Development of a self-reported version of the G8 screening tool

Introduction: The G8 is a widely used frailty screening tool in patients with cancer that was designed to be completed by healthcare professionals. A patient-reported version would enable a broader application. Aim of this study was to develop a self-reported version of the G8 and to assess its agreement with the original G8. Materials and Methods: A self-reported version of the G8 was developed with the aid of communication specialists. Patients aged ≥ 70 years from two different study populations were included: 1. Patients with cancer and 2. Patients visiting the geriatric outpatient clinic. The original G8 was completed by an oncology nurse or clinical research assistant and patients completed the self-reported G8. Patients were blinded to results of the original G8. Kappas were calculated to measure the agreement between the self-reported and original G8 for both the individual items as well as for the cut-off for potential frailty (≤14). Results: 161 patients participated, of whom 104 had cancer (65%). Patients with cancer more frequently completed all items than geriatric patients (all items completed in 94% versus 72%, p < 0.001). The agreement for potential frailty was substantial for patients with cancer (Kappa 0.63) and poor for geriatric patients (Kappa 0.05). Conclusion: Completion of the self-reported G8 is feasible and agreement of its outcome with the original G8 outcome is sufficient for patients with cancer but not for geriatric patients. The self-reported G8 may therefore be a useful alternative to the original G8 in older patients with cancer.