578
Views
28
CrossRef citations to date
0
Altmetric
Research Article

Comparison of slow and forced vital capacities on ability to predict survival in ALS

&
Pages 528-533 | Received 07 Apr 2017, Accepted 04 Jul 2017, Published online: 25 Jul 2017
 

Abstract

Introduction: Slow (SVC) and forced (FVC) vital capacities are the most used pulmonary function tests in amyotrophic lateral sclerosis (ALS). It is unknown if they equally predict survival in ALS. The aim of the present study was to compare both measures in predicting survival in this disease. Methods: Consecutive definite/probable ALS patients (2000–2014) in whom respiratory tests were performed at baseline and four months later were included. All patients were evaluated with the revised ALS functional rating scale (ALSFRS-R), respiratory (RofALSFRS-R), bulbar (ALSFRSb), upper and lower limb subscores, SVC, FVC, maximal inspiratory (MIP) and expiratory (MEP) pressures. King’s functional staging system was applied retrospectively. Survival analysis was carried out by univariate Kaplan-Meier log-rank test. Multivariate Cox proportional hazards model determined significant independent variables. Results: We included 469 patients (270 males; mean onset age 61.0 ± 11.5 years; mean disease duration from first symptoms to first visit: 15.8 ± 16.1months; 329 spinal and 140 bulbar onset). FVC and SVC were strongly correlated (r2 = 0.981, p < 0.001). Significant survival prognostic variables (Kaplan-Meier analyses) were onset region, age, disease duration, ALSFRS-R, ALSFRSb, RofALSFRS-R, ALSFRS-R decay, SVC, FVC, MIP, MEP and King’s staging (p ≤ 0.01). Final Cox model including the significant variables showed similar results for FVC and SVC (p < 0.001). Moreover, 1% decrease in either predicted values increased death probability by 1.02. Conclusion: FVC and SVC are inter-changeable in predicting survival in ALS.

Acknowledgements

This study was partially funded through an independent grant from Cytokinetics.

This study is included in ONWebDUALS project (JPND-PS/0001/2013) initiative. This is an EU Joint Programme — Neurodegenerative Disease Research (JPND) project - Fundação para a Ciência e a Tecnologia (JPND-PS/0001/2013).

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.