Back to Journals » Drug Design, Development and Therapy » Volume 9

Modeling the longitudinal latent effect of pregabalin on self-reported changes in sleep disturbances in outpatients with generalized anxiety disorder managed in routine clinical practice

Authors Ruiz M, Álvarez E, Carrasco JL, Olivares JM, Pérez M, Rejas J

Received 8 May 2015

Accepted for publication 29 June 2015

Published 6 August 2015 Volume 2015:9 Pages 4329—4340

DOI https://doi.org/10.2147/DDDT.S88238

Checked for plagiarism Yes

Review by Single-blind

Peer reviewers approved by Dr Rekha Dhanwani

Peer reviewer comments 2

Editor who approved publication: Prof. Dr. Wei Duan


Miguel A Ruiz,1 Enrique Álvarez,2 Jose L Carrasco,3 José M Olivares,4 María Pérez,5 Javier Rejas6

1Department of Methodology, School of Psychology, Universidad Autónoma de Madrid, Madrid, 2Department of Psychiatry, Hospital de la Santa Creu i San Pau, Barcelona, 3Department of Psychiatry, Hospital Clínico San Carlos, Madrid, 4Department of Psychiatry, Hospital Meixoeiro, Complejo Hospitalario Universitario, Vigo, 5Medical Department, Pfizer, S.L.U., Alcobendas, Madrid, 6Health Economics and Outcomes Research Department, Pfizer, S.L.U., Alcobendas, Madrid, Spain

Background: Anxiety disorders are among the most common psychiatric illnesses, with generalized anxiety disorder (GAD) being one of the most common. Sleep disturbances are highly prevalent in GAD patients. While treatment with pregabalin has been found to be associated with significant improvement in GAD-related sleep disturbance across many controlled clinical trials, mediational analysis has suggested that a substantial portion of this effect could be the result of a direct effect of pregabalin. Thus, the objective of this study was to model the longitudinal latent effect of pregabalin or usual care (UC) therapies on changes in sleep in outpatients with GAD under routine clinical practice.
Methods: Male and female GAD outpatients, aged 18 years or above, from a 6-month prospective noninterventional trial were analyzed. Direct and indirect effects of either pregabalin or UC changes in anxiety symptoms (assessed with Hamilton Anxiety Scale) and sleep disturbances (assessed with Medical Outcomes Study-Sleep Scale [MOS-S]) were estimated by a conditional latent curve model applying structural equation modeling.
Results: A total of 1,546 pregabalin-naïve patients were analyzed, 984 receiving pregabalin and 562 UC. Both symptoms of anxiety and sleep disturbances were significantly improved in both groups, with higher mean (95% confidence interval) score reductions in subjects receiving pregabalin: -15.9 (-15.2; -16.6) vs -14.5 (-13.5; -15.5), P=0.027, in Hamilton Anxiety Scale; and -29.7 (-28.1; -31.3) vs -24.0 (-21.6; -26.4), P<0.001, in MOS-S. The conditional latent curve model showed that the pregabalin effect on sleep disturbances was significant (γ =-3.99, P<0.001), after discounting the effect on reduction in anxiety symptoms. A mediation model showed that 70% of the direct effect of pregabalin on sleep remained after discounting the mediated effect of anxiety improvement.
Conclusion: A substantial proportion of the incremental improvements in anxiety-related sleep disturbances with pregabalin vs UC were explained by its direct effect, not mediated by improvements in anxiety symptoms.

Keywords: latent curve analysis, pregabalin, usual care, generalized anxiety disorders, sleep disturbances

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]