Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, USA.
Tufts University School of Medicine, Boston, MA, USA.
Clin Orthop Relat Res. 2023 Feb 1;481(2):268-278. doi: 10.1097/CORR.0000000000002323. Epub 2022 Aug 12.
Racial health disparities across orthopaedic surgery subspecialties, including spine surgery, are well established. However, the underlying causes of these disparities, particularly relating to social determinants of health, are not fully understood.
QUESTIONS/PURPOSES: (1) Is there a racial difference in 90-day mortality, readmission, and complication rates ("safety outcomes") among Medicare beneficiaries after spine surgery? (2) To what degree does the Centers for Disease Control and Prevention Social Vulnerability Index (SVI), a community-level marker of social determinants of health, account for racial disparities in safety outcomes?
To examine racial differences in 90-day mortality, readmission, and complications after spine surgery, we retrospectively identified all 419,533 Medicare beneficiaries aged 65 or older who underwent inpatient spine surgery from 2015 to 2019; we excluded 181,588 patients with endstage renal disease or Social Security disability insurance entitlements, who were on Medicare HMO, or who had missing SVI data. Because of the nearly universal coverage of those age 65 or older, Medicare data offer a large cohort that is broadly generalizable, provides improved precision for relatively rare safety outcomes, and is free of confounding from differential insurance access across races. The Master Beneficiary Summary File includes enrollees' self-reported race based on a restrictive list of mutually exclusive options. Even though this does not fully capture the entirety of racial diversity, it is self-reported by patients. Identification of spine surgery was based on five Diagnosis Related Groups labeled "cervical fusion," "fusion, except cervical," "anterior-posterior combined fusion," "complex fusion," and "back or neck, except fusion." Although heterogeneous, these cohorts do not reflect inherently different biology that would lead us to expect differences in safety outcomes by race. We report specific types of complications that did and did not involve readmission. Although complications vary in severity, we report them as composite measures while being cognizant of the inherent limitations of making inferences based on aggregate measures. The SVI was chosen as the mediating variable because it aggregates important social determinants of health and has been shown to be a marker of high risk of poor public health response to external stressors. Patients were categorized into three groups based on a ranking of the four SVI themes: socioeconomic status, household composition, minority status and language, and housing and transportation. We report the "average race effects" among Black patients compared with White patients using nearest-neighbor Mahalanobis matching by age, gender, comorbidities, and spine surgery type. Mahalanobis matching provided the best balance among propensity-type matching methods. Before matching, Black patients in Medicare undergoing spine surgery were disproportionately younger with more comorbidities and were less likely to undergo cervical fusion. To estimate the contribution of the SVI on racial disparities in safety outcomes, we report the average race effect between models with and without the addition of the four SVI themes.
After matching on age, gender, comorbidities, and spine surgery type, Black patients were on average more likely than White patients to be readmitted (difference of 1.5% [95% CI 0.9% to 2.1%]; p < 0.001) and have complications with (difference of 1.2% [95% CI 0.5% to 1.9%]; p = 0.002) or without readmission (difference of 3.6% [95% CI 2.9% to 4.3%]; p < 0.001). Adding the SVI to the model attenuated these differences, explaining 17% to 49% of the racial differences in safety, depending on the outcome. An observed higher rate of 90-day mortality among Black patients was explained entirely by matching using non-SVI patient demographics (difference of 0.00% [95% CI -0.3% to 0.3%]; p = 0.99). However, even after adjusting for the SVI, Black patients had more readmissions and complications.
Social disadvantage explains up to nearly 50% of the disparities in safety outcomes between Black and White Medicare patients after spine surgery. This argument highlights an important contribution of socioeconomic circumstances and societal barriers to achieving equal outcomes. But even after accounting for the SVI, there remained persistently unequal safety outcomes among Black patients compared with White patients, suggesting that other unmeasured factors contribute to the disparities. This is consistent with evidence documenting Black patients' disadvantages within a system of seemingly equal access and resources. Research on racial health disparities in orthopaedics should account for the SVI to avoid suggesting that race causes any observed differences in complications among patients when other factors related to social deprivation are more likely to be determinative. Focused social policies aiming to rectify structural disadvantages faced by disadvantaged communities may lead to a meaningful reduction in racial health disparities.
Level III, therapeutic study.
在骨科手术的各个亚专科，包括脊柱外科，种族健康差异是既定事实。然而，这些差异的根本原因，特别是与健康决定因素相关的社会决定因素，尚未完全了解。
问题/目的：（1）在 Medicare 受益人群接受脊柱手术后的 90 天死亡率、再入院率和并发症发生率（“安全结果”）方面，种族间是否存在差异？（2）疾病控制与预防中心社会脆弱性指数（SVI），一种社区层面的健康决定因素指标，在多大程度上可以解释安全结果方面的种族差异？
为了研究种族差异对脊柱手术后 90 天死亡率、再入院率和并发症的影响，我们回顾性地确定了 2015 年至 2019 年间所有 419,533 名年龄在 65 岁或以上接受住院脊柱手术的 Medicare 受益人群；我们排除了 181,588 名患有终末期肾病或社会保障残疾保险权益、参加 Medicare HMO 或 SVI 数据缺失的患者。由于几乎所有 65 岁或以上的人都参加了 Medicare，因此 Medicare 数据提供了一个广泛适用的大型队列，提供了相对罕见的安全结果的更高精度，并且不受种族间保险获得情况的混杂影响。主受益摘要文件包含了参保人基于相互排斥的选择清单上的自我报告的种族。尽管这并不能完全反映出种族多样性的全貌，但它是由患者自我报告的。脊柱手术的识别是基于五个诊断相关组，标签为“颈椎融合”、“除颈椎外的融合”、“前后联合融合”、“复杂融合”和“背部或颈部，除融合外”。尽管这些队列存在异质性，但它们并不反映出固有的生物学差异，这将导致我们期望种族间的安全结果存在差异。我们报告了确实涉及再入院和不涉及再入院的特定类型的并发症。虽然并发症的严重程度不同，但我们在报告时将其作为综合指标，同时意识到基于汇总指标进行推断存在内在局限性。选择 SVI 作为中介变量是因为它汇集了重要的健康决定因素，并已被证明是对外界压力源不良公共卫生反应的高风险的标志物。患者根据社会经济地位、家庭构成、少数族裔和语言以及住房和交通这四个 SVI 主题的排名分为三组。我们使用最邻近 Mahalanobis 匹配法，根据年龄、性别、合并症和脊柱手术类型，报告黑人患者与白人患者相比的“平均种族效应”。Mahalanobis 匹配法在倾向匹配方法中提供了最佳的平衡。在匹配之前，接受脊柱手术的 Medicare 中的黑人患者不成比例地更年轻，合并症更多，并且不太可能接受颈椎融合。为了估计 SVI 对安全结果种族差异的影响，我们报告了在有和没有添加四个 SVI 主题的模型之间的平均种族效应。
在匹配年龄、性别、合并症和脊柱手术类型后，黑人患者比白人患者更有可能被再次入院（差异为 1.5% [95%CI 0.9%至 2.1%]；p < 0.001），并且更有可能出现（差异为 1.2% [95%CI 0.5%至 1.9%]；p = 0.002）或不涉及再入院的并发症（差异为 3.6% [95%CI 2.9%至 4.3%]；p < 0.001）。在模型中添加 SVI 可以减轻这些差异，取决于结果，解释了安全方面种族差异的 17%至 49%。黑人患者 90 天死亡率较高的情况完全可以通过使用非 SVI 患者人口统计学数据进行匹配来解释（差异为 0.00% [95%CI -0.3%至 0.3%]；p = 0.99）。然而，即使调整了 SVI，黑人患者的再入院率和并发症发生率仍然更高。
社会劣势可以解释黑人 Medicare 患者与白人患者在脊柱手术后安全结果方面高达近 50%的差异。这一论点强调了社会经济环境和社会障碍对实现公平结果的重要贡献。但即使考虑到 SVI，黑人患者的再入院率和并发症发生率仍然明显高于白人患者，这表明其他未被测量的因素也促成了这些差异。这与记录黑人患者在看似平等的获得资源的系统中处于劣势的证据一致。在骨科领域研究种族健康差异时，应考虑 SVI，以避免在其他与社会剥夺相关的因素更有可能起决定性作用时，暗示种族会导致患者并发症方面的任何观察到的差异。针对弱势社区结构性劣势的有针对性的社会政策可能会显著减少种族健康差异。
三级，治疗研究。
