The development of a short measure of physical function for hip OA HOOS-Physical Function Shortform (HOOS-PS): an OARSI/OMERACT initiative1

https://doi.org/10.1016/j.joca.2007.12.016Get rights and content
Under an Elsevier user license
open archive

Summary

Objective

To derive a cross-culturally valid, short measure of physical function using function subscales (daily living and sports and recreation) of the Hip disability and Osteoarthritis Outcome Score (HOOS).

Methods

Rasch analysis was conducted on data from individuals from multiple countries who had hip osteoarthritis (OA). Fit of the data to the Rasch model was evaluated by model χ2 and item fit statistics (χ2, size of residual, and F-test). Differential item functioning was evaluated by gender, age and country. Unidimensionality was evaluated by factor analysis of residuals. Individual data sets were analyzed and data pooled and re-analyzed for fit to the model. Regression modeling was conducted to derive a nomogram converting raw summed scores to Rasch derived interval scores.

Results

Seven data sets were included (n = 2991), ages 19–96 years, male/female ratio was 1:1.23. The final model included five HOOS items. From the easiest to most difficult, the items (logit) were as follows: sitting (1.832), descending stairs (0.729), getting in/out of bath or shower (0.255), twisting/pivoting on loaded leg (−0.221) and running (−2.595). The separation index was 0.80.

Conclusion

The daily activity and sports and recreational items of the HOOS were reduced to five items achieving a feasible, short measure of physical function with interval level properties. This tool has potential for use as the function component of an OA severity scoring system. Further testing of this measure is warranted.

Key words

Osteoarthritis
Physical function
Outcome measure
Rasch analysis

Cited by (0)

1

New Emerging Team Grant in Early OA sponsored by Canadian Arthritis Network and Canadian Institutes of Health Research, Pfizer, Novartis, Negma, Astra Zeneca, Rottapharm, Expansciences.

AV Perruccio is funded by a CIHR Canada Graduate Scholarship.

There was no involvement of the funding sources in the study design, data collection, analysis and interpretation of the data, in the writing of the manuscript or in the decision to publish the work.