Prevalence of Hemodynamically Significant Internal Carotid Artery Disease Based on the Signs of the Zodiac

Abstract

Vascular sonography requires a basic understanding of statistical concepts used to evaluate exam efficacy. Statistical analysis, however, is often viewed as intimidating and dull. To make this subject less threatening and more interesting, our vascular ultrasound class investigated the prevalence of hemodynamically significant internal carotid artery (ICA) disease based on signs of the zodiac. Randomly selected carotid ultrasound patients were obtained from an accredited vascular laboratory database based on month and day of birth. Each sign of the zodiac was assigned 60 patients. Exam results were defined as (1) normal: bilateral < 50% ICA stenoses, or (2) abnormal: unilateral or bilateral ⩾ 50% ICA stenosis. The Fisher exact test was used to compare normal and abnormal patient groups within each sign of the zodiac. The P value of < .05 was used to define statistical significance. A total of 720 patients were included in this analysis. Patients born under the sign of Gemini had significantly fewer numbers of abnormal stenoses than 6 astrological groups: Capricorn ( P = .004), Virgo ( P = .014), Libra ( P = .007), Pisces ( P = .026), Aries ( P = .000), and Sagittarius ( P = .007). Patients born under the sign of Aries had significantly greater numbers of abnormal results than 7 zodiacal groups: Taurus ( P = .001), Aquarius ( P = .002), Gemini ( P = .000), Pisces ( P = .040), Cancer ( P = .015), Scorpio ( P = .002), and Leo ( P = .022). Hemodynamically significant (⩾50%) ICA stenoses were statistically more prevalent for carotid duplex patients born under the zodiac sign of Aries and significantly less prevalent under the sign of Gemini. While these results may be medically unimportant, this vascular ultrasound assignment helps students understand the value of statistical reporting and, in general, made statistical analysis more relatable and enjoyable.