The effect of air quality on sleep and cognitive performance in school children aged 10-12 years: a double-blinded, placebo-controlled, crossover trial.

OBJECTIVES: To investigate the effect of CO2 during sleep on next-morning cognitive performance in young schoolchildren, the authors performed a double-blind fully balanced crossover placebo-controlled study. MATERIAL AND METHODS: The authors included 36 children aged 10-12 years in the climate chamber. The children slept at 21°C in 6 groups each at 3 different conditions separated by 7 days in a random order. Conditions were as follows: high ventilation with CO2 at 700 ppm, high ventilation with added pure CO2 at 2000-3000 ppm, and reduced ventilation with CO2 at 2-3000 ppm and bioeffluents. Children were subjected to a digital cognitive test battery (CANTAB) in the evening prior to sleep and on the next morning after breakfast. Sleep quality was monitored with wrist actigraphs. RESULTS: There were no significant exposure effects on cognitive performance. Sleep efficiency was significantly lower at high ventilation with CO2 at 700 ppm which is considered to be a chance effect. No other effects were seen, and no relation between air quality during sleep and next-morning cognitive performance was observed in the children emitting an estimated 10 lCO2/h per child. CONCLUSIONS: No effect of CO2 during sleep was found on next day cognition. The children were awakened in the morning, and spent from 45-70 min in well-ventilated rooms before they were tested. Hence, it cannot be precluded that the children have benefitted from the good indoor air quality conditions before and during the testing period. The slightly better sleep efficiency during high CO2 concentrations might be a chance finding. Hence, replication is needed in actual bedrooms controlling for other external factors before any generalizations can be made. Int J Occup Med Environ Health. 2023;36(2):177-91.

Danish Women Want to Participate in a Hypothetical Breast Cancer Screening with Harms and No Reduction in Mortality: A Cross-Sectional Survey.

INTRODUCTION: Informed decision making is recommended in breast cancer screening. Decision aids with balanced information on harms and benefits are recommended to support informed decision making. However, informed screening decision making may be challenged by overly positive attitudes toward cancer screening. We hypothesized that a substantial proportion of Danish women would want to participate in screening regardless of the presented information. Therefore, we aimed to estimate the prevalence of Danish women wanting to participate in a hypothetical breast cancer screening offering no reduction in breast cancer mortality but potential harms related to unnecessary treatment. METHODS: In a cross-sectional study, we invited a random sample of 751 women in the nonscreening population aged 44 to 49 y in the Central Denmark Region to an online questionnaire using the official digital mailbox system. The questionnaire included a description of a hypothetical screening and questions about thoughts on breast cancer, health literacy, and questions on the assessment of the hypothetical screening including intended participation, understanding, and belief in information. Data were linked to register data on sociodemographic factors. RESULTS: In total, 43.0% (323/751) responded to the questionnaire. Of these, 247 (82.3% [95% confidence interval: 77.5-86.5]) wanted to participate in the hypothetical breast cancer screening (participation group). More than two-thirds in both the participation group and nonparticipation group seemed to understand the presented information. Half of the women who understood the information disbelieved it. CONCLUSIONS: Exceeding our expectations, a majority of women wanted to participate in a hypothetical screening with potential harms but no reduction in breast cancer mortality. A large proportion understood but disbelieved the screening information. This could indicate that Danish women make their screening decisions based on beliefs rather than presented screening information. This study was registered at ClinicalTrials.gov (Identifier: NCT04509063). HIGHLIGHTS: The majority of Danish women wanted to participate in a hypothetical breast cancer screening with potential harms related to unnecessary treatment but no reduction in mortality.A large proportion of women understood but disbelieved the hypothetical screening information.Informed decision making may be challenging when women disbelieve the information they receive.Enthusiasm for cancer screening and potential disbelief in information are important factors when developing and improving screening information and invitation.

Training of radiology specialists in local staging of primary rectal cancer on MRI: a prospective intervention study exploring the impact of various educational elements on the interpretive performance.

BACKGROUND: MRI interpretation and accurate radiological staging are crucial to the important treatment decisions and a consequent successful patient outcome in rectal cancer. AIMS: To investigate the effect of intensive training on rectal cancer MRI staging performance of radiologists and the impact of different course elements on learning outcomes. METHODS: In this prospective intervention study, 17 radiology specialists and 1 radiology registrar participated in a training programme including a 6-hour imaging workshop, a 3-hour session of individual feedback and independent MRI readings of primary rectal cancer cases. Their rectal MRI interpretive performance was evaluated through repeated readings of 30 training cases before and after each course element and a time interval with no educational intervention. A proforma template for MRI staging of primary rectal cancer was used and the results were compared with a reference standard of an expert panel. Participants repeatedly reported on confidence scores and self-assessed learning outcome. Outcomes were analysed using mixed-effects models. RESULTS: At baseline the quality of rectal MRI assessment varied significantly, with a higher interpretive performance among participants with shorter radiological experience (10.2 years vs 19.9 years, p=0.02). The ability to perform correct treatment allocation improved from 72% to 82% (adjusted OR=2.36, 95% CI 1.64 to 3.39). The improvement was largely driven by the participants with lower performance at baseline and by prevention of overstaging. Individual feedback had a significant impact on the improved interpretive performance (adjusted OR=1.82, 95% CI 1.27 to 2.63), whereas no significant change was seen after workshop or case readings only. Confidence scores increased significantly during training. CONCLUSIONS: Targeted and individualised training improves the rectal cancer MRI interpretive performance essential to successful patient treatment, especially among radiology specialists with lower performance at baseline.

Reliability and structural validity of the Danish Short 4-item version of the Center for Epidemiological Studies Depression Scale for Children (CES-DC4) in adolescents.

BACKGROUND: The 4-item version of the Center of Epidemiological Studies Depression Scale (CES-DC4) is a self-reported questionnaire used to measure depressive symptoms in adolescents, but the psychometric properties of the scale have been tested to only a limited extent. The aim of this study was to examine the reliability and structural validity of the Danish CES-DC4 in 9th graders. METHODS: Using a sample of 72 adolescents 15 to 17 years of age from five 9th grade classes, the reliability of the CES-DC4 was determined by a test-retest study at a 2-week interval. Descriptive statistics of the adolescents were presented, and internal consistency, structural validity, reliability, and agreement between tests were evaluated. The structural validity of the scale was tested by confirmatory factor analysis (CFA), and the sumscores of the test and retest were presented. RESULTS: The estimated Cronbach's α was 0.61 (95% CI 0.50; 0.71). Inter-item and item-rest correlations indicated that one of the four items (item 20) did not fit well on the scale. CFA found a one-factor model suited for the scale, but the factor loadings indicated that item 20 contributed the least to measure the factor (0.29). Sum scores ranged from 0-9 within a possible interval of 0-12. There were no signs of systematic error of the scale. Limits of Agreement (-3.01; 3.79) were broad. The standard error of measurement (SEM = 1.25 point (95% CI.1.05; 1.47)) and intraclass correlation (ICC(2,1) = 0.60 (95% CI: 0.44; 0.73)) calculations showed low reliability of the CES-DC4. CONCLUSION: This study found low reliability of the CES-DC4 with low estimates of ICC and Cronbach's α. The CES-DC4 needs revision, and removal of item 20 and adding more items from the CES-DC should be considered.

Cross-Cultural Adaptation, Reliability and Validity of the Danish Version of the Readiness for Return to Work Instrument.

The objective of the present study was to translate and validate the Canadian Readiness for Return To Work instrument (RRTW-CA) into a Danish version (RRTWDK) by testing its test-retest and internal consistency reliability and its structural and construct validity. Cross-cultural adaptation of the six-staged RRTW-CA instrument was performed in a standardised, systematic five-step-procedure; forward translation, panel synthesis of the translation, back translation, consolidation and revision by researchers, and finally pre-testing. This RRTW-DK beta-version was tested for its psychometric properties by intra-class correlation coefficient and standard error of measurement (n = 114), Cronbach's alpha (n = 471), confirmatory factor analyses (n = 373), and Spearman's rank correlation coefficient (n = 436) in sickness beneficiaries from a municipal employment agency and hospital wards. The original RRTW-CA stage structure could not be confirmed in the RRTWDK. The psychometric properties were thus inconclusive. The RRTW-DK cannot be recommended for use in the current version as the RRTW construct is questionable. The RRTW construct needs further exploration, preferably in a population that is homogeneous with regard to cause of sickness, disability duration and age.

Balance and walking performance are improved after resistance and aerobic training in persons with chronic stroke.

PURPOSE: To investigate the effect of different types of physical training on balance performance and whether improved balance correlates with improved walking performance. METHODS: Forty eight participants with chronic stroke were randomly assigned to aerobic training on cycle ergometer (AT-group), resistance training of the lower extremities (RT-group), or sham training of upper extremities (ST-group). Participants exercised 3 d/week for 12 weeks. Balance (Berg Balance Scale), peak oxygen uptake rate, isometric knee extensor strength, maximal gait speed, and 6 minute walk test were measured at baseline and after 12 weeks. RESULTS: Training specific effects were observed; the AT-group improved peak oxygen uptake rate by 15.5 (6.0-25.0)%, the RT-group improved non-paretic knee extensor strength by 35.1 (18.3-51.9)% and the ST-group improved non-paretic knee extensor strength by 8.9 (0.7-17.1)%. All groups improved balance (6.0 (95% CI: 3.2-8.8)%), maximal gait speed (10.2 (6.5-14.0)%), and 6 minute walk distance (12.4 (8.8-15.9)%) but balance improvements did not correlate with improvements in muscle strength, peak oxygen uptake rate, or walking. CONCLUSIONS: Physical exercise improves balance and walking performance, but improved balance is not a prerequisite for functional improvements in chronic stroke. Implications for Rehabilitation Aerobic training and progressive resistance training show small significant improvements in balance and walking, indicating a possible clinical relevance of these training modalities. Improvements in balance may not be a prerequisite for improvements in walking distance when assistive devices are allowed during walking tests.

Systemic effects of wood smoke in a short-term experimental exposure study of atopic volunteers.

OBJECTIVE: To investigate whether short-term systemic effects of wood smoke occurred in atopic subjects after experimental wood smoke exposures. METHODS: A double-blind climate chamber study was conducted on 20 healthy atopic subjects with exposures to filtered air and wood smoke. Pneumoproteins, coagulation and adhesion factors, and cytokines were measured. Heart rate was monitored with pulse monitors. Data were analyzed with mixed models. RESULTS: Few differences in the outcomes were observed. Plasma tissue factor remained elevated during filtered air exposure (P = 0.002). P-selectin declined independent of exposure (P = 0.0006). Interleukin-6 increased after filtered air (P = 0.03). CONCLUSIONS: The study confirmed previous observations among nonatopics of limited changes after a 3-hour wood smoke exposure.

Antidepressant exposure in pregnancy and risk of autism spectrum disorders.

BACKGROUND: Both the use of antidepressant medication during pregnancy and the prevalence of autism spectrum disorder have increased during recent years. A causal link has recently been suggested, but the association may be confounded by the underlying indication for antidepressant use. We investigated the association between maternal use of antidepressant medication in pregnancy and autism, controlling for potential confounding factors. METHODS: We identified all children born alive in Denmark 1996-2006 (n=668,468) and their parents in the Danish Civil Registration System. We obtained information on the mother's prescriptions filled during pregnancy from the Danish National Prescription Registry, and on diagnoses of autism spectrum disorders in the children and diagnoses of psychiatric disorders in the parents from the Danish Psychiatric Central Register. In a cohort analysis, we estimated hazard ratios of autism spectrum disorders in children exposed to antidepressant medication during pregnancy compared with children who were not exposed, using Cox proportional hazards regression analysis. Furthermore, we estimated the risk for autism spectrum disorder in a sibling design. RESULTS: Children exposed prenatally to antidepressants had an adjusted hazard ratio of 1.5 (95% confidence interval [CI] 1.2-1.9) for autism spectrum disorder compared with unexposed children. Restricting the analysis to children of women with a diagnosis of affective disorder, the adjusted hazard ratio was 1.2 (95% CI 0.7-2.1), and the risk was further reduced when exposed children were compared with their unexposed siblings (adjusted hazard ratio 1.1; 95% CI 0.5-2.3). CONCLUSION: After controlling for important confounding factors, there was no significant association between prenatal exposure to antidepressant medication and autism spectrum disorders in the offspring.

Prenatal valproate exposure and risk of autism spectrum disorders and childhood autism.

IMPORTANCE: Valproate is used for the treatment of epilepsy and other neuropsychological disorders and may be the only treatment option for women of childbearing potential. However, prenatal exposure to valproate may increase the risk of autism. OBJECTIVE: To determine whether prenatal exposure to valproate is associated with an increased risk of autism in offspring. DESIGN, SETTING, AND PARTICIPANTS: Population-based study of all children born alive in Denmark from 1996 to 2006. National registers were used to identify children exposed to valproate during pregnancy and diagnosed with autism spectrum disorders (childhood autism [autistic disorder], Asperger syndrome, atypical autism, and other or unspecified pervasive developmental disorders). We analyzed the risks associated with all autism spectrum disorders as well as childhood autism. Data were analyzed by Cox regression adjusting for potential confounders (maternal age at conception, paternal age at conception, parental psychiatric history, gestational age, birth weight, sex, congenital malformations, and parity). Children were followed up from birth until the day of autism spectrum disorder diagnosis, death, emigration, or December 31, 2010, whichever came first. MAIN OUTCOMES AND MEASURES: Absolute risk (cumulative incidence) and the hazard ratio (HR) of autism spectrum disorder and childhood autism in children after exposure to valproate in pregnancy. RESULTS: Of 655,615 children born from 1996 through 2006, 5437 were identified with autism spectrum disorder, including 2067 with childhood autism. The mean age of the children at end of follow-up was 8.84 years (range, 4-14; median, 8.85). The estimated absolute risk after 14 years of follow-up was 1.53% (95% CI, 1.47%-1.58%) for autism spectrum disorder and 0.48% (95% CI, 0.46%-0.51%) for childhood autism. Overall, the 508 children exposed to valproate had an absolute risk of 4.42% (95% CI, 2.59%-7.46%) for autism spectrum disorder (adjusted HR, 2.9 [95% CI, 1.7-4.9]) and an absolute risk of 2.50% (95% CI, 1.30%-4.81%) for childhood autism (adjusted HR, 5.2 [95% CI, 2.7-10.0]). When restricting the cohort to the 6584 children born to women with epilepsy, the absolute risk of autism spectrum disorder among 432 children exposed to valproate was 4.15% (95% CI, 2.20%-7.81%) (adjusted HR, 1.7 [95% CI, 0.9-3.2]), and the absolute risk of childhood autism was 2.95% (95% CI, 1.42%-6.11%) (adjusted HR, 2.9 [95% CI, 1.4-6.0]) vs 2.44% (95% CI, 1.88%-3.16%) for autism spectrum disorder and 1.02% (95% CI, 0.70%-1.49%) for childhood autism among 6152 children not exposed to valproate. CONCLUSIONS AND RELEVANCE: Maternal use of valproate during pregnancy was associated with a significantly increased risk of autism spectrum disorder and childhood autism in the offspring, even after adjusting for maternal epilepsy. For women of childbearing potential who use antiepileptic medications, these findings must be balanced against the treatment benefits for women who require valproate for epilepsy control.

Effects of wood smoke particles from wood-burning stoves on the respiratory health of atopic humans.

BACKGROUND: There is growing evidence that particulate air pollution derived from wood stoves causes acute inflammation in the respiratory system, increases the incidence of asthma and other allergic diseases, and increases respiratory morbidity and mortality. The objective of this study was to evaluate acute respiratory effects from short-term wood smoke exposure in humans. Twenty non-smoking atopic volunteers with normal lung function and without bronchial responsiveness were monitored during three different experimental exposure sessions, aiming at particle concentrations of about 200 µg/m(3), 400 µg/m(3), and clean air as control exposure. A balanced cross-over design was used and participants were randomly allocated to exposure orders. Particles were generated in a wood-burning facility and added to a full-scale climate chamber where the participants were exposed for 3 hours under controlled environmental conditions. Health effects were evaluated in relation to: peak expiratory flow (PEF), forced expiratory volume in the first second (FEV1), and forced vital capacity (FVC). Furthermore, the effects were assessed in relation to changes in nasal patency and from markers of airway inflammation: fractional exhaled nitric oxide (FENO), exhaled breath condensate (EBC) and nasal lavage (NAL) samples were collected before, and at various intervals after exposure. RESULTS: No statistically significant effect of wood smoke exposure was found for lung function, for FENO, for NAL or for the nasal patency. Limited signs of airway inflammation were found in EBC. CONCLUSION: In conclusion, short term exposure with wood smoke at a concentration normally found in a residential area with a high density of burning wood stoves causes only mild inflammatory response.