HOOS Score (Hip Disability and Osteoarthritis Outcome Score)

September 06, 2015


Hip Disability and Osteoarthritis Outcome Score (HOOS)

The Hip Disability and Osteoarthritis Outcome Score (HOOS) is a patient reported outcome measure that is used to evaluate patients following Total Hip Arthroplasty (THA).

The HOOS questionnaire was built upon the Western Ontario and MacMaster Universities Osteoarthritis Index (WOMAC) – an instrument that also measures outcomes in osteoarthritis and following THA. Questions from the WOMAC (LK version 3.0) were used as the basis for the HOOS survey and two additional dimensions were added: Sport and Recreation and Hip Related Quality of Life.

To its advantage however, HOOS has been found to be more responsive than the WOMAC survey.

HOOS is composed of forty questions and attempts to assess patient outcomes by looking at five subscales: pain (10 items), symptoms (5 items), activity of daily living (17 items), sport and recreation function (4 items) and hip related quality of life (4 items). A total HOOS score is calculated by using a simple formula to produce a score that ranges from 0-100, with higher scores representing better function. The HOOS survey is easy to administer and relatively easy to score.


The HOOS questionnaire is self-explanatory, user friendly and well represented in literature. Because the HOOS survey contains questions from the WOMAC, WOMAC scores may be calculated from a HOOS questionnaire. As a point of interest, the HOOS is suggested to be more valuable than the WOMAC for younger and more active patients due to the added subscales.

Another advantage of the HOOS is that it may be used over short- and long-term intervals to assess changes induced by treatment (eg. medication, physical therapy, operation), primary injuries or post traumatic osteoarthritis.


The HOOS questionnaire takes approximately 10-15 minutes to complete, which some patients may find difficult or time consuming. The HOOS has undergone psychometric testing with regards to assessing hip osteoarthritis but needs further testing in different groups of patients with other hip disabilities.

Overall, the HOOS is a well-regarded measure for the evaluation of patients following a total hip replacement. If the time required to complete the survey is not an issue, it is a solid PRO measure to consider.


The HOOS survey does not require a license. To learn more about the HOOS, please visit their website: http://www.koos.nu/.


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