At-Home Critical Flicker Frequency Testing in Cirrhosis: A Feasibility Pilot Study Using the Novel Beacon Device

Critical flicker frequency (CFF) is a well-validated neurophysiologic screening test for minimal hepatic encephalopathy (MHE) in cirrhosis. We evaluated the feasibility and reliability of repeated at-home, self-administered CFF testing using a novel device (Beacon).

We enrolled 21 participants with cirrhosis. Each received a Beacon device and smartphone preloaded with an application to measure CFF using 2 protocols: (1) method of limits-descending (MOL-D) and (2) forced choice. Participants were instructed to complete ≥5 tests per week for 2 weeks, followed by ≥ 1 test per week for an additional 4 weeks. Outcomes included adherence, test duration, and longitudinal CFF trends to assess potential learning effects from repeated testing.

Participants were predominantly male (76%) with a mean age of 52.2 years; 43% had alcohol-related liver disease and 38% had prior overt HE. Adherence (completing ≥70% of recommended measurements) was observed in 19 (90.5%) for daily and 16 participants (76.2%) for weekly testing. Median CFF was 42.9 Hz (interquartile range: 38.4-44.4) by MOL-D and 43.7 Hz (interquartile range: 41.7-45.8) by forced choice. Forced choice CFF was significantly lower in those with prior HE (median 40.7 Hz vs 44.9 Hz; P = .02), while MOL-D CFF did not differ by HE status (42.7 Hz vs 42.9 Hz; P = .44). CFF remained stable over time for both protocols (MOL-D: +0.01 Hz/day of testing, P = .67; forced choice: +0.03 Hz/day, P = .09). Forced choice testing required more time than MOL-D to complete (median 4.67 vs 2.48 minutes; P < .001).

Beacon enabled reliable, self-administered CFF testing at home with high adherence and no evidence of learning effects. Further studies incorporating other validated MHE tools are needed to determine whether at-home CFF monitoring can detect MHE early and prevent overt HE episodes and hospitalizations.