Unidimensional Measurement Research Articles

Improved Estimation of Maximal Reliability for Unidimensional Multicomponent Measuring Instruments in Repeated Measure Studies

In repeated measure studies with unidimensional scales, measurement invariance, and specificity stability over time, the specificity variance in each instrument component can be identified. This article describes for that setting an improved point and interval estimation procedure for the maximal reliability coefficient associated with a given set of homogeneous measures. The method is developed within the framework of latent variable modeling and can also be readily used in longitudinal studies for improved point and interval estimation of individual measure reliability and scale reliability at each assessment occasion. The procedure is based on empirically testable conditions and is illustrated with an example.

The psychometric properties of the Quick Inventory of Depressive Symptomatology-Self-Report (QIDS-SR) and the Patient Health Questionnaire-9 (PHQ-9) in depressed inpatients in China

This study examined the psychometric properties of the 16-item Quick Inventory of Depressive Symptomatology-Self-Report (QIDS-SR) and Patient Health Questionnaire-9 (PHQ-9). The study sample comprised 297 depressed inpatients. The severity of depressive symptoms was assessed with the Hamilton Rating Scale for Depression, the QIDS-SR and the PHQ-9 in all subjects at baseline and a random sample of 50 subjects two weeks later. The internal consistency, convergent validity, factor structure and sensitivity to change of these scales were assessed. Internal consistency (Cronbach's alpha) of the PHQ-9 and QIDS-SR were 0.88 and 0.83, respectively at baseline and 0.91 and 0.87, respectively at exit. Item to total score correlations were higher for the PHQ-9 than those for the QIDS-SR at baseline and exit. Three domains at baseline and two at study exit of the QIDS-SR had a correlation less than 0.65; while only two items at baseline and no item at exit were less than 0.65 for the PHQ-9. Both the PHQ-9 and the QIDS-SR showed uni-dimensional measurement properties at baseline; the two instruments were less sensitive than the HAMD to detect changes of depressive symptoms suggesting low convergent validity. The QIDS-SR and the PHQ-9 have similar and acceptable psychometric properties in most domains as tested in depressed inpatients.

A latent trait approach to measuring HIV/AIDS related stigma in healthcare professionals: application of mokken scaling technique.

BackgroundThe attitudes of healthcare professionals towards HIV positive patients and high risk groups are central to the quality of care and therefore to the management of HIV/AIDS related stigma in health settings. Extant HIV/AIDS stigma scales that measure stigmatising attitudes towards people living with HIV/AIDS have been developed using scaling techniques such as principal component analysis. This approach has resulted in instruments that are often long. Mokken scale analysis is a nonparametric hierarchical scaling technique that can be used to develop unidimensional cumulative scales. This technique is advantageous over the other approaches; as the scales are usually shorter, while retaining acceptable psychometric properties. Moreover, Mokken scales also make no distributional assumptions about the underlying data, other than that the data are capable of being ordered by item and by person. In this study we aimed at developing a precise and concise measure of HIV/AIDS related stigma among health care professionals, using Mokken scale analysis.MethodsWe carried out a cross sectional survey of healthcare students at the Monash University campuses in Malaysia and Australia. The survey consisted of demographic questions and an initial item pool of twenty five potential questions for inclusion in an HIV stigma scale.ResultsWe analysed the data using the mokken package in the R statistical environment providing a 9-item scale with high reliability, validity and acceptable psychometric properties, measuring and ranking the HIV/AIDS related stigmatising attitudes.ConclusionMokken scaling procedure not only produced a comprehensive hierarchical scale that could accurately order a person along HIV/AIDS stigmatising attitude, but also demonstrated a unidimensional and reliable measurement tool which could be used in future studies. The principal component analysis confirmed the accuracy of the Mokken scale analysis in correctly detecting the unidimensionality of this scale. We recommend future works to study the generalisability of this scale in a new population.

MP05-10 AUTOMATED STONE VOLUME MEASUREMENT USING REDUCED-DOSE (RD) CT IS COMPARABLE STANDARD-DOSE (SD) CT

You have accessJournal of UrologyImaging/Radiology: Uroradiology I1 Apr 2016MP05-10 AUTOMATED STONE VOLUME MEASUREMENT USING REDUCED-DOSE (RD) CT IS COMPARABLE STANDARD-DOSE (SD) CT John Roger Bell, Amy Lim, Perry Pickhardt, and Stephen Y Nakada John Roger BellJohn Roger Bell More articles by this author , Amy LimAmy Lim More articles by this author , Perry PickhardtPerry Pickhardt More articles by this author , and Stephen Y NakadaStephen Y Nakada More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.1987AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Stone volume measurement via CT is more precise compared to traditional linear measurements. We have shown an automated approach is more reproducible with less inter-observer variability than uni-dimensional measurements. (Patel et al, J Urol 2011; Patel et al, Urol 2012). Our institution has developed a reduced dose sub-millisievert (mSv) CT protocol with effective doses 70-90% less than that of traditional non-contrast CT, averaging 0.9 mSv. We compared automated stone volume measurements using standard dose non-contrasted CT (SD-NCCT) vs reduced dose non-contrasted CT (RD-NCCT) in a prospective clinical trial. METHODS In this prospective trial, we studied a cohort of patients who underwent concurrent SD-NCCT and RD-NCCT scans during the same imaging session. 20 patients were identified as having urolithiasis on these imaging studies and were used in our study. All patients provided signed informed consent. Automated stone volume was assessed using previously validated software (Ziosoft) on both SD-NCCT and RD-NCCT images. SD-NCCT images were reconstructed with the standard FBP algorithm. RD-NCCT images were reconstructed using FBP, PICCS, ASiR, and Veo techniques then compared. A single reader was utilized for all patients to optimize stone matching and minimize variability. RESULTS 42 individual renal stones were identified and included in our analysis. Automated stone volumes on SD-NCCT ranged from 9.9 mm3 to 8757 mm3. Stone volumes on each of the reconstructed RD-NCCT formats were then compared against the SD-NCCT images and the percent error was calculated using absolute values to avoid cancellation. Mean percentage volume error for each RD-NCCT series compared with the reference standard SD-NCCT series was as follows: 19.9% for Veo, 23.6% for ASiR, 24.9% for PICCS, and 35.8% for FBP. The failure rate for automated calculation was significantly higher for the RD-FBP series when compared to Veo (P = 0.009). CONCLUSIONS Automated renal stone volume measurements using CT removes inter-observer variability. With the higher level iterative reconstruction methods using Veo, the error in volume with RD-NCCT measurement relative to SD-NCCT is acceptable (<20%). In comparison, RD-NCCT using standard FBP reconstruction results in much greater error. Follow-up of renal stone burden with sub-mSv RD-NCCT using Veo would provide a surveillance method that maintains accuracy at a lower dose than a 2-view KUB. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e40 Advertisement Copyright & Permissions© 2016MetricsAuthor Information John Roger Bell More articles by this author Amy Lim More articles by this author Perry Pickhardt More articles by this author Stephen Y Nakada More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

MP19-04 CT-BASED VOLUMETRIC CHARACTERIZATION OF RENAL CLEAR CELL CARCINOMA IN VON HIPPEL-LINDAU (VHL) USING NOVEL HISTOGRAM ANALYSIS.

You have accessJournal of UrologyImaging/Radiology: Uroradiology III1 Apr 2016MP19-04 CT-BASED VOLUMETRIC CHARACTERIZATION OF RENAL CLEAR CELL CARCINOMA IN VON HIPPEL-LINDAU (VHL) USING NOVEL HISTOGRAM ANALYSIS. Ashkan Malayeri, Amir Pourmorteza, Nikeith Shah, Rabindra Gautam, Alireza Yazdi, Jana Lovell, Shawna Boyle, Ishan Asokan, Ramaprasad Srinivasan, Adam Metwalli, and W. Marston Linehan Ashkan MalayeriAshkan Malayeri More articles by this author , Amir PourmortezaAmir Pourmorteza More articles by this author , Nikeith ShahNikeith Shah More articles by this author , Rabindra GautamRabindra Gautam More articles by this author , Alireza YazdiAlireza Yazdi More articles by this author , Jana LovellJana Lovell More articles by this author , Shawna BoyleShawna Boyle More articles by this author , Ishan AsokanIshan Asokan More articles by this author , Ramaprasad SrinivasanRamaprasad Srinivasan More articles by this author , Adam MetwalliAdam Metwalli More articles by this author , and W. Marston LinehanW. Marston Linehan More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.2752AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Current guidelines for follow-up of renal lesions in vHL are based on unidimensional or two-dimensional measurements with qualitative evaluation of complexity and enhancement of lesions. Here we evaluate the utility of 3D volumetric characterization of lesions and use automated histogram analysis to monitor the evolution of clear cell carcinoma in vHL patients. METHODS 79 lesions in 10 patients were selected by an experienced radiologist for volumetric analysis. Lesions were retrospectively followed between 3 – 8 years. Margins of the lesions were defined manually using a PACS integrated semi-automated tool, while vodlumetric and histogram analysis of lesions were performed in Matlab. Mean, standard deviation, skewness and kurtosis of the entire volume was calculated from the histogram data. The mean was used as an indicator of tumor enhancement. Degree of cystic and solid composition of the lesions was defined based on mean and skewness with tumor heterogeneity being defined as a measure of standard deviation and kurtosis. RESULTS The majority of the lesions were found to be solid [61 out of 79 (77%)]. The volume of 52 lesions increased during the follow-up period while 10 lesions decreased in volume. Remainder of the lesions did not grow or decrease in size during follow-up. 46 lesions were heterogeneous in density with 26 lesions increasing and 5 lesions decreasing in heterogeneity during the course of the follow-up (figure 1). 62 lesions demonstrated hyper enhancement. 32 lesions remained stable in enhancement during the course of follow-up, while 22 lesions showcased increasing enhancement during the same course of time. CONCLUSIONS Volumetric data and histogram analysis provides a more thorough snapshot of tumor development when compared to conventional RECIST measurements. Obtained data can be used as a gateway into the natural history of vHL, based on which, predictive models can be designed for optimal follow-up algorithms. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e204-e205 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Ashkan Malayeri More articles by this author Amir Pourmorteza More articles by this author Nikeith Shah More articles by this author Rabindra Gautam More articles by this author Alireza Yazdi More articles by this author Jana Lovell More articles by this author Shawna Boyle More articles by this author Ishan Asokan More articles by this author Ramaprasad Srinivasan More articles by this author Adam Metwalli More articles by this author W. Marston Linehan More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Evaluating and Quantifying User and Carer Involvement in Mental Health Care Planning (EQUIP): Co-Development of a New Patient-Reported Outcome Measure.

International and national health policy seeks to increase service user and carer involvement in mental health care planning, but suitable user-centred tools to assess the success of these initiatives are not yet available. The current study describes the development of a new reliable and valid, interval-scaled service-user and carer reported outcome measure for quantifying user/carer involvement in mental health care planning. Psychometric development reduced a 70-item item bank to a short form questionnaire using a combination of Classical Test, Mokken and Rasch Analyses. Test-retest reliability was calculated using t-tests of interval level scores between baseline and 2–4 week follow-up. Items were worded to be relevant to both service users and carers. Nine items were removed following cognitive debriefing with a service user and carer advisory group. An iterative process of item removal reduced the remaining 61 items to a final 14-item scale. The final scale has acceptable scalability (Ho = .69), reliability (alpha = .92), fit to the Rasch model (χ2(70) = 97.25, p = .02), and no differential item functioning or locally dependent items. Scores remained stable over the 4 week follow-up period, indicating good test-retest reliability. The ‘Evaluating the Quality of User and Carer Involvement in Care Planning (EQUIP)’ scale displays excellent psychometric properties and is capable of unidimensional linear measurement. The scale is short, user and carer-centred and will be of direct benefit to clinicians, services, auditors and researchers wishing to quantify levels of user and carer involvement in care planning.

Unidimensional Measurement May Evaluate Target Lymph Nodal Response After Induction Chemotherapy for Nasopharyngeal Carcinoma.

The aim of the study was to evaluate whether short axis and long axis on axial and coronal magnetic resonance imaging planes would reflect the tumor burden or alteration in size after induction chemotherapy in nasopharyngeal carcinoma.Patients with pathologically confirmed nasopharyngeal carcinoma (n = 37) with at least 1 positive cervical lymph node (axial short axis ≥15 mm) were consecutively enrolled in this prospective study. Lymph nodal measurements were performed along its short axis and long axis in both axial and coronal magnetic resonance imaging planes at diagnosis and after 2 cycles of induction chemotherapy. In addition, lymph nodal volumes were automatically calculated in 3D treatment-planning system, which were used as reference standard. Student's t test or nonparametric Mann–Whitney U test was used to compare the continuous quantitative variables. Meanwhile, the κ statistic and McNemar's test were used to evaluate the degree of agreement and discordance in response categorization among different measurements.Axial short axis was significantly associated with volumes at diagnosis (P < 0.001). A good agreement (κ=0.583) was found between axial short axis and volumetric criteria. However, the inconsistent lymph nodal shrinkage in 4 directions was observed. Axial short-axis shrinking was more rapid than the other 3 parameters. Interestingly, when utilizing the alternative planes for unidimensional measurements to assess tumor response, coronal short-axis showed the best concordance (κ=0.792) to the volumes.Axial short axis may effectively reflect tumor burden or change in tumor size in the assessment of target lymph nodal response after induction chemotherapy for nasopharyngeal carcinoma. However, it should be noted that axial short axis may amplify the therapeutic response. In addition, the role of coronal short axis in the assessment of tumor response needs further evaluation.

The Effects of Political Cynicism and National Siege Mentality on the Internalization of an Anti-European Sentiment

&lt;p&gt;This paper aims to provide an insight into the political-psychological understanding of an attitudinal construct labeled anti-European sentiment. A structural equation model for prediction was developed and evaluated by using full information mximum likelihood estimates obtained from LISREL 8.52 computer program. Assumption was that both political cynicism and national siege mentality would have an effect on anti-European sentiment. The data reported here were obtained by standard survey methods on the sample of adult population in Croatia (N=533). Confirmatory factor analysis (CFA) was performed to explore factorial and construct validity of the measures used in this research. CFA yielded unidimensional construct measurements with acceptable fit indices. Structural model indicated that exogenous variables (political cynicism, national siege mentality) have significant effects on the anti-European sentiment used as an endogenous (dependent) variable. Goodness-of-fit indices suggested acceptable fit of the model (RMSEA=0.07, CFI=0.97, NNFI=0.97, SRMR=0.05). Given the amount of variance of anti-European sentiment, it was showen that political cynicism and national siege mentality have strong predictive validity for anti-European sentiment (43 percent of the variance was explained by the structural model). In order to explain the interactions among the variables investigated, the author proposed the distrust-threat model of political hostility.&lt;/p&gt;

RE: Ultrasonic Measurement of Testicular Tumors and the Correlation with Pathologic Specimen Sizes.

We read with great interest the article “The value of testicular ultrasound in the prediction of the type and size of testicular tumors” by Shtricker et al. (1). They aimed to assess the correlation between ultrasound (US) findings and testicular tumor type and size. The authors concluded that the testis US findings underestimated the size in 25% of the malignant testicular lesions and 16% of the cases were proven to be benign. Thus they recommended putting into practice frozen sections for borderline cases. This study gives substantial information on this clinically relevant condition. The awareness of this diagnostic finding and its clinical results may increase the accuracy of preoperative management of the patients with testicular lesions. Thanks to the authors for this contribution. Several medical subspecialties manage their treatments with respect to anatomic measurements. The reproducibility and accuracy of the measurements are especially crucial in radiology as important clinical decisions are often based on the assumption that radiologic measurements are accurate and any measurement differences on follow-up imagings represent a real change in size. Favorably, measurements of the tumors on images should be accurate, reproducible, and practiced in a standardized method with low rates of intra-and interobserver variability. Even so, there a lot of factors, which may affect the consistency of the measurement, including patientdependent factors, technical factors and radiologist-dependent factors (2,3). World Health Organization criteria (WHO) (4) and the Response Evaluation Criteria in Solid Tumors (RECIST) (5) are two widely accepted guidelines of measurement methods to obtain standardized results (6). WHO criteria recommend the measurement method on the basis of an approximation of cross-sectional area (bidimensional measurement), whereas RECIST suggests to measure only the tumor’s greatest diameter (unidimensional measurement) on a transverse plane (7). Shtricker et al. have designed this study as a multicenter study (1). This design may increase the variabilities in the tumor measurement. However, the authors did not mention any measurement method for standardization in the study. A lot of published studies based on the variability and reproducibility of tumor measurements define their measurement methods and they generally use WHO or RECIST criteria. Therefore a measurement variability might occur due to lack of measurement standardization. Vol. 42 (1): 172-173, January February, 2016

Comparison of CT volumetric measurement with RECIST response in patients with lung cancer

PurposeTo examine the correlations between uni-dimensional RECIST and volumetric measurements in patients with lung adenocarcinoma and to assess their association with overall survival (OS) and progression-free survival (PFS). Materials and methodsIn this study of patients receiving chemotherapy for lung cancer in the setting of a clinical trial, response was prospectively evaluated using RECIST 1.0. Retrospectively, volumetric measurements were recorded and response was assessed by two different volumetric methods at each followup CT scan using a semi-automated segmentation algorithm. We subsequently evaluated the correlation between the uni-dimensional RECIST measurements and the volumetric measurements and performed landmark analyses for OS and PFS at the completion of the first and second follow-ups. Kaplan–Meier curves together with log-rank tests were used to evaluate the association between the different response criteria and patient outcome. ResultsForty-two patients had CT scans at baseline, after the first follow up scan and second followup scan, and then every 8 weeks. The uni-dimensional RECIST measurements and volumetric measurements were strongly correlated, with a Spearman correlation coefficient (ρ) of 0.853 at baseline, ρ=0.861 at the first followup, ρ=0.843 at the 2nd followup, and ρ=0.887 overall between-subject. On first follow-up CT, partial responders and non responders as assessed by an “ellipsoid” volumetric criteria showed a significant difference in OS (p=0.008, 1-year OS of 70% for partial responders and 46% for non responders). There was no difference between the groups when assessed by RECIST criteria on first follow-up CT (p=0.841, 1-year OS rate of 64% for partial responders and 64% for non responders). ConclusionVolumetric response on first follow-up CT may better predict OS than RECIST response. Clinical relevance statementAssessment of tumor size and response is of utmost importance in clinical trials. Volumetric measurements may help to better predict OS than uni-dimensional RECIST criteria.

Bidimensional Data Allow for Better Age Estimation on Immature Specimens than Unidimensional Data: A Preliminary Study on the Ilium

Most biometric age estimation methods used in anthropological and forensic science for juveniles are based on unidimensional measurements (length or width). Here, a new method using bidimensional data was tested. A 3D morphometric analysis was performed on 108 CT scans of ilium bone of juveniles (from 20 gestational weeks to 12 years old). The sample was divided into training and validation groups. Best predictors were determined by comparing the efficiency of each variable (length, width, area, and module: a product of length and width). We established linear and polynomial regressions for each parameter for both sides. Applying the equations to the validation sample showed no significant difference between real and predicted ages. For age estimation, the area and module parameters yielded better results than unidimensional measurements. The results from this preliminary study were highly conclusive, and it would be interesting to extend the work, covering larger samples, and other bones.

Outcome measurement of refractory breathlessness: endpoints and important differences.

Standardized measurement of self-rated breathlessness using appropriate tools is essential for research and clinical care. The purpose was to review recent advances in the measurement of breathlessness and the minimal clinically important differences (MCIDs) in intensity of chronic breathlessness. Two tools have been validated in people with chronic obstructive pulmonary disease (COPD) to measure daily symptoms and breathlessness related to daily activities. Two multidimensional tools have been developed for different settings and aetiologies, which measure both the perceived intensity, unpleasantness, quality of breathlessness, and the person's emotional response to it. MCIDs have been reported for the intensity of chronic refractory breathlessness, the daily symptom diary, and breathlessness related to daily activities in COPD. There have been substantial developments in instruments able to provide reliable and valid unidimensional and multidimensional measurement of self-reported breathlessness and in the understanding of the MCID for chronic breathlessness. Routine use of agreed outcome measures in clinical practice and research are crucial steps to improve our understanding of the science of breathlessness and its impact on patients' outcomes.

Assessing splenic enlargement on CT by unidimensional measurement changes in patients with colorectal liver metastases.

The aim of this study was to assess splenic volume and to correlate unidimensional measurements with reference volumetric changes in chemotherapy-treated patients with colorectal cancer (CRC) liver metastases. Forty consecutive patients were selected from the cohort of a previously reported study of chemotherapy-related morbidity following major hepatectomy for CRC liver metastases. Patients were treated for 6months prior to resection, with imaging performed at baseline and after 6months of chemotherapy. Three unidimensional spleen measurements were recorded-width, thickness, and height (W, T, and H). Reference splenic volume was measured at baseline and after chemotherapy. The best unidimensional splenic measurement was determined by regression analysis. The 95% CI for the predicted values and R (2) values was calculated for each regression. The percentage of volume increase at 6months was calculated. W and H showed the highest correlation with splenic volume prior to and following chemotherapy (R (2)=0.65-0.74, p<0.001), while T showed a low correlation (R (2)=0.11 and 0.18, p<0.05). The mean reference splenic volume increased after 6months of chemotherapy compared to baseline (326 vs. 278mL). Splenic volume changes showed the highest correlation with changes in W (R (2)=0.56, p<0.001), then H (R (2)=0.40, p<0.001), but were not significantly correlated with changes in T (R (2)=0.01, p=0.055). Our results show the potential utility of measuring changes in splenic width to predict clinically significant changes in splenic volume in chemotherapy-treated patients with CRC liver metastases.

Rasch measurement: the Arm Activity measure (ArmA) passive function sub-scale

Purpose: To evaluate the conformity of the Arm Activity measure (ArmA) passive function sub-scale to the Rasch model. Methods: A consecutive cohort of patients (n = 92) undergoing rehabilitation, including upper limb rehabilitation and spasticity management, at two specialist rehabilitation units were included. Rasch analysis was used to examine scaling and conformity to the model. Responses were analysed using Rasch unidimensional measurement models (RUMM 2030). The following aspects were considered: overall model and individual item fit statistics and fit residuals, internal reliability, item response threshold ordering, item bias, local dependency and unidimensionality. Results: ArmA contains both active and passive function sub-scales, but in this analysis only the passive function sub-scale was considered. Four of the seven items in the ArmA passive function sub-scale initially had disordered thresholds. These items were rescored to four response options, which resulted in ordered thresholds for all items. Once the items with disordered thresholds had been rescored, item bias was not identified for age, global disability level or diagnosis, but with a small difference in difficulty between males and females for one item of the scale. Local dependency was not observed and the unidimensionality of the sub-scale was supported and good fit to the Rasch model was identified. The person separation index (PSI) was 0.95 indicating that the scale is able to reliably differentiate at least two groups of patients. Conclusions: The ArmA passive function sub-scale was shown in this evaluation to conform to the Rasch model once disordered thresholds had been addressed. Using the logit scores produced by the Rasch model it was possible to convert this back to the original scale range.Implications for RehabilitationThe ArmA passive function sub-scale was shown, in this evaluation, to conform to the Rasch model once disordered thresholds had been addressed and therefore to be a clinically applicable and potentially useful hierarchical measure.Using Rasch logit scores it has be possible to convert back to the original ordinal scale range and provide an indication of real change to enable evaluation of clinical outcome of importance to patients and clinicians.

Early tumor response to intraarterial or intravenous administration of carboplatin to treat naturally occurring lower urinary tract carcinoma in dogs.

BackgroundSurvival times and tumor responses associated with malignant neoplasia of the lower urinary tract are poor despite the vast array of current treatments. Therefore, the evaluation of alternative treatments, such as intraarterial administration of chemotherapy (IAC) should be considered.ObjectiveTo describe a technique for superselective catheterization for IAC and to evaluate initial tumor response by ultrasonography after both IAC and intravenous administration of chemotherapy (IVC).AnimalsClient‐owned dogs with lower urinary tract neoplasia treated with either IVC (n = 15) or IAC (n = 11).MethodsRetrospective study. An arterial approach via the carotid or femoral artery was utilized to obtain superselective access and administer chemotherapy in the IAC cases. Medical record review was performed, data were recorded, and recorded variables were evaluated statistically.ResultsIntraarterial chemotherapy was successfully administered in all cases. There was a significantly greater decrease in longest unidimensional measurement in the IAC group as compared to the IVC group (P = .013). The IAC group was also significantly more likely to have a tumor response as assessed by modified RECIST guidelines (P = .049). Dogs in the IAC group were significantly less likely to develop anemia (P = .001), lethargy (P = .010) and anorexia (P = .024).Conclusion and Clinical ImportanceThis study demonstrated the feasibility and efficacy of performing IAC for lower urinary tract neoplasia. Further investigation is necessary as the follow‐up time was short and the impact on long‐term outcome and survival was not determined.

When Are Multidimensional Data Unidimensional Enough for Structural Equation Modeling? An Evaluation of the DETECT Multidimensionality Index

In structural equation modeling (SEM), researchers need to evaluate whether item response data, which are often multidimensional, can be modeled with a unidimensional measurement model without seriously biasing the parameter estimates. This issue is commonly addressed through testing the fit of a unidimensional model specification, a strategy previously determined to be problematic. As an alternative to the use of fit indexes, we considered the utility of a statistical tool that was expressly designed to assess the degree of departure from unidimensionality in a data set. Specifically, we evaluated the ability of the DETECT “essential unidimensionality” index to predict the bias in parameter estimates that results from misspecifying a unidimensional model when the data are multidimensional. We generated multidimensional data from bifactor structures that varied in general factor strength, number of group factors, and items per group factor; a unidimensional measurement model was then fit and parameter bias recorded. Although DETECT index values were generally predictive of parameter bias, in many cases, the degree of bias was small even though DETECT indicated significant multidimensionality. Thus we do not recommend the stand-alone use of DETECT benchmark values to either accept or reject a unidimensional measurement model. However, when DETECT was used in combination with additional indexes of general factor strength and group factor structure, parameter bias was highly predictable. Recommendations for judging the severity of potential model misspecifications in practice are provided.

The Shoulder Function Index (SFInX): a clinician-observed outcome measure for people with a proximal humeral fracture.

BackgroundProximal humeral fractures are amongst the most common fractures. Functional recovery is often slow and many people have ongoing disability during activities of daily life. Unidimensional measurement of activity limitations is required to monitor functional progress during rehabilitation. However, currentshoulder measures are multidimensional incorporating constructs such as activities, range of motion and pain into a single scale. Psychometric information of these measures is scarce in this population, and indicate measurement issues with reliability. Therefore, the aim was to develop the clinician-observed Shoulder Function Index (SFInX), a unidimensional, interval-level measure of ‘shoulder function’ based on actual performance of activities, reflecting activity limitations following a proximal humeral fracture.MethodsAn outcome measure development study was performed including item generation (existing shoulder measures, focus groups) and item selection (selection criteria, importance and feasibility ratings, pilot testing, Rasch analysis). Clinicians (n=15) and people with a proximal humeral fracture (n=13) participated in focus groups. Items were pilot tested (n=12 patients) and validated in a Rasch study. The validation study sample (n=92, 86% female) were recruited between 5 and 52 weeks post-fracture and had a mean age of 63.5 years (SD13.9). Measurements at recruitment and 6 and 7 weeks later were taken in three public metropolitan hospitals or during home visits. Raw SFInX data were analysed with WINSTEPS v3.74 using polytomous Rasch models.ResultsFrom 282 generated items, 42 items were selected to be rated by clinicians and patients; 34 items were pilot tested and 16 items were included for Rasch analysis. The final SFInX, developed with the Partial Credit Model, contains 13 items and has the response categories: ‘unable’, ‘partially able’ and ‘able’. It is unidimensional measuring ‘shoulder function’, and can measure from early functional use (drinking from a cup) to independence around the house (lifting items above head, carrying heavy items).ConclusionsThe SFInX is a promising outcome measure of shoulder function for people with a proximal humeral fracture. It has content relevant to patients and clinicians, is unidimensional and feasible for use in clinical and home settings. In its current form, the SFInX is ready for further psychometric evaluation, and for subsequent use in clinical settings and research.Electronic supplementary materialThe online version of this article (doi:10.1186/s12891-015-0481-x) contains supplementary material, which is available to authorized users.

Rasch analysis of the Chronic Pain Acceptance Questionnaire Revised in people with knee osteoarthritis.

To examine the measurement properties of the Chronic Pain Acceptance Questionnaire Revised (CPAQ-R) and its subscales with people with knee osteoarthritis using Rasch analysis. Cross-sectional questionnaire study. A total of 176 participants with radiographic evidence of osteoarthritis of the knee, as identified by a Kellgren-Lawrence grade ≥ 2, and pain on most days for at least the past month. Participants completed the CPAQ-R at home within a set of measures covering different aspects of osteoarthritis pain. The questionnaires were returned by pre-paid envelope. Rasch analysis was conducted on the Activity Engagement and Pain Willingness subscales and the Total scale using Rasch Unidimensional Measurement Models (RUMM2020). The Activity Engagement and Pain Willingness subscales fit the Rasch model following minimal changes, including re-scoring and removal of item 14 due to misfit. Both subscales passed tests of unidimensionality. Although the Total scale could be adjusted to yield adequate fit statistics, it demonstrated multidimensionality. The Activity Engagement and Pain Willingness subscales have good measurement properties for 2 distinct factors relevant to pain acceptance. CPAQ-R is a valid measurement tool that may help target and evaluate response to treatments that address low activity engagement and pain willingness in people with osteoarthritis.

Validation of the brief version of the Recovery Self-Assessment (RSA-B) using Rasch measurement theory.

In psychiatry, the recovery paradigm is increasingly identified as the overarching framework for service provision. Currently, the Recovery Self-Assessment (RSA), a 36-item rating scale, is commonly used to assess the uptake of a recovery orientation in clinical services. However, the consumer version of the RSA has been found challenging to complete because of length and the reading level required. In response to this feedback, a brief 12-item version of the RSA was developed (RSA-B). This article describes the development of the modified instrument and the application of traditional psychometric analysis and Rasch Measurement Theory to test the psychometrics properties of the RSA-B. Data from a multisite study of adults with serious mental illnesses (n = 1256) who were followed by assertive community treatment teams were examined for reliability, clinical meaning, targeting, response categories, model fit, reliability, dependency, and raw interval-level measurement. Analyses were performed using the Rasch Unidimensional Measurement Model (RUMM 2030). Adequate fit to the Rasch model was observed (χ2 = 112.46, df = 90, p = .06) and internal consistency was good (r = .86). However, Rasch analysis revealed limitations of the 12-item version, with items covering only 39% of the targeted theoretical continuum, 2 misfitting items, and strong evidence for the 5 option response categories not working as intended. This study revealed areas for improvement in the shortened version of the 12-item RSA-B. A revisit of the conceptual model and original 36-item rating scale is encouraged to select items that will help practitioners and researchers measure the full range of recovery orientation.

Could the Quick Inventory of Depressive Symptomatology-Self-Report (QIDS-SR) be used in depressed schizophrenia patients?

BackgroundDeveloping accurate and time-efficient tools to measure depressive symptoms in schizophrenia is important for research and clinical practice. This study tested the psychometric properties of the Chinese version of the 16-item Quick Inventory of Depressive Symptomatology (QIDS-SR) in depressed schizophrenia patients. MethodsThis study included 337 clinically stable patients with schizophrenia. The severity of depressive symptoms was assessed using the Montgomery–Asberg Depression Rating Scale (MADRS), QIDS-SR at baseline and 2 weeks later. Negative symptoms and extrapyramidal symptoms were measured with the negative symptom score of Brief Psychiatric Rating Scale (BPRS) and the Simpson–Angus Scale of Extrapyramidal Symptoms (SAS), respectively. ResultsInternal consistency (Cronbach׳s alpha) was 0.73 and 0.67 for QIDS-SR at the baseline and endpoint, respectively. The intra-class correlation coefficient (ICC) for test–retest reliability over the two weeks was 0.77. Two domains (involvement and energy) at baseline and one domain (energy) at endpoint had the highest item-total correlations. The QIDS-SR total score was significantly correlated with the MADRS total score at baseline (r=0.44, p<0.01). Weak correlations of the QIDS-SR score with the scores of the BPRS negative (r=0.18) and the SAS (r=0.05) indicate good discriminant validity. The QIDS-SR showed unidimensional measurement properties in exploratory factor analysis at both baseline. The main limitation of the study is that only clinically stable schizophrenia patients were included. ConclusionsThe QIDS-SR has acceptable psychometric properties in stable schizophrenia patients and may be useful in both research and clinical practice.