HOOS-PS

Clinical intent

The Hip disability and Osteoarthritis Outcome Score (HOOS) – Physical Function Shortform (HOOS-PS)-Control was developed from the original long version using Rasch analysis. The Rasch analysis resulted in a 5 item questionnaire that is cross culturally valid and that provides a true interval level measure such that it can be used to measure change in physical function. The reliability of the 5 items is 0.80 (Cronbach’s alpha). It is a unidimensional construct as demonstrated by the fit to the Rasch model [1].

Calculation

The HOOS-PS questionnaire is scored by summing the raw response (range 0-20) and then using the nomogram in Table 2 to convert the raw score to a true interval score (0-100). HOOS-PS can be scored in two directions, best to worst and worst to best (see section "Interpretation" for more information).

Clinical interpretation

HOOS-PS can be scored in two directions:

1. From no difficulty (0) to extreme difficulty (100), as in the original HOOS-PS publication [2]
2. From extreme difficulty (0) to no difficulty (100) in accordance with HOOS.

The method of interpretation used in Awell is according to direction #2 (0 = extreme difficulty and 100 = no difficulty).

Nomogram for converting raw summed HOOS-PS scores to 0 representing extreme difficulty and 100 representing no difficulty:

References

[1] HOOS-PS User’s Guide. http://www.koos.nu/hoospsusers.html
[2] Davis AM et al. 2008, Osteoarthritis Cartilage