School of Population and Public Health, Faculty of Medicine, University of British Columbia, 2206 East Mall, Vancouver, British Columbia, Canada V6T 1Z3; International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Centre, University of British Columbia, 6133-818 W. 10th Ave., Vancouver, British Columbia, Canada V5Z 1M9; Combined Neurosurgical and Orthopaedic Spine Program, Division of Spine, Department of Orthopaedics, Vancouver Hospital and Health Sciences Centre, University of British Columbia, 3114 - 910 West 10th Ave., Vancouver, British Columbia, Canada V5Z 1M9.
Spine J. 2013 Dec;13(12):1736-48. doi: 10.1016/j.spinee.2013.05.038. Epub 2013 Jul 11.
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.
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.
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.
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.
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.
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).
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.
在加拿大，候诊名单通常用于管理手术（如选择性手术腰椎间盘切除术（ESLD））的就诊机会。登记到候诊名单上的时间很重要，因为这是患者和外科医生对手术偏好一致性的代理指标。登记后，实际手术前的等待时间延长了术前症状的持续时间，这可能会影响 ESLD 的结果。等待时间还具体反映了医疗保健系统能力有限所导致的服务提供延迟。
确定 ESLD 治疗的系统延迟（即较长的等待时间）是否与术后残留疼痛的可能性更高相关。
研究设计/设置：在加拿大一个主要的三级保健中心进行了一项具有 2 年回顾性和 3 年前瞻性部分的双向队列研究。
在 ESLD 等候名单上登记时，招募了年龄在 16 岁或以上的因椎间盘突出而出现坐骨神经痛、经高级影像学证实的患者。患有严重合并症或紧急手术指征的患者被排除在外。在 391 名参与者中，291 名在术后 6 个月时具有完整的随访信息。
在等待名单登记时和术后 6 个月时，使用 11 点数字评分量表评估主要症状（背部或腿部疼痛更严重的一侧）的强度。疼痛评分高度偏态，因此分为由四分位数定义的四个有序水平。
在主要分析中，从等待名单登记到手术的时间根据 12 周的临床有意义的预定切点进行二分。使用有序逻辑回归比较两组之间经历更高疼痛强度的可能性。通过倾向评分和常规多变量模型控制混杂因素。
在未调整的分析中，与短等待时间患者相比，长等待时间患者在术后 6 个月时更有可能经历更高的疼痛强度；未调整的比例优势比（POR）=1.8（95%置信区间[CI]，1.2-2.8）。在控制所有测量混杂因素的不平衡后，这种关联仍然存在，长等待时间患者报告疼痛更严重的可能性仍高出 70%；调整后的 POR=1.7（95% CI，1.0-2.8）。
ESLD 等候名单登记后等待 12 周或以上与术后 6 个月时经历更严重疼痛的可能性适度相关。这一结果并不是由于测量混杂因素的差异所致。鼓励未来的研究确定其他尚未测量的变量，这些变量可能与 ESLD 患者的较长等待时间和较差结局相关。在那之前，在高度限制 ESLD 就诊机会的司法管辖区，手术的预期等待时间可能是对那些对手术治疗仍有未解决偏好的患者的一个有用的决策标准。
