Challenges in the analysis of longitudinal pain data : practical lessons from a randomized trial of annular closure in lumbar disc surgery

  • Purpose: To analyze leg pain severity data from a randomized controlled trial (RCT) of lumbar disc surgery using integrated approaches that adjust pain scores collected at scheduled follow-up visits for confounding clinical events occurring between visits. Methods. Data were derived from an RCT of a bone-anchored annular closure device (ACD) following lumbar discectomy versus lumbar discectomy alone (Control) in patients with large postsurgical annular defects. Leg pain was recorded on a 0 to 100 scale at 6 weeks, 3 months, 6 months, 1 year, and 2 years of follow-up. Patients with pain reduction ≥20 points relative to baseline were considered responders. Unadjusted analyses utilized pain scores reported at follow-up visits. Since symptomatic reherniation signifies clinical failure of lumbar discectomy, integrated analyses adjusted pain scores following a symptomatic reherniation by baseline observation carried forward for continuous data or classification as nonresponders for categorical data. Results: Among 550 patients (272 ACD, 278 Control), symptomatic reherniation occurred in 10.3% of ACD patients and in 21.9% of controls (p < 0.001) through 2 years. There was no difference in leg pain scores at the 2-year visit between ACD and controls (12 versus 14; p = 0.33) in unadjusted analyses, but statistically significant differences favoring ACD (19 versus 29; p < 0.001) in integrated analyses. Unadjusted nonresponder rates were 6.0% with ACD and 6.7% with controls (p = 0.89), but 15.7% and 27.8% (p = 0.001) in integrated analyses. The probability of nonresponse was 16.4% with ACD and 18.3% with controls (p = 0.51) in unadjusted analysis, and 23.7% and 31.2% (p = 0.04) in integrated analyses. Conclusion: In an RCT of lumbar disc surgery, an integrated analysis of pain severity that adjusted for the confounding effects of clinical failures occurring between follow-up visits resulted in different conclusions compared to an unadjusted analysis of pain scores reported at follow-up visits only.

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Author:Gerrit J. Bouma, Martin Barth, Larry E. Miller, Sandro Eustacchio, Charlotte Flüh, Richard Bostelmann, Senol Jadik
URN:urn:nbn:de:hebis:30:3-489932
DOI:https://doi.org/10.1155/2019/3498603
ISSN:2090-1550
ISSN:2090-1542
Pubmed Id:https://pubmed.ncbi.nlm.nih.gov/30854236
Parent Title (English):Pain research and treatment
Publisher:Hindawi
Place of publication:New York, NY [u. a.]
Contributor(s):Giustino Varrassi
Document Type:Article
Language:English
Year of Completion:2019
Date of first Publication:2019/02/03
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2019/03/14
Volume:2019
Issue:Art. 3498603
Page Number:7
First Page:1
Last Page:6
Note:
Copyright © 2019 Gerrit J. Bouma et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
HeBIS-PPN:44805700X
Institutes:Medizin / Medizin
Dewey Decimal Classification:6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit
Sammlungen:Universitätspublikationen
Licence (German):License LogoCreative Commons - Namensnennung 4.0