Digital Phenotyping and Noninvasive Quality-of-Life Monitoring in Glioblastoma: Feasibility and Usability Study of the Lalaby-Glio App.

Abstract

Background: Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor in adults, with a poor prognosis despite Stupp protocol treatment. Given the substantial burden of the disease and its therapies, monitoring health-related quality of life (HRQoL) is essential. Smartphone-based approaches may enable continuous, low-burden monitoring.

Objective: This study aims to evaluate the feasibility and usability of the Lalaby-Glio app for monitoring HRQoL in patients with GBM and to explore preliminary hypothesis-generating associations between subjective global quality of life (QoL) and passive smartphone sensor data.

Methods: The study comprised four phases: (1) adaptation of Lalaby for GBM-specific monitoring by combining passive smartphone sensors (movement, step count, location, sound, light exposure, internet use, and call activity) with a clinician-designed daily 5-item questionnaire and weekly European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (QLQ-C30) and Quality of Life Questionnaire-Brain Neoplasm 20 (QLQ-BN20); (2) a 6-week feasibility study in 4 adults (aged ≥18 years) initiating Stupp treatment; (3) usability testing in patients with GBM and a complementary nonpatient sample of 103 healthy adults using either screenshot mock-ups or the installed app; and (4) exploratory Spearman correlation analyses of associations between passive sensor data and subjective global QoL using patient-level bootstrap, with no causal or predictive claims inferred due to the small sample size.

Results: We enrolled 4 patients (3 men, 1 woman; mean age 54.3, SD 8 years), of whom 3 completed all 6 weeks, and 1 died after 2 weeks. Engagement was high, with 168 questionnaires completed (22 QLQ-C30, 19 QLQ-BN20, and 127 daily status entries). Mean app use was 1.8 (SD 2.7) minutes per day, and mean completion time for the weekly questionnaires was 7.2 (SD 3.3) minutes. Weekly patient-reported outcome measures (PROMs) revealed substantial interindividual and intraindividual variability in functioning, symptoms, and global QoL during treatment. Usability among patients with GBM was favorable (overall mean 3.7/5). Among healthy participants (mean age 20.9, SD 1.4 years; 72/103, 69.9% women), those who installed the app (n=46) achieved a mean System Usability Scale score of 72.9 (SD 10.2), above the standard benchmark, and 91.3% (94/103) judged the nature-inspired design appropriate for oncology. Passive sensing yielded 91.7 MB of data; global QoL correlated negatively with calls (ρ=-0.598; P=.01) and movement (ρ=-0.604; P<.001), while steps showed a positive but nonsignificant association (ρ=0.392; P=.63). These correlations should be interpreted as preliminary signals rather than robust evidence of digital biomarkers.

Conclusions: Lalaby-Glio appears feasible and usable for monitoring HRQoL in patients with GBM in an early proof-of-concept setting and can capture patient-reported fluctuations over time. Passive smartphone sensing shows promise for complementing PROM-based monitoring and generating preliminary hypotheses about objective behavioral correlates of QoL.