Abstract
Background context
Waitlists are commonly used in Canada to manage access to surgical procedures such
as elective surgical lumbar discectomy (ESLD). The timing of enrollment onto the waitlist
is important as this is a proxy measure for the concordance of preferences for surgery
between a patient and surgeon. After enrollment, the waiting time to actual surgery
extends the duration of preoperative symptoms, which possibly affects the outcome
of ESLD. Waiting time also specifically reflects the delay in service delivery imposed
by the limited capacity of the health-care system.
Purpose
To determine if a system-imposed delay in treatment, that is, longer waiting time,
for ESLD is associated with a higher odds of experiencing residual postoperative pain.
Study design/setting
Ambidirectional cohort study with 2-year retrospective and 3-year prospective components,
conducted at a major tertiary care center serving a metropolitan area in Canada.
Patient sample
Patients aged 16 years or older with sciatica because of herniated lumbar disc, confirmed
on advanced imaging, were recruited at the time of waitlist enrollment for ESLD. Patients
with significant comorbidity or emergency indications for surgery were excluded. Of
391 participants, 291 had complete follow-up information at 6 months postoperatively.
Outcome measure
Intensity of the predominant symptom (worse of either back or leg pain) was assessed
on the 11-point numerical rating scale at waitlist enrollment and 6 months postoperatively.
Pain scores were highly skewed and therefore categorized into four ordinal levels
defined by quartiles.
Methods
For the primary analysis, time to surgery from waitlist enrollment was dichotomized
based on a predetermined clinically meaningful cut-point of 12 weeks. Ordinal logistic
regression was used to compare the odds of experiencing higher pain intensity between
wait groups. Control of confounders was achieved using both propensity scores and
conventional multivariable modeling.
Results
In unadjusted analyses, long-wait patients were 80% more likely than short-wait patients
to experience higher ordinal pain intensity at 6 months; unadjusted proportional odds
ratio (POR)=1.8 (95% confidence interval [CI], 1.2–2.8). The association held after
controlling for all imbalances in measured confounders, with long-wait patients still
being 70% more likely to report worse pain; adjusted POR=1.7 (95% CI, 1.0–2.8).
Conclusions
A waiting time of 12 weeks or more after waitlist enrollment for ESLD is associated
with a modest likelihood of experiencing worse pain at 6 months postoperatively. This
result was not because of differences in measured confounders. Future studies are
encouraged to identify other, as-of-yet unmeasured, variables that might be associated
with both longer waiting times and worse outcomes among ESLD patients. Until then,
in jurisdictions where highly constrained access to ESLD is managed through waitlists,
the expected waiting time for the operation could be an informative deciding criterion
for patients with otherwise unresolved preferences for operative treatment.
Keywords
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Article info
Publication history
Published online: July 15, 2013
Accepted:
May 22,
2013
Received in revised form:
February 6,
2013
Received:
January 24,
2011
Footnotes
FDA device/drug status: Not applicable.
Author disclosures: JAQ: Nothing to disclose. BGS: Nothing to disclose. ARL: Private Investments: Oxford Outcomes (C); Grant: Canadian Institutes for Health Research (C, Paid directly to institution/employer). CGF: Royalties: Medtronic (D); Consulting: Medtronic (F, Paid directly to institution/employer); Speaking/Teaching Arrangements: Medtronic (Amount not disclosed, research and fellowship support, Paid directly to institution/employer), DePuy (Amount not disclosed, research and fellowship support, Paid directly to institution), AOSpine (Amount not disclosed, research and fellowship support, Paid directly to institution/employer); Trips/Travel: Medtronic (Amount not disclosed), AOSpine (Amount not disclosed), DePuy (Amount not disclosed); Research Support (Staff/Materials): Medtronic (E, Paid directly to institution/employer), DePuy (E, Paid directly to institution/employer); Fellowship Support: Medtronic (F, Paid directly to institution/employer), Synthes (F, Paid directly to institution/employer). PBB: Nothing to disclose. JAK: Nothing to disclose. MFD: Royalties: Medtronic (D); Consulting: Medtronic (unknown); Speaking/Teaching Arrangements: Medtronic (expenses paid), AO Spine (expenses paid), Synthes (expenses paid); Endowments: Paetzold Chair in Clinical Spinal Cord Injury Research (E); Research Support, Staff/Materials: Medtronic (E); Grants: CIHR (I), NSERC (I), Rick Hansen Institute (I); Fellowship Support: Medtronic, Synthes, DePuy (E). MTS: Nothing to disclose.
The disclosure key can be found on the Table of Contents and at www.TheSpineJournalOnline.com.
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© 2013 Elsevier Inc. Published by Elsevier Inc. All rights reserved.
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