Tic disorders in children and adolescents: does the clinical presentation differ in males and females? A report by the EMTICS group

Tic disorders have a strong male predominance, with a male-to-female ratio of 4:1 in Tourette syndrome (TS) and 2:1 in persistent tic disorders. In other neurodevelopmental conditions, such as autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD), the disparity in sex distribution has been partially related to differences in symptom presentation between males and females. In tic disorders, however, little research has been conducted on this topic, probably due to the limited access to large samples with a significant proportion of females. The aim of this study was to describe sex differences in the clinical presentation of tic disorders in children and adolescents in one of the largest pediatric samples with TS/persistent tic disorders (n = 709, 23.3% females) recruited as part of the European Multicenter Tics in Children Study (EMTICS). Validated measures assessed the severity of tics and comorbid psychiatric symptoms. Using mixed-effect models, we found that sex had a significant influence on the severity of tics, ADHD symptoms, ASD symptoms, and emotional problems. Males had more severe symptoms than females, except for emotional problems. We also observed a statistically significant interaction between sex and age on the severity of tics and compulsions, with females showing higher symptom severity with increasing age than males. These findings indicate that the clinical presentation of TS/persistent tic disorders varies with sex. Males seem to exhibit a more noticeable pattern of clinical symptoms at a younger age that may contribute to their earlier detection in comparison to females.

     

The relevance of psychosocial variables and working conditions in predicting nurses' coping strategies during the SARS crisis: an online questionnaire survey

OBJECTIVES: The purpose of this investigation was to examine the relationship between psychosocial variables and working conditions, and nurses' coping methods and distress in response to the severe acute respiratory syndrome (SARS) crisis in Canada. PARTICIPANTS AND PROCEDURE: The sample consisted of 333 nurses (315 women, 18 men) who completed an Internet-mediated questionnaire that was posted on the Registered Nurses' Association of Ontario (RNAO) website between March and May 2004. The questionnaire was restricted to respondents who had to authenticate their RNAO membership with a valid username and password before accessing the questionnaire. This served a dual purpose: to ensure that only RNAO nurses completed the questionnaire and thereby safeguarding the generalizability of the findings; and second, to prevent any one nurse from contributing more than once to the overall sample. RESULTS: Correlational analysis yielded several significant relationships between psychosocial variables and working conditions, and the traditional correlates of burnout and stress. Three multiple regression analysis revealed that the model we evolved--including higher levels of vigor, organizational support, and trust in equipment/infection control initiative; and lower levels of contact with SARS patients, and time spent in quarantine--predicted to lower levels of avoidance behavior, emotional exhaustion, and state anger. CONCLUSIONS: By employing models of stress and burnout that combine psychosocial variables and working conditions, researchers can account for significant amounts of variance in outcomes related to burnout. These findings highlight the importance of vigor and perceived organizational support in predicting nurses' symptoms of burnout. For healthcare administrators, this means that a likely strategy for assuaging the negative outcomes of stress should address nurses' psychosocial concerns and the working conditions that they face during novel times of crisis.     

A note on the use of outlier criteria in Ontario laboratory quality control schemes

OBJECTIVES: This paper examines the pitfalls that arise when an outlier is assessed using a criterion based on a fixed multiple of the standard deviation rather than an established statistical test. Although the former approach is statistically invalid, it is the favored method for identifying outliers in Ontario laboratory quality control protocols. DESIGN AND METHODS: Computer simulations are used to calculate the probability of a false positive result (classifying a valid observation as an outlier) when outlier criteria based on fixed multiples of the standard deviation are applied to samples containing no outliers. RESULTS: The estimated probability of a false positive result is tabulated over various sample sizes. Outlier criteria based on fixed multiples of the standard deviation are shown to be highly inefficient. CONCLUSIONS: This work presents arguments for discontinuing the widespread practice of using outlier criteria based on fixed multiples of the standard deviation to identify outliers in univariate samples.     

Higher order aberrations,refractive error development and myopia control: a review

Evidence from animal and human studies suggests that ocular growth is influenced by visual experience. Reduced retinal image quality and imposed optical defocus result in predictable changes in axial eye growth. Higher order aberrations are optical imperfections of the eye that alter retinal image quality despite optimal correction of spherical defocus and astigmatism. Since higher order aberrations reduce retinal image quality and produce variations in optical vergence across the entrance pupil of the eye, they may provide optical signals that contribute to the regulation and modulation of eye growth and refractive error development. The magnitude and type of higher order aberrations vary with age, refractive error, and during near work and accommodation. Furthermore, distinctive changes in higher order aberrations occur with various myopia control treatments, including atropine, near addition spectacle lenses, orthokeratology and soft multifocal and dual-focus contact lenses. Several plausible mechanisms have been proposed by which higher order aberrations may influence axial eye growth, the development of refractive error, and the treatment effect of myopia control interventions. Future studies of higher order aberrations, particularly during childhood, accommodation, and treatment with myopia control interventions are required to further our understanding of their potential role in refractive error development and eye growth.