Concurrent evaluation of data quality, reliability and validity of the Australian/Canadian Osteoarthritis Hand Index and the Functional Index for Hand Osteoarthritis.
OBJECTIVE
Concurrent evaluation of data quality, internal consistency, test-retest reliability and validity of two patient-reported outcome measures (PROMs) for measuring functional impairment in hand OA (HOA); the Australian/Canadian Osteoarthritis Hand Index (AUSCAN; 15 items) and the Functional Index of HOA (FIHOA; 10 items).


METHODS
Patients from an HOA cohort [n=128, mean age 68.6 (s.d. 5.8) years, 91% women] completed PROMs and performance measures during routine follow-up. One week later, a subsample (n=40) reporting no change on an HOA-specific transition question contributed with test-retest data.


RESULTS
Both instruments had satisfactory levels of data quality, internal consistency, test-retest reliability and construct validity. The AUSCAN performed slightly better than the FIHOA relating to levels of missing data (0 vs 5%), floor effects, principal component analysis loadings (0.62-0.83 vs 0.52-0.83), item-total correlation (0.77-0.91 vs 0.45-0.76) and Cronbach's α (0.94-0.96 vs 0.90), respectively. AUSCAN items had slightly lower test-retest κ-values (0.29-0.77 vs FIHOA 0.41-0.77) and AUSCAN scales lower intra-class correlations (0.80-0.92 vs FIHOA 0.94). Correlations between the two instruments ranged from 0.58 to 0.88 for the AUSCAN scales of stiffness and physical function, respectively. AUSCAN physical function scale was generally slightly strongly correlated with the other PROMS and performance measures.


CONCLUSIONS
The AUSCAN and the FIHOA are reliable and valid instruments suitable for measuring physical functioning in HOA. The FIHOA had higher test-retest reliability and is shorter, but the AUSCAN performed slightly better concerning data quality and construct validity.
Moe
Rikke H
RH
National Resource Centre for Rehabilitation in Rheumatology, Department of Rheumatology, Diakonhjemmet Hospital, and Institute of Nursing and Health Sciences, Faculty of Medicine, University of Oslo, PO Box 23 Vinderen, 0319 Oslo, Norway. rikke.moe@nrrk.no
Garratt
Andrew
A
Slatkowsky-Christensen
Barbara
B
Maheu
Emmanuel
E
Mowinckel
Petter
P
Kvien
Tore K
TK
Kjeken
Ingvild
I
Hagen
Kåre Birger
KB
Uhlig
Till
T
D000368:Aged; D001315:Australia; D002170:Canada; D015331:Cohort Studies; D016208:Databases, Factual / Q000592:standards*; D005260:Female; D006225:Hand; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000503:physiopathology*; D012042:Registries / Q000592:standards*; D015203:Reproducibility of Results; D012107:Research Design / Q000592:standards; D012720:Severity of Illness Index