The University of St Andrews

Research@StAndrews:FullText >
University of St Andrews Research >
University of St Andrews Research >
University of St Andrews Research >

Please use this identifier to cite or link to this item:
View Statistics

Files in This Item:

File Description SizeFormat
PriorBMC2011Prevalidation.pdf278.51 kBAdobe PDFView/Open
Title: Pre-validation methods for developing a patient reported outcome instrument
Authors: Prior, Maria E.
Hamzah, Jemaima Che
Francis, Jillian J.
Ramsay, Craig R.
Castillo, Mayret M.
Campbell, Susan E.
Azuara-Blanco, Augusto
Burr, Jennifer M.
Keywords: Quality-of-life
Visual function questionnaire
Vision impairment
R Medicine
Issue Date: 9-Aug-2011
Citation: Prior , M E , Hamzah , J C , Francis , J J , Ramsay , C R , Castillo , M M , Campbell , S E , Azuara-Blanco , A & Burr , J M 2011 , ' Pre-validation methods for developing a patient reported outcome instrument ' BMC Medical Research Methodology , vol 11 , 112 . , 10.1186/1471-2288-11-112
Abstract: Background: Measures that reflect patients' assessment of their health are of increasing importance as outcome measures in randomised controlled trials. The methodological approach used in the pre-validation development of new instruments (item generation, item reduction and question formatting) should be robust and transparent. The totality of the content of existing PRO instruments for a specific condition provides a valuable resource (pool of items) that can be utilised to develop new instruments. Such 'top down' approaches are common, but the explicit pre-validation methods are often poorly reported. This paper presents a systematic and generalisable 5-step pre-validation PRO instrument methodology. Methods: The method is illustrated using the example of the Aberdeen Glaucoma Questionnaire (AGQ). The five steps are: 1) Generation of a pool of items; 2) Item de-duplication (three phases); 3) Item reduction (two phases); 4) Assessment of the remaining items' content coverage against a pre-existing theoretical framework appropriate to the objectives of the instrument and the target population (e. g. ICF); and 5) qualitative exploration of the target populations' views of the new instrument and the items it contains. Results: The AGQ 'item pool' contained 725 items. Three de-duplication phases resulted in reduction of 91, 225 and 48 items respectively. The item reduction phases discarded 70 items and 208 items respectively. The draft AGQ contained 83 items with good content coverage. The qualitative exploration ('think aloud' study) resulted in removal of a further 15 items and refinement to the wording of others. The resultant draft AGQ contained 68 items. Conclusions: This study presents a novel methodology for developing a PRO instrument, based on three sources: literature reporting what is important to patient; theoretically coherent framework; and patients' experience of completing the instrument. By systematically accounting for all items dropped after the item generation phase, our method ensures that the AGQ is developed in a transparent, replicable manner and is fit for validation. We recommend this method to enhance the likelihood that new PRO instruments will be appropriate to the research context in which they are used, acceptable to research participants and likely to generate valid data.
Version: Publisher PDF
Description: This study is one component of a Medical Research Council funded strategic grant, G0701759: Developing the intervention and outcome components of a proposed randomised controlled trial of a national screening programme for open angle glaucoma. The Health Services Research Unit receives a core grant from the Chief Scientist Office of the Scottish Government Health Directorates.
Status: Peer reviewed
ISSN: 1471-2288
Type: Journal article
Rights: © 2011 Prior et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Appears in Collections:University of St Andrews Research
Medicine Research

This item is protected by original copyright

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.


DSpace Software Copyright © 2002-2012  Duraspace - Feedback
For help contact: | Copyright for this page belongs to St Andrews University Library | Terms and Conditions (Cookies)