Interpreting differences in quality of life: the FACT-H&N in laryngeal cancer patients
Ringash, Jolie; Bezjak, Andrea; O'Sullivan, Brian; Redelmeier, Donald A.
Quality of Life Research
UNLABELLED: Quality of life (QOL) scores can be difficult to interpret, because small statistically significant differences can be clinically unimportant. Our goal was to estimate the magnitude of difference in QOL that is noticeable to patients. METHODS: Laryngeal cancer patients (n = 98, male = 83%, mean age = 65) completed a QOL questionnaire, FACT-H&N. Paired participants rated their own QOL as compared to each other. We estimated the smallest difference in QOL score that was associated with a noticeable difference in patients’ subjective ratings. RESULTS: Differences in FACT-H&N score were somewhat correlated with patients’ ratings of their well-being relative to other patients (r = 0.195, p < 0.0001). The FACT-H&N score had to differ by 6.22 for patients to rate themselves as 'a little bit better' relative to other patients (95% CI: 1.42-11.02), and by 12.40 for patients to rate themselves as 'a little bit worse' relative to others (95% CI: 5.09-19.71). Results were consistent regardless of patient age, gender or laryngeal subsite but were imperfect predictors of individual judgements. CONCLUSION: The minimal important difference for the FACT-H&N score is about 6-12 units, but laryngeal cancer survivors may be more sensitive to gains than losses.