Marginal and Conditional Confounding Using Logits.

This article presents two ways of quantifying confounding using logistic response models for binary outcomes. Drawing on the distinction between marginal and conditional odds ratios in statistics, we define two corresponding measures of confounding (marginal and conditional) that can be recovered from a simple standardization approach. We investigate when marginal and conditional confounding may differ, outline why the method by Karlson, Holm, and Breen recovers conditional confounding under a "no interaction"-assumption, and suggest that researchers may measure marginal confounding by using inverse probability weighting. We provide two empirical examples that illustrate our standardization approach.

Sources of mathematics self-efficacy: The interactive role of parental education and perceptions of teachers.

Using US National Education Longitudinal Study (NELS) data, we explore how parental education and primary students' perceptions of their teachers interact to impact students' self-efficacy in mathematics. Our results demonstrate that students tend to have higher self-efficacy if they perceive that their teacher promotes the importance of mathematics. This relationship holds regardless of parental education, though it is strongest for children of parents without a university education. Children of less educated parents also tend to have lower self-efficacy if they attend private schools, which typically have high average parental socio-economic status (SES). School type has no discernable impact on children of university-educated parents. These findings are highly relevant to the Canadian context, which is characterized by schools being stratified by SES and the high importance of STEM education for occupational outcomes.

En utilisant les données de l'étude longitudinale de l'éducation nationale américaine, nous explorons comment l'éducation parentale et les perceptions qu'ont les élèves du primaire de leurs enseignants interagissent pour influencer l'auto-efficacité des élèves en mathématiques. Nos résultats démontrent que les élèves ont tendance à avoir une plus grande efficacité personnelle s'ils perçoivent que leur enseignant promeut l'importance des mathématiques. Cette relation est valable quel que soit le niveau d'éducation des parents, bien qu'elle soit plus forte pour les enfants dont les parents n'ont pas fait d'études universitaires. Les enfants de parents moins éduqués ont également tendance à avoir une moins bonne auto-efficacité s'ils fréquentent des écoles privées, où le statut socio-économique moyen des parents est généralement élevé. Le type d'école n'a pas d'impact perceptible sur les enfants dont les parents ont fait des études universitaires. Ces résultats sont très pertinents dans le contexte canadien, qui se caractérise par une stratification des écoles en fonction du statut socio-économique et une grande importance de l'enseignement des STIM pour les résultats professionnels.

Psychosocial working conditions and sickness absence among younger employees in Denmark: a register-based cohort study using job exposure matrices.

OBJECTIVE: Previous literature has established associations between psychosocial working conditions and sickness absence (SA), but only few studies have examined associations among younger employees. This study aimed to investigate associations between psychosocial working conditions and SA among employees, aged 15-30 years, who entered the labor market in Denmark between 2010 and 2018. METHOD: We followed 301 185 younger employees in registers for on average 2.6 years. Using job exposure matrices, we assessed job insecurity, quantitative demands, decision authority, job strain, emotional demands, and work-related physical violence. Adjusted rate ratios of SA spells of any length were estimated for women and men separately with Poisson models. RESULTS: Among women, employment in occupations with high quantitative demands, low decision authority, high job strain, high emotional demands, or high work-related physical violence was associated with higher rates of SA. Being employed in occupations with high versus low emotional demands showed the strongest association with SA, with a rate ratio of 1.44 [95% confidence interval (CI) 1.41-1.47]. Among men, being employed in occupations with low decision authority showed the strongest association with SA (1.34, 95% CI 1.31-1.37), whereas occupations with high quantitative demands, high job strain, and high emotional demands were associated with lower rates of SA. CONCLUSION: We found that several psychosocial working conditions were associated with SA spells of any length. Associations with SA spells of any length resemble associations with long-term SA, suggesting that results from previous studies on long-term SA may be generalizable to all lengths of SA among younger employees.

What cultural hierarchy? Cultural tastes, status and inequality.

Research on cultural stratification often draws on Bourdieu's misrecognition model to interpret socioeconomic gradients in cultural tastes and participation. In this model, an assumed cultural hierarchy leads individuals to adopt cultural tastes and behaviours whose status is congruent with that of their socioeconomic position (SEP). Yet, this assumed cultural hierarchy remains opaque. In this paper, we derive and test three empirical implications of the cultural hierarchy: (1) cultural activities have different status (recognition); (2) individuals in high and low SEPs have similar perceptions of the status of cultural activities (necessary condition for misrecognition); and (3) individuals prefer and engage in cultural activities whose status matches that of their SEP (status congruence). We collected survey data in Denmark and find that cultural activities differ in terms of perceived status (e.g., opera has higher perceived status than flea market), status perceptions are similar in high- and low-SEP groups and individuals prefer activities whose status matches that of their SEP. These results are consistent with the idea that a cultural hierarchy exists that sustains SEP gradients in cultural tastes and participation.

Employment success of social assistance recipients: A provincial analysis by industry.

Poverty continues to burden millions of Canadians each year, and social assistance (SA) is one program that provides last-resort financial assistance, conditional upon looking for and accepting work. Using tax panel data of SA recipients from across seven Canadian regions between 2000 and 2018, we model the probabilities of employment success (ES) across industry of employment, SA benefit amounts, unionization, and individual-level characteristics. We adopt an economic stance to explain reliance upon SA, examining the broader macroeconomic indicators of ES, and to demonstrate the factors associated with exiting SA. We find that many SA recipients do not present evidence of recent employment, indicating a disconnect between stated SA program aims and their outcomes. We provide evidence for increased SA benefits and unionization as significant predictors of ES of SA recipients.

La pauvreté continue de peser sur des millions de Canadiens chaque année, et l'aide sociale (AS) est un programme qui fournit une aide financière de dernier recours, à condition de chercher et d'accepter un emploi. À l'aide de données fiscales de panel sur les bénéficiaires de l'aide sociale de sept régions canadiennes entre 2000 et 2018, nous modélisons les probabilités de réussite professionnelle en fonction du secteur d'emploi, du montant des prestations d'aide sociale, de la syndicalisation et des caractéristiques individuelles. Nous adoptons une position économique pour expliquer le recours à l'AS, en examinant les indicateurs macroéconomiques plus larges de la réussite professionnelle, et pour démontrer les facteurs associés à la sortie de l'AS. Nous constatons que de nombreux bénéficiaires de l'AS ne présentent pas de preuve d'emploi récent, ce qui indique un décalage entre les objectifs déclarés du programme d'AS et leurs résultats. Nous fournissons des preuves que l'augmentation des prestations d'AS et la syndicalisation sont des prédicteurs importants de la réussite de l'emploi des bénéficiaires de l'AS.

Work-related violence and depressive disorder among 955,573 employees followed for 6.99 million person-years. The Danish Work Life Course Cohort study: Work-related violence and depression.

BACKGROUND: We examined the association between probability of work-related violence and first diagnosis of depressive disorder whilst accounting for the potential selection of individuals vulnerable to depression into occupations with high probability of work-related violence. METHODS: Based on a pre-published study protocol, we analysed nationwide register data from the Danish Work Life Course Cohort study, encompassing 955,573 individuals followed from their entry into the workforce, and free from depressive disorder before work-force entry. Depressive disorder was measured from psychiatric in- and outpatient admissions. We measured work-related violence throughout the worklife by the annual average occupational risk of violence exposure. Using Cox proportional hazards regression, we examined the longitudinal association between work-related violence (both past year and cumulative life-long exposure) and first depressive disorder diagnosis, whilst adjusting for numerous confounders including parental psychiatric and somatic diagnoses, childhood socioeconomic position, and health services use before workforce entry. RESULTS: The risk of depressive disorder was higher in individuals with high probability of past year work-related violence (hazard ratio: 1.11, 95% CI: 1.06-1.16) compared to employees with low probability of exposure, after adjustment for confounders. Among women, associations were robust across industries, whereas among men, associations were limited to certain industries. LIMITATIONS: Violence was measured on the job group and not the individual level, likely resulting in some misclassification of the exposure. CONCLUSIONS: Work-related violence may increase the risk of depressive disorder, independent of pre-existing risk factors for depressive disorder. These findings underline the importance of preventing work-related violence.

The student mental health crisis: Assessing psychiatric and developmental explanatory models.

INTRODUCTION: Student mental health problems are now commonly understood using a psychiatric model in which diagnosed anxiety and mood disorders are viewed to be so widespread as to constitute a crisis. Less attention is given to the role of developmental processes, such as identity formation and purpose, in understanding the types of distress current university students can experience. We fill this void by simultaneously assessing the effectiveness of both psychiatric and developmental variables in predicting how often students feel emotional distress in the form of frequently feeling too anxious, depressed, or overwhelmed to study. METHODS: Binary logit models were fitted to online survey data collected from a cross-sectional, nation-wide sample of 1010 Canadian full-time university students aged 18 to 24 (63% female). RESULTS: Our findings confirm that the psychiatric and developmental models both explain variance in academic distress. We also found that a developmental model operationalized using key measures of identity formation and purpose significantly accounted for academic distress, over and above variance explained by psychiatric diagnoses. In other words, not only do many students with a psychiatric diagnosis experience distress linked to problems with identity/purpose that interferes with studying, but so do a considerable proportion of students without any diagnosis. This impact persists after controlling for a host of variables assessing demographic/family background, academic preparation and performance, and a number of factors believed to aggravate emotional distress. CONCLUSIONS: Universities can respond to the mental health crisis by approaching some forms of distress as developmental problems associated with identity and purpose.

Cumulated and most recent job control and risk of disability pension in the Danish Work Life Course Cohort (DaWCo).

BACKGROUND: Previous studies have found low job control to be associated with a higher risk of disability pension (DP). Most studies have measured job control only at one time-point, and there is a lack of knowledge regarding the role of exposure duration. This study examines the prospective association between job control and DP measuring exposure both cumulated throughout work life and most recent. METHODS: We included 712 519 individuals (about 4.5 million person-years) from The Danish Work Life Course Cohort which follows young employees in Denmark from their entry into the labour market. Job control was assessed with a job exposure matrix and DP with register data on public transfer payments. We adjusted for several potential life course confounders, including physical demands at work and parental socioeconomic position and psychiatric and somatic diagnoses. RESULTS: Employees in occupations with low job control had a higher risk of DP. There were effects of both cumulated and most recent job control when mutually adjusted. Fully adjusted hazard ratios (HRs) were 1.14 [95% confidence intervals (CIs) 1.11-1.17] and 1.15 (95% CI 1.02-1.29) for cumulated and most recent job control, respectively. Without mutual adjustment, estimates were 1.15 (95% CI 1.13-1.18) and 1.55 (95% CI 1.39-1.72) for cumulated and most recent low job control, respectively. CONCLUSIONS: Low job control predicts a higher risk of DP, even after adjustment for physical demands at work. The results indicate both gradual and short-term effects of low job control on DP risk.

Psychosocial working conditions and depressive disorder: disentangling effects of job control from socioeconomic status using a life-course approach.

PURPOSE: Job control, the combination of skill discretion and decision authority, is considered a central component of the psychosocial working environment. This longitudinal study examines the relation between job control and risk of incident depressive disorder using a life-course approach. METHODS: We analyze data from The Danish Work Life Course Cohort study, including all Danish individuals aged 15-30 who entered the Danish labor market during 1995-2009 and were free from depressive disorder at entry (955,573 individuals). We measured job control using a job exposure matrix. Depressive disorders were measured using information from nationwide registers of psychiatric in- and outpatient admissions. Using Cox regression models we estimated the prospective association between job control and risk of incident depressive disorders. Analyses accounted for a range of potential confounders prior to workforce entry including socioeconomic status in adolescence and parental psychiatric and somatic diagnoses prior to labor market entry, together with potential confounders in adulthood including income, education, and demographics. RESULTS: Lower levels of past year job control were associated with a higher risk of depressive disorder after adjustment for all covariates (HR = 1.27, 95% CI 1.16-1.38). Results stratified by gender showed associations for both men (HR = 1.38, 95% CI 1.19-1.61) and women (HR = 1.19, 95% CI 1.08-1.32). CONCLUSIONS: Our findings suggest that the level of job control at work affects the risk of clinically diagnosed depressive disorder, and that this association is not due to confounding by socioeconomic status.

Socioeconomic Position Across the Life Course and Cognitive Ability Later in Life: The Importance of Considering Early Cognitive Ability.

Objective: Investigate direct and indirect associations between markers of socioeconomic position (SEP) across the life course and midlife cognitive ability while addressing methodological limitations in prior work. Method: Longitudinal data from the Danish Metropolit cohort of men born in 1953 (N = 2,479) who completed ability tests at age 12, 18, and 56-58 linked to register-based information on paternal occupational class, educational attainment, and occupational level. Associations were assessed using structural equation models, and different models were estimated to examine the importance of accounting for childhood ability and measurement error. Results: Associations between adult SEP measures and midlife ability decreased significantly when adjusting for childhood ability and measurement error. The association between childhood and midlife ability was by far the strongest. Discussion: The impact of adult SEP on later life ability may be exaggerated when not accounting for the stability of individual differences in cognitive ability and measurement error in test scores.

Medical treatment of Attention Deficit/Hyperactivity Disorder (ADHD) and children's academic performance.

Attention Deficit/Hyperactivity Disorder (ADHD) is negatively associated with a range of academic achievement measures. We use Danish administrative register data to study the impact of medical treatment of ADHD on children's academic performance assessed by student grade point average (GPA). Using administrative register data on children, who begin medical treatment, we conduct a natural experiment and exploit plausible exogenous variation in medical nonresponse to estimate the effect of medical treatment on school-leaving GPA. We find significant effects of treatment on both exam and teacher evaluated GPAs: Compared to consistent treatment, part or full discontinuation of treatment has large significant negative effects reducing teacher evaluation and exam GPA with .18 and .22 standard deviations, respectively. The results demonstrate that medical treatment may mitigate the negative social consequences of ADHD. Placebo regressions indicate that a causal interpretation of our findings is plausible.

Education and Cognitive Aging: Accounting for Selection and Confounding in Linkage of Data From the Danish Registry and Survey of Health, Ageing and Retirement in Europe.

Earlier studies report inconsistent associations between education and cognitive aging. We assessed the association, accounting for selective dropout due to death or dementia, and, in a subsample, accounting for confounding by early-life intelligence. Data from the Danish component of the Survey of Health, Ageing and Retirement in Europe (n = 3,400) were linked to registry data (education records, dementia diagnoses, and mortality) and the Danish Conscription Database (youth intelligence measurements for 854 men). Word recall and verbal fluency were assessed up to 4 times over 10 years (2004-2013) and combined by averaging the z scores. We fitted a joint model linking a time-to-event model for dementia or death to a linear mixed-effects model for cognitive change. Rate of cognitive decline was slower among people with high education compared with low education (ß = 0.112, 95% confidence interval (CI): 0.056, 0.170). Adjusting for youth intelligence did not attenuate the association between education and cognitive decline (crude ß = 0.136, 95% CI: 0.028, 0.244 vs. adjusted ß = 0.145, 95% CI: 0.022, 0.269). The results suggest that higher education may slow cognitive decline in later life. In this sample, results changed little when accounting for selective attrition and confounding by intelligence.

Effect of different oral oxytetracycline treatment regimes on selection of antimicrobial resistant coliforms in nursery pigs.

A major concern derived from using antimicrobials in pig production is the development of resistance. This study aimed to assess the impact of selected combinations of oral dose and duration of treatment with oxytetracycline (OTC) on selection of tetracycline resistant (TET-R) coliforms recovered from swine feces. The work encompassed two studies: 1) OTC 5mg/kg and 20mg/kg were administered to nursery pigs for 3 and 10days, respectively, under controlled experimental conditions, and 2) 10mg/kg, 20mg/kg and 30mg/kg OTC were given to a higher number of pigs for 6, 3 and 2days, respectively, under field conditions. Statistical modeling was applied to analyze trends in the proportion of TET-R coliforms. In the experimental study, no statistical difference in proportion of TET-R coliforms was observed between treatments at the end of the trial (day 18) and compared to day 0. In the field study, treatment had a significant effect on the proportion of TET-R bacteria two days after the end of treatment (2dAT) with the regimes "low dose-six days" and "medium dose-three days" yielding the highest and lowest proportions of TET-R strains, respectively. No indication of co-selection for ampicillin- and sulphonamide -R bacteria was observed for any treatment at 2dAT. By the end of the nursery period, the proportion of TET-R bacteria was not significantly different between treatments and compared to day 0. Our results suggest that similar resistance levels might be obtained by using different treatment regimes regardless of the combinations of oral dose-duration of treatment.

Amblyopia treatment of adults with dichoptic training using the virtual reality oculus rift head mounted display: preliminary results.

BACKGROUND: The gold standard treatments in amblyopia are penalizing therapies, such as patching or blurring vision with atropine that are aimed at forcing the use of the amblyopic eye. However, in the last years, new therapies are being developed and validated, such as dichoptic visual training, aimed at stimulating the amblyopic eye and eliminating the interocular supression. PURPOSE: To evaluate the effect of dichoptic visual training using a virtual reality head mounted display in a sample of anisometropic amblyopic adults and to evaluate the potential usefulness of this option of treatment. METHODS: A total of 17 subjects (10 men, 7 women) with a mean age of 31.2 years (range, 17-69 year) and anisometropic amblyopia were enrolled. Best corrected visual acuity (BCVA) and stereoacuity (Stereo Randot graded circle test) changes were evaluated after 8 sessions (40 min per session) of dichoptic training with the computer game Diplopia Game (Vivid Vision) run in the Oculus Rift OC DK2 virtual reality head mounted display (Oculus VR). RESULTS: Mean BCVA in amblyopic eye improved significantly from a logMAR value of 0.58 ± 0.35 before training to a post-training value of 0.43 ± 0.38 (p < 0.01). Forty-seven percent of the participants achieved BCVA of 20/40 or better after the training as compared to 30% before the training. Mean stereoacuity changed from a value of 263.3 ± 135.1 before dichoptic training to a value of 176.7 ± 152.4 s of arc after training (p < 0.01). A total of 8 patients (47.1%) before dichoptic treatment had unmeasurable stereoacuity while this only occurred in 2 patients (11.8%) after training. CONCLUSIONS: Dichoptic training using a virtual reality head mounted display seems to be an effective option of treatment in adults with anisometropic amblyopia. Future clinical trials are needed to confirm this preliminary evidence. TRIAL REGISTRATION: Trial ID: ISRCTN62086471 . Date registered: 13/06/2017. Retrospectively registered.

Effect of Tetracycline Dose and Treatment Mode on Selection of Resistant Coliform Bacteria in Nursery Pigs.

This study describes the results of a randomized clinical trial investigating the effect of oxytetracycline treatment dose and mode of administration on the selection of antibiotic-resistant coliform bacteria in fecal samples from nursery pigs. Nursery pigs (pigs of 4 to 7 weeks of age) in five pig herds were treated with oxytetracycline for Lawsonia intracellularis-induced diarrhea. Each group was randomly allocated to one of five treatment groups: oral flock treatment with a (i) high (20 mg/kg of body weight), (ii) medium (10 mg/kg), or (iii) low (5 mg/kg) dose, (iv) oral pen-wise (small-group) treatment (10 mg/kg), and (v) individual intramuscular injection treatment (10 mg/kg). All groups were treated once a day for 5 days. In all groups, treatment caused a rise in the numbers and proportions of tetracycline-resistant coliform bacteria right after treatment, followed by a significant drop by the time that the pigs left the nursery unit. The counts and proportions of tetracycline-resistant coliforms did not vary significantly between treatment groups, except immediately after treatment, when the highest treatment dose resulted in the highest number of resistant coliforms. A control group treated with tiamulin did not show significant changes in the numbers or proportions of tetracycline-resistant coliforms. Selection for tetracycline-resistant coliforms was significantly correlated to selection for ampicillin- and sulfonamide-resistant strains but not to selection for cefotaxime-resistant strains. In conclusion, the difference in the dose of oxytetracycline and the way in which the drug was applied did not cause significantly different levels of selection of tetracycline-resistant coliform bacteria under the conditions tested.IMPORTANCE Antimicrobial resistance is a global threat to human health. Treatment of livestock with antimicrobials has a direct impact on this problem, and there is a need to improve the ways that we use antimicrobials in livestock production. We hypothesized that antibiotic resistance development following treatment of diarrhea in nursery pigs could be reduced either by lowering the dose of oxytetracycline or by replacing the commonly used practice of flock treatment with individual or small-group treatments, since this would reduce the number of pigs treated. However, the study showed no significant difference between treatment groups with respect to the number or proportion of tetracycline-resistant coliforms selected. The most important conclusion is that under practical field conditions, there will be no added value, in terms of lowering resistance development, by exchanging flock treatment for individual or small-group treatment of nursery pigs. The reason for the lack of an effect of single-animal treatment is probably that such animals share the environment with treated animals and take up resistant bacteria from the environment.

Employment effects of active labor market programs for sick-listed workers.

We use register data of 88,948 sick-listed workers in Denmark over the period 2008-2011 to investigate the effect of active labor market programs on the duration until returning to non-subsidized employment and the duration of this employment. To identify causal treatment effects, we exploit over-time variation in the use of active labor market programs in 98 job centers and time-to- event. We find that ordinary education and subsidized job training have significant positive employment effects. Subsidized job training has a large, positive effect on the transition into employment but no effect on the subsequent employment duration. In contrast, ordinary education has a positive effect on employment duration but no effect on the transition into employment. The latter effect is the result of two opposing effects, a large positive effect of having completed education and a large negative lock-in effect, with low re-employment chances during program participation.

Novel serum and bile protein markers predict primary sclerosing cholangitis disease severity and prognosis.

BACKGROUND & AIMS: Prognostic biomarkers are lacking in primary sclerosing cholangitis, hampering patient care and the development of therapy. We aimed to identify novel protein biomarkers of disease severity and prognosis in primary sclerosing cholangitis (PSC). METHODS: Using a bead-based array targeting 63 proteins, we profiled a derivation panel of Norwegian endoscopic retrograde cholangiography bile samples (55 PSC, 20 disease controls) and a Finnish validation panel (34 PSC, 10 disease controls). Selected identified proteins were measured in serum from two Norwegian PSC cohorts (n=167 [1992-2006] and n=138 [2008-2012]), inflammatory bowel disease (n=96) and healthy controls (n=100). RESULTS: In the bile derivation panel, the levels of 14 proteins were different between PSC patients and controls (p<0.05); all were confirmed in the validation panel. Twenty-four proteins in the bile derivation panel were significantly (p<0.05) different between PSC patients with mild compared to severe cholangiographic changes (modified Amsterdam criteria); this was replicated for 18 proteins in the validation panel. Interleukin (IL)-8, matrix metallopeptidase (MMP)9/lipocalin (LCN)2-complex, S100A8/9, S100A12 and tryptophan hydroxylase (TPH)2 in the bile were associated with both a PSC diagnosis and grade of cholangiographic changes. Stratifying PSC patients according to tertiles of serum IL-8, but not MMP9/LCN2 and S100A12, provided excellent discrimination for transplant-free survival both in the serum derivation and validation cohort. Furthermore, IL-8 was associated with transplant-free survival in multivariable analyses in both serum panels independently of age and disease duration, indicating an independent influence on PSC progression. However, the Enhanced Liver Fibrosis (ELF®) test and Mayo risk score proved to be stronger predictors of transplant-free survival. CONCLUSIONS: Based on assaying of biliary proteins, we have identified novel biliary and serum biomarkers as indicators of severity and prognosis in PSC. LAY SUMMARY: Prognostic biomarkers are lacking in primary sclerosing cholangitis, hampering patient care and the development of therapy. We have identified inflammatory proteins including calprotectin and IL-8 as important indicators of disease severity and prognosis in bile and serum from patients with primary sclerosing cholangitis.

A randomised clinical trial on the efficacy of oxytetracycline dose through water medication of nursery pigs on diarrhoea, faecal shedding of Lawsonia intracellularis and average daily weight gain.

Oral treatment with antimicrobials is widely used in pig production for the control of gastrointestinal infections. Lawsonia intracellularis (LI) causes enteritis in pigs older than six weeks of age and is commonly treated with antimicrobials. The objective of this study was to evaluate the efficacy of three oral dosage regimens (5, 10 and 20mg/kg body weight) of oxytetracycline (OTC) in drinking water over a five-day period on diarrhoea, faecal shedding of LI and average daily weight gain (ADG). A randomised clinical trial was carried out in four Danish pig herds. In total, 539 animals from 37 batches of nursery pigs were included in the study. The dosage regimens were randomly allocated to each batch and initiated at presence of assumed LI-related diarrhoea. In general, all OTC doses used for the treatment of LI infection resulted in reduced diarrhoea and LI shedding after treatment. Treatment with a low dose of 5mg/kg OTC per kg body weight, however, tended to cause more watery faeces and resulted in higher odds of pigs shedding LI above detection level when compared to medium and high doses (with odds ratios of 5.5 and 8.4, respectively). No association was found between the dose of OTC and the ADG. In conclusion, a dose of 5mg OTC per kg body weight was adequate for reducing the high-level LI shedding associated with enteropathy, but a dose of 10mg OTC per kg body weight was necessary to obtain a maximum reduction in LI shedding.

Socioeconomic inequality in health in the British household panel: Tests of the social causation, health selection and the indirect selection hypothesis using dynamic fixed effects panel models.

Despite social inequality in health being well documented, it is still debated which causal mechanism best explains the negative association between socioeconomic position (SEP) and health. This paper is concerned with testing the explanatory power of three widely proposed causal explanations for social inequality in health in adulthood: the social causation hypothesis (SEP determines health), the health selection hypothesis (health determines SEP) and the indirect selection hypothesis (no causal relationship). We employ dynamic data of respondents aged 30 to 60 from the last nine waves of the British Household Panel Survey. Household income and location on the Cambridge Scale is included as measures of different dimensions of SEP and health is measured as a latent factor score. The causal hypotheses are tested using a time-based Granger approach by estimating dynamic fixed effects panel regression models following the method suggested by Anderson and Hsiao. We propose using this method to estimate the associations over time since it allows one to control for all unobserved time-invariant factors and hence lower the chances of biased estimates due to unobserved heterogeneity. The results showed no proof of the social causation hypothesis over a one to five year period and limited support for the health selection hypothesis was seen only for men in relation to HH income. These findings were robust in multiple sensitivity analysis. We conclude that the indirect selection hypothesis may be the most important in explaining social inequality in health in adulthood, indicating that the well-known cross-sectional correlations between health and SEP in adulthood seem not to be driven by a causal relationship, but instead by dynamics and influences in place before the respondents turn 30 years old that affect both their health and SEP onwards. The conclusion is limited in that we do not consider the effect of specific diseases and causal relationships in adulthood may be present over a longer timespan than 5 years.

Enhanced liver fibrosis score predicts transplant-free survival in primary sclerosing cholangitis.

UNLABELLED: There is a need to determine biomarkers reflecting disease activity and prognosis in primary sclerosing cholangitis (PSC). We evaluated the prognostic utility of the enhanced liver fibrosis (ELF) score in Norwegian PSC patients. Serum samples were available from 305 well-characterized large-duct PSC patients, 96 ulcerative colitis patients, and 100 healthy controls. The PSC patients constituted a derivation panel (recruited 1992-2006 [n = 167]; median age 41 years, 74% male) and a validation panel (recruited 2008-2012 [n = 138]; median age 40 years, 78% male). We used commercial kits to analyze serum levels of hyaluronic acid, tissue inhibitor of metalloproteinases-1, and propeptide of type III procollagen and calculated ELF scores by the previously published algorithm. Results were also validated by analysis of ELF tests using the ADVIA Centaur XP system and its commercially available reagents. We found that PSC patients stratified by ELF score tertiles exhibited significantly different transplant-free survival in both panels (P < 0.001), with higher scores associated with shorter survival, which was confirmed in the validation panel stratified by ELF test tertiles (P = 0.003). The ELF test distinguished between mild and severe disease defined by clinical outcome (transplantation or death) with an area under the curve of 0.81 (95% confidence interval [CI] 0.73-0.87) and optimal cutoff of 10.6 (sensitivity 70.2%, specificity 79.1%). In multivariate Cox regression analysis in both panels, ELF score (hazard ratio = 1.9, 95% CI 1.4-2.5, and 1.5, 95% CI 1.1-2.1, respectively) was associated with transplant-free survival independently of the Mayo risk score (hazard ratio = 1.3, 95% CI 1.1-1.6, and 1.6, 95% CI 1.2-2.1, respectively). The ELF test correlated with ultrasound elastography in separate assessments. CONCLUSION: The ELF score is a potent prognostic marker in PSC, independent of the Mayo risk score.