Determining the clinical significance of the improvement in health-related quality of life (HRQoL) measures in oncology patients

Abstract

20622 Background: Cancer-related fatigue is gaining importance as an outcome measure. Perform Questionnaire (PQ) is a recently developed and validated scale for the assessment of perceptions about chronic renal failure (CRF). The minimally important difference (MID) that implies a clinically meaningful outcome has been determined to enable better interpretation of the observed numerical differences in PQ. Methods: In an observational, longitudinal, multicentre study in cancer patients with CRF, data (demographics, haemoglobin (Hb) levels, and HRQoL measures (PQ and FACT-F) were collected at inclusion and 3 months later. An Hb increase of 1g/dL was considered as the minimally important clinical change by which to evaluate HRQoL results. ‘Improved’ patients were those who experienced an increase in Hb≥1g/dL. ‘Stable’ patients had a change in Hb<1g/dL to a lower limit of -1g/dL. The difference in the mean HRQoL change score between the two groups was the MID of the measurement; MID was determined for PQ and FACT-F. Results: In total, 288 patients were included; 34.6% had breast cancer, 12% colon cancer, 12% lung cancer; 28.4% had anaemia (Hb<11g/dL). At 3 months, 87 patients (30.2%) improved while 201 (69.8%) remained stable; the difference in mean change in Hb level between stable and improved patients was 2.09g/dL. Pearson’s correlation between Hb level and PQ score at baseline was 0.24. Conclusions: MID can be useful to help interpret HRQoL score changes. An improvement of approximately 4 and 3 in PQ and FACT-F, respectively, can be considered as MIDs when an Hb≥1g/dL is seen as the minimally important clinical change. # items Theoretical range in questionnaire score Mean change (SD) of score in stable patients (N=87) Mean change (SD) of score in improved patients (N=201) MID PQ 12 12 (worse) - 60 (better) 0.03 (12.69) 3.72 (10.22) 3.69 FACT-F 13 13 (better) - 65 (worse) -0.87 (11.14) -3.64 (9.66) 2.77 No significant financial relationships to disclose.