Psychometric properties

Designed as a quick and easy tool to help assess the essential traits of the social and therapeutic atmosphere in forensic psychiatric settings (subsequently expanded for use in correctional facilities), the Essen Climate Evaluation Schema (EssenCES) was originally developed and first published in Germany. It has since been translated into a number of other languages and been included in a considerable number of studies, among them a broad validation study inthe UK. Following this study andthe UK Commissioning for Quality and Innovation (CQUIN) initiating the regular use of the scale in forensic psychiatric services inthe UK, we have received a large number of enquiries regarding support in using the scale and interpreting its findings. In particular, many researchers and clinicians have requested reference norms that would allow them to compare the EssenCES scores obtained in their particular unit/service with the scores obtained in other settings. This manual aims to respond to these enquiries. It outlines the background and the concept of the instrument and discusses the variety of ways in which the EssenCES might be used to support research and practice within forensic services.It also includes considerations regarding the limitations of previous studies that have utilised the concept of social climate and a discussion of how the contribution of climate evaluations might be further improved in the future.

How reliable is internet-based self-reported identity, socio-demographic and obesity measures in European adults?

In e-health intervention studies, there are concerns about the reliability of internet-based, self-reported (SR) data and about the potential for identity fraud. This study introduced and tested a novel procedure for assessing the validity of internet-based, SR identity and validated anthropometric and demographic data via measurements performed face-to-face in a validation study (VS). Participants (n = 140) from seven European countries, participating in the Food4Me intervention study which aimed to test the efficacy of personalised nutrition approaches delivered via the internet, were invited to take part in the VS. Participants visited a research centre in each country within 2 weeks of providing SR data via the internet. Participants received detailed instructions on how to perform each measurement. Individual's identity was checked visually and by repeated collection and analysis of buccal cell DNA for 33 genetic variants. Validation of identity using genomic information showed perfect concordance between SR and VS. Similar results were found for demographic data (age and sex verification). We observed strong intra-class correlation coefficients between SR and VS for anthropometric data (height 0.990, weight 0.994 and BMI 0.983). However, internet-based SR weight was under-reported (Δ -0.70 kg [-3.6 to 2.1], p < 0.0001) and, therefore, BMI was lower for SR data (Δ -0.29 kg m(-2) [-1.5 to 1.0], p < 0.0001). BMI classification was correct in 93 % of cases. We demonstrate the utility of genotype information for detection of possible identity fraud in e-health studies and confirm the reliability of internet-based, SR anthropometric and demographic data collected in the Food4Me study. TRIAL REGISTRATION: NCT01530139 ( http://clinicaltrials.gov/show/NCT01530139 ).

Construct validity of the Dutch version of the 12-item Partners in Health scale : measuring self-management behaviour and knowledge in COPD patients

The 12-item Partner in Health (PIH) scale was developed in Australia to measure self-management behaviour and knowledge in patients with chronic diseases. The scale has undergone several changes since first published. Our study aim was to validate the latest PIH in Dutch COPD patients.The 12 items of the PIH are scored on a self-rated 9-point Likert scale (range: 0-8; higher scores indicate better self-management), providing total and subscale scores (knowledge, coping, recognition and management of functions, adherence to treatment).We used forward-backward translation of the latest version of the Australian PIH. Dimensionality and reliability analyses were performed to investigate the psychometric properties, and to determine whether the Dutch PIH replicated the same four subscales of self-management as the original PIH.Reanalysis of the original PIH validation study (186 Australian patients with chronic diseases) showed a single scale. Two scales (1. knowledge and coping; 2. recognition and management of symptoms, adherence to treatment) were found for the Dutch PIH (118 Dutch COPD patients). The correlation between the two Dutch scales was 0.43. The lower-bound of the reliability of the total scale was 0.81 (Australian PIH) and 0.84 (Dutch PIH).Different scale structures were found for the original Australian and the Dutch PIH. Our results did not support the 4-scale structure reported previously. To increase comparability and generalisability of our findings, the scale structure of the revised Australian PIH needs to be investigated further. Meanwhile, we advise using the PIH total score or two subscale scores when assessing COPD patients.

Cross cultural validation of the preventive health model for colorectal cancer screening : an Australian study

We investigated whether the five-factor structure of the Preventive Health Model for colorectal cancer screening, developed in the United States, has validity in Australia. We also tested extending the model with the addition of the factor Self-Efficacy to Screen using Fecal Occult Blood Test (SESFOBT). Randomly selected men and women aged between 50 and 76 years (n = 414) responded to a survey. Confirmatory factor analyses indicated that the U.S. model provided adequate fit for the group as a whole and for men and women separately, thereby demonstrating cross-cultural validity for measuring factors influencing the decision to screen. The inclusion of SESFOBT in the model resulted in a comparable, but less parsimonious, fit. However, self-efficacy is a demonstrated mediator of intention and action, and it is argued that the addition of SESFOBT as a sixth factor may have utility for the design of strategies to increase actual uptake of FOBT.

Validation of de-identified record linkage to ascertain hospital admissions in a cohort study

Background Cohort studies can provide valuable evidence of cause and effect relationships but are subject to loss of participants over time, limiting the validity of findings. Computerised record linkage offers a passive and ongoing method of obtaining health outcomes from existing routinely collected data sources. However, the quality of record linkage is reliant upon the availability and accuracy of common identifying variables. We sought to develop and validate a method for linking a cohort study to a state-wide hospital admissions dataset with limited availability of unique identifying variables.

Methods A sample of 2000 participants from a cohort study (n = 41 514) was linked to a state-wide hospitalisations dataset in Victoria, Australia using the national health insurance (Medicare) number and demographic data as identifying variables. Availability of the health insurance number was limited in both datasets; therefore linkage was undertaken both with and without use of this number and agreement tested between both algorithms. Sensitivity was calculated for a sub-sample of 101 participants with a hospital admission confirmed by medical record review.

Results Of the 2000 study participants, 85% were found to have a record in the hospitalisations dataset when the national health insurance number and sex were used as linkage variables and 92% when demographic details only were used. When agreement between the two methods was tested the disagreement fraction was 9%, mainly due to "false positive" links when demographic details only were used. A final algorithm that used multiple combinations of identifying variables resulted in a match proportion of 87%. Sensitivity of this final linkage was 95%.

Conclusions High quality record linkage of cohort data with a hospitalisations dataset that has limited identifiers can be achieved using combinations of a national health insurance number and demographic data as identifying variables.

Generic and diabetes-specific well-being in the AT.LANTUS follow-on study : further psychometric validation of the W-BQ28 indicates its utility in research and clinical practice in type 2 diabetes in the UK

Aims  To undertake further psychometric validation of the W-BQ28 to determine its suitability for use in adults with Type 2 diabetes in the UK using data from the AT.LANTUS follow-on study.

Methods  A total of 353 people with Type 2 diabetes participated in the AT.LANTUS Follow-on study, completing measures of well-being (W-BQ28), treatment satisfaction (DTSQ) and self-care (SCI-R). Confirmatory factor analyses was used to confirm the W-BQ28 structure and internal consistency reliability was assessed. Additional statistical tests were conducted to explore convergent, divergent and known-groups validity. Minimal important differences were calculated using distribution and anchor-based techniques.

Results  Structure of the W-BQ28 (seven four-item subscales plus 16-item generic and 12-item diabetes-specific scales) was confirmed (comparative fit index = 0.917, root mean square error of approximation (RMSEA) = 0.057). Internal consistency reliability was satisfactory (four-item subscales: alpha = 0.73–0.90; 12/16-item scales: α = 0.84–0.90). Convergent validity was supported by expected moderate to high correlations (rs = 0.35–0.67) between all W-BQ28 subscales (except Energy); divergent validity was supported by expected low to moderate correlations with treatment satisfaction (rs = −0.03–0.52) and self-care (rs = 0.02–0.22). Known-groups validity was supported with statistically significant differences by sex, age and HbA1c for expected subscales. Minimal important differences were established (range 0.14–2.90).

Conclusions  The W-BQ28 is a valid and reliable measure of generic and diabetes-specific well-being in Type 2 diabetes in the UK. Confirmation of the utility of W-BQ28 (including establishment of minimal important differences) means that its use is indicated in research and clinical practice.

The development and validation of an urbanicity scale in a multi-country study

Background : Although urban residence is consistently identified as one of the primary correlates of non-communicable disease in low- and middle-income countries, it is not clear why or how urban settings predispose individuals and populations to non-communicable disease (NCD), or how this relationship could be modified to slow the spread of NCD. The urban–rural dichotomy used in most population health research lacks the nuance and specificity necessary to understand the complex relationship between urbanicity and NCD risk. Previous studies have developed and validated quantitative tools to measure urbanicity continuously along several dimensions but all have been isolated to a single country. The purposes of this study were 1) To assess the feasibility and validity of a multi-country urbanicity scale; 2) To report some of the considerations that arise in applying such a scale in different countries; and, 3) To assess how this scale compares with previously validated scales of urbanicity.

Methods : Household and community-level data from the Young Lives longitudinal study of childhood poverty in 59 communities in Ethiopia, India and Peru collected in 2006/2007 were used. Household-level data include parents’ occupations and education level, household possessions and access to resources. Community-level data include population size, availability of health facilities and types of roads. Variables were selected for inclusion in the urbanicity scale based on inspection of the data and a review of literature on urbanicity and health. Seven domains were constructed within the scale: Population Size, Economic Activity, Built Environment, Communication, Education, Diversity and Health Services.

Results : The scale ranged from 11 to 61 (mean 35) with significant between country differences in mean urbanicity; Ethiopia (30.7), India (33.2), Peru (39.4). Construct validity was supported by factor analysis and high corrected item-scale correlations suggest good internal consistency. High agreement was observed between this scale and a dichotomized version of the urbanicity scale (Kappa 0.76; Spearman’s rank-correlation coefficient 0.84 (p < 0.0001). Linear regression of socioeconomic indicators on the urbanicity scale supported construct validity in all three countries (p < 0.05).

Conclusions : This study demonstrates and validates a robust multidimensional, multi-country urbanicity scale. It is an important step on the path to creating a tool to assess complex processes like urbanization. This scale provides the means to understand which elements of urbanization have the greatest impact on health.

Psychometric validation of the Self-Care Inventory-Revised (SCI-R) in UK adults with type 2 diabetes using data from the AT.LANTUS follow-on study.

Background:
Achieving optimal outcomes in type 2 diabetes (T2DM) involves several demanding self-care behaviours, e.g. managing diet, activity, medications, monitoring glucose levels, footcare. The Self-Care Inventory-Revised (SCI-R) is valid for use in people with T2DM in the US. Our aim was to determine its suitability for use in the UK.

Validation of patient health questionnaire (PHQ) for major depression in Chinese outpatients with multiple somatic symptoms: A multicenter cross-sectional study

Background: Despite the high co-morbidity of depressive symptoms in patients with multiple somatic symptoms, the validity of the 9-item Patient Health Questionnaire (PHQ-9) has not yet been investigated in Chinese patients with multiple somatic symptoms. Methods: The multicenter cross-sectional study was conducted in ten outpatient departments located in four cities in China. The psychometric properties of the PHQ-9 were examined by confirmative factor analysis (CFA). Criterion validation was undertaken by comparing results with depression diagnoses obtained from the Mini International Neuropsychiatric Interview (MINI) as the gold standard. Results: Overall, 491 patients were recruited of whom 237 had multiple somatic symptoms (SOM+ group, PHQ-15 ≥ 10). Cronbach's α of the PHQ-9 was 0.87, 0.87, and 0.90 for SOM+ patients, SOM- patients, and total sample respectively. All items and the total score were moderately correlated. The factor models of PHQ-9 tested by CFA yielded similar diagnostic performance when compared to sum score estimation. Multi-group confirmatory factor analysis based on unidimensional model showed similar psychometric properties over the groups with low and high somatic symptom burden. The optimal cut-off point to detect depression in Chinese outpatients was 10 for PHQ-9 (sensitivity=0.77, specificity=0.76) and 3 for PHQ-2 (sensitivity=0.77, specificity=0.74). Limitations: Potential selection bias and nonresponse bias with applied sampling method. Conclusions: PHQ-9 (cut-off point=10) and PHQ-2 (cut-off point=3) were reliable and valid to detect major depression in Chinese patients with multiple somatic symptoms.

Development and validation of the physical disability sexual and body esteem scale

The Physical Disability Sexual and Body Esteem (PDSBE) scale was developed to assess respondents' capacity to feel positive about their sexuality and their body while living with a physical impairment. The current paper presents four studies that were conducted to develop and assess the psychometric properties of the 10 item PDSBE scale. The first study was an exploratory factor analysis involving 348 participants with physical disabilities. The factors were: Sexual Esteem, Attractiveness to Others, and Body Esteem. The second study was a confirmatory factor analysis, with a total of 338 participants. This analysis confirmed the factor structure established in study 1. The third study revealed good test-retest reliability on a total of 47 participants with physical disabilities. The final study was conducted with 748 participants with physical disabilities and showed that the PDSBE had high reliability and good convergent and divergent validity. Mean scores showed that women scored significantly higher than men on the total PDSBE scale and on the Sexual Esteem and Attractiveness to Others subscales. Future applications for the PDSBE scale are discussed.