Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2010 Jul:1:119-26.
doi: 10.2147/PROM.S10621. Epub 2010 Sep 23.

Meta-analysis provides evidence-based interpretation guidelines for the clinical significance of mean differences for the FACT-G, a cancer-specific quality of life questionnaire

Madeleine T King  1 , David Cella, David Osoba, Martin Stockler, David Eton, Joanna Thompson, Amy Eisenstein
Affiliations

Meta-analysis provides evidence-based interpretation guidelines for the clinical significance of mean differences for the FACT-G, a cancer-specific quality of life questionnaire

Madeleine T King et al. Patient Relat Outcome Meas. 2010 Jul.

Abstract

Our aim was to develop evidence-based interpretation guidelines for the Functional Assessment of Cancer Therapy-General (FACT-G), a cancer-specific health-related quality of life (HRQOL) instrument, from a range of clinically relevant anchors, incorporating expert judgment about clinical significance. Three clinicians with many years' experience managing cancer patients and using HRQOL outcomes in clinical research reviewed 71 papers. Blinded to the FACT-G results, they considered the clinical anchors associated with each FACT-G mean difference, predicted which dimensions of HRQOL would be affected, and whether the effects would be trivial, small, moderate, or large. These size classes were defined in terms of clinical relevance. The experts' judgments were then linked with FACT-G mean differences, and inverse-variance weighted mean differences were calculated for each size class. Small, medium, and large differences (95% confidence interval) from 1,118 cross-sectional comparisons were as follows: physical well-being 1.9 (0.6-3.2), 4.1 (2.7-5.5), 8.7 (5.2-12); functional well-being 2.0 (0.5-3.5), 3.8 (2.0-5.5), 8.8 (4.3-13); emotional well-being 1.0 (0.1-2.6), 1.9 (0.3-3.5), no large differences; social well-being 0.7 (-0.7 to 2.1), 0.8 (-2.9 to 4.5), no large differences. Results from 436 longitudinal comparisons tended to be smaller than the corresponding cross-sectional results. These results augment other interpretation guidelines for FACT-G with information on sample size, power calculations, and interpretation of cancer clinical trials that use FACT-G.

Keywords: health-related quality of life; patient-reported outcomes.

PubMed Disclaimer

References

    1. Cella D, Bullinger M, Scott C, Barofsky I, Clinical Significance Consensus Meeting Group Group versus individual approaches to understanding the clinical significance of difference or changes in quality of life. Mayo Clin Proc. 2002;77:384–392. - PubMed
    1. Guyatt G, Osoba D, Wu AW, Wyrwich KW, Norman GR, Clinical Significance Consensus Meeting Group Methods to explain the clinical significance of health status measures. Mayo Clin Proc. 2002;77:371–383. - PubMed
    1. Osoba D, King MT. Interpreting quality of life in individuals and groups: meaningful differences. In: Fayers PM, Hays RD, editors. Assessing quality of life in clinical trials: Methods and practice. 2nd ed. Oxford, UK: Oxford University Press; 2005. pp. 243–257.
    1. Aaronson NK, Ahmedzai S, Bergman B, et al. The European Organization for Research and Treatment of Cancer : a quality-of-life instrument for use in international clinical trials in oncology. J Natl Cancer Inst. 1993;85:365–376. - PubMed
    1. Cella DF, Tulsky DS, Gray G, et al. The functional assessment of cancer therapy scale: development and validation of the general measure. J Clin Oncol. 1993;11(3):570–579. - PubMed