Documenting Compliance and Symptom Reactivity for Ambulatory Assessment Methodology Following Concussion in Adolescents and Young Adults: Feasibility of the Mobile Neurocognitive Health (MNCH) Project.

OBJECTIVE: Evaluate compliance, symptom reactivity, and acceptability/experience ratings for an ecological momentary assessment (EMA) protocol involving ultra-brief ambulatory cognitive assessments in adolescent and young adult patients with concussion. SETTING: Outpatient concussion clinic. PARTICIPANTS: 116 patients aged 13 to 25 years with concussion. DESIGN: Prospective research design was used to examine compliance, symptom reactivity, and acceptability/experience for the Mobile Neurocognitive Health Project (MNCH); an EMA study of environmental exposures, symptoms, objective cognitive functioning, and symptom reactivity involving 4, daily EMA surveys (7:30 am, 10:30 am, 3:00 pm, 8:00 pm) for a period of 7 days following concussion. Overall compliance rates, symptom reactivity scores, and participant acceptability/experience ratings were described. A series of non-parametric Friedman Tests with post-hoc Wilcoxon signed-rank tests were used to examine differences in compliance and reactivity related to time of day and over the course of the protocol (first 3 days [Early Week] vs last 4 days [Late Week]). MAIN MEASURES: Compliance rates, symptom reactivity scores, participant experience/acceptability. RESULTS: Overall median compliance was 71%, and there were significantly fewer 7:30 am surveys completed compared to the 10:30 am (Z = -4.88,P ≤ .001), 3:00 pm (Z = -4.13,P ≤ .001), and 8:00 pm (Z = -4.68, P ≤ .001) surveys. Compliance for Early Week surveys were significantly higher than Late Week (Z = -2.16,P = .009). The median symptom reactivity score was 34.39 out of 100 and was significantly higher for Early Week compared to Late Week (Z = -4.59,P ≤ .001). Ninety-nine percent (89/90) of the sample agreed that the app was easy to use, and 18% (16/90) indicated that the app interfered with their daily life. CONCLUSION: Adolescents and young adults with concussion were compliant with the MNCH EMA protocol. Symptom reactivity to the protocol was low and the majority of participants reported that the app and protocol were acceptable. These findings support further investigation into applications of EMA for use in concussion studies.

Racial differences in links between perceived discrimination, depressive symptoms, and ambulatory working memory.

OBJECTIVES: Perceived discrimination is associated with racial cognitive health disparities. Links between discrimination and cognitive performance, like working memory, in everyday settings (i.e. ambulatory performance) require investigation. Depressive symptoms may be a mechanism through which discrimination relates to ambulatory working memory. METHOD: Discrimination, retrospective and momentary depressive symptoms/mood, and aggregated and momentary working memory performance among older Black and White adults were examined within the Einstein Aging Study. RESULTS: Racially stratified analyses revealed that discrimination did not relate to Black or White adults' ambulatory working memory. Among Black adults, however, more frequent discrimination was associated with greater retrospectively reported depressive symptoms, which related to more working memory errors across two weeks (indirect effect p < 0.05). This path was not significant among White adults. Links between discrimination and momentary working memory were not explained by momentary reports of depressed mood for Black or White adults. CONCLUSION: Depressive symptoms may play an important role in the link between discrimination and ambulatory working memory among Black adults across extended measurements, but not at the momentary level. Future research should address ambulatory cognition and momentary reports of discrimination and depression to better understand how to minimize cognitive health disparities associated with discrimination.

Child Behavior Problems and Maltreatment Exposure.

OBJECTIVES: Establish the longitudinal cross-lagged associations between maltreatment exposure and child behavior problems to promote screening and the type and timing of interventions needed. METHODS: The Longitudinal Studies of Child Abuse and Neglect, a multiwave prospective cohort study of maltreatment exposure, enrolled children and caregivers (N = 1354) at approximately age 4 and followed them throughout childhood and adolescence. Families completed 7 waves of data collection with each wave occurring 2 years apart. Maltreatment was confirmed using official case records obtained from Child Protective Services. Six-month frequencies of behavior problems were assessed via caregiver-report. Two random-intercept, cross-lagged panel models tested the directional relations between maltreatment exposure and externalizing and internalizing behaviors. RESULTS: Maltreatment exposure predicted increases in externalizing behaviors at ages 8 (b = 1.06; 95% confidence interval [CI] 0.14-1.98), 12 (b = 1.09; 95% CI 0.08-2.09), and 16 (b = 1.67; 95% CI 0.30-3.05) as well as internalizing behaviors at ages 6 (b = 0.66; 95% CI 0.03-1.29), 12 (b = 1.25; 95% CI 0.33-2.17), and 14 (b = 1.92; 95% CI 0.76-2.91). Increases in externalizing behaviors predicted maltreatment exposure at age 12 (odds ratio 1.02; 95% CI 1.00-1.05). CONCLUSIONS: Maltreatment exposure is robustly associated with subsequent child behavior problems, strengthening inferences about the directionality of these relations. Early screening of externalizing behaviors in pediatric settings can identify children likely to benefit from intervention to reduce such behaviors as well as prevent maltreatment exposure at entry to adolescence.

Contamination bias in the estimation of child maltreatment causal effects on adolescent internalizing and externalizing behavior problems.

BACKGROUND: When unaddressed, contamination in child maltreatment research, in which some proportion of children recruited for a nonmaltreated comparison group are exposed to maltreatment, downwardly biases the significance and magnitude of effect size estimates. This study extends previous contamination research by investigating how a dual-measurement strategy of detecting and controlling contamination impacts causal effect size estimates of child behavior problems. METHODS: This study included 634 children from the LONGSCAN study with 63 cases of confirmed child maltreatment after age 8 and 571 cases without confirmed child maltreatment. Confirmed child maltreatment and internalizing and externalizing behaviors were recorded every 2 years between ages 4 and 16. Contamination in the nonmaltreated comparison group was identified and controlled by either a prospective self-report assessment at ages 12, 14, and 16 or by a one-time retrospective self-report assessment at age 18. Synthetic control methods were used to establish causal effects and quantify the impact of contamination when it was not controlled, when it was controlled for by prospective self-reports, and when it was controlled for by retrospective self-reports. RESULTS: Rates of contamination ranged from 62% to 67%. Without controlling for contamination, causal effect size estimates for internalizing behaviors were not statistically significant. Causal effects only became statistically significant after controlling contamination identified from either prospective or retrospective reports and effect sizes increased by between 17% and 54%. Controlling contamination had a smaller impact on effect size increases for externalizing behaviors but did produce a statistically significant overall effect, relative to the model ignoring contamination, when prospective methods were used. CONCLUSIONS: The presence of contamination in a nonmaltreated comparison group can underestimate the magnitude and statistical significance of causal effect size estimates, especially when investigating internalizing behavior problems. Addressing contamination can facilitate the replication of results across studies.

Effects of Receiving Pain-Related Support on Psychological Well-Being: The Moderating Roles of Emotional Responses to Support.

OBJECTIVES: We investigated whether receiving greater pain-related instrumental support is associated with poorer psychological well-being among chronic pain patients who report less positive (e.g., grateful) or more negative (e.g., angry) emotional responses to support. METHODS: We conducted regression analyses, utilizing data from two waves of interviews with 152 knee osteoarthritis patients. Three indicators of psychological well-being were examined: depressive symptoms, positive affect, and negative affect. RESULTS: Receiving greater support was associated with poorer psychological well-being at baseline, as well as higher depressive symptoms and negative affect at the 18-month follow-up, only among patients with low positive emotional responses to support. Furthermore, receiving greater support was related to poorer psychological well-being at baseline only among patients with high negative emotional responses to support. DISCUSSION: Care recipients' less positive emotional responses to support may be a risk factor for poorer psychological well-being in both the short- and long-term, when receiving greater support.

Contamination in Observational Research on Child Maltreatment: A Conceptual and Empirical Review With Implications for Future Research.

Contamination is a methodological phenomenon occurring in child maltreatment research when individuals in an established comparison condition have, in reality, been exposed to maltreatment during childhood. The current paper: (1) provides a conceptual and methodological introduction to contamination in child maltreatment research, (2) reviews the empirical literature demonstrating that the presence of contamination biases causal estimates in both prospective and retrospective cohort studies of child maltreatment effects, (3) outlines a dual measurement strategy for how child maltreatment researchers can address contamination, and (4) describes modern statistical methods for generating causal estimates in child maltreatment research after contamination is controlled. Our goal is to introduce the issue of contamination to researchers examining the effects of child maltreatment in an effort to improve the precision and replication of causal estimates that ultimately inform scientific and clinical decision-making as well as public policy.

Epigenetic age acceleration as a biomarker for impaired cognitive abilities in adulthood following early life adversity and psychiatric disorders.

Background: Early life adversity and psychiatric disorders are associated with earlier declines in neurocognitive abilities during adulthood. These declines may be preceded by changes in biological aging, specifically epigenetic age acceleration, providing an opportunity to uncover genome-wide biomarkers that identify individuals most likely to benefit from early screening and prevention. Methods: Five unique epigenetic age acceleration clocks derived from peripheral blood were examined in relation to latent variables of general and speeded cognitive abilities across two independent cohorts: 1) the Female Growth and Development Study (FGDS; n = 86), a 30-year prospective cohort study of substantiated child sexual abuse and non-abused controls, and 2) the Biological Classification of Mental Disorders study (BeCOME; n = 313), an adult community cohort established based on psychiatric disorders. Results: A faster pace of biological aging (DunedinPoAm) was associated with lower general cognitive abilities in both cohorts and slower speeded abilities in the BeCOME cohort. Acceleration in the Horvath clock was significantly associated with slower speeded abilities in the BeCOME cohort but not the FGDS. Acceleration in the Hannum clock and the GrimAge clock were not significantly associated with either cognitive ability. Accelerated PhenoAge was associated with slower speeded abilities in the FGDS but not the BeCOME cohort. Conclusions: The present results suggest that epigenetic age acceleration has the potential to serve as a biomarker for neurocognitive decline in adults with a history of early life adversity or psychiatric disorders. Estimates of epigenetic aging may identify adults at risk of cognitive decline that could benefit from early neurocognitive screening.

Examining the Bidirectional Nature of Loneliness and Anxiety Among Older Adults in Daily Life.

OBJECTIVES: Loneliness in later life increases the risk for adverse health outcomes; however, less is known about how loneliness is maintained. Anxiety may play an important role in maintaining loneliness, but little is known about how this connection plays out over time in daily life. This study thus focused on the within-person associations between momentary loneliness and anxiety among older adults. METHODS: Participants were 317 diverse older adults (40% Black; 13% Hispanic, mean age = 77.45 years, 67% women) systematically recruited from the Bronx, NY, who completed ecological momentary assessments 5 times daily for 14 consecutive days. Multilevel models tested bidirectional contemporaneous, momentary cross-lagged (t - 1), day-level cross-lagged (average day to end of day), and day-to-day cross-lagged associations between loneliness and anxiety. Separate sensitivity analyses controlled for concurrent overall mood valence or depressed state. Gender and mild cognitive impairment (MCI) status were tested as moderators at all timescales. RESULTS: Significant bidirectional associations between loneliness and anxiety were found at the contemporaneous and momentary cross-lagged (t - 1) timescales. Higher average daily loneliness predicted higher end-of-day anxiety, but not vice versa. Loneliness and anxiety were not significantly associated from day to day. Sensitivity analyses revealed some associations varied depending on inclusion of either concurrent mood valence or depressed state. Neither gender nor MCI status moderated associations at any timescale. DISCUSSION: Findings shed light on the complex temporal ordering of loneliness and anxiety in daily life and extend contemporary theoretical notions of loneliness, including the possibility of interventions that target key moments in daily life.

The mediating role of self-regulation on the link between child maltreatment and later substance use among Latinx youth.

BACKGROUND: Children who experience maltreatment are at heightened risk for substance use initiation and mental health disorders later in life. Few studies have assessed the relationship between child maltreatment and substance use among Latinx youth. OBJECTIVE: The current study assessed the potential mediating effect of three aspects of self-regulation (emotional, behavioral, and cognitive) on the association between child maltreatment and substance use and examined whether effects varied depending on maltreatment type and severity. PARTICIPANTS AND SETTING: This study involved a random sample of 504 Latinx youth (52 % girls, 48 % boys) between the ages of 10-12 at the start of the study. METHODS: Study hypotheses were tested through structural equation modeling and bootstrapped random errors using the R programming language. RESULTS: Our results indicated that higher levels of child maltreatment predicted higher levels of later substance use, as mediated by emotional and behavioral dysregulation (ß = 0.09, p < 0.01), but not cognitive regulation. When separating maltreatment by subtype, we found the mediating effect was present for abuse (ß = 0.09, p < 0.01), but not neglect. CONCLUSIONS: Findings contribute to our understanding of potential causal mechanisms for the association between child maltreatment and substance use for Latinx youth.

Within-person associations of optimistic and pessimistic expectations with momentary stress, affect, and ambulatory blood pressure.

BACKGROUND AND OBJECTIVES: Although dispositional optimism and pessimism have been prospectively associated with health outcomes, little is known about how these associations manifest in everyday life. This study examined how short-term optimistic and pessimistic expectations were associated with psychological and physiological stress processes. METHODS: A diverse sample of adults (N = 300) completed a 2-day/1-night ecological momentary assessment and ambulatory blood pressure (ABP) protocol at ∼45-minute intervals. RESULTS: Moments that were more optimistic than typical for a person were followed by moments with lower likelihood of reporting a stressor, higher positive affect (PA), lower negative affect (NA), and less subjective stress (SS). Moments that were more pessimistic than typical were not associated with any affective stress outcome at the following moment. Neither optimism nor pessimism were associated with ABP, and did not moderate associations between reporting a stressor and outcomes. DISCUSSION: These findings suggest that intraindividual fluctuations in optimistic and pessimistic expectations are associated with stressor appraisals.

Receptive Language Abilities for Females Exposed to Early Life Adversity: Modification by Epigenetic Age Acceleration at Midlife in a 30-Year Prospective Cohort Study.

OBJECTIVES: Deviations from normative trajectories of receptive language abilities following early life adversity (ELA) may indicate an elevated risk for advanced cognitive aging and related morbidities. Accelerated epigenetic aging at midlife may further identify those at greatest risk for advanced cognitive aging following ELA. We examined whether accelerations in epigenetic aging at midlife can identify those individuals who demonstrated the greatest change in receptive language abilities following ELA. METHODS: Data were drawn from the Female Growth and Development Study (n = 86), a 30-year prospective cohort study of females exposed to substantiated child sexual abuse (CSA), a severe ELA, and a non-CSA comparison condition. The Peabody Picture Vocabulary Test-Revised (PPVT-R) measured receptive language abilities on 6 occasions from childhood to mid-life. Interindividual differences in PPVT-R trajectories were examined in relation to CSA exposure and across 5 independent measures of epigenetic age acceleration derived from first (Horvath DNAmAge, Hannum DNAmAge) and second (GrimAge, PhenoAge, Dunedin Pace of Aging) generation epigenetic clocks. RESULTS: Quadratic growth models revealed that PPVT-R scores were significantly lower at age 25 for females exposed to CSA. Specifically, CSA exposed females had lower intercepts when GrimAge was accelerated and a smaller quadratic trend when PhenoAge was accelerated. DISCUSSION: ELA is associated with significant differences in development of receptive language abilities with the most pronounced differences observed for females with accelerated epigenetic ages at mid-life. These findings suggest that epigenetic age acceleration could serve as an indicator of differences in cognitive aging and portend to later adulthood cognitive functioning.

Respiratory Sinus Arrhythmia Change during Trauma-Focused Cognitive-Behavioral Therapy: Results from a Randomized Controlled Feasibility Trial.

Trauma-Focused Cognitive-Behavioral Therapy (TF-CBT) is a well-established treatment for pediatric posttraumatic stress disorder (PTSD). Animal-assisted therapy (AAT) has been proposed as an adjunct to TF-CBT that may improve treatment effects through enhanced targeting of affect regulation, as indexed by specific changes in the respiratory sinus arrhythmia (RSA). The current study reports results from a randomized controlled feasibility trial (N = 33; Mage = 11.79 [SD = 3.08]; 64% White; 67% female) that measured RSA during Sessions 1, 4, 8, and 12 of a twelve-session TF-CBT protocol and tested whether: 1) TF-CBT + AAT achieved higher average RSA amplitudes relative to TF-CBT alone, and 2) RSA regulation, defined as less variability around person-specific RSA slopes during treatment, explained variation in post-treatment PTSD symptoms. Multilevel modeling failed to support an effect for TF-CBT + AAT on RSA amplitudes (δ001 = 0.08, p = 0.844). However, regardless of treatment condition, greater RSA withdrawal was observed within Sessions 4 (γ11 = -.01, p < .001) and 12 (γ13 = -.01, p = .015) relative to the Session 1 baseline. The average level of RSA amplitude in Session 8 was also significantly lower compared to Session 1 (γ02 = -0.70, p = .046). Intraindividual regression models demonstrated that greater RSA regulation predicted improved PTSD symptoms at post-treatment after adjusting for pre-treatment levels (b3 = 20.00, p = .012). These preliminary results offer support for future confirmatory trials testing whether affect regulation, as indexed by changes in RSA, is a mechanism of action for TF-CBT in the treatment of pediatric PTSD.

Cortisol trajectories measured prospectively across thirty years of female development following exposure to childhood sexual abuse: Moderation by epigenetic age acceleration at midlife.

Lasting changes in the hypothalamic-pituitary-adrenal (HPA) axis are a potential indication of the biological embedding of early life adversity, yet, prospective and repeatedly collected data are needed to confirm this relation. Likewise, integrating information from multiple biological systems, such as the HPA axis and the epigenome, has the potential to identify individuals with enhanced embedding of early life adversity. The current study reports results from the Female Growth and Development Study, a 30-year prospective cohort study of childhood sexual abuse (CSA). Females exposed to substantiated CSA and a demographically-similar comparison condition were enrolled and resting state cortisol concentrations were sampled on seven subsequent occasions across childhood, adolescence, and adulthood. Differences in participants' cortisol trajectories were examined in relation to prior CSA exposure and DNA methylation-derived epigenetic age acceleration at midlife. Bilinear spline growth models revealed a trajectory where cortisol secretion increased until approximately age twenty and then declined into mid-life, consistent with normative trends. However, cortisol concentrations peaked at a lower level and transitioned to the decline phase at an earlier age for females in the CSA condition with increased epigenetic age acceleration. Robustness tests across three independent measures of epigenetic age acceleration demonstrated similar results for lower peak cortisol levels and earlier ages at transition. Results suggest that CSA is associated with significant changes in HPA-axis activity over extended periods of time with these changes most pronounced in females with accelerated epigenetic aging in mid-life. Implications for biological embedding models of early life adversity and adulthood health are discussed.

Parent-Focused Sexual Abuse Prevention: Results From a Cluster Randomized Trial.

This study tested whether a child sexual abuse (CSA) prevention program, Smart Parents-Safe and Healthy Kids (SPSHK), could be implemented as an additional module in evidence-based parent training and whether the added module might detract from the efficacy of the original program. In a cluster randomized trial, six community-based organizations were randomized to deliver Parents as Teachers (PAT) with SPSHK (PAT+SPSHK) or PAT as usual (PAT-AU). CSA-related awareness and protective behaviors, as well as general parenting behaviors taught by PAT were assessed at baseline, post-PAT, post-SPSHK, and 1-month follow-up. Multilevel analyses revealed significant group by time interactions for both awareness and behaviors (ps < .0001), indicating the PAT+SPSHK group had significantly greater awareness of CSA and used protective behaviors more often (which were maintained at follow-up) compared to the PAT-AU group. No differences were observed in general parenting behaviors taught by PAT suggesting adding SPHSK did not interfere with PAT efficacy as originally designed. Results indicate adding SPHSK to existing parent training can significantly enhance parents' awareness of and readiness to engage in protective behavioral strategies. Implementing SPHSK as a selective prevention strategy with at-risk parents receiving parent training through child welfare infrastructures is discussed.

Stress and information processing: acute psychosocial stress affects levels of mental abstraction.

BACKGROUND: One mechanism by which acute psychosocial stress effects health-related cognitions and behaviors is through changes in the level of mental abstraction when processing information. However, it is unclear whether levels of mental abstraction would be higher or lower after an acute psychosocial stressor. OBJECTIVES: This research examined acute psychosocial stress's impact on levels of mental abstraction. DESIGN: Randomized between-subjects experimental design. METHODS: A diverse sample of 164 undergraduate students aged 18-24 years old were randomly assigned to an acute psychosocial stressor or non-stressful control condition. Blood pressure (BP), heart rate (HR), and negative affect were monitored throughout the study and mental abstraction was measured at the end of each condition. RESULTS: Mental abstraction was statistically significantly higher (i.e., more abstract) after the stress condition than after the control condition (p = 0.005, d = 0.44). This association was partially explained by negative affect (p = 0.017), but not BP or HR (ps > 0.60). CONCLUSIONS: Acute psychosocial stress is associated with higher levels of mental abstraction after the stressor. These findings may have implications for stress-relevant interventions as accounting for the level of mental abstraction may enhance the efficacy of the intervention.

A multimethod approach examining the relative contributions of optimism and pessimism to cardiovascular disease risk markers.

Although dispositional optimism and pessimism are associated with cardiovascular disease (CVD), their relative independence and unique contributions to CVD risk are unclear. This study addressed these issues by using multiple indicators of optimism and pessimism and linking them to objective risk factors for CVD. A diverse sample of adults (N = 300) completed baseline assessments (including global reports of optimism and pessimism), a 2-day/1-night EMA protocol with ambulatory blood pressure (BP) at 45-min intervals, and had inflammatory markers and carotid intima media imaging collected. EMA reports of momentary positive and negative expectations were averaged to form intraindividual (person) means of optimism and pessimism, respectively. Optimism and pessimism were only modestly correlated between- and within-assessment methods. Higher pessimism, regardless of assessment method, predicted both lower odds of whether BP dipping occurred and a smaller degree of dipping, but was unrelated to other biomarkers. Optimism was not uniquely predictive of CVD risk factors. Pessimism thus appears to exhibit stronger relative contribution to risk indicators of CVD than optimism.

Associations of Parental General Monitoring with Adolescent Weight-Related Behaviors and Weight Status.

OBJECTIVE: This study examined how parental general monitoring (PGM), which refers to parental awareness of adolescents' activities in various domains, is associated with adolescents' weight status and related behaviors and whether these relationships differ among racial/ethnic groups. METHODS: Data are from 4,088 Black, Latino, and White youth assessed in seventh grade (mean age = 13.06). BMI percentile based on measured height and weight indicated weight status. PGM was assessed by adolescent report of parents' awareness of money spending, friends, and whereabouts. Adolescents reported both healthy and unhealthy dietary intake (DI), physical activity, and screen time over the past 7 days. Total sample and multigroup structural models were estimated. RESULTS: PGM was associated with lower weight status for the total sample, as well as being positively associated with healthy DI and physical activity and inversely associated with screen time across racial/ethnic groups. PGM was also inversely associated with unhealthy DI, except for in Black adolescents. There was an indirect effect from PGM to lower weight status via reduced screen time among Latino and White adolescents. CONCLUSIONS: Positive outcomes associated with PGM are extended to weight status and related behaviors. Efforts at improving weight status and related behaviors could benefit from addressing general parenting practices with their children.

The performance of the IES-R for Latinos and non-Latinos: Assessing measurement invariance.

Violent acts on university campuses are becoming more frequent. Enrollment rates of Latinos at universities is increasing. Research has indicated that youths are more susceptible to trauma, particularly Latinos. Thus, it is imperative to evaluate the validity of commonly used posttraumatic stress measures among Latino college students. The Impact of Event Scale-Revised (IES-R) is one of the most commonly used metrics of posttraumatic stress disorder symptomatology. However, it is largely unknown if the IES-R is measuring the same construct across different sub-samples (e.g. Latino versus non-Latino). The current study aimed to assess measurement invariance for the IES-R between Latino and non-Latino participants. A total of 545 participants completed the IES-R. One- and three-factor scoring solutions were compared using confirmatory factor analyses. Measurement invariance was then evaluated by estimating several multiple-group confirmatory factor analytic models. Four models with an increasing degree of invariance across groups were compared. A significant χ2 difference test was used to indicate a significant change in model fit between nested models within the measurement invariance testing process. The three-factor scoring solution could not be used for the measurement invariance process because the subscale correlations were too high for estimation (rs 0.92-1.00). Therefore, the one-factor model was used for the invariance testing process. Invariance was met for each level of invariance: configural, metric, scalar, and strict. All measurement invariance testing results indicated that the one-factor solution for the IES-R was equivalent for the Latino and non-Latino participants.

Assessment of health surveys: fitting a multidimensional graded response model.

The multidimensional graded response model, an item response theory (IRT) model, can be used to improve the assessment of surveys, even when sample sizes are restricted. Typically, health-based survey development utilizes classical statistical techniques (e.g. reliability and factor analysis). In a review of four prominent journals within the field of Health Psychology, we found that IRT-based models were used in less than 10% of the studies examining scale development or assessment. However, implementing IRT-based methods can provide more details about individual survey items, which is useful when determining the final item content of surveys. An example using a quality of life survey for Cushing's syndrome (CushingQoL) highlights the main components for implementing the multidimensional graded response model. Patients with Cushing's syndrome (n = 397) completed the CushingQoL. Results from the multidimensional graded response model supported a 2-subscale scoring process for the survey. All items were deemed as worthy contributors to the survey. The graded response model can accommodate unidimensional or multidimensional scales, be used with relatively lower sample sizes, and is implemented in free software (example code provided in online Appendix). Use of this model can help to improve the quality of health-based scales being developed within the Health Sciences.

Latent Growth Curve Models for Biomarkers of the Stress Response.

Objective: The stress response is a dynamic process that can be characterized by predictable biochemical and psychological changes. Biomarkers of the stress response are typically measured over time and require statistical methods that can model change over time. One flexible method of evaluating change over time is the latent growth curve model (LGCM). However, stress researchers seldom use the LGCM when studying biomarkers, despite their benefits. Stress researchers may be unaware of how these methods can be useful. Therefore, the purpose of this paper is to provide an overview of LGCMs in the context of stress research. We specifically highlight the unique benefits of using these approaches. Methods: Hypothetical examples are used to describe four forms of the LGCM. Results: The following four specifications of the LGCM are described: basic LGCM, latent growth mixture model, piecewise LGCM, and LGCM for two parallel processes. The specifications of the LGCM are discussed in the context of the Trier Social Stress Test. Beyond the discussion of the four models, we present issues of modeling nonlinear patterns of change, assessing model fit, and linking specific research questions regarding biomarker research using different statistical models. Conclusions: The final sections of the paper discuss statistical software packages and more advanced modeling capabilities of LGCMs. The online Appendix contains example code with annotation from two statistical programs for the LCGM.