This prospective cohort study of 1,335 Danish THA patients established specific cut-points for two key PRO benchmarks at 1 year: the minimal clinically important improvement (MCII) and the patient-acceptable symptom state (PASS). The study addresses a practical gap: statistically significant PRO changes after THA do not automatically signal meaningful improvement to patients. These cut-points apply to the HOOS (Pain, Physical Function, Quality of Life subscales) and EQ-5D, the most commonly used outcome tools in hip arthroplasty registries.
When a THA patient's HOOS Pain score improves by 10 points, is that a success? Without a clinical anchor, it is impossible to say.
This study gives you the numbers to answer that question: an improvement of at least 24 HOOS Pain points is the minimum that patients themselves consider meaningful (MCII), and a postoperative score of at least 91 is required for patients to feel their symptoms are in an acceptable state (PASS).
Two methodologic distinctions matter for applying these thresholds. MCII should be adjusted for baseline severity — a patient starting at HOOS Pain 20 needs a larger improvement than one starting at 60 to reach the same perceptual threshold. PASS, by contrast, is fixed at 91 regardless of where the patient started, making it a cleaner benchmark for registry comparisons.
For boards and for registry interpretation, the core concept is that statistical significance and clinical meaningfulness are not the same thing. A 10-point improvement may reach p<0.05 in a large cohort study while falling well short of what any individual patient would notice. These cut-points are the tool for translating group-level statistics into patient-level meaning.
This prospective cohort study of 1,335 Danish THA patients established specific cut-points for two key PRO benchmarks at 1 year: the minimal clinically important improvement (MCII) and the patient-acceptable symptom state (PASS). The study addresses a practical gap: statistically significant PRO changes after THA do not automatically signal meaningful improvement to patients. These cut-points apply to the HOOS (Pain, Physical Function, Quality of Life subscales) and EQ-5D, the most commonly used outcome tools in hip arthroplasty registries.
When a THA patient's HOOS Pain score improves by 10 points, is that a success? Without a clinical anchor, it is impossible to say.
This study gives you the numbers to answer that question: an improvement of at least 24 HOOS Pain points is the minimum that patients themselves consider meaningful (MCII), and a postoperative score of at least 91 is required for patients to feel their symptoms are in an acceptable state (PASS).
Two methodologic distinctions matter for applying these thresholds. MCII should be adjusted for baseline severity — a patient starting at HOOS Pain 20 needs a larger improvement than one starting at 60 to reach the same perceptual threshold. PASS, by contrast, is fixed at 91 regardless of where the patient started, making it a cleaner benchmark for registry comparisons.
For boards and for registry interpretation, the core concept is that statistical significance and clinical meaningfulness are not the same thing. A 10-point improvement may reach p<0.05 in a large cohort study while falling well short of what any individual patient would notice. These cut-points are the tool for translating group-level statistics into patient-level meaning.