Quality of life measurement after stroke: uses and abuses of the SF-36

Stroke. 2002 May;33(5):1348-56. doi: 10.1161/01.str.0000015030.59594.b3.

Abstract

Background and purpose: The Medical Outcomes Study 36-item Short-Form Health Survey (SF-36) is widely used to measure health status after stroke. However, a fundamental assumption for its valid use after stroke has not been comprehensively tested: is it legitimate to generate scores for 8 scales and 2 summary measures using the standard algorithms? We tested this assumption.

Methods: SF-36 data from 177 people after stroke were examined (71% male; mean age, 62). We tested 6 scaling criteria to determine the legitimacy of generating the 8 SF-36 scale scores using Likert's method of summed ratings, and we tested 2 scaling criteria to determine the appropriateness of the standard SF-36 algorithms for weighting and combining scale scores to generate 2 summary measures (physical and mental).

Results: Scaling assumptions were fully satisfied for 6 of the 8 scales, but 3 of these 6 scales had notable floor and/or ceiling effects. Assumptions for generating 2 SF-36 summary measures were not satisfied.

Conclusions: In this sample, 5 of the 8 SF-36 scales had limited validity as outcome measures after stroke, and the reporting of physical and mental summary scores was not supported. Results raise questions about the use of the SF-36 in stroke, and the SF-12 that is developed from it, and highlight the importance of testing scaling assumptions when applying existing scales to new populations.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Female
  • Hospitals, County / statistics & numerical data
  • Hospitals, University / statistics & numerical data
  • Hospitals, Urban / statistics & numerical data
  • Hospitals, Veterans / statistics & numerical data
  • Humans
  • Indiana
  • Male
  • Middle Aged
  • Outcome Assessment, Health Care / methods*
  • Quality of Life*
  • Reproducibility of Results
  • Sickness Impact Profile*
  • Stroke Rehabilitation*
  • Surveys and Questionnaires / standards*