variety of STRFs. In over 70% of cases, A1 units also track the fine-structure modulations precisely, throughout the stimulus, and for frequencies up to several hundred Hertz. Such a dual response, however, is contingent on the cell being driven by both fast and slow modulations, in that the response to the slowly modulated envelope gates the expression of the fine structure. We also demonstrate that either a simplified model of synaptic depression and facilitation, and/or a cortical network of thalamic excitation and cortical inhibition can account for major trends in the observed findings. Finally, we discuss the potential functional significance and perceptual relevance of these coexistent, complementary dynamic response modes.

Acoustic Stimulation↗