A brief symptom index for advanced renal cell carcinoma.
BACKGROUND
Our objective was to test a brief, symptom index for advanced renal cell carcinoma, a disease affecting over 38,000 Americans each year and often diagnosed in late stages.


METHODS
We conducted secondary data analyses on patient-reported outcomes of 209 metastatic renal cell carcinoma patients participating in a Phase III clinical trial. Patient-reported outcomes, obtained from the FACT-Biological Response Modifier (FACT-BRM) scale, were available at baseline, 2, and 8 weeks. We analyzed data from eight FACT-BRM items previously identified by clinical experts to represent the most important symptoms of advanced renal cell carcinoma. Items comprising this index assess nausea, pain, appetite, perceived sickness, fatigue and weakness, with higher scores indicating fewer symptoms. We determined reliability and validity of the index and estimated a minimally important difference.


RESULTS
The index had excellent internal reliability at all three time points (alphas > or = 0.83). Baseline scores were able to discriminate patients across Karnofsky performance status, number of metastatic sites, and risk group categories (ps < .01). Mean index scores declined over time likely indicative of the toxic nature of the administered treatments. Distribution- and anchor-based methods converged on a minimally important difference estimate of 2 to 3 points.


CONCLUSIONS
The 8-item index of patient-reported symptoms of renal cell carcinoma appears to be a psychometrically sound measure. It is a brief, reliable, and valid measure that can easily be adapted for use in clinical trials and observational studies.
Eton
David T
DT
Center on Outcomes, Research and Education, Evanston Northwestern Healthcare, 1001 University Place, Suite 100, Evanston IL 60201, USA. d-eton@northwestern.edu
Cella
David
D
Bacik
Jennifer
J
Motzer
Robert J
RJ
D000970:Antineoplastic Agents / Q000627:therapeutic use; D002292:Carcinoma, Renal Cell / Q000188:drug therapy / Q000503:physiopathology*; D017326:Clinical Trials, Phase III as Topic; D015897:Comorbidity; D023381:Endpoint Determination; D005260:Female; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use; D007167:Immunotherapy; D017567:Karnofsky Performance Status; D007680:Kidney Neoplasms / Q000188:drug therapy / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D011594:Psychometrics / Q000295:instrumentation* / Q000379:methods; D011788:Quality of Life; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D007155:Immunologic Factors