The HHS was developed for the assessment of the results of hip surgery, and is intended to evaluate various hip disabilities and methods of treatment in an adult population. The original version was published 1969. The HHS is a clinician-based outcome measure administered by a qualified health care professional, such as a physician or a physical therapist.
Total hip replacement (THR), femoral neck fractures and osteoarthritis.
The domains covered are pain, function, absence of deformity, and range of motion. The pain domain measures pain severity and its effect on activities and need for pain medication.
The function domain consists of daily activities (stair use, using public transportation, sitting, and managing shoes and socks) and gait (limp, support needed, and walking distance). Deformity takes into account hip flexion, adduction, internal rotation, and extremity length discrepancy. Range of motion measures hip flexion, abduction, external and internal rotation, and adduction.
There are 10 items. The score has a maximum of 100 points (best possible outcome) covering pain (1 item, 0–44 points), function (7 items, 0–47 points), absence of deformity (1 item, 4 points), and range of motion (2 items, 5 points).
No formal training is necessary. Data calculating can be performed automatically during data processing using computer-based algorithms. Takes 5 minutes to complete.
Thirty-eight (31 men) individuals who had undergone THR operations due to traumatic arthritis were the first patients who were evaluated with the HHS. The items were generated based on the opinion by experts that pain and functional capacity are the 2 basic considerations. They were the indications for surgery and hence received the heaviest weighting: 91 of 100 points. Wamper et al report unacceptable ceiling effects in 31 of 59 studies. Pooled data across the studies included (n = 6,667 patients) suggested ceiling effects of 20% (95% confidence interval 18–22).
HHS responsiveness has been determined in a study of 335 THRs. The effect size between preoperative and 6-months postoperative was excellent for pain (2.80) and function (1.72), but weak in the 2-years followup, i.e., pain (0.15) and function (0.18). When comparing the HHS, Barthel Index, and EuroQol 5-domain (EQ-5D) in patients with femoral neck fractures 4 and 12 months after surgery, the standardized response mean was 0.75 for HHS, 0.40 for Barthel Index, and 0.46 for EQ-5D.
Cronbach's alpha coefficient showed high internal consistency reliability except for deformity, which could not be calculated.
The test–retest interval was 3 to 4 weeks. The total score reliability was excellent for physicians (r = 0.94) and physiotherapists (r = 0.95). The physiotherapist and the orthopedic surgeon showed excellent test–retest reliability in the domains of pain (r = 0.93 and r = 0.98, respectively) and function (r = 0.95 and r = 0.93, respectively). The calculations were done with Pearson's and Spearman's correlation coefficients.
The interrater correlations were good to excellent (0.74–1.0) for the domain scores in Söderman's study, as well as in study by Kirmit et al.