Quality of life in low-income patients with metastatic prostate cancer: Divergent and convergent validity of three instruments

L. K. Sharp*, S. J. Knight, R. Nadler, M. Albers, E. Moran, T. Kuzel, R. Sharifi, C. Bennett

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


Few studies have evaluated Quality Of Life (QOL) among low-income patients with cancer. Information is needed about the feasibility and psychometric characteristics of QOL instruments in these populations. The purpose of this study was to examine the convergent and discriminant relationships between scales of three QOL instruments: European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC), Functional Assessment of Cancer Therapy - General (FACT), and Quality of Life Index (QLI). Participants included 110 men with metastatic prostate cancer of whom 94% were low income and 62% were African-American. Interviewers administered the questionnaires. Cronbach α internal consistency reliabilities were 0.57 to 0.90 for the EORTC, 0.65 to 0.86 for the FACT, and 0.63 for the QLI. Convergent validity was supported for the EORTC and FACT scales measuring emotional, physical, and role/functional dimensions (r = 0.54 to 0.72), but not on scales measuring social function (r = 0.12). Divergent validity was supported between dissimilar scales (r = 0.14 to 0.38). Analysis with receiver operating characteristics curves provided empirical support for the EORTC and FACT as multidimensional measures. These findings suggest that, even in busy clinical settings with low literacy patients, interviewer-administered EORTC and FACT QOL instruments can provide valid and reliable information.

Original languageEnglish (US)
Pages (from-to)461-470
Number of pages10
JournalQuality of Life Research
Issue number5
StatePublished - 1999


  • Blacks
  • Metastatic disease
  • Prostatic neoplasms
  • Quality of life
  • Socioeconomic factors

ASJC Scopus subject areas

  • Public Health, Environmental and Occupational Health


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