What is the HOOS?

HOOS is developed as an instrument to assess the patients’ opinion about their hip and associated problems.

HOOS is intended to be used for hip disability with or without osteoarthritis (OA).

HOOS is validated in two slightly different versions LK 1.1 and LK 2.0.

HOOS is meant to be used over both short and long time intervals; to assess changes from week to week induced by treatment (medication, operation, physical therapy) or over years due to the primary injury or post traumatic OA.

HOOS can be used to assess groups and to monitor individuals.

HOOS content validity was ensured through literature search, through interviews with more than 100 patients with hip disability, with and without hip OA [1] and by questioning 90 patients undergoing total hip replacement [5].

HOOS consists of 5 subscales; Pain, other Symptoms, Function in daily living (ADL), Function in sport and recreation (Sport/Rec) and hip related Quality of life (QOL). The last week is taken into consideration when answering the questions. Standardized answer options are given (5 Likert boxes) and each question gets a score from 0 to 4. A normalized score (100 indicating no symptoms and 0 indicating extreme symptoms) is calculated for each subscale. The result can be plotted as an outcome profile.

HOOS is patient-administered, the format is user friendly, and takes about 10 minutes to fill out.

HOOS is self-explanatory and can be administered in the waiting room or used as a mailed survey.

HOOS has been used in patients 42-89 years old.

HOOS has high test-retest reproducibility (ICC >0.78) [1].

HOOS includes WOMAC Osteoarthritis Index LK 3.0 [2, 3] in its complete and original format (with permission), and WOMAC scores can be calculated. WOMAC is valid for elderly subjects with hip OA.

HOOS construct validity has been determined by comparing it with SF-36 [4] and expected correlations were found [5].

HOOS responsiveness has been determined in one study (n=90) after total hip replacement [5]. The responsiveness, calculated as SRM (standardized response mean), was significantly higher for the HOOS subscales Pain and Symptoms than for the WOMAC subscales Pain and Stiffness. High SRM were was also found for the subscales "Sport and Recreation function" and "Quality of life". High SRM indicates that fewer subjects are needed to yield statistically significant differences.

HOOS validation work is ongoing. HOOS is currently being used in several clinical studies involving patients with or without hip OA. Two methodological papers regarding the HOOS were published during 2003 [1] [5]

HOOS is available in several language versions and can be downloaded here.

1. Klassbo M, Larsson E, Mannevik E. Hip disability and osteoarthritis outcome score. An extension of the Western Ontario and McMaster Universities Osteoarthritis Index. Scand J Rheumatol. 2003;32(1):46-51.
2. Bellamy N, Buchanan W, Goldsmith C, Campbell J, Stitt LW. Validation Study of WOMAC: A Health Status Instrument for Measuring Clinically Important Patient Relevant Outcomes to Antirheumatic Drug Therapy in Patients with Osteoarhritis of the Hip or Knee. The Journal of Rheumatology. 1988;15(12):1833-1840.
3. Bellamy N. WOMAC Osteoarthritis User's Guide London, Ontario: Victoria Hospital; 1995.
4. Ware JE, Sherbourne CD. The MOS 36-Item Short-Form Health Survey (SF-36). Medical Care. 1992;30(6):473-483.
5. Nilsdotter AK, Lohmander LS, Klassbo M, Roos EM. Hip Disability and
Osteoarthritis Outcome Score (HOOS)- Validity and responsiveness in total
hip replacement. BMC Musculoskeletal Disorders. 2003;4:10