Reasons Why Data from the Nationwide Inpatient Sample Can Be Misleading for Carotid Endarterectomy and Carotid Stenting
Section snippets
Neurologic Indications for CEA and CAS
Table 1 shows the prevalence of asymptomatic stenosis as an indication for carotid intervention in the six NIS studies selected for review, for three statewide surveys that also have been based on claims data within the past decade,12, 13, 14 and for two prospective registries maintained by the Society for Vascular Surgery (SVS)15 and the Vascular Study Group of Northern New England16 during the same period of time. The prevalence of asymptomatic patients in the NIS studies ranges from 92% to
Stroke Rates for CEA and CAS
The NIS dataset does not include strokes that occur after hospital discharge but within the 30-day periprocedural period used in other studies.4, 6, 8 Stroke rates during this missing interval are rarely reported elsewhere, but data from the SVS registry suggest that 29% of the 30-day strokes after CEA and 43% of those after CAS happen after patients have left the hospital.15 In contrast, however, the Vascular Study Group of Northern New England registry indicates that just 10% of the 30-day
Clinical Pitfalls of Administrative Datasets
According to McPhee et al,8 the limitations of miscoded or absent data in administrative datasets like the NIS are well known. This may be correct for investigators who use the NIS, but it might not be so obvious to clinicians who have no personal experience with administrative data. Although the authors of the six NIS studies on CEA and CAS in the present review do encourage caution in the interpretation of their findings,3, 4, 5, 6, 7, 8 these disclaimers are not conventionally disclosed
Conclusions
The mortality rates of CEA and CAS are undoubtedly accurate in the NIS dataset because deaths are invariably noted in medical records by clinicians and are unmistakable to coding specialists who prepare discharge abstracts. Information about preprocedural symptoms and periprocedural strokes is a different matter, however. Its accuracy depends entirely on adequate documentation by physicians (or their assistants) and uniform ICD-9-CM coding throughout the United States. It might be unrealistic
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Cited by (22)
Carotid artery disease-What we still don’t know
2021, Vascular Disease in Women: An Overview of the Literature and Treatment RecommendationsCarotid Revascularization Procedures and Perioperative Outcomes: A Multistate Analysis, 2007-2014
2019, Journal of Cardiothoracic and Vascular AnesthesiaCitation Excerpt :The reported in-hospital mortality or stroke rates are not equivalent to 30-day periprocedural or 1-year event rates. The authors acknowledge that such a methodology may underestimate the rate of total adverse outcomes after CEA and CAS.40–43 Patient baseline demographics differed between the CEA and CAS cohorts (Table 2).
Long-term comparative effectiveness of carotid stenting versus carotid endarterectomy in a large tertiary care vascular surgery practice
2018, Journal of Vascular SurgeryCitation Excerpt :Second, because this study used administrative data based on medical coding, important clinical events may have been missed or coded incorrectly, thus introducing errors into the data set. Recent publications by other authors have already identified potential pitfalls with use of the National Surgical Quality Improvement Program data,17 National Inpatient Sample data,18 and even data from state-specific databases that contain the “present on admission” indicator in the study of outcomes of carotid interventions.19 However, we believe that the limitations of administrative data sets would apply equally to both endarterectomy and stent patients in our study, not lending bias toward one vs the other in our study.