Inter-observer reliability of radiographic classifications and measurements in the assessment of Perthes' disease

We evaluated the inter-observer agreement of radiographic methods when evaluating patients with Perthes' disease. The radiographs were assessed at the time of diagnosis and at the 1-year follow-up by local orthopaedic surgeons (O) and 2 experienced pediatric orthopedic surgeons (TT and SS). The Catterall, Salter-Thompson, and Herring lateral pillar classifications were compared, and the femoral head coverage (FHC), center-edge angle (CE-angle), and articulo-trochanteric distance (ATD) were measured in the affected and normal hips. On the primary evaluation, the lateral pillar and Salter-Thompson classifications had a higher level of agreement among the observers than the Catterall classification, but none of the classifications showed good agreement (weighted kappa values between O and SS 0.56, 0.54, 0.49, respectively). Combining Catterall groups 1 and 2 into one group, and groups 3 and 4 into another resulted in better agreement (kappa 0.55) than with the original 4-group system. The agreement was also better (kappa 0.62-0.70) between experienced than between less experienced examiners for all classifications. The femoral head coverage was a more reliable and accurate measure than the CE-angle for quantifying the acetabular covering of the femoral head, as indicated by higher intraclass correlation coefficients (ICC) and smaller inter-observer differences. The ATD showed good agreement in all comparisons and had low interobserver differences. We conclude that all classifications of femoral head involvement are adequate in clinical work if the radiographic assessment is done by experienced examiners. When they are less experienced examiners, a 2-group classification or the lateral pillar classification is more reliable. For evaluation of containment of the femoral head, FHC is more appropriate than the CE-angle.

Cliometric metatheory: II. Criteria scientists use in theory appraisal and why it is rational to do so

Definitive tests of theories are often impossible in the life sciences because auxiliary assumptions are problematic. In the appraisal of competing theories, history of science shows that scientists use various theory characteristics such as aspects of parsimony, the number, qualitative diversity, novelty, and numerical precision of facts derived, number of misderived facts, and reducibility relations to other accepted theories. Statistical arguments are offered to show why, given minimal assumptions about the world and the mind, many of these attributes are expectable correlates of verisimilitude. A statistical composite of these attributes could provide an actuarial basis for theory appraisal (cliometric metatheory).

Comments on the Meehl-Waller (2002) procedure for appraisal of path analysis models

P. E. Meehl and N. G. Waller (2002) proposed an innovative method for assessing path analysis models wherein they subjected a given model, along with a set of alternatives, to risky tests using selected elements of a sample correlation matrix. Although the authors find much common ground with the perspective underlying the Meehl-Waller approach, they suggest that there are aspects of the proposed procedure that require close examination and further development. These include the selection of only one subset of correlations to estimate parameters when multiple solutions are generally available, the fact that the risky tests may test only a subset of parameters rather than the full model of interest, and the potential for different results to be obtained from analysis of equivalent models.

Commentary on Meehl and Waller's (2002) path analysis and verisimilitude

P. E. Meehl and N. G. Waller's (2002) proposed method may not yield unique solutions for model parameters nor unique solutions for model lack of fit. The author argues from a naturalistic-cognitive philosophy of science that science seeks objective knowledge and that hypothesis testing is central to achieving that goal. It is also argued that P. E. Meehl and N. G. Waller's proposal blurs the distinction between hypothesis testing and explorations of the data seeking an optimal model to serve as a prospective inductive generalization. But it is noted that inductive generalizations are never unique and must be tested to eliminate those that reflect subjective aspects of the researcher's methods and points of view.

The priority of just-identified, recursive models

Theories often place constraints on causal relationships, and such constraints are often assessed with causal models. Causal models should be recursive and just identified because cause is recursive and is more likely to be just identified than overidentified. A just-identified, recursive model (JIRM) is specified that satisfies both requirements and that can be used to assess a wide range of causal implications in either a norm-referenced or criterion-referenced manner. P. E. Meehl and N. G. Waller (2002) proposed an innovative method for theory appraisal called the delete one-add one (D1-A1) method, which assesses a relatively narrow range of causal implications, allows nonrecursive models, and is only norm referenced. The JIRM and D1-A1 methods are compared.

The "I," the "we," and the "when": a meta-analysis of motivational primacy in self-definition

What is the primary motivational basis of self-definition? The authors meta-analytically assessed 3 hypotheses: (a) The individual self is motivationally primary, (b) the collective self is motivationally primary, and (c) neither self is inherently primary; instead, motivational primacy depends on which self becomes accessible through contextual features. Results identified the individual self as the primary motivational basis of self-definition. People react more strongly to threat and enhancement of the individual than the collective self. Additionally, people more readily deny threatening information and more readily accept enhancing information when it pertains to the individual rather than the collective self, regardless of contextual influences. The individual self is the psychological home base, a stable system that can react flexibly to contextual influences.

Observational visual analog scale in pediatric pain assessment: useful tool or good riddance?

DESIGN

The authors reviewed the available pediatric pain literature and selected those studies that reported quantitative information on the reliability and validity of, and the optimal cutoff points for, the visual analog scale (VAS) when used as an observational pediatric pain tool.

RESULTS

Available psychometric findings concerning the observational VAS (VAS obs ) are limited. The estimated interrater reliability of the VAS (obs) from 9 studies ranged from 0.36 to 0.91. The correlation between self-report and the VAS (obs) was variable and ranged 0.23 to 0.83 in 6 studies. The concurrent validity of the VAS (obs) and other pain instruments ranged from 0.42 to 0.86.

CONCLUSIONS

Further psychometric testing needs to be conducted on intraobserver reliability, responsiveness, and optimal cutoff points. Future research may guide the choice between VAS (obs) and the numerous behavioral pain instruments.

Fatigue in multiple sclerosis: reciprocal relationships with physical disabilities and depression

OBJECTIVE

To explore relations of fatigue, physical disabilities, and depression in patients with multiple sclerosis (MS) cross-sectionally and over time.

METHODS

Ninety-eight MS patients were interviewed twice at an interval of a year. Relationships of physical and mental fatigue, and reduced activity and motivation with depression and physical disabilities were established cross-sectionally by regression analyses and longitudinally by structural equation modelling.

RESULTS

Cross-sectionally, physical fatigue was related with physical disabilities, and mental fatigue was associated with depression. Prospectively, physical fatigue was a predictor of the physical disabilities of a year later. The reverse relationship of physical disabilities predicting the physical fatigue of one year later was, however, not significant, while depression predicted this physical fatigue and reduced activity of a year later. Depression did not predict the later mental fatigue nor was depression predicted by preceding fatigue experiences.

CONCLUSIONS

Fatigue in MS should be studied over time as relationships of fatigue with physical and mental health change during the course of a year. Moreover, differentiating in fatigue experiences sheds light on the relationship of fatigue with physical and mental health.

Patient adherence and medical treatment outcomes: a meta-analysis

BACKGROUND

Adherence is a factor in the outcome of medical treatment, but the strength and moderators of the adherence-outcome association have not been systematically assessed.

OBJECTIVES

A quantitative review using meta-analysis of three decades of empirical research correlating adherence with objective measures of treatment outcomes.

METHOD

Sixty-three studies assessing patient adherence and outcomes of medical treatment were found involving medical regimens recommended by a nonpsychiatrist physician, and measuring patient adherence and health outcomes. Studies were analyzed according to disease (acute/chronic, severity), population (adult/child), type of regimen (preventive/treatment, use of medication), and type and sensitivity of adherence and outcomes measurements.

RESULTS

Overall, the outcome difference between high and low adherence is 26%. According to a stringent random effects model, adherence is most strongly related to outcomes in studies of nonmedication regimens, where measures of adherence are continuous, and where the disease is chronic (particularly hypertension, hypercholesterolemia, intestinal disease, and sleep apnea). A less stringent fixed effects model shows a trend for higher adherence-outcome correlations in studies of less serious conditions, of pediatric patients, and in those studies using self-reports of adherence, multiple measures of adherence, and less specific measures of outcomes. Intercorrelations among moderator variables in multiple regression show that the best predictor of the adherence-outcome relationship is methodological-the sensitivity/quality of the adherence assessment.

Influence of adult domestic violence on children's internalizing and externalizing problems: an environmentally informative twin study

OBJECTIVE

Externalizing and internalizing problems may aggregate in families because (1) siblings share genetic risks for problem behaviors or (2) siblings are exposed to similar environmental risks. A genetically sensitive design was used to determine whether domestic violence accounted significantly for the variation and covariation of externalizing and internalizing problems, independent of additive genetic effects on these behavior problems.

METHOD

Using the Achenbach family of instruments, mothers and teachers reported internalizing and externalizing problems for 1,116 monozygotic and dizygotic 5-year-old twin pairs in the United Kingdom (93% response rate). Mothers reported their experiences of domestic violence in the previous 5 years. Structural equation models were tested to determine the effect of mothers' experiences of domestic violence on children's emotional and conduct problems, controlling for latent genetic and environmental effects on these behaviors.

RESULTS

A multivariate model showed that adult domestic violence accounted for 2% and 5% of the variation in children's internalizing and externalizing problems, respectively, independent of genetic effects. The co-occurrence of externalizing and internalizing scores was accounted for by genetic (62.6%) and shared environmental (29.2%) factors and by domestic violence (8%).

CONCLUSIONS

Because domestic violence affects children's behavior problems beyond genetic influences, programs that successfully reduce domestic violence should also prevent children's psychopathology.

Childhood behavioral profiles leading to adolescent conduct disorder: risk trajectories for boys and girls

OBJECTIVE

To examine the link between childhood behavioral dimensions and adolescent conduct disorder (CD) among a large sample of boys and girls monitored longitudinally.

METHOD

Teachers rated the behaviors of 1,569 children every year between kindergarten and grade 6. On the basis of these seven yearly ratings, groups of children who followed distinct trajectories on three behavioral dimensions--hyperactivity, fearfulness, and helpfulness--were identified with a semiparametric statistical analysis. Children were then categorized into one of eight behavioral profiles, representing different combinations of the trajectories. Logistic regressions were used to estimate the relation between the profiles and CD in adolescence (mean = 15.7 years).

RESULTS

Boys had a significant risk for CD if they were hyperactive (odds ratio [OR] = 4.27; 95% confidence interval [CI], 1.8-10.16); hyperactive and unhelpful (OR = 2.83; CI, 1.07-7.46); or hyperactive, fearless, and unhelpful (OR = 3.93; CI, 1.27-12.17). Girls had a significant risk for CD only if they were both hyperactive and unhelpful (OR = 4.61; CI, 1.31-16.24). More boys than girls exhibited profiles of risk and met criteria for CD in adolescence.

CONCLUSIONS

Sex-specific childhood behavioral profiles that represented risk for CD in adolescence were identified. There were sex differences in the prevalence of the childhood profiles representing risk for CD.

Teen-aged mothers in contemporary Britain

BACKGROUND

This paper describes the circumstances of contemporary young mothers and their children from a nationally representative sample, and compares them to the circumstances of mothers who delayed childbearing beyond age 20.

METHODS

The participants are members of the Environmental Risk (E-risk) Longitudinal Twin Study, which follows an epidemiological sample of 1,116 women who became mothers in England and Wales in 1994-95, and their children, and contains an over-sample of young mothers. Home visits were conducted when the children were aged 5 years. Data were collected from mothers via interviews, from children via experimental tasks and observations, and from teachers via postal questionnaires.

RESULTS

Young mothers encountered more socio-economic deprivation, had significantly less human and social capital, and experienced more mental health difficulties. Their partners were less reliable and supportive, both economically and emotionally, and were more antisocial and abusive. The children of young mothers showed reduced educational attainment, were rated by multiple informants as having more emotional and behavioural problems, were at increased risk of maltreatment or harm, and showed higher rates of illnesses, accidents, and injuries.

CONCLUSIONS

Young mothers today face difficulties known to have long-lasting effects for women and their children. Preventions that target young mothers may reduce harm to the physical health, mental health, and social status of future generations.

Correlates of expressed emotion in mothers of clinically-referred youth: an examination of the five-minute speech sample

BACKGROUND

Most studies applying the adult-derived 'expressed emotion' (EE) measure to children have combined criticism (CRIT) and emotional overinvolvement (EOI). Yet, some of the parent behaviors coded as EOI and shown to have negative implications for parents and their adult children (e.g., multiple positive comments about the son or daughter) may be normative and benign for parents and their juvenile children. Thus, EOI, as currently operationalized, may not be related to child psychopathology in the way CRIT is.

METHOD

We tested this possibility, separating CRIT and EOI and examining the individual scoring criteria for each in relation to psychopathology factors in a sample of 258 clinically-referred children aged 7-17.

RESULTS

Whereas each of the four CRIT criteria related positively to maternal reports of child psychopathology, especially externalizing problems, only two of the five EOI criteria were positively related to child psychopathology, and one (positive comments) was negatively related. Structural Equation Modeling findings supported a model in which CRIT partially mediates the relation between maternal psychopathology and child externalizing symptoms.

CONCLUSIONS

Overall, the results suggest that EE may contribute to the study of parent-child relations and child psychopathology, but that a developmental adjustment may be required in the way EE is operationalized for use with juvenile samples.

Looking at Behavior through Control Theory Glasses

Behavior is always seen through the theoretical preferences of the observer. These preferences act like different prescriptions for glasses. The most popular glasses use the causal theory prescription, through which an organism's behavior appears to be the result of external or internal causes. This article describes glasses that use the less familiar control theory prescription, through which behavior looks like the organism's purposeful efforts to control its own perceptions. The consequences of looking at the same behavior through these different “glasses” are demonstrated by comparing examples of real-life behavior with the behavior of computer simulations available on the Internet. A method is described that makes it possible to determine which “glasses” provide the best view of any particular example of behavior.

Have we lost our way? The need for dynamic formulations of smoking relapse proneness

Current smoking cessation treatments seem to differ from one another in the proportion of ex-smokers who survive the first few days of the quit attempt. After this initial effect, parallel relapse processes appear to unfold in all treatment groups; no available treatments seem to alter the nature of this late relapse process. True relapse prevention will require that we obtain a better understanding of the forces contributing to relapse across the span of the cessation attempt. A working model of dynamic relapse processes may be necessary before treatments can be improved. In this paper, we suggest that the conceptual model of relapse proneness (RP) described originally by the National Working Conference on Smoking Relapse can serve as an ecumenical organizational framework that may be used to integrate and conceptualize relapse data in ways that could generate new strategies for relapse research and inform treatment design. As an illustration, we sketch a preliminary model of RP which postulates that physical withdrawal, stressors/temptations, and cessation fatigue each make independent, time-shifted contributions to relapse risk. A new round of descriptive research focused on relapse proneness processes may be a prerequisite for improving existing smoking cessation interventions.

What predicts incident use of cannabis and progression to abuse and dependence? A 4-year prospective examination of risk factors in a community sample of adolescents and young adults

OBJECTIVES

To determine risk factors of incident onset of use, abuse and dependence of cannabis in a community sample of adolescents and young adults.

METHODS

Risk factors were examined in a prospective longitudinal design across 4 years in a representative sample (N = 2,446) aged 14-24 at the outset of the study (EDSP). Patterns of DSM-IV defined cannabis use, abuse and dependence were assessed with the Composite International Diagnostic Interview (M-CIDI). Potential risk factors were assessed at baseline. Incident cannabis use, abuse and dependence at second follow-up (on average 42 months after baseline) were the main outcome measures in this study. Associations were analyzed with logistic and negative binomial regressions.

RESULTS

Using 11 of a total of 56 variables examined, the predictive value of the final multiple logistic regression for incident cannabis use was moderately good (area under the ROC curve = 0.78). Cannabis use frequency was predicted in the final model by 18 variables, cannabis abuse by two variables in the younger subsample and nine factors in the older group, and dependence by eight variables (dependence: ROC curve area = 0.97). Incident cannabis use was predicted mainly by availability of drugs, peers' drug use, a more 'positive' attitude towards future drug use, and regular previous use of licit drugs, while cannabis dependence was predicted primarily by parental death before age 15, deprived socio-economic status, and baseline use of other illicit drugs.

CONCLUSION

Different factors predict the onset or severity of cannabis use and the progression to abuse and dependence. In addition to well-documented risk factors such as peer group pressure, drug availability, and low self-esteem, findings suggest that family history (e.g. parental mental disorders, early parental death), and prior experiences with legal drugs play a significant role in the initiation of cannabis consumption and the transition to cannabis use disorders in adolescents and young adults. Findings suggest that early intervention and prevention might be improved by better targeted treatment.

A theoretical approach to measuring quality of life

The purpose of this article is to discuss conceptual issues surrounding health-related quality of life (HRQOL) and to provide an example of how structural equation modeling can address some of these conceptual issues. This article reports the development of the measurement model for overall quality of life, a dimension of HRQOL as conceptualized by Wilson and Cleary (1995). The sample (N = 1410) is from the AIDS Time-Oriented Health Outcome Study (ATHOS) databank, a longitudinal observational database of persons with HIV-associated illness. The hypothesized second-order factor model consists of 5 latent variables and 17 measured items. The fit indicators (RMSEA = .0717; SRMR = .0450; CFI = .951) suggest that the model provides an adequate description of the pattern of relationships in the data. A theoretical approach to HRQOL will expand its clinical use as an outcome measure and increase its relevance.

Delineating the impact of Tai Chi training on physical function among the elderly

BACKGROUND

Through a re-analysis of a Tai Chi intervention data set, the study objective was to determine which, if any, subgroups of the study sample evidenced differential benefits from the intervention.

METHOD

Re-analysis of a Tai Chi intervention study, a randomized controlled trial in Eugene and Springfield, Oregon. Physically inactive participants aged > or =65 years were randomly assigned to one of two groups: Tai Chi (n=49) and a wait-list control (n=45). The main outcome measure was self-reported physical function.

RESULTS

Initial latent curve analyses indicated significant Tai Chi training effects: Participants in the Tai Chi group reported significant improvements in perceived physical function compared to those in the control group. However, there was significant interindividual variability in response to Tai Chi. The overall intervention effect was further delineated by identifying two subgroups. This delineation showed that Tai Chi participants with lower levels of physical function at baseline benefited more from the Tai Chi training program than those with higher physical function scores. Inclusion of additional measures of individual characteristics at baseline, change in movement confidence, and class attendance further explained differences in treatment responses.

CONCLUSIONS

Findings from this study suggest that although an intervention may show an overall effect (or no overall effect), it may be differentially effective for subgroups of participants that differ in their pre-intervention characteristics. Examination of variability in outcome measures can provide important information for refining and tailoring appropriate interventions targeted to specific subgroups.

Preventing schizophrenia and psychotic behaviour: definitions and methodological issues

Although schizophrenia onset usually occurs in late adolescence or early adulthood, much research shows that its seeds are planted early in life and that eventual onset occurs at the end of a neurodevelopmental process leading to aberrant brain functioning. This idea, along with the fact that current therapies are far from fully effective, suggests that preventive treatments may be needed to achieve an ideal outcome for schizophrenia patients and those predisposed to the disorder. In this article, we review the methodological challenges that must be overcome before effective preventive interventions can be created. Prevention studies will need to define the target population. This requires the identification of risk factors that will be useful in selecting at-risk people for preventive treatment. We review currently identified risk factors for schizophrenia: genes, psychosocial factors, pregnancy and delivery complications, and viruses. We also review 3 different types of prevention programs: universal, indicated, and selective. For schizophrenia, we distinguish prevention programs that target prodromal cases and those that target the disorder's premorbid precursors. Although those targeting prodromal cases provide a useful framework for early treatment of the disorder, studies of premorbid individuals are needed to design a truly preventive treatment.

A finite mixture model of growth trajectories of adolescent alcohol use: predictors and consequences

The current study sought to identify classes of growth trajectories of adolescent alcohol use and to examine the predictors and outcomes associated with the classes. Alcohol use was assessed from Grades 7 to 12 in a school-based sample. Latent growth mixture modeling was used, and results indicated 5 discrete longitudinal drinking patterns. The 2 most common drinking patterns included occasional very light drinking from Grades 7 to 12 and moderate escalation in both quantity and frequency of alcohol use. One group drank infrequently but at high levels throughout the study period. Another group exhibited rapid escalation in both quantity and frequency. The final group started at high levels of frequency and quantity in Grade 7 and showed rapid de-escalation in frequency. Emotional distress and risk taking distinguished the classes, and all classes, particularly rapid escalators, showed elevated levels of alcohol-related problems relative to occasional very light drinkers.

Effects and generalizability of communally oriented HIV-AIDS prevention versus general health promotion groups for single, inner-city women in urban clinics

A primary prevention, behavioral intervention designed to reduce HIV risk behavior was tested in a randomized, controlled trial with single, inner-city women. A total of 935 women were randomly assigned to 1 of 3 conditions: a small group, 6-session communally oriented HIV prevention intervention; a yoked general health promotion intervention control; or a standard care control. Both interventions involved the interactive use of videotapes by live group leaders. The HIV prevention intervention, in particular, resulted in significant positive effects on self-reported and behaviorally assessed safer-sex behavior. Women in the HIV prevention group showed reduced point prevalences of medically tested sexually transmitted diseases at follow-up in some comparisons.

A new frame for frame-of-reference training: enhancing the construct validity of assessment centers

The authors undertook a comprehensive examination of the construct validity of an assessment center in this study by (a) gathering many different types of evidence to evaluate the strength of the inference between predictor measures and constructs (e.g., reliability, accuracy, convergent and discriminant relationships), (b) introducing a theoretically relevant intervention (frame-of-reference [FOR] training) aimed at improving construct validity, and (c) examining the effect of this intervention on criterion-related validity (something heretofore unexamined in the assessment center literature). Results from 58 assessees and 122 assessors suggested that FOR training was effective at improving the reliability, accuracy, convergent and discriminant validity, and criterion-related validity of assessment center ratings. Findings are discussed in terms of implications and future directions for both FOR training and assessment center practice.

Multicenter trial of fluoxetine as an adjunct to behavioral smoking cessation treatment

The authors evaluated the efficacy of fluoxetine hydrochloride (Prozac; Eli Lilly and Company, Indianapolis, IN) as an adjunct to behavioral treatment for smoking cessation. Sixteen sites randomized 989 smokers to 3 dose conditions: 10 weeks of placebo, 30 mg, or 60 mg fluoxetine per day. Smokers received 9 sessions of individualized cognitive-behavioral therapy, and biologically verified 7-day self-reported abstinence follow-ups were conducted at 1, 3, and 6 months posttreatment. Analyses assuming missing data counted as smoking observed no treatment difference in outcomes. Pattern-mixture analysis that estimates treatment effects in the presence of missing data observed enhanced quit rates associated with both the 60-mg and 30-mg doses. Results support a modest, short-term effect of fluoxetine on smoking cessation and consideration of alternative models for handling missing data.

Goal-directedness and personal identity as correlates of life outcomes

Although much research has been conducted on goal setting, researchers have not examined goal-directedness or propensity to set goals as a stable human characteristic in adults. In this study, a survey was developed and distributed to 104 adult participants to assess their goal-directedness, personal identity, and various life outcomes. A theoretical model was developed and tested using structural equation modeling that proposed that both goal-directedness and personal identity should positivcly influence important life outcomes. Analysis showed that goal-directedness and personal identity are positively related to personal well-being, salary, and marital satisfaction. Further, personal identity was positively related to job satisfaction but, contrary to related research, goal-directedness did not predict job satisfaction.

Testing discrepancy effects: a critique, a suggestion, and an illustration

To assess the effects of discrepancy between two independent variables, investigators sometimes compute difference scores and correlate such scores with a criterion variable. However, the correlation of the difference with the criterion is accounted for by the correlations of the difference constituents with the criterion and the constituents' variances. It follows that when investigators are testing a prediction that is not captured by the difference constituents' main effects, using the difference correlation analysis may be misleading. Under these circumstances, the effects of a discrepancy between two independent variables can be assessed by a test of their interaction. The problems inherent in using difference scores and the advantage of testing the interaction are illustrated in relation to research programs on two separate topics in social psychology.

Comparing the relationships between different types of self-efficacy and physical activity in youth

A preliminary study was conducted to compare the relationships between different types of self-efficacy and youth physical activity. Two samples of sixth- and seventh-grade students (Sample 1: N= 57; Sample 2: N= 49) reported their confidence to be physically active (physical activity efficacy), to overcome barriers to physical activity (barriers efficacy), to ask others to be active with them (asking efficacy), and to find and create environments that support physical activity (environmental-change efficacy). Physical activity was measured by averaging three 24-hour recalls of physical activity. Regression analyses were used to test the relationships between the types of self-efficacy and youth physical activity. Compared with the other types of self-efficacy, environmental-change efficacy had the strongest relationship with youth physical activity. This suggests that strengthening young persons' belief in their ability to find and create environments that support physical activity might promote increases in their physical activity.

Lapses of intention and performance variability reveal age-related increases in fluctuations of executive control

We examine the hypothesis that the efficiency of executive control processes is less stable over time in older than younger adults. An age-related decrease in the efficiency of executive control should result in an increase in performance variability in task conditions requiring the recruitment of executive control processes and not in task conditions requiring minimal involvement of executive control. Performance variability was similar for younger and older adults in task conditions requiring minimal executive control and greater for older than younger adults in task conditions requiring executive control. These and other data are consistent with the proposal that aging is associated with a decrease in the stability of executive control over time.

Cultural differences in responses to a Likert scale

Cultural differences in responses to a Likert scale were examined. Self-identified Chinese, Japanese, and Americans (N=136, 323, and 160, respectively) recruited at ethnic or general supermarkets in Southern California completed a 13-question Sense of Coherence scale with a choice of either four, five, or seven responses in either Chinese, Japanese, or English. The Japanese respondents more frequently reported difficulty with the scale, the Chinese more frequently skipped questions, and both these groups selected the midpoint more frequently on items that involved admitting to a positive emotion than did the Americans, who were more likely to indicate a positive emotion. Construct validity of the scale tended to be better for the Chinese and the Americans when there were four response choices and for the Japanese when there were seven. Although culture affected response patterns, the association of sense of coherence and health was positive in all three cultural groups.

Reconsidering the use of the general linear model with single-case data

Using a low point estimate of autocorrelation to justify analyzing single-case data with the general linear model (GLM) is questioned. Monte Carlo methods are used to examine the degree to which bias in the estimate of autocorrelation depends on the complexity of the linear model used to describe the data. A method is then illustrated for determining the range of autocorrelation parameters that could reasonably have led to the observed autocorrelation. The argument for using a GLM analysis can be strengthened when the GLM analysis functions appropriately across the range of plausible autocorrelations. For situations in which the GLM analysis does not function appropriately across this range, a method is provided for adjusting the confidence intervals to ensure adequate coverage probabilities for specified levels of autocorrelation.

Alcohol use disorders and cognitive abilities in young adulthood: a prospective study

The effect of alcohol use disorder (AUD) on cognitive and neuropsychological abilities was investigated in a prospective study of 68 freshmen who met past-year criteria for AUD on 2 or more occasions during their college years and 66 matched controls. At baseline, participants were administered a total of 14 subtests from the Wechsler Adult Intelligence Scale-Revised, Wechsler Memory Scale, and Halstead-Reitan Neuropsychological Battery. At 7-year follow-up, most measures were readministered, along with the Reflective Judgment Interview, Watson-Glaser Critical Thinking Appraisal, and Plant Test. Analyses revealed few differences between AUD and control groups. However, visuospatial deficits may be present among AUD participants with poor baseline visuospatial performance. Alcohol exposure measures yielded similar patterns to those shown with AUD.

Personality and leadership: a qualitative and quantitative review

This article provides a qualitative review of the trait perspective in leadership research, followed by a meta-analysis. The authors used the five-factor model as an organizing framework and meta-analyzed 222 correlations from 73 samples. Overall, the correlations with leadership were Neuroticism = -.24, Extraversion = .31, Openness to Experience = .24, Agreeableness = .08, and Conscientiousness = .28. Results indicated that the relations of Neuroticism, Extraversion, Openness to Experience, and Conscientiousness with leadership generalized in that more than 90% of the individual correlations were greater than 0. Extraversion was the most consistent correlate of leadership across study settings and leadership criteria (leader emergence and leadership effectiveness). Overall, the five-factor model had a multiple correlation of .48 with leadership, indicating strong support for the leader trait perspective when traits are organized according to the five-factor model.

Neurocognitive impairment associated with alcohol use disorders: implications for treatment

Between 50% and 80% of individuals with alcohol use disorders experience mild to severe neurocognitive impairment. There is a strong clinical rationale that neurocognitive impairment is an important source of individual difference affecting many aspects of addiction treatment, but empirical tests of the direct influence of impairment on treatment outcome have yielded weak and inconsistent results. The authors address the schism between applied-theoretical perspectives and research evidence by suggesting alternative conceptual models of the relationship between neurocognitive impairment and addiction treatment outcome. Methods to promote neurocognitive recovery and ways in which addiction treatments may be modified to improve psychosocial adaptation are suggested. Specific suggestions for future research that may help clarify the complex relations between neurocognitive impairment and addiction treatment are outlined.

Kappa coefficients in medical research

Kappa coefficients are measures of correlation between categorical variables often used as reliability or validity coefficients. We recapitulate development and definitions of the K (categories) by M (ratings) kappas (K x M), discuss what they are well- or ill-designed to do, and summarize where kappas now stand with regard to their application in medical research. The 2 x M(M>/=2) intraclass kappa seems the ideal measure of binary reliability; a 2 x 2 weighted kappa is an excellent choice, though not a unique one, as a validity measure. For both the intraclass and weighted kappas, we address continuing problems with kappas. There are serious problems with using the K x M intraclass (K>2) or the various K x M weighted kappas for K>2 or M>2 in any context, either because they convey incomplete and possibly misleading information, or because other approaches are preferable to their use. We illustrate the use of the recommended kappas with applications in medical research.

A Comparison of Data Analysis Strategies for Testing Omnibus Effects in Higher-Order Repeated Measures Designs

Methods for analyzing repeated measures data, in addition to the conventional and corrected degrees of freedom univariate and multivariate solutions, are presented in this review. These "newer" methods offer researchers either improved control over Type I errors and/or greater power to detect treatment effects when (a) certain assumptions are violated, and/or (b) missing data exists. In particular, Huynh's (1978) Improved General Approximate method, a multivariate Welch (1951)/James (1951)-type test, the mixedmodel approach (Littell, Milliken, Stroup, & Wolfinger, 1996) and Boik's (1997) empirical Bayes method are discussed. We review the literature regarding these procedures with respect to their robustness, ability to handle missing data, and availability of software to obtain numerical results.

Goal importance and students at risk of having language difficulties: an underexplored aspect of student motivation

The purpose of this study was to compare the motivational determinants of students at risk of language difficulties (in reading and spelling) and students with high language skills. Teachers' evaluations in language and mathematics at the end of the academic year constituted the dependent variable. Motivational orientations were examined using the constructs that reflect the theory of planned behavior and goal importance. Participants were 202 elementary school students-22 at risk of language difficulties and 180 with high language skills-drawn from 30 elementary schools in northern Greece. The results indicated that the two groups differed significantly, with the at-risk students exhibiting significantly lower perceptions of goal importance, intention to achieve, belief strength, outcome evaluation, and normative beliefs, and eventually scoring lower in language and mathematics at the end of the academic year. A finer analysis of students' motivational orientations was conducted using covariance structural modeling (CSM) and EQS 5.7b. The planned behavior model with goal importance produced a comparative fit index (CFI) of 1.00 in language and mathematics for the at-risk group. The respective CFIs for the high language skills group were .97 and 1.00 in language and mathematics, respectively. Although model fit was excellent across samples, different weights and signs linking motivational orientations to achievement partly explained the observed differences in language and mathematics manifested in the two groups.