Validating the functional capacity index: a comparison of predicted versus observed total body scores.
BACKGROUND
The Functional Capacity Index (FCI) was designed to predict physical function 12 months after injury. We report a validation study of the FCI.


METHODS
This was a consecutive case series registered in the Queensland Trauma Registry who consented to the prospective 12-month telephone-administered follow-up study. FCI scores measured at 12 months were compared with those originally predicted.


RESULTS
Complete Abbreviated Injury Scale score information was available for 617 individuals, of whom 587 (95%) could be assigned at least one FCI score (range, 1-17). Agreement between the largest predicted FCI and observed FCI score was poor (kappa = 0.05; 95% confidence interval, 0.00-0.10) and explained only 1% of the variability in observed FCI. Using an encompassing model that included all FCI assignments, agreement remained poor (kappa = 0.05; 95% confidence interval, -0.02-0.12), and the model explained only 9% of the variability in observed FCI.


CONCLUSIONS
The predicted functional capacity poorly agrees with actual functional outcomes. Further research should consider including other (noninjury) explanatory factors in predicting FCI at 12 months.
Schluter
Philip J
PJ
School of Population Health, University of Queensland, and the Queensland Institute of Medical Research, Queensland, Australia. p.schluter@sph.uq.edu.au
Neale
Rachel
R
Scott
Deborah
D
Luchter
Stephen
S
McClure
Roderick J
RJ
D015998:Abbreviated Injury Scale; D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D020127:Recovery of Function; D012042:Registries; D015203:Reproducibility of Results; D014947:Wounds and Injuries / Q000145:classification*