Browsing by Subject "Factor Analysis, Statistical"
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Item Open Access A latent factor linear mixed model for high-dimensional longitudinal data analysis.(Statistics in medicine, 2013-10) An, Xinming; Yang, Qing; Bentler, Peter MHigh-dimensional longitudinal data involving latent variables such as depression and anxiety that cannot be quantified directly are often encountered in biomedical and social sciences. Multiple responses are used to characterize these latent quantities, and repeated measures are collected to capture their trends over time. Furthermore, substantive research questions may concern issues such as interrelated trends among latent variables that can only be addressed by modeling them jointly. Although statistical analysis of univariate longitudinal data has been well developed, methods for modeling multivariate high-dimensional longitudinal data are still under development. In this paper, we propose a latent factor linear mixed model (LFLMM) for analyzing this type of data. This model is a combination of the factor analysis and multivariate linear mixed models. Under this modeling framework, we reduced the high-dimensional responses to low-dimensional latent factors by the factor analysis model, and then we used the multivariate linear mixed model to study the longitudinal trends of these latent factors. We developed an expectation-maximization algorithm to estimate the model. We used simulation studies to investigate the computational properties of the expectation-maximization algorithm and compare the LFLMM model with other approaches for high-dimensional longitudinal data analysis. We used a real data example to illustrate the practical usefulness of the model.Item Open Access Abuse and dependence on prescription opioids in adults: a mixture categorical and dimensional approach to diagnostic classification.(Psychological medicine, 2011-03) Wu, L-T; Woody, GE; Yang, C; Pan, J-J; Blazer, DGFor the emerging DSM-V, it has been recommended that dimensional and categorical methods be used simultaneously in diagnostic classification; however, little is known about this combined approach for abuse and dependence.Using data (n=37 708) from the 2007 National Survey on Drug Use and Health (NSDUH), DSM-IV criteria for prescription opioid abuse and dependence among non-prescribed opioid users (n=3037) were examined using factor analysis (FA), latent class analysis (LCA, categorical), item response theory (IRT, dimensional), and factor mixture (hybrid) approaches.A two-class factor mixture model (FMM) combining features of categorical latent classes and dimensional IRT estimates empirically fitted more parsimoniously to abuse and dependence criteria data than models from FA, LCA and IRT procedures respectively. This mixture model included a severely affected group (7%) with a comparatively moderate to high probability (0.32-0.88) of endorsing all abuse and dependence criteria items, and a less severely affected group (93%) with a low probability (0.003-0.16) of endorsing all criteria. The two empirically defined groups differed significantly in the pattern of non-prescribed opioid use, co-morbid major depression, and substance abuse treatment use.A factor mixture model integrating categorical and dimensional features of classification fits better to DSM-IV criteria for prescription opioid abuse and dependence in adults than a categorical or dimensional approach. Research is needed to examine the utility of this mixture classification for substance use disorders and treatment response.Item Open Access Alcohol and drug dependence symptom items as brief screeners for substance use disorders: results from the Clinical Trials Network.(Journal of psychiatric research, 2012-03) Wu, Li-Tzy; Blazer, Dan G; Woody, George E; Burchett, Bruce; Yang, Chongming; Pan, Jeng-Jong; Ling, WalterAIM:To address an urgent need for screening of substance use problems in medical settings, we examined substance-specific dependence criteria as potential brief screeners for the detection of patients with a substance use disorder (SUD). METHODS:The sample included 920 opioid-dependent adults who were recruited from outpatient treatment settings at 11 programs in 10 U.S. cities and who completed intake assessments of SUDs for a multisite study of the National Drug Abuse Treatment Clinical Trials Network (CTN003). Data were analyzed by factor analysis, item response theory (IRT), sensitivity, and specificity procedures. RESULTS:Across all substances (alcohol, amphetamines, cannabis, cocaine, sedatives), withdrawal was among the least prevalent symptoms, while taking large amounts and inability to cut down were among the most prevalent symptoms. Items closely related to the latent trait of a SUD showed good-to-high values of area under the receiver operating characteristic curve in identifying cases of a SUD; IRT-defined severe and less discriminative items exhibited low sensitivity in identifying cases of a SUD (withdrawal for all substances; time using for alcohol and sedatives; giving up activities for sedatives). CONCLUSIONS:Study results suggest that withdrawal and time using are much less reliable indicators for a SUD than taking larger amounts than intended and inability to cut down and that the latter two items should be studied further for consideration in developing a simplified tool for screening patients for SUDs in medical settings. These findings have implications for the use of common health indicators in electronic health records systems to improve patient care.Item Open Access Construct and differential item functioning in the assessment of prescription opioid use disorders among American adolescents.(Journal of the American Academy of Child and Adolescent Psychiatry, 2009-05) Wu, Li-Tzy; Ringwalt, Christopher L; Yang, Chongming; Reeve, Bryce B; Pan, Jeng-Jong; Blazer, Dan GOBJECTIVE:To examine the psychometric properties of diagnostic criteria for prescription analgesic opioid use disorders (OUDs) and to identify background predictors of a latent continuum for OUD liability. METHOD:Data were drawn from the adolescent sample of the 2006 National Survey of Drug Use and Health. Item response theory (IRT) and multiple indicators-multiple causes methods were used to examine DSM-IV criteria for OUDs in a subsample of adolescents who reported nonmedical prescription opioid use in the past year (N = 1,290). RESULTS:Among nonmedical users of prescription opioids, the criteria of OUDs were arrayed along a single continuum of severity. All abuse criteria were endorsed at a severity level higher than D1 (tolerance) and D5 (time spent) but lower than D3 (taking larger amounts) and D4 (inability to cut down). Differential item functioning in reports of dependence symptoms across adolescents' sex and race/ethnicity were identified: withdrawal, time spent, and continued use despite medical or psychological problems. Adjusting for the effects of differential item functioning and the demographic variables examined, female subjects were more likely than male subjects to exhibit a higher level of OUD liability. CONCLUSIONS:Study findings do not support the DSM-IV's current hierarchical distinction between abuse of and dependence on prescription opioids. Abuse symptoms in adolescents are not necessarily less severe than those of dependence. There is evidence of some differential item functioning in the assessment of OUDs.Item Open Access Differential predictability of four dimensions of affect intensity.(Cogn Emot, 2012) Rubin, David C; Hoyle, Rick H; Leary, Mark RIndividual differences in affect intensity are typically assessed with the Affect Intensity Measure (AIM). Previous factor analyses suggest that the AIM is comprised of four weakly correlated factors: Positive Affectivity, Negative Reactivity, Negative Intensity and Positive Intensity or Serenity. However, little data exist to show whether its four factors relate to other measures differently enough to preclude use of the total scale score. The present study replicated the four-factor solution and found that subscales derived from the four factors correlated differently with criterion variables that assess personality domains, affective dispositions, and cognitive patterns that are associated with emotional reactions. The results show that use of the total AIM score can obscure relationships between specific features of affect intensity and other variables and suggest that researchers should examine the individual AIM subscales.Item Open Access Examining the factor structure of the Connor-Davidson Resilience Scale (CD-RISC) in a post-9/11 U.S. military veteran sample.(Assessment, 2014-08) Green, Kimberly T; Hayward, Laura C; Williams, Ann M; Dennis, Paul A; Bryan, Brandon C; Taber, Katherine H; Mid-Atlantic Mental Illness Research, Education and Clinical Center Workgroup; Davidson, Jonathan RT; Beckham, Jean C; Calhoun, Patrick SThe present study examined the structural validity of the 25-item Connor-Davidson Resilience Scale (CD-RISC) in a large sample of U.S. veterans with military service since September 11, 2001. Participants (N = 1,981) completed the 25-item CD-RISC, a structured clinical interview and a self-report questionnaire assessing psychiatric symptoms. The study sample was randomly divided into two subsamples: an initial sample (Sample 1: n = 990) and a replication sample (Sample 2: n = 991). Findings derived from exploratory factor analysis (EFA) did not support the five-factor analytic structure as initially suggested in Connor and Davidson's instrument validation study. Although parallel analyses indicated a two-factor structural model, we tested one to six factor solutions for best model fit using confirmatory factor analysis. Results supported a two-factor model of resilience, composed of adaptability- (8 items) and self-efficacy-themed (6 items) items; however, only the adaptability-themed factor was found to be consistent with our view of resilience-a factor of protection against the development of psychopathology following trauma exposure. The adaptability-themed factor may be a useful measure of resilience for post-9/11 U.S. military veterans.Item Open Access Influence of comorbid alcohol and psychiatric disorders on utilization of mental health services in the National Comorbidity Survey.(The American journal of psychiatry, 1999-08) Wu, LT; Kouzis, AC; Leaf, PJOBJECTIVE: This study sought to determine how comorbidity of psychiatric and substance abuse disorders affects the likelihood of using mental health services. METHOD: The analysis was based on data on adults aged 18-54 years in the National Comorbidity Survey (N = 5,393). Users and nonusers of mental health and substance abuse services were compared in terms of their demographic characteristics, recent stressful life events, social support, parental history of psychopathology, self-medication, and symptoms of alcohol abuse/dependence. RESULTS: The prevalence of service utilization varied by diagnostic configurations. Comorbid psychiatric or alcohol disorders were stronger predictors of service utilization than a pure psychiatric or alcohol disorder. Factors predicting utilization of services differed for each disorder. CONCLUSIONS: Since comorbidity increases the use of mental health and substance abuse services, research on the relationship of psychiatric and alcohol-related disorders to service utilization needs to consider the coexistence of mental disorders. Attempts to reduce barriers to help seeking for those in need of treatment should be increased.Item Open Access Measuring social health in the patient-reported outcomes measurement information system (PROMIS): item bank development and testing.(Quality of life research : an international journal of quality of life aspects of treatment, care and rehabilitation, 2010-09) Hahn, Elizabeth A; Devellis, Robert F; Bode, Rita K; Garcia, Sofia F; Castel, Liana D; Eisen, Susan V; Bosworth, Hayden B; Heinemann, Allen W; Rothrock, Nan; Cella, David; PROMIS Cooperative GroupPurpose
To develop a social health measurement framework, to test items in diverse populations and to develop item response theory (IRT) item banks.Methods
A literature review guided framework development of Social Function and Social Relationships sub-domains. Items were revised based on patient feedback, and Social Function items were field-tested. Analyses included exploratory factor analysis (EFA), confirmatory factor analysis (CFA), two-parameter IRT modeling and evaluation of differential item functioning (DIF).Results
The analytic sample included 956 general population respondents who answered 56 Ability to Participate and 56 Satisfaction with Participation items. EFA and CFA identified three Ability to Participate sub-domains. However, because of positive and negative wording, and content redundancy, many items did not fit the IRT model, so item banks do not yet exist. EFA, CFA and IRT identified two preliminary Satisfaction item banks. One item exhibited trivial age DIF.Conclusion
After extensive item preparation and review, EFA-, CFA- and IRT-guided item banks help provide increased measurement precision and flexibility. Two Satisfaction short forms are available for use in research and clinical practice. This initial validation study resulted in revised item pools that are currently undergoing testing in new clinical samples and populations.Item Open Access Quantification of the whole-body burden of radiographic osteoarthritis using factor analysis.(Arthritis Res Ther, 2011) Nelson, Amanda E; DeVellis, Robert F; Renner, Jordan B; Schwartz, Todd A; Conaghan, Philip G; Kraus, Virginia B; Jordan, Joanne MINTRODUCTION: Although osteoarthritis (OA) commonly involves multiple joints, no widely accepted method for quantifying whole-body OA burden exists. Therefore, our aim was to apply factor analytic methods to radiographic OA (rOA) grades across multiple joint sites, representing both presence and severity, to quantify the burden of rOA. METHODS: We used cross-sectional data from the Johnston County Osteoarthritis Project. The sample (n = 2092) had a mean age of 65 ± 11 years, body mass index (BMI) 31 ± 7 kg/m2, with 33% men and 34% African Americans. A single expert reader (intra-rater κ = 0.89) provided radiographic grades based on standard atlases for the hands (30 joints, including bilateral distal and proximal interphalangeal [IP], thumb IP, metacarpophalangeal [MCP] and carpometacarpal [CMC] joints), knees (patellofemoral and tibiofemoral, 4 joints), hips (2 joints), and spine (5 levels [L1/2 to L5/S1]). All grades were entered into an exploratory common factor analysis as continuous variables. Stratified factor analyses were used to look for differences by gender, race, age, and cohort subgroups. RESULTS: Four factors were identified as follows: IP/CMC factor (20 joints), MCP factor (8 joints), Knee factor (4 joints), Spine factor (5 levels). These factors had high internal consistency reliability (Cronbach's α range 0.80 to 0.95), were not collapsible into a single factor, and had moderate between-factor correlations (Pearson correlation coefficient r = 0.24 to 0.44). There were no major differences in factor structure when stratified by subgroup. CONCLUSIONS: The 4 factors obtained in this analysis indicate that the variables contained within each factor share an underlying cause, but the 4 factors are distinct, suggesting that combining these joint sites into one overall measure is not appropriate. Using such factors to reflect multi-joint rOA in statistical models can reduce the number of variables needed and increase precision.Item Open Access Validation of a measure of family experience of patients with serious illness: the QUAL-E (Fam).(Journal of pain and symptom management, 2014-12) Steinhauser, Karen E; Voils, Corrine I; Bosworth, Hayden B; Tulsky, James AContext
Family members of seriously ill patients experience significant burden as they advocate with providers and participate in key decisions for loved ones. Most assessments focus on patient experience, yet family members' own quality of experience is central to comprehensive care.Objectives
This study validated a measure of the quality of family experience, the QUAL-E (Fam), in palliative care.Methods
We enrolled family members of terminally ill patients admitted to general medicine services at two hospitals. Items were based on foundational work originally done for the patient instrument, QUAL-E, and interviews of family members of terminally ill patients. Cognitive interviewing was used to refine items, which then underwent formal testing factor analysis. In the first sample, we assessed factor structure. A subsequent sample established predictive validity and test-retest reliability.Results
The initial item pool was reduced to a four-domain, 35-item scale and administered to the validation sample. Further analyses produced a final brief scale comprising 17 items, demonstrating appropriate convergent and divergent validity. Test-retest reliability demonstrated expected levels of stability in a highly changeable population. The scale provides an assessment of family experience and includes subscales assessing relationship with health care provider and completion. Additional scale items assess symptom experience and issues of preparation.Conclusion
The QUAL-E (Fam) is a companion instrument to the patient QUAL-E measure of quality of life at the end of life and is part of a package of assessment tools that can help evaluate the entire patient experience and contribute to quality care.Item Open Access Validation of the Arabic Version of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale.(Movement disorders : official journal of the Movement Disorder Society, 2022-04) Khalil, Hanan; Aldaajani, Zakiyah F; Aldughmi, Mayis; Al-Sharman, Alham; Mohammad, Tareq; Mehanna, Raja; El-Jaafary, Shaimaa I; Dahshan, Ahmed; Ben Djebara, Mouna; Kamel, Walaa A; Amer, Hanan A; Farghal, Mohammed; Abdulla, Fatema; Al-Talai, Nouf; Snineh, Muneer Abu; Farhat, Nouha; Jamali, Fatima A; Matar, Rawan K; Abdelraheem, Heba S; Ghonimi, Nesma AM; Al-Melh, Mishal Abu; Elbhrawy, Sonia; Alotaibi, Majid S; Elaidy, Shaimaa A; Almuammar, Shahad A; Al-Hashel, Jasem Y; Gouider, Riadh; Samir, Hatem; Mhiri, Chokri; Skorvanek, Matej; Lin, Jeffrey; Martinez-Martin, Pablo; Stebbins, Glenn T; Luo, Sheng; Goetz, Christopher G; Bajwa, Jawad ABackground
The Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) has become the gold standard for evaluating different domains in Parkinson's disease (PD), and it is commonly used in clinical practice, research, and clinical trials.Objectives
The objectives are to validate the Arabic-translated version of the MDS-UPDRS and to assess its factor structure compared with the English version.Methods
The study was carried out in three phases: first, the English version of the MDS-UPDRS was translated into Arabic and subsequently back-translated into English by independent translation team; second, cognitive pretesting of selected items was performed; third, the Arabic version was tested in over 400 native Arabic-speaking PD patients. The psychometric properties of the translated version were analyzed using confirmatory factor analysis (CFA) as well as exploratory factor analysis (EFA).Results
The factor structure of the Arabic version was consistent with that of the English version based on the high CFIs for all four parts of the MDS-UPDRS in the CFA (CFI ≥0.90), confirming its suitability for use in Arabic.Conclusions
The Arabic version of the MDS-UPDRS has good construct validity in Arabic-speaking patients with PD and has been thereby designated as an official MDS-UPDRS version. The data collection methodology among Arabic-speaking countries across two continents of Asia and Africa provides a roadmap for validating additional MDS rating scale initiatives and is strong evidence that underserved regions can be energically mobilized to promote efforts that apply to better clinical care, education, and research for PD. © 2022 International Parkinson and Movement Disorder Society.Item Open Access Validation of the Dutch language version of the Safety Attitudes Questionnaire (SAQ-NL).(BMC health services research, 2016-08-15) Haerkens, Marck Htm; van Leeuwen, Wouter; Sexton, J Bryan; Pickkers, Peter; van der Hoeven, Johannes GAs the first objective of caring for patients is to do no harm, patient safety is a priority in delivering clinical care. An essential component of safe care in a clinical department is its safety climate. Safety climate correlates with safety-specific behaviour, injury rates, and accidents. Safety climate in healthcare can be assessed by the Safety Attitudes Questionnaire (SAQ), which provides insight by scoring six dimensions: Teamwork Climate, Job Satisfaction, Safety Climate, Stress Recognition, Working Conditions and Perceptions of Management. The objective of this study was to assess the psychometric properties of the Dutch language version of the SAQ in a variety of clinical departments in Dutch hospitals.The Dutch version (SAQ-NL) of the SAQ was back translated, and analyzed for semantic characteristics and content. From October 2010 to November 2015 SAQ-NL surveys were carried out in 17 departments in two university and seven large non-university teaching hospitals in the Netherlands, prior to a Crew Resource Management human factors intervention. Statistical analyses were used to examine response patterns, mean scores, correlations, internal consistency reliability and model fit. Cronbach's α's and inter-item correlations were calculated to examine internal consistency reliability.One thousand three hundred fourteen completed questionnaires were returned from 2113 administered to health care workers, resulting in a response rate of 62 %. Confirmatory Factor Analysis revealed the 6-factor structure fit the data adequately. Response patterns were similar for professional positions, departments, physicians and nurses, and university and non-university teaching hospitals. The SAQ-NL showed strong internal consistency (α = .87). Exploratory analysis revealed differences in scores on the SAQ dimensions when comparing different professional positions, when comparing physicians to nurses and when comparing university to non-university hospitals.The SAQ-NL demonstrated good psychometric properties and is therefore a useful instrument to measure patient safety climate in Dutch clinical work settings. As removal of one item resulted in an increased reliability of the Working Conditions dimension, revision or deletion of this item should be considered. The results from this study provide researchers and practitioners with insight into safety climate in a variety of departments and functional positions in Dutch hospitals.