Rasch fit statistics and sample size considerations for polytomous data

Smith, Adam B.; Rush, Robert; Fallowfield, Lesley; Velikova, Galina; Sharpe, Michael

doi:10.1186/1471-2288-8-33

Cited by 273 publications

(224 citation statements)

References 21 publications

(22 reference statements)

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“…In a successful Rasch analysis, there is only one dimension, called the Rasch dimension, captured by the Rasch model and there should be no presence of subdimensions in the principal component analysis. An eigenvalue of the first factor (the Rasch dimension) greater than three or an eigenvalue of each item greater than 1.4 suggests that additional subdimensions are likely to be present [13,21]. No items were identified as unacceptably correlated during this process.…”

Section: Validation Processmentioning

confidence: 99%

Validation of the KOOS, JR: A Short-form Knee Arthroplasty Outcomes Survey

Lyman

Lee

Franklin

et al. 2016

Clinical Orthopaedics &Amp; Related Research

286

209

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Background Medicare is rapidly moving toward using patient-reported outcome measures (PROMs) for outcomes assessment and justification of orthopaedic and other procedures. Numerous measures have been developed to study knee osteoarthritis (OA); however, many of these surveys are long, disruptive to clinic flow, and result in incomplete data capture and/or low followup rates. The Knee injury and Osteoarthritis Outcome (KOOS) physical function short-form (KOOS-PS), while shorter, ignores pain, which is a primary concern of patients with advanced knee OA. Questions/purposes Our objective was to derive and validate a short-form survey focused on the patient with end-stage knee OA undergoing TKA.Methods Using our hospital's knee replacement registry, we retrospectively identified 2291 patients with knee OA who underwent primary unilateral TKA and had completed preoperative and 2-year postoperative PROMs. We assessed 30 items from the 42-item KOOS that were quantitatively most difficult for patients to perform before TKA and qualitatively most relevant to patients with endstage knee OA. Rasch analysis identified the KOOS, JR, a seven-item instrument, representing a single dimension, which we define as ''knee health'' because it reflects aspects of pain, symptom severity, and activities of daily living (ADL) including movements or activities that are directly relevant and difficult for patients with advanced knee OA. We assessed the internal consistency, external One or more of the authors (SL, PDF) has received funding from the Agency for Healthcare Research and Quality (Rockville, MD, USA). One of the authors certifies that he (MBC), or a member of his or her immediate family, has or may receive payments or benefits, during the study period, an amount of USD 10,000 to USD 100,00 from Intellijoint (Waterloo, ON, Canada), an amount of USD 10,000 to USD 100,000 from Smith & Nephew (London, UK), an amount of USD 10,000 to USD 100,00 from Exactech (Gainesville, FL, USA), an amount of USD 10,000 to USD 100,00 from Link (Hamburg, Germany), and an amount of USD 10,000 to USD 100,000 from Acelity (San Antonio, TX, USA). One of the authors certifies that he (DEP) or a member of his or her immediate family, has or may receive payments or benefits, during the study period, an amount of more than USD 1,000,001 from Stryker-Mako (Fort Lauderdale, FL, USA). All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research 1 editors and board members are on file with the publication and can be viewed on request. Each author certifies that his or her institution approved the human protocol for this investigation, that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained.

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Section: Validation Processmentioning

confidence: 99%

Validation of the KOOS, JR: A Short-form Knee Arthroplasty Outcomes Survey

Lyman

Lee

Franklin

et al. 2016

Clinical Orthopaedics &Amp; Related Research

286

209

View full text Add to dashboard Cite

show abstract

“…For the Rasch analysis, a random subsample of 400 respondents was used, as there is evidence that some Rasch fit statistics for polytomous scales such as the CORE-OM are dependent on sample size and larger samples can have a higher chance of type 1 errors. 73 The Rasch results were validated on an additional random subsample of 400 respondents.…”

Section: Developing the Health-state Classificationmentioning

confidence: 99%

Developing and testing methods for deriving preference-based measures of health from condition-specific measures (and other patient-based measures of outcome).

Brazier

Rowen²,

Mavranezouli³

et al. 2012

Health Technol Assess

148

215

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An electronic version of this title, in Adobe Acrobat format, is available for downloading free of charge for personal use from the HTA website (www.hta.ac.uk). A fully searchable DVD is also available (see below).Printed copies of HTA journal series issues cost £20 each (post and packing free in the UK) to both public and private sector purchasers from our despatch agents.Non-UK purchasers will have to pay a small fee for post and packing. For European countries the cost is £2 per issue and for the rest of the world £3 per issue. How to order:-fax (with credit card details) -post (with credit card details or cheque) -phone during office hours (credit card only).Additionally the HTA website allows you to either print out your order or download a blank order form. Contact details are as follows:Synergie UK (HTA Department) Digital House, The Loddon Centre Wade Road Basingstoke Hants RG24 8QW Email: orders@hta.ac.uk Tel: 0845 812 4000 -ask for 'HTA Payment Services' (out-of-hours answer-phone service) Fax: 0845 812 4001 -put 'HTA Order' on the fax header Payment methods Paying by chequeIf you pay by cheque, the cheque must be in pounds sterling, made payable to University of Southampton and drawn on a bank with a UK address.Paying by credit card You can order using your credit card by phone, fax or post. SubscriptionsNHS libraries can subscribe free of charge. Public libraries can subscribe at a reduced cost of £100 for each volume (normally comprising 40-50 titles). The commercial subscription rate is £400 per volume (addresses within the UK) and £600 per volume (addresses outside the UK). Please see our website for details. Subscriptions can be purchased only for the current or forthcoming volume.How do I get a copy of HTA on DVD?Please use the form on the HTA website (www.hta.ac.uk/htacd/index.shtml). HTA on DVD is currently free of charge worldwide.The website also provides information about the HTA programme and lists the membership of the various committees. NIHR Health Technology Assessment programmeThe Health Technology Assessment (HTA) programme, part of the National Institute for Health Research (NIHR), was set up in 1993. It produces high-quality research information on the effectiveness, costs and broader impact of health technologies for those who use, manage and provide care in the NHS. 'Health technologies' are broadly defined as all interventions used to promote health, prevent and treat disease, and improve rehabilitation and long-term care. The research findings from the HTA programme directly influence decision-making bodies such as the National Institute for Health and Clinical Excellence (NICE) and the National Screening Committee (NSC). HTA findings also help to improve the quality of clinical practice in the NHS indirectly in that they form a key component of the 'National Knowledge Service' . The HTA programme is needs led in that it fills gaps in the evidence needed by the NHS. There are three routes to the start of projects. First is the commissioned route. Suggestions for research are ...

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“…Bond and Fox (2007) noted the incumbent difficulties in formulating definitive cut-off points where items may be regarded as so misfitting as to warrant exclusion. Central to much debate among various researchers, these pertain to a balancing of interpreting t-values relative to the magnitudes of both fit statistics and sample size (Bond & Fox, 2007;Smith, Rush, Fallowfield, Velikova & Sharpe, 2008). Bond and Fox (2007: 243) do, however, offer "reasonable item mean square ranges" for rating scales (likert/survey) such as those used in this investigation, of 0.6 to 1.4.…”

Section: Resultsmentioning

confidence: 99%

Cross-cultural differences in the character strength of citizenship in South Africa

Plessis

Saccaggi

Bruin

2015

PINS

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The psychological conceptualisation of the character strength of citizenship as a trait ubiquitous across cultures is examined within the context of a diverse South African sample. The theoretically supposed elements common to the definition of citizenship as a dispositional trait (rather than a situational or cultural phenomenon) are examined by means of considering Peterson and Seligman's (2004) conceptualisation of citizenship as espoused in their work on character strength and virtues. Using the Rasch model of item response theory the International Personality Item Pool (IPIP) Value in Action Inventory (VIA) Citizenship scale was examined for fit and differential item functioning (DIF). A diverse sample of 902 South African university students who completed the Citizenship scale was examined for DIF as a function of self-asserted ethnicities and home language groups, which serve as indicators of culture within the South African context. The findings of the study suggest that while certain conceptual aspects of trait-based citizenship as espoused by Peterson and Seligman (2004) are common across the heterogeneous cultures (as defined by ethnicity and language group) examined, there is sound evidence that there are also qualitative distinctions that are exclusively a function of cultural grouping, suggesting difficulties with the exclusive conceptualisation of citizenship as an individual trait. The implications of these findings speak to the importance of considering citizenship as a nuanced and complex notion that requires further consideration in terms of the philosophical, theoretical and empirical qualification of its conceptualisation. IntroductionThe concept of citizenship has been debated and discussed by scholars from numerous disciplines, including PINS, 2015PINS, , 48, 22 -44, http://dx.doi.org/10.17159/2309PINS, -8708/2015 psychology (Dahlsgaard, Peterson & Seligman, 2005). At the broadest level, citizenship is linked to concepts such as membership and belonging. Although it was initially linked to belonging to a specific nation state, in recent times understandings of citizenship have moved beyond simplistic linkages with nation states to the idea that citizenship can be related to belonging to any grouping (Barnes, Auburn & Lea, 2004;Hamilton, 2009). Within psychology, citizenship has recently been conceptualised as one of the trait like character strengths identified by Peterson and Seligman (2004) and as such forms part of the growing positive psychology movement. This study examined this particular conceptualisation of citizenship within the South African context, making use of Peterson and Seligman's (2004: 13) seminal conceptualisation of citizenship as a trait-like construct that is "ubiquitously recognized and valued". It is acknowledged that despite the prominence of Peterson and Seligman's (2004) conceptualisation of citizenship other, contrasting, notions exist within psychology that view citizenship as being more situationally and culturally, rather than dispositionally, ...

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Rasch fit statistics and sample size considerations for polytomous data

Cited by 273 publications

References 21 publications

Validation of the KOOS, JR: A Short-form Knee Arthroplasty Outcomes Survey

Validation of the KOOS, JR: A Short-form Knee Arthroplasty Outcomes Survey

Developing and testing methods for deriving preference-based measures of health from condition-specific measures (and other patient-based measures of outcome).

Cross-cultural differences in the character strength of citizenship in South Africa

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