The SF-36 is a 36-item generic health survey that produces eight health scales plus physical and mental component summary scores. This update reviews its construction, the improvements in version 2.0, and the psychometric evidence for its reliability and validity. It also describes the shorter SF-12 and international translation through the IQOLA Project.
When you see a patient-reported outcome in an orthopedic trial, the SF-36 is often the generic health measure being used. Know that it splits into two summaries: PCS for physical health and MCS for mental health.
For an orthopedic population, the physical scales (Physical Functioning, Role-Physical, Bodily Pain) are the responsive ones after joint replacement, so watch the PCS to gauge surgical benefit.
A key mental model: because norm-based scoring centers every scale at 50 with an SD of 10, a score below 50 means below-average health and every 10 points equals one standard deviation. This lets you read a profile at a glance.
The tradeoff to understand for study design: the SF-36 sacrifices about 10-20% of precision versus longer instruments but cuts respondent burden dramatically, which is why it dominates as a generic core measure. Remember its limits. As a generic tool it omits sexual function, sleep, and condition-specific symptoms, so it usually supplements rather than replaces a disease-specific score.
The SF-36 is a 36-item generic health survey that produces eight health scales plus physical and mental component summary scores. This update reviews its construction, the improvements in version 2.0, and the psychometric evidence for its reliability and validity. It also describes the shorter SF-12 and international translation through the IQOLA Project.
When you see a patient-reported outcome in an orthopedic trial, the SF-36 is often the generic health measure being used. Know that it splits into two summaries: PCS for physical health and MCS for mental health.
For an orthopedic population, the physical scales (Physical Functioning, Role-Physical, Bodily Pain) are the responsive ones after joint replacement, so watch the PCS to gauge surgical benefit.
A key mental model: because norm-based scoring centers every scale at 50 with an SD of 10, a score below 50 means below-average health and every 10 points equals one standard deviation. This lets you read a profile at a glance.
The tradeoff to understand for study design: the SF-36 sacrifices about 10-20% of precision versus longer instruments but cuts respondent burden dramatically, which is why it dominates as a generic core measure. Remember its limits. As a generic tool it omits sexual function, sleep, and condition-specific symptoms, so it usually supplements rather than replaces a disease-specific score.