Hip Disability and Osteoarthritis Outcome Score

Hip Disability With or Without Hip OA (Full Scale): (Nilsdotter, 2011)

• SEM for group (full scale range) = 3.7 – 6.94

Osteoarthritis patients undergoing total hip replacement (THR): (Gojło & Paradowski, 2020; n = 157; Mean Age (at hip replacement) = 66.8 (11.1); assessment administered 3 times: pre-THR, 1 year post THR (n = 95), and again a mean of 10.8 days after that (n = 77); HOOS translated and culturally adapted into Polish)

• SEM for test-retest group sub tests (n = 77)
  • Pain = 9.46
  • Symptoms = 5.41
  • ADL = 4.32
  • Sports/Rec = 8.82
  • QoL = 7.00

Hip Disability with or without Hip OA: (Nilsdotter, 2011)

• MDC95 = 10.3 - 19.2

Clinically Diagnosed Primary Hip OA (Ornetti et al., 2010; n = 88: Medicine group (no indication for joint replacement), n = 58, Mean Age (SD) = 61.8 (9), age range = 42-81 years, female = 70%; Surgery Group (waiting for THR, n = 30, Mean Age (SD) = 67.5 (9), age range = 50-81, female = 68%; Assessment administered prior to intervention and once again 2 weeks to 3 months later; HOOS translated and culturally adapted into French).

• MDC for HOOS subscales:
  • Pain = 15.1
  • Symptoms = 10.5
  • ADLs = 9.6
  • Sports/rec = 15.5
  • QoL = 16.2

Hip Disability with or without Hip OA (Emara et al., 2024; n = (4,161; Mean Age = 65.0 years (patients w/osteoarthritis (OA): n = 3,613; mean age = 66.0 years; patients w/o arthritis (non-OA): n = 548, mean age = 58 years); Patients underwent primary total hip arthroplasty from January 2016 to December 2018 and completed a one-year follow up).

• MCID thresholds were slightly higher in the non-OA cohort
  • HOOS-Pain: OA: 8.35 vs. non-OA: 8.85 points
  • HOOS-Physical Short Form (PS): OA: 9.47 vs. non-OA: 9.90 points
  • HOOS-Joint Replacement (JR): OA: 7.76 vs. non-OA: 8.46 points

Hip Disability with or without Hip OA (Emara et al., 2024)

• >91 indicates a favorable outcome for one-year patient acceptable symptom state (PASS)

Clinically Diagnosed Primary Hip OA: (Ornetti et al., 2010)

• Acceptable test-retest reliability for all HOOS scales (n = 43):
  • Pain (ICC = 0.83)
  • Symptoms (0.84)
  • ADLs (0.86)
  • Sports/Rec (0.89)
  • QoL (0.86)

Hip Disability With or Without Hip OA: (Nilsdotter, 2011)

• Acceptable test-retest reliability for HOOS subscales: (ICC = 0.75 – 0.97)

Hip Osteoarthritis: (Singh et al., 2014; n = 195 (141 knee OA, 54 hip OA), completed questionnaires at baseline and at 2-week follow-up

• Acceptable test-retest reliability for HOOS-PS scale (n = 54): (ICC = 0.82)

Clinically Diagnosed Primary Hip OA: (Ornetti et al., 2010)

• Excellent: Cronbach’s alpha ≥ 0.8 for Pain (0.86), ADLs (0.94), Sport/Rec (0.85), and QoL (0.82)
• Poor: Cronbach’s alpha < 0.7 for Symptoms (0.66)

Hip Disability With or Without Hip OA: (Nilsdotter, 2011)

• Excellent internal consistency for HOOS scales: (α = 0.82 – 0.98) 

Concurrent Validity:

Hip Pain: (Bergman et al., 2024; n = 2,782; mean age = 55.54 (18.9); male = 1056 (38.9%), female = 1659 (59.6%), sex not recorded = 67 (2.4%); patients at initial evaluation with a hip preservation specialist; 504 patients reported a prior history of surgery)

• Adequate correlation between HOOS and Single Assessment Numerical Evaluation (SANE) (r = -0.55; 95% CI -0.51 to -0.58; p < 0.001). The HOOS was recorded as a lower score, indicating better function, which accounts for the negative r values 

Hip Osteoarthritis: (Riglet et al., 2025; n = 124; Mean Age (SD) = 61.4 (7.9), female = 73, age range = 40 to 80 years, unilateral primary symptomatic OA of radiological stage II, III, or IV with no indication for a total hip replacement (Lequesne index < 10), Traj1 (progressor) = higher disease severity at baseline with rapid decline in functional capacity, Traj2 (non-progressor) = low to moderate disease severity with stable scores) 

• For HOOS symptoms/stiffness, gait speed was found to be predictive of Traj1 (OR = 0.61, 95% CI: 0.45 to 0.83, AUC = 75%).
• For pain, gait speed (OR = 0.72, 95% CI: 0.53 to 0.97, AUC = 72%) and baseline HOOS pain (OR = 1.07, 95% CI: 1.03 to 1.11, AUC = 81%) were found to be predictive of Traj1.
• Baseline HOOS function in ADL score was the best predictive factor for Traj1 (OR = 1.13, 95% CI: 1.07 to 1.18, AUC = 91%).

• Baseline QoL HOOS (OR = 1.04, 95% CI: 1.02 to 1.07, AUC = 78%), along with KL radiological grading III/IV vs II (OR = 6.19, 95% CI: 2.02 to 18.97, AUC = 61%) and hip extension (OR = 0.84, 95% CI: 0.73 to 0.95, AUC = 66%) were simultaneously predictive of Traj1. 

   

Convergent validity:

Clinically Diagnosed Primary Hip OA: (Ornetti et al., 2010)

• Adequate to Excellent correlations between HOOS subscales and the visual analog scale for pain (VAS) and Lequesne’s Index (n = 32)

Correlations between HOOS subscales and the VAS for pain and Lequesne's Index (n = 32) 

Measured level of importance of each item to the patient, ranked unimportant, important, and very important (Klassbo, 2003).

Face validity for the Persian translation of the HOOS was determined by orthopedic researchers through probing techniques that ensured items were understood by participants. Acceptable validity was determined through adequate responses to probing questions (Mousavian et al., 2018).

After reviewing and evaluating various outcome measures used after osteoarthritis, HOOS was found to have face validity that was implicitly established through the involvement of patients in both the item creation and item relevance rating process, as well as the measures' subsequent use in clinical settings (Mohtadi et al., 2011).

Clinically Diagnosed Primary Hip OA: (Klassbo et al., 2003)

• Poor: 38% of items with a floor effect

Clinically Diagnosed Primary Hip OA: (Ornetti et al., 2010)

• Adequate ceiling effect of 17.8% for the Sport/rec subscale in the Surgery group prior to surgery (Note: additional evaluation revealed this ceiling effect disappeared following surgery)  

Hip Disability with or without Hip OA: (Nilsdotter, 2011)

• Adequate floor effects are more common on the Sports/Rec subscale where worst possible scores have been reported to range from 4.1 – 17.8% in subjects eligible for THR 

Clinically Diagnosed Primary Hip OA: (Ornetti et al., 2010)

• Moderate to Large effect size for the Medical group (SRM = 0.51 to 1.04, Effect size 0.73 – 1.86)
  • The change in the Sport/rec subscales appeared to be less than the other scales
• Large effect size for the Surgery group (SRM = 1.97 to 3.24, Effect size 1.47 – 2.08)
  • The QoL domain appeared to be less responsive than the other scales

Primary Hip OA Assigned to Hip Replacement Surgery: (Nilsdotter et al., 2003; n = 90, Mean Age= 71.5; assessment assigned pre and 6 months post THR).

• SEM for Group; Full Scale range: 4.78 – 10.07

Hip Arthroscopic Surgery for Intra-Articular Hip Lesions: (Kemp et al., 2013; n = 100 [surgery, n = 50; control, n = 50]; Surgery group: Mean Age (SD) = 37.4 (11.3), age range = 18-57, female = 51%, Undergone hip arthroscopic surgery 12 to 24 months previously and pain-free; Control group: Mean Age (SD) = 35.2 (11.0), age range = 19-55, female = 78%, exclusions: hip pain in the past 6 months, previous hip surgery, low back pain or other lower limb injuries).

• SEM for HOOS subscales for entire group (n = 100):
  • Pain: 3
  • Symptoms: 5
  • ADL: 3
  • Sports/Rec: 6
  • QoL: 5

Primary Hip OA Assigned to Hip Replacement Surgery

• MDC for Group; Full Scale range: MDC95 = 13.2 – 27.9 (Nilsdotter et al., 2003)

Hip Arthroscopic Surgery for Hip Intra-Articular Hip Lesions: (Kemp et al., 2013)

• MDC95 for HOOS subscales (n = 100):
  • Pain = 10
  • Symptoms = 14
  • ADLs = 9
  • Sports/Rec = 17
  • QoL = 15

Hip Arthroplasty: (Pasqualini et al., 2024; n = 1,613; Mean Age (SD) = 54 (8.8) years; Men who underwent Birmingham Hip Resurfacing (BHR) at a single academic institution between October 28, 2015, and May 3, 2022, with one-year follow-up).

• MCID for HOOS Pain (n = 1613): 9.2 (achieved by > 95% of patients)
• MCID for HOOS Physical Function Short Form (PS) (n = 1613): 9.3 (achieved by nearly 90% of patients)

Total Hip Replacement: (Lyman, 2018; n = 2630; Mean Age (SD) = 73 (6); Medicare patients that underwent THA at the Hospital for Special Surgery Joint Replacement Registry between May 2007 and April 2012)

Distribution- and Anchor-based MCID values for HOOS Subscales and HOOS Jr.

Total Hip Arthroplasty: (Weber et al., 2019 n=126; Mean Age (SD) = 61.6 (71.4) years; assessed preoperatively and at 1 year post surgery)

• < 40.3 on the preoperative HOOS indicates a high probability of a positive postoperative response (sensitivity 91.7%; specificity 68.9%)

Hip Arthroplasty with Mild to Moderate and Severe Hip OA (de Groot et al., 2007; THR group n = 68; Mean Age = 62.5; Mean duration after THR was 9.5 months).

• Acceptable to Excellent test-retest reliability: (ICC for Full scale range = 0.78 - 0.91)

Hip Arthroscopic Surgery for Intra-Articular Hip Lesions: (Kemp et al., 2013)

• Excellent test-retest reliability for HOOS subscales:
  • Pain (ICC = 0.96)
  • Symptoms (0.93)
  • ADLs (0.96)
  • Sports/Rec (0.93)
  • QoL (0.95)

OA Patients Undergoing Total Hip-Replacement Surgery: (Gojło and Paradowski, 2020; n = 157; mean age = 66.8 (11.1) years, age range = 25-87 years; assessed at follow-up, twice, test-retest interval = 1 to 3 weeks; Polish translation of HOOS)

• Acceptable to Excellent test-retest reliability: (ICC values range from 0.82 to 0.96)

Pre and Post Total Hip Replacement (Davis et al., 2009; n = 201, Mean Age (SD) = 62.3(12.1) years, HOOS-PS assessment administered before THR and again 6 months post THR).

• Adequate for THR group: (α = 0.79)

Hip Arthroplasty with Mild to Moderate and Severe Hip OA: (de Groot, 2007)

• Adequate to Excellent for Full scale: (α = 0.75 - 0.97)

Hip Arthroscopic Surgery for Intra-Articular Hip Lesions: (Kemp et al., 2013, n = 100)

• Excellent internal consistency for all HOOS subscales (α)
  • Pain (0.93)
  • Symptoms (0.91)
  • ADL (0.96)
  • Sports/Rec (0.96)
  • QOL (0.95)

OA Patients Undergoing Total Hip-Replacement Surgery: (Gojło and Paradowski, 2020)

• Adequate to Excellent internal consistency at baseline: (Cronbach’s α range from 0.76 to 0.95)
• Excellent internal consistency at follow-up: (Cronbach’s α range from 0.87 to 0.97)

Convergent validity:

Pre and Post Total Hip Replacement: (Davis et al., 2009)

• Excellent correlations between HOOS-PS (short form) and:
  • Physical function (r = 0.90)
  • Physical function exclusion (0.86)
  • WOMAC pain (0.70)
• Adequate correlations between HOOS-PS (short form) and:
  • Chronic pain grade (r = 0.56)
  • POMS fatigue (0.38)
  • HADS depression (0.36)
• Poor correlation between HOOS-PS (short form) and HADS anxiety (r = 0.19) 

Primary Hip OA Assigned to Hip Replacement Surgery: (Nilsdotter et al., 2003; n = 90, mean age = 71.5 years, age range = 49-85 years, assessment completed pre and six months post THR) 

• Excellent correlations between HOOS subscales and SF-36 subscales:
  • HOOS ADL and SF-36 Physical function (r = 0.66)
  • HOOS ADL and SF-36 Bodily pain (r = 0.62)
  • HOOS Pain and SF-36 Bodily pain (r = 0.61)
• Adequate correlations between HOOS subscales and SF-36 subscales:
  • HOOS Sport/Rec and SF-36 Physical function (r = 0.49)
  • HOOS QoL and SF-36 Bodily pain (r = 0.56)
  • HOOS Pain and SF-36 Physical function (r = 0.52)

Primary Hip OA Assigned to Total Hip Replacement: (Nilsdotter et al., 2003)

• A subgroup (n = 26) of patients were asked to rank the relevance or importance of the questions on the HOOS to their condition on a scale of 1 (irrelevant, unimportant) to 3 (very relevant, very important)
  • It was considered that for inclusion in the HOOS, the mean relevance of items should be at least 2 and that at least 67% of patients grade the item as being at least somewhat important

Face validity was determined by a group of musculoskeletal professionals to provide accurate results. This was determined through anchor-based calculations of the MCID (Lyman et al., 2018).

Hip Arthroplasty with Mild to Moderate and Severe Hip OA: (de Groot, 2007)

• Adequate floor effect of 5.1% floor for Sports/Rec subscale adequate

Primary Hip OA Assigned to Hip Replacement Surgery: (Nilsdotter et al., 2003)

Preoperative:

• Adequate floor effects for HOOS scales:
  • Sports/Rec function (13.3%)
  • QOL (4.4%)
  • Symptoms (2.2%)
• Adequate ceiling effect for the Symptoms subscale (1.1%)

Postoperative:

• Excellent: no floor effects for any of the HOOS subscales
• Adequate ceiling effects for HOOS scales:
  • Pain scale (19%)
  • Symptoms scale (10%)
  • ADLs (5%)
  • Sports/Rec (9%)
  • Hip related QOL (9%) 

Hip Arthroscopic Surgery for Intra-Articular Hip Lesions: (Kemp et al., 2013)

• Adequate ceiling effect of 16% for HOOS Sports/Rec scale
• Poor ceiling effect of 28% for HOOS ADL scale

Pre and Post Total Hip Replacement: (Davis et al., 2009)

• Large responsiveness for HOOS-PS: (SRM = 1.5)

Primary Hip OA Assigned to Hip Replacement Surgery: (Nilsdotter et al., 2003)

• Large Change in standardized response means (SRM) for all HOOS subscales (greater responsiveness when compared to the WOMAC):
  • Pain (SRM = 2.11)
  • Symptoms (1.83)
  • Sports/Rec (1.29)
  • QoL (1.64)
• Large Change in SRMs for WOMAC subscales:
  • Pain (SRM = 1.83)
  • Stiffness (1.28)
• Higher SRM for all 5 HOOS subscales for individuals ≤ 66 years old (n = 17) compared to individuals > than 66 years old (n = 47) (Note: Large responsiveness for both groups)
  • Pain (2.60 vs 1.97)
  • Symptoms (3.05 vs 1.60)
  • ADL (2.51 vs 1.52)
  • Sports/Rec (1.53 vs 1.21)
  • Hip-related QoL (1.95 vs 1.57)