Application of the Parent Attitudes about Childhood Vaccines (PACV) survey in three national languages in Switzerland: Exploratory factor analysis and Mokken scale analysis.

Vaccine hesitancy (VH) is a complex and context-specific phenomenon that is linked to under-immunization and poses challenges to immunization programs. The Parent Attitudes about Childhood Vaccines (PACV) is an instrument developed to measure VH. We translated the PACV into three languages (German, French and Italian) and administered it to 1388 Swiss parents. We used exploratory factor analysis (EFA) to confirm the scale sub-domains, Cronbach's alpha to assess internal consistency reliability, and Mokken scale analysis (MSA), to explore unidimensionality of each language version. We determined to construct validity by linking parental PACV score to children's immunization status for the first dose of measles vaccine. For the 15-item PACV, EFA extracted three sub-domains in German and French and four sub-domains in Italian. Cronbach's alpha was >0.8 across the three languages, and MSA produced a 13-item German, 14-item French, and 11-item Italian PACV. EFA and MSA of the short version PACV extracted a single factor and scale with Cronbach's alpha >0.7 in all three language versions. VH was significantly associated with non-timely receipt of the first dose of measles in all languages (odds ratio of 20.7, 21.3, and 8.3 for German, French, and Italian languages, respectively). The translated and revised PACV-15 versions are valid and reliable instruments for VH measurement. The structure and reliability of the short version of the PACV was as good as the long version. Our results suggest that the PACV can be used to measure parental VH outside the US in the validated languages.

The Youth Attitudes about Vaccines (YAV-5) scale: adapting the parent attitudes about childhood vaccines short scale for use with youth in German, French, and Italian in Switzerland, exploratory factor analysis and mokken scaling analysis.

No validated measures of vaccine hesitancy (VH) for youth vaccination currently exist. We adapted the Parent Attitudes about Childhood Vaccines survey (PACV-15) for use in youth to create the version Youth Attitudes about Vaccines survey (YAV-14 and YAV-5), then translated it into three languages (German, French, and Italian). We administered the YAV-14 to 1,003 youth aged 15-26 years in Switzerland. We used exploratory factor analysis and Mokken scale analysis to explore the psychometric properties, Cronbach's alpha to investigate the reliability for the YAV-14 and the YAV-5, but we only report results of the YAV-5 analysis here. We determined construct validity by logistic regression of the association between youth VH as measured by the YAV-5 and non-receipt of the first human papillomavirus (HPV) vaccine dose. EFA produced a single scale in German and French while two factors were obtained in Italian. All language versions fit the Mokken scale models with medium-scale strength. There was a significant association between VH and HPV vaccine non-receipt for the full sample (odds ratio (OR); 1.93, 95% confidence interval (CI); 1.31-2.85). Language-stratified analyses found a significant association between VH and non-immunization in the German-language sample. Our results demonstrate that the German version of YAV-5 is a valid and reliable scale for identifying vaccine hesitant youth regardless of sex, and the French version is a valid and reliable scale for identifying vaccine hesitant female youth. Further validation is needed for Italian and French-speaking male youth.

Value of "functional" magnetic resonance imaging in the diagnosis of ligamentous affection at the craniovertebral junction.

INTRODUCTION: Objective of this investigation was to evaluate the rotational mobility at the craniocervical junction and changes in the width of the subarachnoid space during head rotation in healthy volunteers using Magnetic Resonance Imaging (MRI). MATERIALS AND METHODS: In 30 healthy volunteers axial 3mm Half-Fourier Acquisition Single-Shot Turbo Spin-Echo (HASTE) sequences were obtained with the subject's head in neutral position, and in maximal rotation to the left and right respectively. All MRI examinations were evaluated by two neuroradiologists in consensus. The ranges of axial rotation at C0-C2 as well as the width of the subarachnoid space in neutral, and in maximal rotated position were measured. Student's t-tests were used to compare group differences. RESULTS: Total range of right-to-left-rotation at C0-C2 was 59-183° with mean rotation to the right and left side of 70° (±12.7°) and 75° (±13.0°). Difference between degrees of rotation to both sides was on average 4.9° (±7.1°) with a significantly greater rotational range to the left compared to the right. In neutral position, distance between the dura and the ventral wall of the cervical spinal cord was 1.6-4.2mm. In active rotation interface between dura and myelon was evident in 19 volunteers with unilateral contact in 7, and bilateral contact in 12 cases. CONCLUSIONS: High variablity of rotational mobility at the craniocervical junction and attenuation of width of the subarachnoid space during head rotation are frequent findings in an asymptomatic population. Our results indicate that the assessment of these parameters is of limited diagnostic value in patients with whiplash-associated disorders.

Effect of magnetic resonance imaging field strength on delineation and signal intensity of alar ligaments in healthy volunteers.

STUDY DESIGN: A prospective study of healthy volunteers. OBJECTIVE: To evaluate the influence of magnetic resonance imaging (MRI) field strength on the delineation and signal intensity of alar ligaments (AL) in healthy volunteers. SUMMARY OF BACKGROUND DATA: The fact that AL physiologically show morphologic variabilities is well established. However, presence and etiology of high-signal intensities within the AL as well as the influence of the MRI field strength on the signal characteristics of AL are still not completely understood. METHODS.: Coronal and sagittal 2-mm proton-density weighted sequences were acquired in 50 healthy volunteers using different MRI field strengths (1 T, 1.5 T, 3 T). Delineation and signal characteristics of AL were evaluated by 2 neuroradiologists independently. Differences concerning delineation and signal intensity between the MRI scanners, inter rater reliability between the 2 readers, and intrarater reliability at different time points were calculated. RESULTS: Delineation of AL was significantly better both on 3 T and 1.5 T than on 1 T (P = 0.05) in sagittal as well as in coronal view. In coronal view delineation was significantly better on 3 T than on 1.5 T, whereas in sagittal view no significant difference was evident when comparing 1.5 T and 3 T. Concerning signal intensity of AL in sagittal view, there was no significant difference between the 3 different field strengths. Inter-rater and intrarater agreements were fair to moderate with respect to delineation as well as signal intensity of AL. CONCLUSION: 1.5 T and 3 T significantly improve the delineation of AL when compared with lower field strength (1 T), but signal intensity of the AL in healthy volunteers is not influenced by the field strength. Increased signal is present in asymptomatic subjects on both low- and high-field magnetic resonance systems. Accordingly, the pathologic relevance of increased signal intensity of the AL, regardless of field strength, may not be indicative of traumatic AL injury.