This study examined the correlation between improvements in excessive daytime sleepiness in participants with obstructive sleep apnea or narcolepsy and changes in functional status, work productivity and health-related quality of life. Data from two 12-week randomized controlled trials of solriamfetol were analyzed. Participants completed the Epworth Sleepiness Scale, 10-item Functional Outcomes of Sleep Questionnaire, Work Productivity and Activity Impairment questionnaire and 36-Item Short Form Health Survey and performed the Maintenance of Wakefulness Test at baseline and weeks 4, 8 and 12. Patient Global Impression of Change was assessed at weeks 4, 8 and 12. Pearson correlations were calculated for change in scores from baseline to week 12. For both studies, changes in the 10-item Functional Outcomes of Sleep Questionnaire were highly correlated (absolute value >0.5) with changes in Epworth Sleepiness Scale scores; changes in multiple domain scores of the 36-Item Short Form Health Survey and Work Productivity and Activity Impairment questionnaire were moderately correlated (0.3-0.5) with changes in Epworth Sleepiness Scale scores in both studies and highly correlated for participants with narcolepsy. Changes in Maintenance of Wakefulness Test scores correlated moderately with changes in Epworth Sleepiness Scale scores in both studies. At week 12, Patient Global Impression of Change ratings correlated highly with Epworth Sleepiness Scale and 10-item Functional Outcomes of Sleep Questionnaire scores for both disorders.Other correlations were low. Self-reported assessments of sleepiness and global improvement appear to be more strongly correlated with measures of functioning and health-related quality of life than objectively assessed sleepiness.
Purpose
This study estimated thresholds for clinically important responses and minimally important differences for two indicators of improvement for the 10-item version of the functional outcomes of sleep questionnaire (FOSQ-10).
Methods
Participants with excessive daytime sleepiness with narcolepsy or obstructive sleep apnea received 12 weeks of solriamfetol treatment. Participants completed the FOSQ-10 and other patient-reported outcome measures, including the single-item patient global impression of change (PGI-C) assessment. Clinicians completed the single-item clinician global impression of change (CGI-C) for each participant. Data from the two studies were analyzed separately, both without regard to treatment assignment. In total, 690 participants (47% female, mean age 48 years, 77% Caucasian, 91% from North America) were enrolled. Two clinically important changes, defined as a minimally important difference and a clinically important response, were determined using distribution and anchor-based analyses. A receiver operating characteristic analysis was used to determine the optimal FOSQ-10 change threshold.
Results
Spearman correlations between change in FOSQ-10 scores and PGI-C and CGI-C were − 0.57 and − 0.49 for participants with narcolepsy and − 0.42 and − 0.37 for participants with obstructive sleep apnea. Receiver operating characteristic analysis suggested minimally important difference and clinically important response estimates of 1.7 and 2.5 and 1.8 and 2.2 points in narcolepsy and obstructive sleep apnea, respectively.
Conclusions
Minimally important difference and clinically important response estimates for the FOSQ-10 for adults with excessive daytime sleepiness in narcolepsy or obstructive sleep apnea will be helpful for interpreting changes over time and defining a clinical responder.
ClinicalTrials.gov identifiers
NCT02348593 (first submitted January 15, 2015) and NCT02348606 (first submitted January 15, 2015)
Key Points
Question
What is the association between health care spending and survival in patients with chronic heart failure across US Veterans Affairs Medical Centers?
Findings
This cohort study of 265 714 patients found that mean annual expenditures varied from $21 300 to $52 800 per patient, and annual survival varied between 81.4% and 88.9%. There was a modest, statistically significant
V
-shaped association between spending and survival; however, the general association between spending and survival was weak.
Meaning
Several Veterans Affairs Medical Centers with high expenditures may be less economically efficient than their peer institutions in producing good health outcomes in their patients with chronic heart failure.
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