Prediction of prognosis in oral squamous cell carcinoma using infrared microspectroscopy.

BACKGROUND: Estimation of prognosis of oral squamous cell carcinoma (OSCC) is inaccurate prior to surgery, only being effected following subsequent pathological analysis of the primary tumour and excised lymph nodes. Consequently, a proportion of patients are overtreated, with an increase in morbidity, or undertreated, with inadequate margins and risk of recurrence. We hypothesise that it is possible to accurately characterise clinical outcomes from infrared spectra arising from diagnostic biopsies. In this first step, we correlate survival with IR spectra derived from the primary tumour. METHODS: Infrared spectra were collected from tumour tissue from 29 patients with OSCC and subject to classification modelling. RESULTS: The model had a median AUROC of 0.89 with regard to prognosis, a median specificity of 0.83, and a hazard ratio of 6.29 in univariate Cox proportional hazard modelling. CONCLUSION: The data suggest that FTIR spectra may be a useful early biomarker of prognosis in OSCC.

Stress Symptoms Among Children and Their Parents After ICU Hospitalization.

Objective: Child survival after intensive care unit (ICU) hospitalization has increased, yet many children experience acute stress that may precipitate mental/behavioral health comorbidities. Parents report stress after their child's hospitalization. Little is known about the individual and family characteristics that may moderate intergenerational relationships of acute stress. Design: Following ICU admission at a large academic medical center, a prospective cross-sectional cohort study assessed the associations between intergenerational characteristics and acute stress among children and families. Patients: Parent-child dyads (N = 88) were recruited from the pediatric ICU and pediatric cardiovascular ICU (CVICU) following ICU discharge. Eligible children were between 8 and 18 years old with ICU stays longer than 24 hours. Children with developmental delays were excluded. Caregivers were proficient in English or Spanish. Surveys were collected before hospital discharge. Measurements/Main Results: The primary outcome was "child stress" defined as a score≥17, measured by the Children's Revised Impact of Events Scale (CRIES-8). "Parent stress" was defined as an elevated composite score on the Stanford Acute Stress Reaction Questionnaire. We used validated scales to assess the child's clinical and family social characteristics. Acute stress was identified in 34 (39.8%) children and 50 (56.8%) parents. In multivariate linear regression analyses adjusting for social characteristics, parent stress was associated with increased risk of child stress (adjusted odds ratio 2.58, 95% confidence interval 0.69, 4.46, p < .01). In unadjusted analyses, Hispanic ethnicity was associated with greater child stress. In adjusted analyses, race, income, ICU length of stay, and language were not associated with child stress and did not moderate the parent-child stress relationship. Conclusions: Parent stress is closely correlated with child stress during ICU hospitalization. Hispanic ethnicity may be associated with increased risk for child stress, but further studies are required to define the roles of other social and clinical measures.

Determining the Effectiveness of Fibrin Sealants in Reducing Complications in Patients Undergoing Lateral Neck Dissection (DEFeND): A Randomised External Pilot Trial.

OBJECTIVES: High-quality randomised controlled trials (RCT) to support the use of Fibrin Sealants (FS) in neck dissection (ND) are lacking. The DEFeND trial assessed critical pilot/feasibility questions and signals from clinical outcomes to inform a future definitive trial. PATIENTS AND METHODS: The study design piloted was a blinded surgical RCT. All participants underwent unilateral ND for head and neck cancer. Interventional arm: ND with application of FS. CONTROL ARM: ND alone. Feasibility outcomes included recruitment, effectiveness of blinding, protocol adherence and evaluating administrative processes. Clinical outcomes included surgical complications (primary outcome), drainage volume, time to drain removal, length of hospital stay, pain and the Neck Dissection Impairment Index. RESULTS: Recruitment completed ahead of time. Fifty-three patients were recruited, and 48 were randomised at a rate of 5.3 patients/month. Blinding of patients, research nurses and outcome assessors was effective. Two protocol deviations occurred. Two patients were lost to follow-up. The mean (SD) Comprehensive Complication Index in the interventional arm was 6.5 (12.8), and it was 9.9 (14.2) in the control arm. The median (IQR) time to drain removal (days) was shorter in the interventional arm (2.67 (2.42, 3.58) vs. 3.40 (2.50, 4.27)). However, this did not translate to a clinically significant reduction in median (IQR) length of hospital stay in days (intervention: 3.48 (2.64, 4.54), control: 3.74 (3.11, 4.62)). CONCLUSION: The proposed trial design was effective, and a definitive surgical trial is feasible. Whilst there was a tendency for FS to improve clinical outcomes, the effect size did not reach clinical or statistical significance. (ISRCTN99181100).

Preterm infant mental health in the neonatal intensive care unit: A review of research on NICU parent-infant interactions and maternal sensitivity.

Caregiving relationships in the postnatal period are critical to an infant's development. Preterm infants and their parents face unique challenges in this regard, with infants experiencing separation from parents, uncomfortable procedures, and increased biologic vulnerability, and parents facing difficulties assuming caregiver roles and increased risk for psychological distress. To better understand the NICU parent-infant relationship, we conducted a review of the literature and identified 52 studies comparing observed maternal, infant, and dyadic interaction behavior in preterm dyads with full-term dyads. Eighteen of 40 studies on maternal behavior found less favorable behavior, including decreased sensitivity and more intrusiveness in mothers of preterm infants, seven studies found the opposite, four studies found mixed results, and 11 studies found no differences. Seventeen of 25 studies on infant behavior found less responsiveness in preterm infants, two studies found the opposite, and the remainder found no difference. Eighteen out of 14 studies on dyad-specific behavior reported less synchrony in preterm dyads and the remainder found no differences. We identify confounding factors that may explain variations in results, present an approach to interpret existing data by framing differences in maternal behavior as potentially adaptive in the context of prematurity, and suggest future areas for exploration.

Las relaciones de prestación de cuidados en el período postnatal son críticas para el desarrollo del infante. Los infantes nacidos prematuramente y sus progenitores enfrentan retos únicos a este respecto, con los infantes que experimentan la separación de sus progenitores, procedimientos incómodos, así como un aumento en la vulnerabilidad biológica; y los progenitores enfrentando dificultades al asumir el papel de cuidadores y el aumento de riesgo de angustia sicológica. Para comprender mejor la relación progenitor-infante en la Unidad Neonatal de Cuidados Intensivos (NICU), llevamos a cabo una revisión de la literatura e identificamos 52 estudios que comparan la observada conducta de interacción materna, del infante y de la díada en díadas de infantes prematuros con díadas de infantes de gestación completa. Dieciocho de 40 estudios sobre la conducta materna encontraron una menos favorable conducta, incluyendo una baja en la sensibilidad y más intrusión en el caso de madres de infantes prematuros; 7 estudios encontraron que se daba la situación opuesta; 4 estudios presentaron resultados mixtos; y 11 estudios no encontraron diferencias. Diecisiete de 25 estudios sobre el comportamiento del infante encontraron una menor capacidad de respuesta en infantes prematuros; dos estudios encontraron que se daba la situación opuesta; y el resto de los estudios no encontró ninguna diferencia. Ocho de 14 estudios sobre el comportamiento específico de la díada reportaron menos sincronía en las díadas con infantes prematuros y el resto de los estudios no encontró ninguna diferencia. Identificamos factores confusos que pudieran explicar las variaciones en los resultados, presentamos un acercamiento para interpretar la información existente por medio de enmarcar las diferencias en la conducta materna como potencialmente adaptable en el contexto del nacimiento prematuro, y sugerimos futuras áreas para ser exploradas.

Les relations de soin dans la période postnatale sont critiques pour le développement du nourrisson. Les bébés nés avant terme et leurs parents font face à des défis uniques à cet égard, avec les bébés faisant l'expérience de la séparation des parents, des procédures désagréables et difficiles, et une vulnérabilité biologique accrue, et les parents faisant face aux difficultés assumant des rôles de soignants et étant à risque plus élevé de détresse psychologique. Afin de comprendre la relation parent-nourrisson USIN nous avons passé en revue toutes les recherches et identifié 52 études comparant le comportement d'interaction dyadique, maternel et du nourrisson chez des dyades prématurées avec des dyades à plein terme. 18 des 40 études sur le comportement maternel ont trouvé un comportement moins que favorable, y compris une sensibilité décrue et plus d'intrusion chez les mères de nourrissons prématurés, 7 études ont trouvé le contraire, 4 études ont trouvé des résultats mélangés, et 11 études n'ont trouvé aucune différence. 17 études sur 25 sur le comportement du nourrisson ont trouvé une réaction moindre chez les nourrissons prématurés deux études ont trouvé le contraire, et le reste n'a trouvé aucune différence. 8 études sur 14 sur le comportement spécifique à la dyade ont fait état de moins de synchronie chez les dyades avant terme et les autres études n'ont trouvé aucune différence. Nous identifions des facteurs confondants qui pourraient expliquer des variations dans les résultats et nous présentons une approche pour interpréter les données existantes en cadrant des différences dans le comportement maternel comme étant potentiellement adaptatives dans le contexte de la prématurité et nous suggérons des domaines futurs d'exploration.

Associations between SARS-CoV-2 infection and subsequent economic inactivity and employment status: pooled analyses of five linked longitudinal surveys.

Introduction: Following the acute phase of the COVID-19 pandemic, record numbers of people became economically inactive (i.e., neither working nor looking for work), or non-employed (including unemployed job seekers and economically inactive people). A possible explanation is people leaving the workforce after contracting COVID-19. We investigated whether testing positive for SARS-CoV-2 is related to subsequent economic inactivity and non-employment, among people employed pre-pandemic. Methods: The data came from five UK longitudinal population studies held by both the UK Longitudinal Linkage Collaboration (UK LLC; primary analyses) and the UK Data Service (UKDS; secondary analyses). We pooled data from five long established studies (1970 British Cohort Study, English Longitudinal Study of Ageing, 1958 National Child Development Study, Next Steps, and Understanding Society). The study population were aged 25-65 years between March 2020 to March 2021 and employed pre-pandemic. Outcomes were economic inactivity and non-employment measured at the time of the last follow-up survey (November 2020 to March 2021, depending on study). For the UK LLC sample (n=8,174), COVID-19 infection was indicated by a positive SARS-CoV-2 test in NHS England records. For the UKDS sample we used self-reported measures of COVID-19 infection (n=13,881). Logistic regression models estimated odds ratios (ORs) with 95% confidence intervals (95%CIs) adjusting for potential confounders including sociodemographic variables, pre-pandemic health and occupational class. Results: Testing positive for SARS-CoV-2 was very weakly associated with economic inactivity (OR 1.08 95%CI 0.68-1.73) and non-employment status (OR 1.09. 95%CI 0.77-1.55) in the primary analyses. In secondary analyses, self-reported test-confirmed COVID-19 was not associated with either economic inactivity (OR 1.01 95%CI 0.70-1.44) or non-employment status (OR 1.03 95%CI 0.79-1.35). Conclusions: Among people employed pre-pandemic, testing positive for SARS-CoV-2 was either weakly or not associated with increased economic inactivity or non-employment. Research on the recent increases in economic inactivity should focus on other potential causes.

Neurodevelopmental, Mental Health, and Parenting Issues in Preterm Infants.

The World Health Organization in its recommendations for the care of preterm infants has drawn attention to the need to address issues related to family involvement and support, including education, counseling, discharge preparation, and peer support. A failure to address these issues may translate into poor outcomes that extend across the lifespan. In this paper, we review the often far-reaching impact of preterm birth on the health and wellbeing of the parents and highlight the ways in which psychological stress may have a negative long-term impact on the parent-child interaction, attachment, and the styles of parenting. This paper addresses the following topics: (1) neurodevelopmental outcomes in preterm infants, including cognitive, sensory, and motor difficulties, (2) long-term mental health issues in premature infants that include elevated rates of anxiety and depressive disorders, autism, and somatization, which may affect social relationships and quality of life, (3) adverse mental health outcomes for parents that include elevated rates of depression, anxiety, and symptoms of post-traumatic stress, as well as increased rates of substance abuse, and relationship strain, (4) negative impacts on the parent-infant relationship, potentially mediated by maternal sensitivity, parent child-interactions, and attachment, and (5) impact on the parenting behaviors, including patterns of overprotective parenting, and development of Vulnerable Child Syndrome. Greater awareness of these issues has led to the development of programs in neonatal mental health and developmental care with some data suggesting benefits in terms of shorter lengths of stay and decreased health care costs.

Tissue discrimination in head and neck cancer using image fusion of IR and optical microscopy.

A regression-based fusion algorithm has been used to merge hyperspectral Fourier transform infrared (FTIR) data with an H&E image of oral squamous cell carcinoma metastases in cervical lymphoid nodal tissue. This provides insight into the success of the ratio of FTIR absorbances at 1252 cm-1 and 1285 cm-1 in discriminating between these tissue types. The success is due to absorbances at these two wavenumbers being dominated by contributions from DNA and collagen, respectively. A pixel-by-pixel fit of the fused spectra to the FTIR spectra of collagen, DNA and cytokeratin reveals the contributions of these molecules to the tissue at high spatial resolution.

Associations between self-reported healthcare disruption due to covid-19 and avoidable hospital admission: evidence from seven linked longitudinal studies for England.

OBJECTIVES: To examine whether there is an association between people who experienced disrupted access to healthcare during the covid-19 pandemic and risk of an avoidable hospital admission. DESIGN: Observational analysis using evidence from seven linked longitudinal cohort studies for England. SETTING: Studies linked to electronic health records from NHS Digital from 1 March 2020 to 25 August 2022. Data were accessed using the UK Longitudinal Linkage Collaboration trusted research environment. PARTICIPANTS: Individual level records for 29 276 people. MAIN OUTCOME MEASURES: Avoidable hospital admissions defined as emergency hospital admissions for ambulatory care sensitive and emergency urgent care sensitive conditions. RESULTS: 9742 participants (weighted percentage 35%, adjusted for sample structure of longitudinal cohorts) self-reported some form of disrupted access to healthcare during the covid-19 pandemic. People with disrupted access were at increased risk of any (odds ratio 1.80, 95% confidence interval 1.39 to 2.34), acute (2.01, 1.39 to 2.92), and chronic (1.80, 1.31 to 2.48) ambulatory care sensitive hospital admissions. For people who experienced disrupted access to appointments (eg, visiting their doctor or an outpatient department) and procedures (eg, surgery, cancer treatment), positive associations were found with measures of avoidable hospital admissions. CONCLUSIONS: Evidence from linked individual level data shows that people whose access to healthcare was disrupted were more likely to have a potentially preventable hospital admission. The findings highlight the need to increase healthcare investment to tackle the short and long term implications of the pandemic, and to protect treatments and procedures during future pandemics.

Head and neck reconstruction in the vessel depleted neck using robot-assisted harvesting of the internal mammary vessels.

We report a novel technique of robot-assisted harvesting of the internal mammary vessels to provide effective recipient vessels in a patient with bilateral vessel depleted neck (VDN). A 44-year-old with a Notani grade III osteoradionecrosis (ORN) of the anterior mandible underwent robot-assisted (Da Vinci® Surgical System, Intuitive Surgical) harvesting of the left internal mammary vessels (LIMA, LIMV). Reconstruction of the mandibular defect was done with a virtually planned composite fibular free flap and microvascular anastomosis of the peroneal vessels to the LIMA and LIMV. Successful reconstruction of the anterior mandible was achieved with excellent recipient arterial diameter and length, devoid of any significant thoracic morbidities resulting from robot-assisted harvesting of the internal mammary vessels. Robot-assisted harvesting of internal mammary vessels is a viable alternative to an open approach. The advantages in tissue handling, vessel length, and favourable profile of complications may extend the indications for this otherwise 'niche' solution in the VDN.

Home working and social and mental wellbeing at different stages of the COVID-19 pandemic in the UK: Evidence from 7 longitudinal population surveys.

BACKGROUND: Home working has increased since the Coronavirus Disease 2019 (COVID-19) pandemic's onset with concerns that it may have adverse health implications. We assessed the association between home working and social and mental wellbeing among the employed population aged 16 to 66 through harmonised analyses of 7 UK longitudinal studies. METHODS AND FINDINGS: We estimated associations between home working and measures of psychological distress, low life satisfaction, poor self-rated health, low social contact, and loneliness across 3 different stages of the pandemic (T1 = April to June 2020 -first lockdown, T2 = July to October 2020 -eased restrictions, T3 = November 2020 to March 2021 -second lockdown) using modified Poisson regression and meta-analyses to pool results across studies. We successively adjusted the model for sociodemographic characteristics (e.g., age, sex), job characteristics (e.g., sector of activity, pre-pandemic home working propensities), and pre-pandemic health. Among respectively 10,367, 11,585, and 12,179 participants at T1, T2, and T3, we found higher rates of home working at T1 and T3 compared with T2, reflecting lockdown periods. Home working was not associated with psychological distress at T1 (RR = 0.92, 95% CI = 0.79 to 1.08) or T2 (RR = 0.99, 95% CI = 0.88 to 1.11), but a detrimental association was found with psychological distress at T3 (RR = 1.17, 95% CI = 1.05 to 1.30). Study limitations include the fact that pre-pandemic home working propensities were derived from external sources, no information was collected on home working dosage and possible reverse association between change in wellbeing and home working likelihood. CONCLUSIONS: No clear evidence of an association between home working and mental wellbeing was found, apart from greater risk of psychological distress during the second lockdown, but differences across subgroups (e.g., by sex or level of education) may exist. Longer term shifts to home working might not have adverse impacts on population wellbeing in the absence of pandemic restrictions but further monitoring of health inequalities is required.

Group trauma focused cognitive behavior therapy for parents of premature infants compared to individual therapy intervention.

BACKGROUND: The current study compares results of a group-based intervention developed to reduce symptoms of posttraumatic stress, depression, and anxiety in parents of premature infants with a prior study using an individual version of the treatment manual. METHODS: 26 mothers of preterm infants (25-34 weeks' gestational age; >600 g) received 6 sessions of trauma-focused cognitive behavior therapy (CBT). Outcomes were compared with those of a previously published RCT, which tested an individual therapy based on the same model in a group of 62 mothers. Results were also compared across in-person and telehealth treatment. RESULTS: From baseline to follow up, the individual intervention showed greater improvement in trauma symptoms assessed with the Davidson Trauma Scale (d = 0.48, p = 0.016), although both conditions showed clinically significant improvement. Similar patterns were found for maternal depression and anxiety. In-person treatment was found to be superior to telehealth treatment administered during the COVID-19 pandemic, although the difference was not significant. CONCLUSIONS: Group-based trauma focused CBT is an effective treatment modality for parents of premature infants with symptoms of psychological distress but not as effective as individual therapy using the same treatment model.

Maternal mental health and engagement in developmental care activities with preterm infants in the NICU.

OBJECTIVE: To examine associations between maternal mental health and involvement in developmental care in the NICU. STUDY DESIGN: Mothers of infants born <32 weeks gestation (n = 135) were approached to complete mental health screening questionnaires at two weeks after admission. Mothers who completed screening (n = 55) were further classified as with (n = 19) and without (n = 36) elevated scores. Mothers' frequency, rate, and duration of developmental care activities were documented in the electronic health record. RESULTS: 35% of screened mothers scored above the cutoff for clinical concern on ≥1 measure. No significant differences between the 3 groups were identified for rates, frequency, or amount of all developmental care, kangaroo care, and swaddled holding. CONCLUSION: Elevated scores on maternal mental health questionnaires did not relate to developmental care. Maternal developmental care engagement may not indicate mental health status. Universal screening for psychological distress is required to accurately detect symptoms in mothers of hospitalized preterm infants.

Whole genome DNA methylation and mutational profiles identify novel changes in proliferative verrucous leukoplakia.

OBJECTIVE: Proliferative verrucous leukoplakia (PVL) is a rare form of oral leukoplakia with a relatively high transformation rate resulting in oral squamous cell carcinoma (OSCC). Molecular analysis of PVL at the genome level is limited and has only identified molecular similarities between PVL and OSCC. However, the clinical profile of PVL suggests that molecular differences may be more important. STUDY DESIGN: Whole exome sequencing of 5 PVL-associated OSCC (PVL-OSCC) and paired blood samples was used to identify somatic mutations common to the tumors. Whole methylome analysis of samples from 4 PVL-associated OSCC and 3 OSCC of non-PVL origin samples was conducted to explore differential methylation. RESULTS: In contrast to conventional OSCC, PVL-associated OSCC showed infrequent TP53 mutation and altered spectra of PIK3CA and NOTCH1 mutations. Unsupervised hierarchical clustering identified 63 probes that discriminated between PVL-associated OSCC and OSCC of non-PVL origin. Differences in methylation were most significant for divalent metal ion transport, particularly calcium movement. CONCLUSIONS: Specific differences in mutation and methylation profiles between PVL-derived OSCC and OSCC of non-PVL origin suggest differences in their transformation pathways. Further studies of early PVL lesions may identify markers of transformation that are also applicable to more common oral premalignant disorders such as oral epithelial dysplasia.

Metric-based analysis of FTIR data to discriminate tissue types in oral cancer.

A machine learning algorithm (MLA) has predicted the prognosis of oral potentially malignant lesions and discriminated between lymph node tissue and metastatic oral squamous cell carcinoma (OSCC). The MLA analyses metrics, which are ratios of Fourier transform infrared absorbances, and identifies key wavenumbers that can be associated with molecular biomarkers. The wider efficacy of the MLA is now shown in the more complex primary OSCC tumour setting, where it is able to identify seven types of tissue. Three epithelial and four non-epithelial tissue types were discriminated from each other with sensitivities between 82% and 96% and specificities between 90% and 99%. The wavenumbers involved in the five best discriminating metrics for each tissue type were tightly grouped, indicating that small changes in the spectral profiles of the different tissue types are important. The number of samples used in this study was small, but the information will provide a basis for further, larger investigations.

Academic Training in Oral and Maxillofacial Surgery - when and how to enter the pathway.

Entering into surgical academia can seem a daunting prospect for an oral and maxillofacial surgery (OMFS) trainee. However, the streamlining of academic training by the NIHR to create the integrated academic training (IAT) pathway has simplified academic training and more clearly defined academic positions and entry points for trainees. In this article we review the current NIHR IAT pathway and the various grades and entry points available to OMF surgeons, both pre- and post-doctoral. We highlight the unique challenges facing OMF trainees and provide advice and insight from both junior and senior OMFS academics. Finally, we focus on the planning and application for a doctoral research fellowship - discussing funding streams available to OMF surgeons.

Characterising patterns of COVID-19 and long COVID symptoms: evidence from nine UK longitudinal studies.

Multiple studies across global populations have established the primary symptoms characterising Coronavirus Disease 2019 (COVID-19) and long COVID. However, as symptoms may also occur in the absence of COVID-19, a lack of appropriate controls has often meant that specificity of symptoms to acute COVID-19 or long COVID, and the extent and length of time for which they are elevated after COVID-19, could not be examined. We analysed individual symptom prevalences and characterised patterns of COVID-19 and long COVID symptoms across nine UK longitudinal studies, totalling over 42,000 participants. Conducting latent class analyses separately in three groups ('no COVID-19', 'COVID-19 in last 12 weeks', 'COVID-19 > 12 weeks ago'), the data did not support the presence of more than two distinct symptom patterns, representing high and low symptom burden, in each group. Comparing the high symptom burden classes between the 'COVID-19 in last 12 weeks' and 'no COVID-19' groups we identified symptoms characteristic of acute COVID-19, including loss of taste and smell, fatigue, cough, shortness of breath and muscle pains or aches. Comparing the high symptom burden classes between the 'COVID-19 > 12 weeks ago' and 'no COVID-19' groups we identified symptoms characteristic of long COVID, including fatigue, shortness of breath, muscle pain or aches, difficulty concentrating and chest tightness. The identified symptom patterns among individuals with COVID-19 > 12 weeks ago were strongly associated with self-reported length of time unable to function as normal due to COVID-19 symptoms, suggesting that the symptom pattern identified corresponds to long COVID. Building the evidence base regarding typical long COVID symptoms will improve diagnosis of this condition and the ability to elicit underlying biological mechanisms, leading to better patient access to treatment and services.

Carbohydrate larval antigen (CarLA IgA) responses to mixed species nematode infection in pasture grazed Angora goats.

The genetics of indicator traits for resistance of Angora goats to gastrointestinal nematode parasite infections, and their relationships with productivity traits, were investigated on a commercial mixed-enterprise farm in the eastern North Island of New Zealand. Faecal egg counts (FEC), specific Immunoglobulin A (IgA) and Immunoglobulin G (IgG) antibody titres against carbohydrate larval antigen (CarLA) in saliva, live weight and fleece weights were recorded from 278 goats of 19-20 months of age, run as four separate mobs (breeding bucks, castrated males (wethers), or 2 groups of breeding does). Summary statistics showed the mobs differed significantly in liveweight, loge (FEC+50), loge (IgA) and loge (IgG). Genetic parameters were estimated using an animal model with repeated records where appropriate, after adjusting for the different contemporary animal groups, using the restricted maximum likelihood (REML) package. Heritability estimates from repeated measures were 0.19 ± 0.16 for FEC, 0.28 ± 0.16 for CarLA specific IgA and 0.23 ± 0.15 for CarLA specific IgG. The CarLA specific IgA response was negatively genetically correlated with FEC (-0.99 ± 0.31) suggesting that it could be used as a selection tool for breeding resistant animals. Although the genetic and phenotypic correlations between CarLA IgA and IgG were high and significant, the analysis between loge (FEC+50) and loge CarLA IgG did not converge. Further, both FEC and CarLA IgA showed significant and favourable genetic correlations with live weight. In contrast, CarLA IgG showed an unfavourable phenotypic correlation with liveweight. While this is only a preliminary study, the results do suggest that the immunoassay measuring salivary CarLA IgA response may have utility as a selection tool for parasite resistance in some breeds of goats.

Biases arising from linked administrative data for epidemiological research: a conceptual framework from registration to analyses.

Linked administrative data offer a rich source of information that can be harnessed to describe patterns of disease, understand their causes and evaluate interventions. However, administrative data are primarily collected for operational reasons such as recording vital events for legal purposes, and planning, provision and monitoring of services. The processes involved in generating and linking administrative datasets may generate sources of bias that are often not adequately considered by researchers. We provide a framework describing these biases, drawing on our experiences of using the 100 Million Brazilian Cohort (100MCohort) which contains records of more than 131 million people whose families applied for social assistance between 2001 and 2018. Datasets for epidemiological research were derived by linking the 100MCohort to health-related databases such as the Mortality Information System and the Hospital Information System. Using the framework, we demonstrate how selection and misclassification biases may be introduced in three different stages: registering and recording of people's life events and use of services, linkage across administrative databases, and cleaning and coding of variables from derived datasets. Finally, we suggest eight recommendations which may reduce biases when analysing data from administrative sources.