Repeatability of Serial Carotid Intima Media Thickness Scanning on Individual Subjects

Background. Heart disease affects millions of Americans each year. In order to improve primary prevention, early risk identification is essential. B-mode ultrasound of the common carotid artery (CCA) intima-media thickness (IMT) assesses risk of a coronary event early in the process of plaque development. Because IMT changes are so small over time, in order to determine clinically significant versus clinically insignificant changes in IMT over a 12 month time period, a protocol is needed which can detect the least significant difference (LSD) of at least 0.030 mm. Purpose. The purpose of this study was to develop and test a well-defined protocol for CCA IMT testing, using an edge detection software program, in order to reach this LSD goal. Methodology. Using a repeated measures study design, 26 subjects were scanned over four weeks, one session a week for a total of four separate sessions. Three operators performed scanning at the first session and two operators at the following three sessions on each subject. Operators obtained far wall measurements of a 10 mm section of IMT, centered at five mm proximal to the bulb. Images were recorded from two angles of both the right and left CCA. Six measures (three with EKG gating and three without), were recorded per angle for a total of 24 per subject or 2,400 total images. Analysis. Analysis of data using generalizability theory was performed to determine the optimal number of sessions, measurements, operators and machines and to assess whether a LSD of at least 0.030 mm can be detected. Data were also analyzed to determine whether the max or the mean IMT has a higher repeatability estimate and whether EKG gating is a significant factor in repeatability of IMT images. Generalizability coefficients were computed using seven facets [session, replication (one measure-three were taken per angle), angle, machine (instrument), readings (measurements), operator, and reader] and interactions of each. Four more generalizability coefficients were computed based on EKG gating and whether max or mean IMT values were used. Significance to Preventive Care. IMT scanning is useful in the identification of subclinical atherosclerotic disease risk. The ability to track and assess the efficacy of prescribed measures intended to reduce cardiovascular disease risk can also be accomplished with IMT scanning. Results. The percentage of error variance for mean, non-gated IMT values showed results of the 16 variance components comprised of the seven facets and their interactions. The greatest contributors to measurement error were machine (16.79%), and the following interactions: subject*operator (13.29%), subject*session (11.2%), and subject*machine (6.95%). If one operator uses only one model machine to acquire three images from each of two specific angles (both left and right sides, 12 images), and the same operator scans the same subject in the same way the next time (within 4 weeks), then the same reader measures the IMT images twice, one can expect IMT results will be within 96.5% of the first IMT value, 90% of the time. At maximal standardization, non-EKG gating provides consistently superior LSD and reproducibility over EKG gating. In this study, a LSD of 0.030mm was detected. There was a significant difference when using two different model ultrasound scanners for serial tracking of individuals; one consistent model of machine is recommended. Conclusion. Based on results of this study, when performing serial carotid ultrasounds, it is important to use a consistent model of ultrasound machine. EKG gating does not improve repeatability. Use of IMT promises to be a useful noninvasive measurement which will allow practitioners to identify subclinical atherosclerotic disease risk and to track and assess the efficacy of prescribed measures aimed at reducing the amount of cardiovascular disease risk in those who are at high risk

Decisions to Choose COVID-19 Vaccination by Health Care Workers in a Southern California Safety Net Medical Center Vary by Sociodemographic Factors

Background: Limited information exists regarding COVID-19 vaccine hesitancy among healthcare workers (HCWs). Our previous survey analyzed the reasons for HCWs’ decisions to accept vaccination, suggesting that a “one-size fits all” approach may not suffice to increase vaccine uptake. Methods: Based on the vaccination acceptance group (acceptor, hesitant, refuser), we examined differences by sociodemographic factors (race/ethnicity, household income, education) from Likert Scale responses to fourteen influences affecting a decision to be vaccinated using the Kruskal–Wallis test and multinomial logistic regression with mutual adjustment for these sociodemographic factors, age, and sex. Results: Non-Hispanic White vaccine acceptors ranked lower confidence in preventing, withstanding, or treating COVID-19, while Non-Hispanic Blacks more highly regarded the motivation of a religious leader, colleague, or family member. Social media was ranked more influential among Non-Hispanic Asians. Acceptors with lower incomes ranked a job requirement influential; conversely, higher income vaccine hesitant HCWs highly rated this reason. More highly educated acceptors ranked being motivated by colleagues, family, and other HCWs higher. Adjustment weakened some but not all the differences between groups. Conclusions: Sociodemographic factors affect HCWs’ decisions to be vaccinated against COVID-19. Our findings may help develop more focused and tailored strategies to improve vaccination acceptance

Characterization of COVID-19 Vaccine Hesitancy Among Essential Workforce Members of a Large Safety Net Urban Medical Center

ObjectivesVaccine hesitancy among essential workers remains a significant public health challenge. We examined psychological constructs of perceived susceptibility, threat, and self-efficacy and their associations with COVID-19 vaccine hesitancy among a racially and ethnically diverse essential workforce population.MethodsWe performed a cross-sectional survey of essential workers from September-December 2020 at a large Los Angeles safety-net medical center as part of a program offering free COVID-19 serology testing. Program participants completed a standardized survey at the time of phlebotomy. Hierarchical logistic regression was utilized to determine factors independently associated with vaccine hesitancy.ResultsAmong 1327 persons who had serology testing, 1235 (93%) completed the survey. Of these, 958 (78%) were healthcare workers. Based on expressed intent, 22% were vaccine-hesitant 78% were vaccine acceptors. In our multivariate model, vaccine hesitancy was associated with female gender [aOR = 2.09; 95% CI (1.44-3.05)], African American race [aOR = 4.32; (2.16-8.62)], LatinX ethnicity [aOR = 2.47; 95% CI (1.51-4.05)] and history of not/sometimes receiving influenza vaccination [aOR = 4.39; 95% CI (2.98-6.48)]. Compared to nurses, vaccine hesitancy was lower among physicians [aOR = 0.09; 95% CI (0.04-0.23)], non-nursing/non-physician healthcare workers [aOR = 0.55; 95% CI (0.33-0.92)], and non-healthcare care workers [aOR = 0.53; 95% CI (0.36-0.78)].ConclusionsAmong a racially/ethnically diverse group of safety net medical center essential workers, COVID-19 vaccine hesitancy was associated with racial/ethnic minority groups, employment type, and prior influenza vaccination hesitancy. Interestingly, we found no association with the Health Belief Model construct measures of perceived susceptibility, threat, and self-efficacy. Psychological constructs not assessed may be drivers of vaccine hesitancy in our population

Characterization of COVID-19 Vaccine Hesitancy Among Essential Workforce Members of a Large Safety Net Urban Medical Center

Objectives: Vaccine hesitancy among essential workers remains a significant public health challenge. We examined psychological constructs of perceived susceptibility, threat, and self-efficacy and their associations with COVID-19 vaccine hesitancy among a racially and ethnically diverse essential workforce population. Methods: We performed a cross-sectional survey of essential workers from September-December 2020 at a large Los Angeles safety-net medical center as part of a program offering free COVID-19 serology testing. Program participants completed a standardized survey at the time of phlebotomy. Hierarchical logistic regression was utilized to determine factors independently associated with vaccine hesitancy. Results: Among 1327 persons who had serology testing, 1235 (93%) completed the survey. Of these, 958 (78%) were healthcare workers. Based on expressed intent, 22% were vaccine-hesitant 78% were vaccine acceptors. In our multivariate model, vaccine hesitancy was associated with female gender [aOR = 2.09; 95% CI (1.44-3.05)], African American race [aOR = 4.32; (2.16-8.62)], LatinX ethnicity [aOR = 2.47; 95% CI (1.51-4.05)] and history of not/sometimes receiving influenza vaccination [aOR = 4.39; 95% CI (2.98-6.48)]. Compared to nurses, vaccine hesitancy was lower among physicians [aOR = 0.09; 95% CI (0.04-0.23)], non-nursing/non-physician healthcare workers [aOR = 0.55; 95% CI (0.33-0.92)], and non-healthcare care workers [aOR = 0.53; 95% CI (0.36-0.78)]. Conclusions: Among a racially/ethnically diverse group of safety net medical center essential workers, COVID-19 vaccine hesitancy was associated with racial/ethnic minority groups, employment type, and prior influenza vaccination hesitancy. Interestingly, we found no association with the Health Belief Model construct measures of perceived susceptibility, threat, and self-efficacy. Psychological constructs not assessed may be drivers of vaccine hesitancy in our population