RESUMEN
OBJECTIVES: To identify associations between frailty and non-response to follow-up questionnaires, in a longitudinal head and neck cancer (HNC) study with patient-reported outcome measures (PROMs). MATERIALS AND METHODS: Patients referred with HNC were included in OncoLifeS, a prospective data-biobank, underwent Geriatric Assessment (GA) and frailty screening ahead of treatment, and were followed up at 3, 6, 12 and 24 months after treatment using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 and Head and Neck 35. Statistical analysis for factors associated with non-response was done using Generalized Linear Mixed Models. RESULTS: 289 patients were eligible for analysis. Mean age was 68.4 years and 68.5% were male. Restrictions in Activities of Daily Living [OR 4.46 (2.04-9.78)] and Instrumental Activities of Daily Living [OR 4.33 (2.27-8.24)], impaired mobility on Timed Up and Go test [OR 3.95 (1.85-8.45)], cognitive decline [OR 4.85 (2.28-10.35)] and assisted living (OR 5.54 (2.63-11.67)] were significantly associated with non-response. Frailty screening, with Geriatric 8 and Groningen Frailty Indicator, was also associated with non-response [OR, respectively, 2.64 (1.51-4.59) and 2.52 (1.44-4.44)]. All findings remained significant when adjusted for other factors that were significantly associated with non-response, such as higher age, longer study duration and subsequent death. CONCLUSION: Frail HNC patients respond significantly worse to follow-up PROMs. The drop-out and underrepresentation of frail patients in studies may lead to attrition bias, and as a result underestimating the effect sizes of associations. This is of importance when handling and interpreting such data.
