Quality of life scores differed according to mode of administration in a review of three major oncology questionnaires.
OBJECTIVE
To assess whether scores on the three major quality-of-life questionnaires in oncology (FACT-G, FLIC, and EORTC QLQ-C30) are associated with modes of administration in a realistic clinical research setting.


METHODS
A heterogeneous sample of 1,265 cancer patients was recruited in Singapore. About one-fourth of the patients chose to have the interview administered by research staff; the rest self-completed the questionnaires. Multiple regression was used to adjust for differences in demographic and clinical characteristics between patients. An equivalence margin was defined as 0.25 standard deviations.


RESULTS
Apart from one exception (the EORTC QLQ-C30 global functioning scale), all scales showed higher mean values in patients who were interviewed than patients who self-administered the questionnaires. For the physical and functional well-being scales of FACT-G and the physical and social functioning scales of EORTC QLQ-C30, the differences were small and the confidence intervals fell totally within the equivalence zone. The emotional well-being score of the FACT-G was different across modes of administration and the confidence interval fell outside the equivalence zones. There was no interaction between modes of administration and respondents' education level.


CONCLUSIONS
The physical aspect of quality-of-life is not sensitive to interviewer administration but the psychological aspect is. Statistical adjustment for some scales is recommended.
Cheung
Yin Bun
YB
MRC Tropical Epidemiology Group, Room 305a, IDEU, ITD, London School of Hygiene & Tropical Medicine, London WC1E 7HT, United Kingdom. yinbun.cheung@lshtm.ac.uk
Goh
Cynthia
C
Thumboo
Julian
J
Khoo
Kei-Siong
KS
Wee
Joseph
J
D000328:Adult; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000523:psychology / Q000628:therapy*; D015588:Observer Variation; D011237:Predictive Value of Tests; D011788:Quality of Life; D011795:Surveys and Questionnaires; D016896:Treatment Outcome