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
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  and by questioning 90 patients undergoing total hip replacement
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) .
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
 and expected correlations were found .
HOOS responsiveness has been determined in one study (n=90) after total
hip replacement . 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
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  
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
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