The Making of Psychological Methods

Psychological Methods celebrated its 20-year anniversary recently, having published its first quarterly issue in March 1996. It seemed time to provide a brief overview of the history, the highlights over the years, and the current state of the journal, along with tips for submissions. The article is organized to discuss: (1) the background and development of the journal, (2) the top articles, authors and topics over the years, (3) an overview of the journal today, and (4) a summary of the features of successful articles that usually entail rigorous and novel methodology described in clear and understandable writing and that can be applied in meaningful and relevant areas of psychological research

Reporting Practices and Use of Quantitative Methods in Canadian Journal Articles in Psychology

With recent focus on the state of research in psychology, it is important to assess the nature of the methods and analyses used and reported. To study this, we coded information about the statistical content reported in articles in the four major Canadian psychology journals published in 2013. We first classified whether the articles were quantitative, qualitative, or theoretical in nature. Our main focus was on articles that used quantitative methods; whereby we investigated the prevalence of different statistical procedures, as well as further details of reporting practices. Few articles in any of the journals used qualitative approaches, as 92.9% of empirical articles included a quantitative study. Analysis of variance (ANOVA), t-tests, and multiple regression were the statistical analyses most often reported in the investigated articles. The majority of articles used hypothesis testing, and while most of these tests were accompanied by an effect size, this rarely included a confidence interval. Many of the quantitative studies provided minimal details about their statistical analyses and less than a third of the studies presented on data complications such as missing data and statistical assumptions. Further discussion highlights strengths and areas for improvement for reporting quantitative results. The paper concludes with recommendations for how researchers and reviewers can improve comprehension in statistical reporting

Big Data in Psychology: Introduction to the Special Issue

The introduction to this special issue on psychological research involving big data summarizes the highlights of 10 articles that address a number of important and inspiring perspectives, issues, and applications. Four common themes that emerge in the articles with respect to psychological research conducted in the area of big data are mentioned, including: 1. The benefits of collaboration across disciplines, such as those in the social sciences, applied statistics, and computer science. Doing so assists in grounding big data research in sound theory and practice, as well as in affording effective data retrieval and analysis. 2. Availability of large datasets on Facebook, Twitter, and other social media sites that provide a psychological window into the attitudes and behaviors of a broad spectrum of the population. 3. Identifying, addressing, and being sensitive to ethical considerations when analyzing large datasets gained from public or private sources. 4. The unavoidable necessity of validating predictive models in big data by applying a model developed on one dataset to a separate set of data or hold-out sample. Translational abstracts that summarize the articles in very clear and understandable terms are included in Appendix A, and a glossary of terms relevant to big data research discussed in the articles is presented in Appendix B. Keywords: big data, machine learning, statistical learning theory, social media data, digital footprint, decision trees and forests

Modeling multiple health behaviors and general health

Multiple Health Behavior Change assumes health behaviors are related to one another, although research evidence is mixed. More research is needed to understand which behaviors are most closely related and how they collectively predict health. Principle component analysis and structural equation modeling were used to establish a model showing relations between health behaviors, including fruit/vegetable consumption, aerobic and strength exercise, alcohol intake, and smoking, and how these behaviors relate to general physical and mental health functioning in a large, national sample. Although health behaviors were found to coalesce into a health-promoting factor of diet, and exercise, a better overall model fit was found when all behaviors were modeled as separate independent variables. Results suggest that health behaviors relate to one another in complex ways, with perceived health status serving as a mediating variable between specific health behaviors and a factor of physical and mental health. Future research should further investigate how other health behaviors relate to perceptions and overall health, especially among subpopulations

Exercise and Self-Esteem: Validity of Model Expansion and Exercise Associations

The purpose of this research was to test expansion of the Exercise and Self-Esteem Model (EXSEM) to include two levels of perceived physical competence as operationalized by the Physical Self-Perception Profile (PSPP). Female aerobic dancers (N = 216, age M = 38.4) were administered a Self-Esteem scale (SE), the PSPP to assess a general Physical Self-Worth (PSW), and more specific subdomains of perceived Sport Competence (Sport), Physical Condition (Cond), Attractive Body (Body), and Strength (Stren). Subjects also completed self-efficacy scales for jogging, sitting, and aerobic dancing. Confirmatory factor analysis supported model measurement as hypothesized, ?2 = 1,154.88, df = 681, comparative fit index (CFI) = .913, root mean square residual (RMSR) = .047. Structural equation modeling (SEM) supported EXSEM component relationships as proposed. Further SEM associating two exercise self-reports with EXSEM again displayed satisfactory fit indices and explained up to 27.6% of exercise variance. It was concluded that exercise in adult female aerobic dancers is associated with positive evaluations of their physical condition and with negative evaluations of their bodies

A measurement model of women\u27s behavioral risk taking

The current study was designed to gain a better understanding of the nature of the relationship between substance use and sexual risk taking within a community sample of women (N = 1,004). Using confirmatory factor analysis, the authors examined the factor structure of sexual risk behaviors and substance use to determine whether they are best conceptualized as domains underlying a single, higher order, risk-taking propensity. A 2 higher order factor model (sexual risk behavior and substance use) provided the best fit to the data, suggesting that these 2 general risk domains are correlated but independent factors. Sensation seeking had large general direct effects on the 2 risk domains and large indirect effects on the 4 first-order factors and the individual indicators. Negative affect had smaller, yet still significant, effects. Impulsivity and anxiety were unrelated to sexual health risk domains

Increasing Literacy in Quantitative Methods: The Key to the Future of Canadian Psychology

Quantitative methods (QM) dominate empirical research in psychology. Unfortunately most researchers in psychology receive inadequate training in QM. This creates a challenge for researchers who require advanced statistical methods to appropriately analyze their data. Many of the recent concerns about research quality, replicability, and reporting practices are directly tied to the problematic use of QM. As such, improving quantitative literacy in psychology is an important step towards eliminating these concerns. The current paper will include two main sections that discuss quantitative challenges and opportunities. The first section discusses training and resources for students and present descriptive results on the number of quantitative courses required and available to graduate students in Canadian psychology departments. In the second section, we discuss ways of improving quantitative literacy for faculty, researchers, and clinicians. This includes a strong focus on the importance of collaboration. The paper concludes with practical recommendations for improving quantitative skills and literacy for students and researchers in Canada

Longitudinal analysis of intervention effects on temptations and stages of change for dietary fat using parallel process latent growth modeling

The Dietary Guidelines for Americans recommend a 20–35 percent daily intake of fat. Resisting the temptation to eat high-fat foods, in conjunction with stage of readiness to avoid these foods, has been shown to influence healthy behavior change. Data (N = 6516) from three randomized controlled trials were pooled to examine the relationships among direct intervention effects on temptations and stage of change for limiting high-fat foods. Findings demonstrate separate simultaneous growth processes in which baseline level of temptations, but not the rate of change in temptations, was significantly related to the change in readiness to avoid high-fat foods

Pro- and Anti-inflammatory Biomarkers as Predictors of Response to Valproate in Patients with Comorbid Alcohol Use and Bipolar Disorder-Preliminary Findings

Objective/Hypothesis: Bipolar disorder (BD) has the highest association with alcohol and other substance use disorders compared to other major psychiatric disorders. This patient population is particularly challenging to treat. We have previously shown that some patients with co-occurring alcohol use and bipolar disorders respond to the GABAergic agonist valproate (VPA), which is known to modulates the dopaminergic system, and also as an epigenetic modifier. Predictors of therapeutic response to VPA in patients with AUD/BD are not known, and the subgroup which would benefit from VPA is still to be identified. Recent evidence suggests that AUD promotes a pro-inflammatory state while VPA increases levels of anti-inflammatory factors. We hypothesized that VPA has an anti-inflammatory effect and that patients with AUD/BD who respond to VPA have higher baseline inflammatory indices. Methods: Nine patients with DSM-IV-defined diagnoses of AUD and BD (AUD/BD) were enrolled in the study. Patients received a course of VPA for 3 months at an average dose of 1000 mg a day in addition to receiving either naltrexone of 50 mg daily or placebo. Blood was collected prior to the initiation of VPA and throughout the treatment study. Liver function tests and trough VPA serum concentrations were evaluated periodically. Alcohol use outcome was assessed using the Timeline Follow-Back for Recent Drinking. The use of other drugs was monitored through regular urine drug screen. The primary alcohol use outcome was changes in proportion of weekly heavy drinking days (defined as ³ 5 drinks per day for men and ³ 4 drinks per day for women). Plasma levels of cytokines were measured using Multiplex Immunoassay, in accordance to the manufacturers’ recommendations. Results: We found that about one half of enrolled patients responded to VPA. Screening of pro- and anti-inflammatory cytokines showed that responders had higher levels of the chemokine SDF-1a/CXCL12a and the pro-inflammatory marker C-reactive protein (CRP) and lower levels of anti-inflammatory factor matrix metalloproteinase-10 (MMP-10) (p \u3c 0.05). Screening of cytokines in samples before and after treatment with VPA showed that VPA increased levels of anti-inflammatory factors interleukin-10 (IL-10) and MMP-10 (p \u3c 0.05) and tended to decrease levels of pro-inflammatory CRP (p \u3e 0.05). Discussion: Pro- and anti-inflammatory biomarkers may serve as predictors of treatment response to VPA in patients with combined AUD/BD. Our preliminary results also suggest that therapeutic effect of VPA may be in part due to anti-inflammatory action of VPA. Larger studies may be indicated to validate these findings

Demographics and the Cost of Pharmaceuticals in a Private Third-Party Prescription Program

Objective: To compare variance in the cost of pharmaceuticals attributable to demographic variables with variance explained by plan characteristics, using prescription claims data within various therapeutic categories, and to examine differences in average cost of pharmaceuticals among demographic variables after controlling for covariates. Design: Retrospective, cross-sectional study. Data Collection: Data for this study were obtained from 1996 prescription claims information for the commercial population administered by a Rhode Island-based pharmacy benefit management (PBM) company. Six therapeutic categories with the highest expenditures were analyzed. Information on claims for six drug categories was extracted using database management software. Statistical analyses using multiple regression and analysis of covariance were carried out. Results: Plan characteristics outperformed demographic variables sixteenfold for all drug categories combined in explaining variance in cost of pharmaceuticals among plan enrollees. Average cost of pharmaceuticals differed among demographic variables such as age, gender, location, and place of employment after controlling for average wholesale price and days supply. Conclusions: The results obtained in this study have practical significance in the determination of capitation rates when utilization history of prospective members is not available. In this situation, managed care organizations (MCOs) or PBMs may have to set capitation rates based solely on eligibility data. Significant differences in average drug costs among the members based on place of employment suggest that benefit managers should consider differentiating capitation rates according to their clients\u27 businesses. Finally, the data from this study indicated that commercial members residing in Tennessee had the lowest average cost of pharmaceuticals among all states evaluated. The fact that one PBM manages more than 80% of the TennCare prescription program along with a significant commercial client base suggests that a spillover effect may exist