An alternative approach for the analyses and interpretation of attachment sort items

Attachment Q-Sort (AQS) is a tool for quantifying observations about toddler/caregiver relationships. Previous studies have applied factor analysis to the full 90 AQS item set to explore the structure underlying them. Here we explore that structure by applying multidimensional scaling (MDS) to judgements of inter-item similarity. AQS items are arranged in the MDS solution along three easily interpretable axes: a model that is compatible with but more parsimonious than factor analysis solutions. This geometrical approach suggests ways to modify the AQS—primarily a research tool—to make it more practical for clinical applications. Sets of AQS data are represented and interpreted in the three-dimensional model as vectors. Summaries at a finer-grained level are obtained by finding points in the model where variability across datasets is greatest. We report re-analyses of archival (published) data, and also data collected with streamlined procedures more suitable in the field. Although not reported here, collection and analysis can both be performed online via a website. The general methodology is not restricted to the current application of toddler attachment.     

Validation of Two Quality of Care Measures: Results from a Longitudinal Study of Reversible Contraceptive Users in India

Bruce's quality of care framework, developed nearly three decades ago, brought needed international attention to family planning services. Various data collection efforts exist to measure the quality of contraceptive services. Our study validates two process quality measures and tests their predictive validity related to contraceptive continuation among 2,699 married women who started to use a reversible contraceptive method in India. We assessed four process quality domains with 22 items, which were reduced to 10 items using exploratory factor analysis. Weighted additive indices were calculated for the 22‐ and 10‐item measures. Scores were trichotomized into high, medium, and low process quality received. The predictive validity of the two measures was assessed related to modern contraceptive continuation three months later. The adjusted odds of continuing a modern contraceptive three months later was nearly three times greater (AOR: 2.78; 95% CI: 1.83–4.03) for women who received high process quality at enrollment compared with low quality with the 22‐item measure, and 2.2 times greater (95% CI: 1.46–3.26) with the 10‐item measure. Results suggest that the 22‐ and 10‐item measures are valid, and while the larger 22‐item measure can be used in special studies, the 10‐item measure is more suited for routine data collection and monitoring.     

Teacher Re‐creation of Negative Interactions with Toddlers

Fifty two‐year olds and fifty three‐year olds from low‐income families were observed in 10 urban day care centers serving disadvantaged families. Microanalytic chains of child‐teacher interactions were recorded and then recoded to represent positive and negative behaviors. Two‐year old male toddlers behaved more negatively than two‐year old girls or three‐year old children. In turn, male toddlers elicited more negative behaviors from their caregivers. Teachers seemed to be controlled by children's behaviors—responding positively to positive behaviors and negatively to negative behaviors. Providers may unwittingly recreate in group care the negative interactions, predictive of poor socioemotional adjustment, that toddlers are already experiencing at home. These data have important implications for mental health toddler workers involved in training teachers in early childhood settings.     

Robust Inference of Population Structure for Ancestry Prediction and Correction of Stratification in the Presence of Relatedness

Population structure inference with genetic data has been motivated by a variety of applications in population genetics and genetic association studies. Several approaches have been proposed for the identification of genetic ancestry differences in samples where study participants are assumed to be unrelated, including principal components analysis (PCA), multidimensional scaling (MDS), and model‐based methods for proportional ancestry estimation. Many genetic studies, however, include individuals with some degree of relatedness, and existing methods for inferring genetic ancestry fail in related samples. We present a method, PC‐AiR, for robust population structure inference in the presence of known or cryptic relatedness. PC‐AiR utilizes genome‐screen data and an efficient algorithm to identify a diverse subset of unrelated individuals that is representative of all ancestries in the sample. The PC‐AiR method directly performs PCA on the identified ancestry representative subset and then predicts components of variation for all remaining individuals based on genetic similarities. In simulation studies and in applications to real data from Phase III of the HapMap Project, we demonstrate that PC‐AiR provides a substantial improvement over existing approaches for population structure inference in related samples. We also demonstrate significant efficiency gains, where a single axis of variation from PC‐AiR provides better prediction of ancestry in a variety of structure settings than using 10 (or more) components of variation from widely used PCA and MDS approaches. Finally, we illustrate that PC‐AiR can provide improved population stratification correction over existing methods in genetic association studies with population structure and relatedness.     

Development and Validation of the Young Adult Nutrition Literacy Tool

ObjectiveTo create a tool to measure college students’ functional, interactive, and critical nutrition literacy.Design(1) Focus group: item generation, (2) expert review, (3) exploratory factor structure analysis, (4) item refinement and modification, (5) factor structure validation, and (6) criterion validation.SettingTwo land-grant college campuses.ParticipantsCollege students aged between 18 and 24 years.Main Outcome MeasuresSurvey data was used to assess nutrition literacy.AnalysisExploratory factor analysis, confirmatory factor analysis (CFA), item response theory (IRT) analyses, and correlations.ResultsOne-hundred and twenty-three items were generated and tested in an online survey format. Items were eliminated on the basis of face validity, expert feedback, exploratory factor analysis, and CFA/IRT. The 3 measures (functional, interactive, and critical) were analyzed separately. All 3 measures showed reasonable model fit in the CFA/IRT models. Criterion validity showed small to medium effect sizes between measures and fruit/vegetable intake. Reliability estimates met reasonable standards for each measure.Conclusions and ImplicationsThe Young Adult Nutrition Literacy Tool is a novel instrument that measures all 3 domains of nutrition literacy. Strengths include a rigorous 6-step development process, reasonable psychometric properties, and a large breadth of items.     

Validation of an instrument to assess toddler feeding practices of Latino mothers

This paper describes qualitative and quantitative aspects of testing a 34-item Toddler-Feeding Questionnaire (TFQ), designed for use in Latino families, and the associations between feeding practices and toddler dietary outcomes. Qualitative methods included review by an expert panel for content validity and cognitive testing of the tool to assess face validity. Quantitative analyses included use of exploratory factor analysis for construct validity; Pearson's correlations for test-retest reliability; Cronbach's alpha (α) for internal reliability; and multivariate regression for investigating relationships between feeding practices and toddler diet and anthropometry. Interviews were conducted using a convenience sample of 94 Latino mother and toddler dyads obtained largely through the Supplemental Nutrition Program for Women, Infants and Children (WIC). Data collection included household characteristics, self-reported early-infant feeding practices, the toddler's dietary intake, and anthropometric measurements. Factor analysis suggests the TFQ contains three subscales: indulgent; authoritative; and environmental influences. The TFQ demonstrated acceptable reliability for most measures. As hypothesized, indulgent practices in Latino toddlers were associated with increased energy consumption and higher intakes of total fat, saturated fat, and sweetened beverages. This tool may be useful in future research exploring the relationship of toddler feeding practices to nutritional outcomes in Latino families.     

A combined-method psychometric analysis recommended modification of the multidimensional health locus of control scales

OBJECTIVE: The Multidimensional Health Locus of Control (MHLC) scales are widely used to measure beliefs about determinants of persons' health. We evaluated the scales over the largest-ever disease-specific sample of subjects using a combined-method psychometric approach. STUDY DESIGN AND SETTING: We performed a secondary analysis of data from 1,206 subjects from three osteoarthritis studies, using Rasch analysis and confirmatory factor analysis simultaneously. Differential item functioning (DIF) by gender and data source, scale dimensionality, and item fit were examined. The Rasch model fit the data if Rasch residual principal components analysis (PCA) corroborated three distinct dimensions and item fit statistics fell between 0.80 and 1.20. The confirmatory factor (CFA) model fit the data if factor loadings exceeded 0.50 for all items. RESULTS: DIF by gender or data source was not materially evident for any items. PCA supported existence of three dimensions in the data. Both Rasch and CFA models fit the data for 16 items; two items were detected as misperforming. When these items were removed, fit of both models improved. CONCLUSION: Results of this large-sample evaluation of the MHLC scales corroborated earlier findings that removal of certain items improves the scales. The combined Rasch-CFA approach provided better insight to scale performance problems than either method alone provided.     

早期教育对婴幼儿发育影响的效果评价

目的：探讨早期教育对婴幼儿智能发育的影响。方法：选择109名正常健康儿童作为训练组，随机抽取117名正常儿童作为对照组。受训练组每周集中训练一次，两组儿童在研究期间每三个月使用Gesell进行一次发育评价。结果：受训练组儿童各能区的发育商均高于对照组，差异有显著性（P＜0．05）；进行自身对照，受训练儿童发育商有显著性提高（P＜0．05）。结论：早期教育对婴幼儿智能发育有明显的促进作用。     

Structure of the sense of coherence scale in a nationally representative sample: the Finnish Health 2000 survey

Objective  To examine the structure of the sense of coherence (SOC) scale in a general population. Methods  This study analysed the responses of 6,217 subjects aged 30 years and over who participated in the Finnish Health 2000 survey (response rate 77.4%). Participants completed an abbreviated 12-item version of the SOC scale. Two alternative structures were tested using confirmatory factor analysis: a one-factor model, with all scale items loaded onto a single latent factor representing the SOC construct, versus a second-order factor model, with scale items loaded onto their corresponding latent factors representing the three SOC components (comprehensibility, manageability and meaningfulness), which are, in turn, dependent on one single higher-order SOC construct. Results  The one-factor model was fitted to the data after allowing the errors of comprehensibility item 5 and manageability item 6 to correlate, as was done in previous studies among Finnish adults. The comparative fit index (CFI), Tucker–Lewis index (TLI) and root mean square error of approximation (RMSEA) for the one-factor model were, respectively, 0.97–0.98, 0.96–0.97 and 0.05–0.09 across both sexes and three age groups. The second-order factor model had correlations between latent factors higher than 1, even after alternative model modifications, casting doubts on this more complex structure. Conclusion  These data suggest that the components of comprehensibility, manageability and meaningfulness should be merged when measuring SOC with the 12-item SOC scale in the Finnish general population.     

Sparse multivariate factor analysis regression models and its applications to integrative genomics analysis

The multivariate regression model is a useful tool to explore complex associations between two kinds of molecular markers, which enables the understanding of the biological pathways underlying disease etiology. For a set of correlated response variables, accounting for such dependency can increase statistical power. Motivated by integrative genomic data analyses, we propose a new methodology—sparse multivariate factor analysis regression model (smFARM), in which correlations of response variables are assumed to follow a factor analysis model with latent factors. This proposed method not only allows us to address the challenge that the number of association parameters is larger than the sample size, but also to adjust for unobserved genetic and/or nongenetic factors that potentially conceal the underlying response‐predictor associations. The proposed smFARM is implemented by the EM algorithm and the blockwise coordinate descent algorithm. The proposed methodology is evaluated and compared to the existing methods through extensive simulation studies. Our results show that accounting for latent factors through the proposed smFARM can improve sensitivity of signal detection and accuracy of sparse association map estimation. We illustrate smFARM by two integrative genomics analysis examples, a breast cancer dataset, and an ovarian cancer dataset, to assess the relationship between DNA copy numbers and gene expression arrays to understand genetic regulatory patterns relevant to the disease. We identify two trans‐hub regions: one in cytoband 17q12 whose amplification influences the RNA expression levels of important breast cancer genes, and the other in cytoband 9q21.32‐33, which is associated with chemoresistance in ovarian cancer.     

Using automatic item generation to create multiple-choice test items

Medical Education 2012: 46: 757–765 Context Many tests of medical knowledge, from the undergraduate level to the level of certification and licensure, contain multiple‐choice items. Although these are efficient in measuring examinees’ knowledge and skills across diverse content areas, multiple‐choice items are time‐consuming and expensive to create. Changes in student assessment brought about by new forms of computer‐based testing have created the demand for large numbers of multiple‐choice items. Our current approaches to item development cannot meet this demand. Methods We present a methodology for developing multiple‐choice items based on automatic item generation (AIG) concepts and procedures. We describe a three‐stage approach to AIG and we illustrate this approach by generating multiple‐choice items for a medical licensure test in the content area of surgery. Results To generate multiple‐choice items, our method requires a three‐stage process. Firstly, a cognitive model is created by content specialists. Secondly, item models are developed using the content from the cognitive model. Thirdly, items are generated from the item models using computer software. Using this methodology, we generated 1248 multiple‐choice items from one item model. Conclusions Automatic item generation is a process that involves using models to generate items using computer technology. With our method, content specialists identify and structure the content for the test items, and computer technology systematically combines the content to generate new test items. By combining these outcomes, items can be generated automatically.     

Evidence for a unidimensional 15-item version of the CASP-19 using a Rasch model approach

Aim

The aim of this study is to explore the dimensionality of the CASP-19—a quality-of-life measure for early old age—and to assess the stability of the item locations over time and changes in person measures.

Methods

The Rasch partial credit model was applied to the CASP-19 data obtained from Waves 1 and 3 (N = 9,407 and N = 7,732) of the English Longitudinal Study of Ageing to assess item fit, dimensionality and differential item functioning (DIF).

Results

Five items demonstrated category disordering for the last two response categories of the CASP-19 (which were collapsed), and 4 items demonstrated item misfit and were removed from the analysis. Cronbach’s alpha indicated good internal consistency for both waves (0.87 for Wave 1 and 0.88 for Wave 3). There was no evidence of multidimensionality, and no significant DIF was observed for gender. When the two datasets were combined, no statistically significant differences were observed between the two sets of item locations. A statistically significant difference was found for the mean person measure [t(5,524) = 17.88, p < 0.001)], suggesting quality of life improves as people age.

Conclusion

A 15-item unidimensional factor structure was observed for the CASP-19, which was stable over time.     

Measuring the psychological consequences of breast cancer screening: a confirmatory factor analysis of the Psychological Consequences Questionnaire

Objectives

To use confirmatory factor analysis (CFA) to test the proposed factor structure of the Psychological Consequences Questionnaire (PCQ), a measure of the psychological impact of breast cancer screening. A further aim was to examine the robustness of the proposed factor structure across key demographic and clinical variables.

Method

Following visits to breast cancer screening clinics, women who received a false-positive diagnosis and a matched sample of women who had received all-clear diagnoses were sent a questionnaire package containing the PCQ and a demographics measure. A total of 220 women returned completed questionnaires. CFA was used to test the factor structure and multiple indicator–multiple cause (MIMIC) models were used to test the robustness of the factor structure across the test result group, age, and family history of breast cancer diagnosis.

Results

The CFA results suggested support for both a three- and a one-factor model; a one-factor model was preferred, however, due to the very high covariance between the three latent factors in the three-factor model. A CFA MIMIC model suggested that the test result impacted on the latent factor: women who initially received a false-positive diagnosis showed significantly higher levels of psychological dysfunction after screening.

Conclusions

The PCQ appears to be a promising tool for assessing psychological dysfunction after breast cancer screening; however, a one-factor model received more support than the initially proposed three-factor model. There was little evidence of differential item functioning across key demographic and clinical variables for the PCQ.     

Focusing the Conceptualization of Erotophilia and Erotophobia on Global Attitudes Toward Sex: Development and Validation of the Sex Positivity–Negativity Scale

Previous measures of erotophobia/erotophilia like the Sexual Opinion Survey (SOS) assessed gut-level positive–negative affective and evaluative reactions to a wide range of sexual stimuli, resulting in purposefully diverse item content. Although an effective strategy, the item content of existing erotophilia/erotophobia scales is now potentially too generalized, encompassing what have since developed as an array of more focused constructs in the current literature like attitudes toward (1) casual sex, (2) pornography, (3) non-heterosexual orientations (e.g., homophobia), and (4) masturbation. The current study therefore sought to evaluate existing scales and to develop a conceptually focused measure of sex-positivity and sex-negativity using a distinct strategy designed to obviate the need for overly generalized (and potentially imbalanced or confounding) item content. Using responses from 2205 online respondents (82% Caucasian, 66% heterosexual, and 50% female) completing an item pool of 158 items, the current study employed a combination of classic test-theory analyses (e.g., exploratory and confirmatory factor analyses) and item response theory analyses to develop a psychometrically optimized scale—the Sex Positivity–Negativity (SPN) scale. The SPN scale demonstrated: (1) a stable 2-subscale structure distinguishing sex-negativity from sex-positivity, (2) consistently high levels of internal consistency across 31 demographic subsamples, (3) more discriminant than convergent validity with existing erotophilia scales given its novel focus, (4) discriminant validity with more specific sexual attitudes, (5) greater levels of power and precision for detecting differences between individuals, (6) stronger links to individual, sexual, and relationship functioning than existing scales, and (7) incremental validity over the SOS for predicting change in relationship dynamics over 6 months. The findings therefore suggested that the SPN scale is a conceptually focused measure of sex-positivity and sex-negativity offering researchers a comparatively short and effective tool. Implications are discussed.

     

Single‐item measure of food insecurity used in the National Health Survey may underestimate prevalence in Australia

Objectives : To compare prevalence estimates of food insecurity using a single‐item measure, with three adaptations of the United States Department of Agriculture Food Security Survey Module (USDA‐FSSM). Methods : Data were collected by postal survey, from individuals aged ≥18 years from disadvantaged suburbs of Brisbane, Australia (n= 505, 53% response). Food security status was ascertained by the Australian single‐item measure, and the 6‐, 10‐ and 18‐item versions of the USDA‐FSSM. Prevalence estimates of food insecurity and different levels of severity of food insecurity estimated by each tool were determined. Data were analysed using McNemar's test, polychoric correlation and Rasch analyses. Results : The prevalence of food insecurity was 19.5% using the single‐item measure; significantly less than the 24.4%, 22.8% and 21.1% identified using the 18‐item, 10‐item and 6‐item versions of the USDA‐FSSM, respectively. Rasch analyses revealed that overall the USDA‐FSSM may be a valid tool for the measurement of food insecurity within the current sample. Conclusion : The measure of food insecurity employed in national surveys in Australia may underestimate its prevalence and public health significance. Implications for public health : Future monitoring and surveillance efforts should seek to employ a more accurate measure as the first step in recognising the right to food for all Australians.     

PRODUCTION COST STRUCTURE IN US OUTPATIENT PHYSICAL THERAPY HEALTH CARE

This paper investigates the technology cost structure in US physical therapy care. We exploit formal economic theories and a rich national data of providers to tease out implications for operational cost efficiencies. The 2008–2009 dataset comprising over 19 000 bi‐weekly, site‐specific physical therapy center observations across 28 US states and Occupational Employment Statistics data (Bureau of Labor Statistics) includes measures of output, three labor types (clinical, support, and administrative), and facilities (capital). We discuss findings from the iterative seemingly unrelated regression estimation system model. The generalized translog cost estimates indicate a well‐behaved underlying technology structure. We also find the following: (i) factor demands are downwardly sloped; (ii) pair‐wise factor relationships largely reflect substitutions; (iii) factor demand for physical therapists is more inelastic compared with that for administrative staff; and (iv) diminishing scale economies exist at the 25%, 50%, and 75% output (patient visits) levels. Our findings advance the timely economic understanding of operations in an increasingly important segment of the medical care sector that has, up‐to‐now (because of data paucity), been missing from healthcare efficiency analysis. Our work further provides baseline estimates for comparing operational efficiencies in physical therapy care after implementations of the 2010 US healthcare reforms. Copyright © 2012 John Wiley & Sons, Ltd.     

Time-to-event analysis of fine particle air pollution and preterm birth: results from North Carolina, 2001-2005

Exposure to air pollution during pregnancy has been suggested to be a risk factor for preterm birth; however, epidemiologic evidence remains mixed and limited. The authors examined the association between ambient levels of particulate matter <2.5 μm in aerodynamic diameter (PM(2.5)) and the risk of preterm birth in North Carolina during the period 2001-2005. They estimated the risks of cumulative and lagged average exposures to PM(2.5) during pregnancy via a 2-stage discrete-time survival model. The authors also considered exposure metrics derived from 1) ambient concentrations measured by the Air Quality System (AQS) monitoring network and 2) concentrations predicted by statistically fusing AQS data with process-based numerical model output (the Statistically Fused Air and Deposition Surfaces (FSD) database). Using the AQS measurements, an interquartile-range (1.73 μg/m(3)) increase in cumulative PM(2.5) exposure was associated with a 6.8% (95% posterior interval: 0.5, 13.6) increase in the risk of preterm birth. Using the FSD-predicted levels and accounting for prediction error, the authors also found significant adverse associations between trimester 1, trimester 2, and cumulative PM(2.5) exposure and preterm birth. These findings suggest that exposure to ambient PM(2.5) during pregnancy is associated with increased risk of preterm birth, even in a region characterized by relatively good air quality.     

Cross‐ministerial collaboration related to paediatric rehabilitation for children with disabilities and their families in one Canadian province

The delivery of paediatric rehabilitation services is complex due to the involvement of different service sectors and diverse models of care. Parents of children with disabilities find it challenging to navigate successfully through complicated service delivery systems. Cross‐sectoral collaboration to improve continuity of care for children with disabilities and their families is viewed as ideal in public policies. The purpose of this research was to explore how ministerial cultures, processes and structures influence inter‐ministerial collaboration for the purpose of enhancing continuity of care for children with disabilities and their families in a Western Canadian province. Six key informants from three government Ministries that funded paediatric rehabilitation services participated in individual, semi‐structured interviews between January and May of 2007. Nineteen provincial public policy documents were reviewed. Hall’s framework guided the analysis of the key informant interviews and policy documents. Influences of organisational culture, processes and structures on cross‐ministerial collaboration were classified into the categories of ideas—values and beliefs that underlie policy development, interests—influence of various policy actors and institutions—structures and processes used to deliver public policy. Fundamental ideological and structural differences were apparent across the three ministries that affected the ease of inter‐ministerial collaboration towards ensuring continuity of care for children with disabilities. Variations in ideas (philosophy and values) and institutions (geography and service delivery structure, relationships with regional governance, mission and function, choice of policy instruments and financial processes) are presented and implications for service delivery are explored.     

Assessment of the upper limb in acute stroke: The validity of hierarchal scoring for the Motor Assessment Scale

Background/aim: Stroke is the greatest contributor to disability in Australian adults and much of this disability results from a stroke‐affected upper limb. This study aimed to determine the validity of hierarchal scoring for the upper limb subscale of the Motor Assessment Scale (UL‐MAS) in acute stroke using Rasch analysis. Method: This study applied Rasch analysis to 40 UL‐MAS assessment results across 25 subjects to determine the validity of the hierarchy of the three upper limb subsets: upper arm function (six), hand movements (seven) and advanced hand activities (eight). Rasch analysis examines the relationship between ‘item difficulty’ and ‘person ability’ and produces an output which represents the difficulty of each item in relation to each other. Results: As hypothesised, the hierarchy was upheld within subset 6. In subset 7, the hierarchy was not upheld. Results indicated that item 3 was the least difficult, followed by items 1, 4, 2, 5 and 6 in order of increasing difficulty. In subset 8 the hierarchy was not upheld. Results indicated that item 1 was the least difficult, followed by item 6, then 2 and 5 of equal value and then 3 and 4 of equal value. Conclusions: The hierarchal scoring is not supported for subsets 7 and 8 and future research is required to explore the validity of alternate scoring methods. At present, the authors recommend that the UL‐MAS should be scored non‐hierarchally, meaning that every item within the subsets should be scored regardless of its place within the hierarchy (UL‐MAS‐NH).     

A qualitative study of the experience of parents attending a psychoanalytically informed parent–toddler group

The paper presents the findings of a qualitative study into the experience of seven parents attending a psychoanalytically informed parent–toddler group. Semi‐structured interviews were carried out with each parent, and analysed using Interpretative Phenomenological Analysis. Analysis of the interviews led us to three ‘superordinate themes’, each of which captures a certain aspect of the parents' experiences of attending the toddler groups. These themes were: the setting of the toddler groups; what it was like as a parent coming to these groups; and how parents felt their toddlers experienced coming. Within each theme there were a number of subordinate themes that captured particular aspects of the overall experience, and these are presented in narrative form, with extracts from the interview data to help illustrate the themes. It is argued that service users' views are an important part of evaluation, and that there may be certain features of a psychoanalytically informed parent–toddler group that are distinctive.