TY  - JOUR
A1  - Bouma, Gerrit J.
A1  - Barth, Martin
A1  - Miller, Larry E.
A1  - Eustacchio, Sandro
A1  - Flüh, Charlotte
A1  - Bostelmann, Richard Klaus Ludwig
A1  - Jadik, Senol
T1  - Challenges in the analysis of longitudinal pain data : practical lessons from a randomized trial of annular closure in lumbar disc surgery
T2  - Pain research and treatment
N2  - 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.
Y1  - 2019
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/48993
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-489932
SN  - 2090-1550
SN  - 2090-1542
N1  - 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.
VL  - 2019
IS  - Art. 3498603
SP  - 1
EP  - 6
PB  - Hindawi
CY  - New York, NY [u. a.]
ER  -