Analysis of Temporal Artery Biopsy by Provider Across a Large Multi-State Health Care Network

Abstract

Temporal artery biopsy (TAB) is the standard test for diagnosing giant cell arteritis. Our objective was to determine which specialists perform TABs and if there is variation across the United States. We performed a cross-sectional analysis in a multi-state health care system, evaluating differences between observed counts of surgical specialty by region, positive diagnoses by region, and positive diagnoses by specialty. Temporal arterial biopsy was performed on 3825 patients with the proportion of specialties performing TAB differing between regions. Temporal artery biopsy was performed by a significantly higher percentage of general surgeons in the Midwest (53.6%) and less vascular surgeons in the West (30.4%). The percentage of positive diagnoses was higher for vascular surgeons (32.7%). We concluded that TAB is performed by physicians of many specialties with the specialty performing most of these procedures varying by region. There is also a difference in the rate of positive diagnoses that varies with surgical specialty.

Temporal artery biopsy (TAB) is the gold-standard test for diagnosing giant cell arteritis (GCA), an auto-immune vasculitis affecting larger-diameter blood vessels with a predisposition to cranial arteries. ¹ The main treatment for this condition involves high-dose steroids, which can come with a litany of side effects (eg, Cushing syndrome, immunosuppression, hepatic damage, or peptic ulcers). The current American College of Rheumatology’s diagnostic criteria include age greater than 50 years, temporal artery tenderness, new-onset localized headache, morning stiffness in shoulders/neck, erythrocyte sedimentation rate >50 mm/h, and positive TAB, with a score of equal to or greater than 6 meeting the classification for GCA. ² Temporal artery biopsy can be performed by physicians from a variety of specialties including ophthalmologists, dermatologists, otolaryngologists, general surgeons, neurosurgeons, vascular surgeons, and potentially others. As a result of the broad range of specialists who perform the procedure, there is great variability in the training received to perform the procedure. ³ Furthermore, some of these aforementioned specialists may receive no formal training on the performance of TAB but receive referrals or consultations to perform it based on practice patterns in their health care system. Although TAB is generally considered a safe procedure, proper training and appropriate procedure volume are important to mitigate unnecessary complications (ie, facial nerve injury, stroke, and scalp necrosis) in practice. ³ We aimed to elucidate the specialties most likely to perform TAB and to determine the percent TAB positivity among physicians in different specialties. We conducted a retrospective cross-sectional analysis across 182 hospitals within the HCA Healthcare System over a 6-year period between January 1, 2016, and December 12, 2022. All patients >18 years old undergoing temporal artery biopsy were included in our data set. Data were extracted from the HCA Healthcare electronic data warehouse which contains patient data from the electronic medical records at 182 hospitals. Specialties reported in the EMR were grouped: CT_SURG; thoracic and cardiothoracic surgery, ENT_OPHTH; ophthalmology and otolaryngology, GEN_SURG; general surgery, bariatric surgery, colorectal surgery, trauma surgery, transplant surgery, and surgical oncology, MULTIPLE; multiple specialties of interest, NEURO; neurosurgery, and VASC_SURG; vascular surgery. Data were categorized by region, in alignment with US Census divisions into the Midwest, Northeast, South, and West. Chi-square analyses were performed to compare differences in observed counts of surgical specialty by region, as well as positive diagnoses by region and differences in positive diagnoses by reported specialty. From the total population of patients (N = 3825), 1100 records included procedure time, which was evaluated using an ANOVA to compare means of procedure time against reported specialty. A covariance matrix with unequal group variances was used due to differences in group sizes.

This research activity was conducted in compliance with HCA requirements and determined to be exempt from institutional review board (IRB) oversight in accordance with current regulations and institutional policy. The internal reference number for this determination was 2023-378. Of the 4163 patient encounters we extracted, 338 were removed due to missing sex, diagnosis, procedure data, surgeon specialty, or an irrelevant surgeon specialty listed. The proportion of surgical specialties performing TAB differed between regions (χ² = 122.04, P < .001). Vascular surgeons and general surgeons completed a high proportion of TAB in all regions. Vascular surgeons and general surgeons, combined, completed 96% of TAB in the Northeast, 96% in the Midwest, 81% in the South, and only 66% in the West. The lower proportion of vascular and general surgeons performing TAB in the West was made up of cardio thoracic-surgeons (11%) and ENT Ophthalmologists (16%), with an expected, smaller proportion of cardiothoracic and ENT Ophthalmology surgeons performing the TAB in the Northeast (1%, 3%, respectively), Midwest (0%, 2%), and South (5%, 9%). The chi-square analysis shows that the proportion of general surgeons performing TAB was significantly higher in the Midwest (53.6%) than in the South (37.2%) and West (36.3). For vascular surgeons performing TAB, the proportion was significantly higher in the Northeast (47.4%) than in the West (30.4%). Overall, the proportions of positive GCA diagnoses differed between specialties (χ² = 18.24, P < .01). The percentage of positive diagnoses was significantly higher for vascular surgeons (32.7%) compared to cardiothoracic surgeons (23.6%), general surgeons (27.7%), and physicians with multiple specialties (21.6%, Table 1). To our knowledge, no US study has been published to evaluate the number of TABs performed by physicians in different specialties. Our findings revealed a significant variability in specialties performing temporal artery biopsies across the United States. Temporal artery biopsy stands as the gold standard in the diagnosis of GCA, the most common form of vasculitis in Western countries. As such, it is critical to ensure a degree of standardization regarding the training and qualifications required to perform this procedure in order to optimize its efficacy and minimize associated complications. In the overall patient cohort, general surgery, vascular surgery, and otolaryngology/ophthalmology were observed to perform the majority of temporal artery biopsies nationally (44%, 40.5%, and 7.5%, respectively), which can inform curricula for each of these respective specialties’ residency programs. A predominance of otolaryngologists and plastic surgeons completing the procedure has been reported in similar studies, indicating some degree of institution-specific availability of certain specialties for TABs. ⁴ Otolaryngology/ophthalmology and vascular surgery had significantly higher rates of positive diagnoses in completed TABs compared to other disciplines studied (31.2% and 32.7%, respectively). ⁴ This higher positive rate may be attributed to factors including but not limited to differences in training resulting in increased selectivity of patients who undergo the procedure. The differences could also be attributed to a referral from primary care specialties of more severe cases to one of these aforementioned subspecialties. Of note, TABs performed in the Northeast were divided almost equally by general surgery and vascular surgery. Conversely, the West had a significantly higher presence of additional surgical subspecialties, with general surgery, vascular surgery, and otolaryngology/ophthalmology/cardiac surgery as a group performing approximately one-third of biopsies, respectively. These trends may be influenced by numerous factors, including the number of rural areas in each of the 4 US divisions. Rural areas may be more likely to have fewer surgical subspecialists in disciplines such as otolaryngology, ophthalmology, vascular surgery, plastic surgery, or dermatology, giving general surgeons a greater representation in temporal artery biopsy procedures.

Table 1.

Positive Diagnosis by Specialty (Chi-Square Tests) Inclusive Dates January 1, 2016, and December 12, 2022 (N = 3825).

GIANT_CELL	SURG_SPEC							Total
		CT_SURG	ENT_OPHTH	GEN_SURG	MULTIPLE	NEURO	VASC_SURG
0 (negative)	Count	152	232	1062	80	60	1104	2690
	Row %	5.7	8.6	39.5	3.0	2.2	41.0	100.0
	Col %	76.4 a	68.8 a, b	72.3 a	78.4 a	75.9 a, b	67.3 b	70.3
1 (positive)	Count	47	105	406	22	19	536	1135
	Row %	4.1	9.3	35.8	1.9	1.7	47.2	100.0
	Col %	23.6 a	31.2 a, b	27.7 a	21.6 a	24.1 a, b	32.7 b	29.7
Total	Count	199	337	1468	102	79	1640	3825
	Row %	5.2	8.8	38.4	2.7	2.1	42.9	100.0
	Col %	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Each subscript letter denotes a subset of SURG_SPEC categories whose column proportions do NOT differ significantly from each other at the .05 level. Bolded numbers indicate percent of each specialty with those results.

In conclusion, temporal artery biopsies are performed by a variety of surgical disciplines across different regions of the United States. The majority of these procedures were performed by general surgeons and vascular surgeons, in the Northeast and Midwest with otolaryngologists and ophthalmologists adding substantially to the total in the South and West. Future research may investigate whether formal training in temporal artery biopsy procedures exists within their respective residency curricula. There also exists a significant difference in the rate of positive diagnosis by surgical discipline, highlighting an avenue for further study in order to assess whether this can be attributed to a function of referral pattern or surgical training and experience.