Validity and reliability of a new instrument to measure cancer-related fatigue in adolescents.

Adolescents undergoing treatment for cancer rate fatigue as their most prevalent and intense cancer- and treatment-related effect. Parents and staff rate it similarly. Despite its reported prevalence, intensity, and distressing effects, cancer-related fatigue in adolescents is not routinely assessed during or after cancer treatment. We contend that the insufficient clinical attention is primarily due to the lack of a reliable and valid self-report instrument with which adolescent cancer-related fatigue can be measured. Our aim was to determine the reliability and construct validity of a new instrument and its ability to measure change in fatigue over time. Initial testing involved 64 adolescents undergoing curative treatment of cancer who completed the Fatigue Scale-Adolescent (FS-A) at two to four key points in treatment in one of four studies. Internal consistency estimates ranged from 0.67 to 0.95. Validity estimates involving the FS-A with the parent version ranged from 0.13 to 0.76; estimates involving the staff version and the Reynolds Depression Scale were 0.27 and 0.87, respectively. Additional validity findings included significant fatigue differences between anemic and nonanemic patients (P=0.042) and the emergence of four factors in an exploratory factor analysis. Findings further indicate that the FS-A can be used to measure change over time (t=2.55, P<0.01). In summary, the FS-A has moderate to strong reliability and impressive validity coefficients for a new research instrument.

Three instruments to assess fatigue in children with cancer: the child, parent and staff perspectives.

The purpose of this study was to develop and test three instruments to measure fatigue in children with cancer from the perspectives of the child, parents and staff. The study consisted of three phases: instrument development, content validation, and estimations of psychometric properties of the three fatigue instruments. One hundred forty-nine children between the ages of 7-12 years presently receiving chemotherapy for cancer, 147 parents and 124 staff participated in this study. The instruments demonstrated strong initial validity and reliability estimates. This study is the first to provide valid and reliable instruments to measure fatigue in children with cancer.