Abstract Details

Title Minimal Clinically Important Difference for the Visual Analog Scale for Sleep Inertia Using Data from a Phase 3 Trial of Low-sodium Oxybate for Idiopathic Hypersomnia

Topic Sleep

Presentation(s) P10 - Poster Session 10 (11:45 AM-12:45 PM)

Poster/Presentation
Number 9-005

Objective Propose a minimal clinically important difference (MCID), anchored in the Patient Global Impression of Change (PGIc), for the visual analog scale for sleep inertia (VAS-SI).

Background The VAS-SI assesses severity of sleep inertia (difficulty awakening), a common, debilitating idiopathic hypersomnia symptom; however, the MCID has not been determined.

Design/Methods

Participants from a phase 3 trial (NCT03533114) of low-sodium oxybate (LXB) for idiopathic hypersomnia began open-label LXB treatment (10–14 weeks), followed by a 2-week stable-dose period (SDP). Participants were randomized to placebo or continued LXB during a 2-week, double-blind, randomized-withdrawal period (DBRWP). Using the VAS-SI, participants rated their difficulty awakening, on a 100-mm line anchored at 0 (very easy) and 100 (very difficult), at baseline, end of SDP, and end of DBRWP. Participants also rated their change in condition on the PGIc, a 7-point Likert-type scale (very much improved to very much worse), at end of SDP and DBRWP. The MCID was estimated based on change in VAS-SI and PGIc scores assessed via Kruskal-Wallis test and a linear mixed model (LMM) with repeated measures.

Results Participants (N=109) were mean (SD) 40.8 (14.1) years of age, primarily female (70%) and White (82%). Median (quartile 1, quartile 3) changes in VAS-SI for PGIc levels were 52.4 (31.6, 59.6) for very much worse; 18.8 (2.4, 34.3) for much worse; 2.5 (–3.2, 14.0) for minimally worse; 0.4 (–3.0, 6.7) for no change; –12.3 (–17.4, 2.2) for minimally improved; –15.6 (–35.7, –5.1) for much improved; and –28.7 (–51.6, –17.6) for very much improved (Kruskal-Wallis test statistic, 110.2; P<0.001). With an LMM, the mean (SE) difference in VAS-SI scores between consecutive PGIc levels was 10.9 (0.8).

Conclusions Using an anchor-based approach, a minimal clinically important difference of 10–12 mm is proposed for the visual analog scale for sleep inertia.

Authors/Disclosures
Logan D. Schneider, MD (Stanford/VA Alzheimer's Center) PRESENTER	Dr. Schneider has received personal compensation for serving as an employee of Alphabet, Inc. Dr. Schneider has received personal compensation in the range of $100,000-$499,999 for serving on a Speakers Bureau for Jazz Pharmaceuticals. Dr. Schneider has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Avadel Pharmaceuticals. Dr. Schneider has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Axsome. Dr. Schneider has received intellectual property interests from a discovery or technology relating to health care.
Richard K. Bogan, MD (SleepMed)	Dr. Bogan has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Jazz Pharmaceutical . Dr. Bogan has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Takeda. Dr. Bogan has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Axsome . Dr. Bogan has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Harmony. Dr. Bogan has received personal compensation in the range of $50,000-$99,999 for serving on a Speakers Bureau for Jazz. Dr. Bogan has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Axsome. Dr. Bogan has received personal compensation in the range of $50,000-$99,999 for serving as an Expert Witness for Jazz. The institution of Dr. Bogan has received research support from Jazz Pharmaceuticals. The institution of Dr. Bogan has received research support from Harmony . The institution of Dr. Bogan has received research support from Eisai. The institution of Dr. Bogan has received research support from Avadel. The institution of Dr. Bogan has received research support from Takeda. The institution of Dr. Bogan has received research support from Suven. The institution of Dr. Bogan has received research support from Axsome. The institution of Dr. Bogan has received research support from Merck. The institution of Dr. Bogan has received research support from Liva Nova. The institution of Dr. Bogan has received research support from Nyxoah. Dr. Bogan has received research support from Bayer. Dr. Bogan has received intellectual property interests from a discovery or technology relating to health care.
Douglas S. Fuller (Jazz Pharmaceuticals)	Mr. Fuller has received personal compensation for serving as an employee of Jazz Pharmaceuticals. Mr. Fuller has stock in Jazz Pharmaceuticals.
Marisa Whalen	Marisa Whalen has received personal compensation for serving as an employee of Jazz Pharmaceuticals.
Cristina Casstevens	Cristina Casstevens has received personal compensation for serving as an employee of Jazz Pharmaceuticals . Cristina Casstevens has stock in Jazz Pharmaceuticals.
Wayne Macfadden, MD, PT	Dr. Macfadden has received personal compensation for serving as an employee of Jazz pharma. Dr. Macfadden has stock in Jazz pharma.

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