The factor structure of the Revised Illness Perception Questionnaire (IPQ-R) in end-stage renal disease patients.
ABSTRACT The purpose of this study was to examine the factor structure of the Revised Illness Perceptions Questionnaire (IPQ-R) in a sample of 374 end-stage renal disease (ESRD) patients. A confirmatory factor analysis of the IPQ-R, including the illness identity subscale, demonstrated adequate model fit for the factor structure as originally defined by (Moss-Morris, R., Weinman, J., Petrie, K. J., Horne, R., Cameron, L. D., & Buick, D. (2002). The revised Illness Perception Questionnaire (IPQ-R). Psychology & Health, 17 (1), 1-16.) Modifying the a-priori IPQ-R factor structure by removing two items with low factor loadings and specifying a path between personal control and item 23 had marginally better fit. A separate exploratory factor analysis of the causal items indicated three factors relating to Biological, Psychological and Behavioural causes. These findings provide evidence towards the validity and reliability of the IPQ-R as a suitable measure of illness perceptions in the context of ESRD.
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- "A poor fit of the original measurement model was also observed in other CFA studies. This comprises an evaluation of the Chinese IPQ-R applied to hypertensive patients in Taiwan , an evaluation of the Swedish IPQ-R applied to patients recovering from myocardial infarction  as well as several CFA studies on the English version of the instrument applied to patients with different chronic diseases [11-13,15,16], including a recent study on populations of African origin with type 2 diabetes . In these studies, several areas of ill-fit were identified and substantial changes to the measurement model such as the deletion of items and the respecification of indicators had to be applied to achieve acceptable model fit. "
ABSTRACT: Background The Revised Illness Perception Questionnaire (IPQ-R) has been used extensively in the study of illness perceptions across different populations. Only few confirmatory factor analytic (CFA) studies of the questionnaire are available. This study examines the construct and discriminant validity of the Turkish IPQ-R in patients with diabetes and cardiovascular disease focusing on the hypothesized seven dimensions of personal controllability, treatment controllability, timeline acute/chronic, timeline cyclical, coherence, consequences and emotional representations. Methods 302 patients (60.6% women) with a medically confirmed diagnosis of diabetes or cardiovascular disease and a mean age of 53.9 years were recruited from out-patient clinics in Turkey and surveyed by means of standardized interviews. Direct maximum likelihood confirmatory factor analysis was conducted. Results Several areas of ill-fit were identified in the original measurement model of the IPQ-R. Four items (items 17, 19, 20, and 31) were deleted because of poor factor loadings. Also, two error covariances (between items 33 and 34 and between items 7 and 8) were added and item 6 respecified to obtain a good model fit. The modified 34-item model showed good reliability and discriminant validity. Conclusion In accordance with studies on other language adaptations of the questionnaire, we identified certain items of the IPQ-R as potential sources of poor model fit. Their inclusion should be reconsidered in future applications of the questionnaire and researchers should examine whether our reduced set of items is stable across different populations. Our modified 34-item model showed a good reliability and discriminant validity and hence could be a valuable instrument in the assessment of illness perceptions in the Turkish health care setting, provided that the model is confirmed in subsequent research.BMC Public Health 10/2012; 12(1):852. DOI:10.1186/1471-2458-12-852 · 2.26 Impact Factor
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- "pulations ( e . g . cancer ( Dempster & McCorry , 2012 ; Giannousi et al . , 2010 ; Hagger & Orbell , 2005 ) , atopic dermatitis ( Wittkowski et al . , 2008 ) , mild brain injury ( Snell et al . , 2010 ) , hypertension ( Chen et al . , 2008 ) , depression ( Cabassa et al . , 2008 ) , fibromyalgia ( van Ittersum et al . , 2009 ) and renal disease ( Chilcot et al . , 2012 ) ) . These studies have all shown some support for the seven - factor model , but this has only been achieved by removing selected items from the questionnaire to improve model fit ( for example , by removing the items ' The problem with my cervix strongly affects the way others see me ' and ' The problem with my cervix has serious fin"
ABSTRACT: Background: The Revised Illness Perceptions Questionnaire (IPQ-R) is commonly used to measure illness perceptions. We tested whether the structure of the IPQ-R was appropriate for use with primary care musculoskeletal pain patients. Methods: Confirmatory (C) and exploratory (E) factor analyses (FA) were used to test whether the structure of the IPQ-R was supported for patients with knee pain (n = 393), hand pain (n = 2113) and back pain (n = 1591). CFA was used to test whether the timeline acute/chronic, timeline cyclical, consequences, personal control, treatment control, illness coherence and emotional representation dimensions of the IPQ-R were distinct; EFA was used to explore potential structure for patients’ views on the cause of their condition. Results: Goodness-of-fit indices for the CFA were below our criteria for good model fit. Removal of six items from the model improved model fit, but our criteria for good model fit was still not achieved. An interpretable factor solution could not be determined for the causal items on the questionnaire. Conclusions: Our data show limited evidence that the seven dimensions of the IPQ-R are distinct. A clear structure for the causal items was not determined. Further work is needed to develop the IPQ-R for use with primary care musculoskeletal pain patients.Psychology & Health 08/2012; 28(1). DOI:10.1080/08870446.2012.714782 · 1.95 Impact Factor
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ABSTRACT: To provide new insights into the psychometrics of the revised Illness Perception Questionnaire (IPQ-R) in cancer patients. To undertake, for the first time using data from breast, colorectal and prostate cancer patients, a confirmatory factor analysis (CFA) to assess the validity of the IPQ-R's core seven-factor structure. Also, for the first time in any illness group, to undertake Rasch analysis to explore the extent to which the IPQ-R factors form unidimensional scales, with linear measurement properties and no Differential Item Functioning (DIF). Patients with potentially curable breast, colorectal or prostate cancer, within 6months post-diagnosis, completed the IPQ-R online (N=531). CFA was conducted, including multi-sample analysis, and for each IPQ-R factor fit to the Rasch model was assessed by examining, amongst other things, item fit, DIF and unidimensionality. The CFA showed a moderate fit of the data to the IPQ-R model, and stability across diagnosis, although fit was significantly improved following the removal of selected items. All seven factors achieved fit to the Rasch model, and exhibited unidimensionality and minimal DIF, although in most cases this was after some item rescoring and/or deletion. In both analyses, IPQ-R items 12, 18 and 24 were indicated as misfitting and removed. Given the rigorous standard of Rasch measurement, and the generic nature of the IPQ-R, it stood up well to the demands of the Rasch model in this study. Importantly, the results show that with some relatively minor, pragmatic modifications the IPQ-R could possess Rasch-standard measurement in cancer patients.Journal of psychosomatic research 12/2013; 75(6):556-62. DOI:10.1016/j.jpsychores.2013.08.005 · 2.74 Impact Factor