Enhancing rigour in the validation of patient reported outcome measures (PROMs): bridging linguistic and psychometric testing.
BACKGROUND
A strong consensus exists for a systematic approach to linguistic validation of patient reported outcome measures (PROMs) and discrete methods for assessing their psychometric properties. Despite the need for robust evidence of the appropriateness of measures, transition from linguistic to psychometric validation is poorly documented or evidenced. This paper demonstrates the importance of linking linguistic and psychometric testing through a purposeful stage which bridges the gap between translation and large-scale validation.


RESULTS
Evidence is drawn from a study to develop a Welsh language version of the Beck Depression Inventory-II (BDI-II) and investigate its psychometric properties. The BDI-II was translated into Welsh then administered to Welsh-speaking university students (n = 115) and patients with depression (n = 37) concurrent with the English BDI-II, and alongside other established depression and quality of life measures. A Welsh version of the BDI-II was produced that, on administration, showed conceptual equivalence with the original measure; high internal consistency reliability (Cronbach's alpha = 0.90; 0.96); item homogeneity; adequate correlation with the English BDI-II (r = 0.96; 0.94) and additional measures; and a two-factor structure with one overriding dimension. Nevertheless, in the student sample, the Welsh version showed a significantly lower overall mean than the English (p = 0.002); and significant differences in six mean item scores. This prompted a review and refinement of the translated measure.


CONCLUSIONS
Exploring potential sources of bias in translated measures represents a critical step in the translation-validation process, which until now has been largely underutilised. This paper offers important findings that inform advanced methods of cross-cultural validation of PROMs.
Centre for Health-Related Research, School of Healthcare Studies, Bangor University, Fron Heulog, Ffriddoedd Road, Bangor, Gwynedd, LL57 2EF, UK. gwerfyl.w.roberts@bangor.ac.uk
Gwerfyl
G
Roberts
Seren
S
Roberts
Richard
R
Tranter
Rhiannon
R
Whitaker
Emma
E
Bedson
Siobhan
S
Tranter
Delyth
D
Prys
Heledd
H
Owen
Yvonne
Y
Sylvestre
D000293:Adolescent; D000328:Adult; D015982:Bias; D003431:Cross-Cultural Comparison; D003866:Depressive Disorder / Q000175:diagnosis / Q000523:psychology*; D005260:Female; D006306:Health Surveys; D006801:Humans; D008037:Linguistics; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D010555:Personality Inventory; D011594:Psychometrics / Q000592:standards*; D011788:Quality of Life; D015203:Reproducibility of Results; D057566:Self Report; D013334:Students / Q000523:psychology; D011795:Surveys and Questionnaires; D014175:Translating; D014852:Wales