Measurement properties of the 12-item Short-Form Health Survey in stroke

• Background: The 12-item Short-Form Health Survey (SF-12) was developed to measure perceived physical and mental health. Some studies of the psychometric properties, using classical test theory, of the SF-12 provide support for its use in patients with stroke, but it has not been scrutinized using recommended modern test theory approaches such as the Rasch measurement model among stroke survivors.Objectives: This study sought to explore the measurement properties of the SF-12 physical and mental health scales among people with stroke using the Rasch measurement model.Design: A cross-sectional design was used in this study.Methods: All patients discharged from a dedicated stroke unit in southern Sweden during 6 months were asked to participate 6 months later. Of 120 stroke survivors, 89 (74%) agreed to participate. Rasch analysis was used to assess the measurement properties of the SF-12 physical and mental component summary scores (PCS-12 and MCS-12, respectively).Results: For the PCS-12, we identified problems with targeting, overall and item-level fit, representing local response dependency, and multidimensionality. For the MCS-12, there were problems related to targeting (the persons felt better than the scale could conceptualize) and response categories that did not function as expected. However, MCS-12 items displayed reasonable model fit without indications of multidimensionality but with signs of local response dependency.Conclusion: The measurement properties of the MCS-12 in stroke appear reasonable unless milder mental health problems are of interest, whereas those of the PCS-12 are less acceptable. Given the interdependence between MCS-12 and PCS-12 that is inherent with the standard SF-12 scoring algorithm, such data should be interpreted with caution.

Subject headings

MEDICAL AND HEALTH SCIENCES  -- Health Sciences -- Nursing (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Hälsovetenskaper -- Omvårdnad (hsv//swe)

MEDICIN OCH HÄLSOVETENSKAP  -- Hälsovetenskaper (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Health Sciences (hsv//eng)

Keyword

classical test theory

health measurement

patient-reported outcomes

Rasch analysis

stroke

SF-12

01376517-201402000-00005

Publication and Content Type

ref (subject category)

art (subject category)