Measuring disease-specific quality of life in rare populations: a practical approach to cross-cultural translation.
BACKGROUND
Disease-specific quality of life (QoL) measures have enhanced the capacity of outcome measures to evaluate subtle changes and differences between groups. However, when the specific disease is rare, the cohort of patients is small and international collaboration is often necessary to accomplish meaningful research. As many of the QoL measures have been developed in North American English, they require translation to ensure their usefulness in a multi-cultural and/or international society. Published guidelines provide formal methods to achieve cross-culturally comparable versions of a QoL tool. However, these guidelines describe a rigorous process that is not always feasible, particularly in rare disease groups. The objective of this manuscript is to describe the process that was developed to achieve accurate cross-cultural translations of a disease-specific QoL measure, to overcome the challenges of a small sample size, i.e. children with a rare disorder.


METHODS
A measurement study was conducted in the United Kingdom (UK), France, Germany and Uruguay, during which the validated measure was translated into the languages of the respective countries.


RESULTS
This is a report of a modified, child-centric, cross-cultural translation and adaptation process in which culturally appropriate and methodologically valid translations of a disease-specific QoL measure, the Kids' ITP Tools (KIT), were performed in children with immune thrombocytopenic purpura (ITP). The KIT was translated from North American English into UK English, French, German, and Spanish.


CONCLUSIONS
This study was a successful international collaboration. The modified process through which culturally appropriate and methodologically valid translations of QoL measures may be achieved in a pediatric population with a relatively rare disorder is reported.
Division of Pediatric Hematology/Oncology, IWK Health Centre, Dalhousie University, Halifax, NS, Canada. vicky.price@iwk.nshealth.ca
Victoria E
VE
Price
Robert J
RJ
Klaassen
Paula H B
PH
Bolton-Maggs
John D
JD
Grainger
Christine
C
Curtis
Cindy
C
Wakefield
Gustavo
G
Dufort
Arne
A
Riedlinger
Christophe
C
Soltner
Victor S
VS
Blanchette
Nancy L
NL
Young
D000293:Adolescent; D000328:Adult; D002648:Child; D003469:Culture; D005602:France; D005858:Germany; D006801:Humans; D007391:International Cooperation; D016553:Purpura, Thrombocytopenic, Idiopathic; D011788:Quality of Life; D035583:Rare Diseases; D011795:Surveys and Questionnaires; D014175:Translating; D014177:Translations; D006113:United Kingdom; D014583:Uruguay