Familial Factors Associated With Symptom Severity in Children and Adolescents With ADHD: A Meta-Analysis and Supplemental Review.

OBJECTIVE: Both genetic and environmental factors contribute to the development of ADHD, but associations between risk factors and ADHD symptom severity in affected children remain unclear. This systematic review and meta-analysis synthesizes evidence on the association between familial factors and symptom severity in children with ADHD (PROSPERO CRD42020076440). METHOD: PubMed and PsycINFO were searched for eligible studies. RESULTS: Forty-three studies (N = 11,123 participants) were meta-analyzed. Five additional studies (N = 2,643 participants) were considered in the supplemental review. Parenting stress (r = .25), negative parenting practices (r = .19), broken parental partnership (r = .19), critical life events (r = .17), parental psychopathologies (r = .14-.16), socioeconomic status (r = -.10), and single-parent family (r = .10) were significantly associated with ADHD symptom severity. CONCLUSION: These results suggest that psychosocial familial factors show small but significant associations with symptom severity in children with ADHD. Implications are discussed.

Atrophic gastritis is inversely associated with gastroesophageal reflux disease in a twin register based study.

BACKGROUND: The association between atrophic gastritis (AG) and symptomatic gastroesophageal reflux disease (GERD) needs to be better assessed. OBJECTIVE: We aimed to study this association in a twin setting, controlling for genetic and familial factors, in addition to a range of known covariates. METHODS: We performed a co-twin control study based on the Swedish Twin Registry, including confirmed monozygotic (MZ) and dizygotic (DZ) twins. AG was determined by the measurement of serum pepsinogen I (PGI) and pepsinogen II (PGII), with different cut-off values. GERD was defined using a structured questionnaire, by questions on symptoms of heartburn, acid regurgitation, pain behind the breastbone, and drug history. Patients were grouped into total GERD, less frequent (<1/week), and frequent GERD (≥1/week). RESULTS: A total of 12,533 twins were included in the study, among whom 37.7% showed less frequent GERD, and 18.7% had frequent GERD. There was an inverse association between AG and GERD, especially for frequent GERD. When PGI<30 was used as cut-off value for AG, the odds ratio (OR) and corresponding 95% confidence interval (CI) was 0.52 (0.44, 0.62). When PGI<70 and PGI/PGII<3 was used as cut-off value for AG, the OR (95% CI) was 0.53 (0.46, 0.63). A risk reduction for GERD was also observed in AG patients when the analysis was restricted in MZ or DZ twins. CONCLUSION: In this co-twin control study from the Swedish Twin Register, AG is persistently associated with a reduced risk for GERD, after controlling for genetic and shared familial factors.

Underlying Familial Factors for Aggressive Behavior in Romantic Relationships: A Systematic Review.

Aggressive behavior in romantic relationship has serious effects, including both intra- and inter-personal issues. Aggressive behaviors in romantic relationships have been linked to underlying familial problems. While there have been previous reviews that studied on many interpersonal and dyadic implications of aggressive behavior in romantic relationships, there is nonetheless a lack of studies on the various components of familial factors for aggressive behavior in romantic relationships. The databases Scopus, MEDLINE, Google Scholar, and SAGE Journals were used to search for terms that are related to familial factors (family factor, family support, family relationship) as well as terms related to aggressive behavior in romantic relationships (aggression in romantic relationship, violence in intimate relationship). The articles considered for this review were original studies, samples, or subsamples of males or females who reported any underlying familial factors in childhood or adulthood that contributed to aggressive behavior in romantic relationship, and the studies must be written in English. This review has 27 papers that met the inclusion criteria. The findings from this review revealed the presence of inconsistent conclusions between familial factors and aggressive behavior in romantic relationships, with some studies failing to establish such links. These findings are reviewed with regards to the existing gaps in the literature as well as potential research options.

Relationships between ENDS-Related Familial Factors and Oral Health among Adolescents in the United States.

The influence of familial and social environments plays a significant role in Electronic Nicotine Delivery System (ENDS) use and may contribute to poor oral health among adolescents. This study utilized the Population Assessment of Tobacco and Health (PATH) database and included youths aged 12 to 17 years who reported no history of dental health issues at baseline. Adjusted odds ratios (AOR) were used to examine the association between END-related familial factors and oral health among adolescents in the United States, with statistical significance set at p < 0.05. The sample consisted of 3892 adolescents (weighted N = 22,689,793). Parents' extremely negative reaction towards ENDS when they found their children using ENDS (AOR = 0.309) was connected to a lower risk of oral health issues. The findings suggest that clinicians and policymakers need to consider the roles of these factors when developing strategies to improve oral health outcomes.

Differential impact of COVID-19 lockdown on physical activity in younger and older adolescents - prospective study.

BACKGROUND: Insufficient physical activity levels (PAL) during adolescence is a major public health concern, which is even more pronounced during the COVID-19 pandemic due to restricting movement opportunities. This study aimed to identify PAL changes and examine the age-specific determinants of PAL in younger and older adolescents during the COVID-19 lockdown. MATERIAL AND METHODS: This study included 859 high-school students from Bosnia and Herzegovina stratified into 2 age groups: younger (N = 420, 14-16 years of age), and older adolescents (N = 439, 16-18 years of age). Participants were tested over 2 testing waves: before the COVID-19 lockdown (January 2020) and during the COVID-19 lockdown (April 2020). Variables included PAL assessed by the Physical Activity Questionnaire for Adolescents, sports factors, and parental factors. RESULTS: The PAL significantly declined as a result of lockdown measures in the total sample (from 2.76±0.79 to 2.50±0.82). Larger absolute and relative decline of PAL was evidenced in younger adolescents. Sport participation positively influenced PAL before lockdown, with no significant influence during the lockdown. Older adolescents whose mothers were better educated were less likely to be in high risk group with regard to a large decline of PAL as a result of COVID lockdown (OR = 0.50, 95% CI: 0.21-0.84). CONCLUSIONS: Results of the study suggest that parental education influences health-related behaviors and that parental education is a protective factor against a decrease in PAL during the COVID-19 pandemic. Main educational agents (i.e., school and parents) should pay more attention to provide children and adolescents adequate information and develop their health literacy, which will hopefully positively impact children's PAL even in challenging situations similar to COVID-19 lockdown. Med Pr. 2021;72(6):633-43.

The impact of atypical sensory processing on adaptive functioning within and beyond autism: The role of familial factors.

LAY ABSTRACT: Individuals diagnosed with autism tend to process sensory information differently than individuals without autism, resulting for instance in increased sensitivity to sounds or smells. This leads to challenges in everyday life and may restrict the individual's daily functioning. How direct this link is, however, is currently unclear. We investigated this question in 289 twins of whom 60 were diagnosed with autism and further 61 were diagnosed with other neurodevelopmental disorders. We looked at the association between unusual sensory processing and adaptive skills, both across individuals and within-twin pairs, testing whether individuals with higher levels of atypical sensory processing showed reduced adaptive skills compared to their twins. Since twins share 50%-100% of their genes and part of their environment (e.g. family background), associations within-twin pairs are free from effects of these familial factors. We found that an increased sensitivity to, as well as the avoiding of, sensory input (hyper-responsiveness) was linked to reduced adaptive skills across individuals-but not within-twin pairs. We also found an association between the degree to which individuals seek for sensory input (sensation seeking) and reduced adaptive skills, but only in individuals diagnosed with autism. The results suggest that sensory hyper-responsiveness has negative effects on individuals' general ability to function, but that this link is influenced by familial factors and hence not direct. In addition, sensation seeking behaviors might have a negative impact on adaptive skills specifically in autistic individuals.

Leisure and Problem Gaming Behaviors Among Children and Adolescents During School Closures Caused by COVID-19 in Hong Kong: Quantitative Cross-sectional Survey Study.

BACKGROUND: School closures during the COVID-19 pandemic may have exacerbated students' loneliness, addictive gaming behaviors, and poor mental health. These mental health issues confronting young people are of public concern. OBJECTIVE: This study aimed to examine the associations between loneliness and gaming addiction behaviors among young people in Hong Kong and to investigate how familial factors, psychological distress, and gender differences moderate these relationships. METHODS: This cross-sectional study was conducted in June 2020 when schools reopened after 6 months of school closures. Participants included 2863 children and adolescents in primary (Grades 4 to 6) and secondary (Grades 7 and 8) schools (female participants: 1502/2863, 52.5%). Chi-square tests, one-way analyses of variance, and independent-samples t tests were performed to compare the differences of distribution in gaming addiction behaviors across gender, age, and other sociodemographic characteristics. Multinomial logistic regression analyses were conducted to identify factors that relate to excessive or pathological gaming behaviors separately, in comparison with leisure gaming. RESULTS: A total of 83.0% (2377/2863) of the participants played video games during the COVID-19 pandemic. The prevalence of excessive and pathological game addiction behaviors was 20.9% (597/2863) and 5.3% (153/2863), respectively. More male students had gaming addiction symptoms than female students. The multinomial logistic regressions showed that feeling lonely was associated with more problematic gaming behaviors, and the association was stronger for older female students. Low socioeconomic status, less parental support and less supervision, and poor mental health were risk factors for gaming addiction behaviors, especially among primary school students. CONCLUSIONS: Loneliness was associated with gaming addiction behaviors; the findings from this study suggested that this association was similar across gender and age groups among young people. Familial support and supervision during school closures can protect young people from developing problematic gaming behaviors. Results of this study have implications for prevention and early intervention on behalf of policy makers and game developers.

Familial and Parental Predictors of Physical Activity in Late Adolescence: Prospective Analysis over a Two-Year Period.

Children's health behaviors are highly influenced by their parents and family. This study aimed to prospectively evaluate the parental/familial factors associated with physical activity levels (PALs) among older adolescents. The participants were 766 adolescents, who were prospectively observed at baseline (when they were 16 years of age), at first follow-up measurement (FU1; 17 years of age), and second follow-up measurement (FU2; 18 years of age). Sociodemographic factors (age, gender, socioeconomic status, and sport participation) and parental/familial variables were evaluated at baseline. PALs (evidenced by the Physical-Activity Questionnaire-for-Adolescents) were prospectively evidenced at baseline, FU1, and FU2. Factorial analysis of variance for repeated measurements showed a significant decrease in PALs during the study course (F = 83.05, p < 0.001). Sport participation and male gender were significant predictors of PALs at baseline, FU1, and FU2. Logistic regression, controlled for sport participation and male gender, evidenced paternal education as a significant predictor of baseline PALs. Parental conflict was a significant predictor of PALs in all three testing waves. The significant influence of paternal education on the children's PALs existed from younger adolescence until the age of 17 years. The association between parental conflict and PALs developed in older adolescence. These results should be used in the development of specific and targeted interventions aimed at the improvement of PALs and a reduction of sedentarism in youth.

The association between familial and environmental factors and prevalence of congenital hypothyroidism in center of Iran.

The aim of this current study is to investigate the association between familial and environmental factors and prevalence of congenital hypothyroidism (CH) in Isfahan province. In this retrospective cohort study, data of the neonates referred for CH screening in different cities of Isfahan province were evaluated. Data regarding air and soil (lead, cadmium) pollutants were collected. The spatial association between mentioned environmental pollutants and prevalence of CH in different cities of Isfahan province was evaluated by using GIS software, and multilevel linear regression was used for evaluating the levels of environmental pollutants and neonates' serum TSH. During the study period, 389,945 neonates were screened, from which 934 diagnosed with CH (1 in 417 neonates).The prevalence rate of CH was ranged from < 20 in 10,000 live births to > 45 in 10,000 live births in different cities of Isfahan province. There was no any significant association between level of soil lead and cadmium and air pollutants with prevalence of CH in different cities of Isfahan province (P > 0.05).There was a significant positive association between soil cadmium and air pollution evaluated by air quality index (AQI) and level of screening serum TSH in CH patients. Considering the significant association between cadmium and AQI with first serum TSH, it is inferred that the interaction of genetic, autoimmune, familial, and environmental factors with each other could influence on neonatal thyroid function. It seems that the role of some mentioned component is more prominent which should be investigated in future researches.

Predictors of teenage pregnancy among girls aged 13-19 years in Uganda: a community based case-control study.

BACKGROUND: Teenage pregnancy is a serious public health and social problem, with 95% occurring in developing countries. The aim of the study was to investigate the behavioural, familial and social factors associated with teenage pregnancy among girls aged 13-19 years in Lira District, Uganda. METHODS: Primary data from a case-control study of teenage girls (aged 13-19 years) in Lira District, Uganda was analysed. A Structured questionnaire was administered using face-to-face interviews to collect data on 495 participants, identified through simple random sampling from 32 villages in two counties in Lira District. Data analyses were done using SPSS Statistics 23 for descriptive, bivariate (i.e. Chi-square tests) and multivariable analyses (i.e. logistics regression) used for determining independent associations. RESULTS: A total of 495 teenage girls participated in the study, however, final analyses were undertaken for 480 respondents. At bivariable analysis, all variables except alcohol consumption were significantly associated with teenage pregnancy. Among the behavioural factors assessed, multivariable analyses showed that having multiple sexual partners, frequent sex and irregular contraceptive use increased the likelihood of teenage pregnancy. Among familial factors, being married was found to increase the likelihood of teenage pregnancy. Peer pressure, sexual abuse and lack of control over sex was observed to increase the likelihood of teenage pregnancy. CONCLUSIONS: Demographic, behavioural, familial and social factors are important predictors of teenage pregnancy in Lira District. Interventions focussing on: retaining pregnant and married girls at school, information on sexual and reproductive health of teenage girls, improving access to and information about contraceptive use among teenage girls, improving socio-economic status of households, and law enforcement on sexual abuse among girls may come a long way to improving adolescent sexual and health services in the low-income settings.

Epidemiology, Diagnosis and Risk Factors of Helicobacter pylori Infection.

Helicobacter pylori is a human-specific pathogen, which leads to gastric pathologies including gastric cancer. It is a highly unique bacterium considered as a carcinogenic agent. H. pylori remains a major human health problem, responsible for ~90% of the gastric cancer cases. Approximately four billion individuals have been detected for H. pylori infection worldwide in 2015. At the turn of the twenty-first century, the prevalence of H. pylori has been declining in highly industrialized countries of the Western world, whereas prevalence has plateaued at a high level in developing and newly industrialized countries. However, the infection status remains high in immigrants coming from countries with high prevalence of H. pylori infection. H. pylori can be diagnosed both by invasive and non-invasive methods. Urea breath test and stool antigens detection are among the most commonly used non-invasive ones. Although the way H. pylori is transmitted remains still not fully clear, the level of contamination is strongly dependent on the familial and environmental context, with a drastic impact of living conditions with poor hygiene and sanitation. However, familial socioeconomic status is the main risk factor for H. pylori infection among children. In addition, food and water source have a high impact on the prevalence of H. pylori infection worldwide. This chapter highlights the latest knowledge in the epidemiology of H. pylori infection, its diagnosis and critical risk factors responsible for its high prevalence in some populations and geographic areas.

Aerobic fitness in late adolescence and the risk of cancer and cancer-associated mortality in adulthood: A prospective nationwide study of 1.2 million Swedish men.

BACKGROUND: The incidence of cancer has steadily risen. It is important to identify modifiable predictors in early life that may decrease cancer risks and mortality. The present study aims to investigate the relationship between aerobic fitness in adolescence and the subsequent risk of cancer and cancer-associated mortality. METHODS: The study included 1 185 439 Swedish men born between 1950 and 1980 that participated in the military conscription (mean age = 18 years). The results from the aerobic fitness test (Wmax) was linked to the risk of cancer and cancer-associated mortality during a 40-years' follow-up using Cox proportional hazards models. A co-sibling design was employed to take familial factors into account. RESULTS: During a mean follow-up of 27 years 15 093 cases of cancer and 4900 cancer-associated mortalities were registered. Higher Wmax (per additional 1 SD) was associated with a decreased risk of cancer at 40 years of follow-up (HR 0.93; 95% CI 0.91-0.96 for cancer and HR 0.82 95% CI 0.76-0.87 for cancer-associated mortality) but not at 5 years of follow-up (HR 1.03; 95% CI 0.99-1.07; and HR 1.04; 95% CI 0.97-1.12). In the co-sibling model the protective effects of high Wmax were increased at 40 years of follow-up for cancer (HR 0.91; 95% CI 0.85-0.98) and cancer-associated mortality (HR 0.78; 95% CI 0.68-0.89). CONCLUSIONS: These findings identify in late adolescence a potentially modifiable predictor of cancer, with higher aerobic fitness associated with a decreased risk of cancer incidence and mortality later in life.

Influencia de los factores psicológicos y familiares en el mantenimiento de la obesidad infantil / Influence of psychological and familial factors on the maintenance of childhood obesity

Resumen En los últimos años la obesidad infantil es considerada uno de los principales problemas de salud a nivel mundial. El objetivo principal de este estudio fue evaluar los factores psicológicos y familiares asociados a la obesidad en un grupo de niños. Participaron 13 niños con obesidad, de entre 7 y 11 años de edad (ocho varones y cinco mujeres), y 21 familiares (padres/madres/abuelas), quienes fueron remitidos por el Servicio de Pediatría del Centro de Investigaciones Médico-Quirúrgicas. Fueron examinadas las variables siguientes: hábitos de alimentación, hábitos de actividad física, imagen corporal, estado afectivo, autoestima, relaciones afectivas familiares compensatorias y actitudes potencialmente generadoras de alteraciones psicológicas en la familia. El análisis realizado fue predominantemente cualitativo, a través de técnicas como la entrevista semiestructurada al niño y a la familia, el análisis psicográfico (dibujo libre y de la familia), así como el empleo de las Siete Figuras de Collins. Se concluye acerca de la relevancia de la influencia de todas las variables analizadas sobre la obesidad infantil. Resulta inminente la necesidad de implementar programas de intervención psicológica que suponga el abordaje no solo de los niños, sino también de sus familiares.

Abstract In recent years, childhood obesity is considered one of the main health problems worldwide. The main objective of this study was to evaluate the psychological and familial factors associated with obesity in a group of children. Thirteen children with obesity, between 7 and 11 years old (eight boys and five girls), and 21 relatives (fathers/mothers/ grandmothers), who were referred by the Pediatric Service of the Medical-Surgical Research Center, participated. The following variables were examined: eating habits, physical activity habits, body image, affective state, self-esteem, compensatory family affective relationships and potential attitudes that lead to psychological alterations in the family. The analysis was predominantly qualitative, through techniques such as the semi-structured interview with the child and the family, the psychographic analysis (free drawing and family drawing), as well as the Seven Figures of Collins. We conclude about the relevance of the influence in all the variables analyzed on childhood obesity. The need to implement psychological intervention programs addressing not only children, but also their families is imminent.

Applied Human Genetic Epidemiology.

This chapter covers the study of human epidemiology, including family studies in genetic epidemiology, linkage analysis, genetic Mapping in human diseases, human genetic influences on diseases, genetic relationships in familial aggregation, and derivation of familial risk.An Illustration is provided of a research project in genetic epidemiology research which included (1) Heritability Analysis (2) Molecular Variation Study Methods (3) Genomics for Human Genetic Epidemiology Complex Traits and Mendelian Inheritance Mendel's Laws Hardy-Weinberg Principle Gene Structure and Genetic Code Genetic Linkage and Linkage Disequilibrium Study Designs for of Rare Genetic Variations Spectrum of Variation Familial Factors in Human Genetic Epidemiology *Human Genetic Association Genetic Epidemiology Owing to Population Stratification Environmental Effects on Genetic Epidemiology Genetic Epidemiology and Public Health.

The Characteristics of Child Sexual Abuse in the School Environment in Turkey.

School may represent a protective factor, boosting the mental health of the student body, while also representing a risk factor that heightens the potential for mental health problems. The present study aims to identify the individual and familial characteristics associated with the incidents of child sexual abuse (CSA) in Turkey's school environment. The incidents involving school-related CSA constituted 5.6% (N = 125) of 2,238 cases. The following was discovered: an adult committed the majority (64%) of CSA in the school environment; most adult perpetrators were teachers (62.5%). This study determined that the perpetrators manipulated the victims via methods that included physical abuse (11.2%), threats (19.2%), tricks/deception (15.2%), and taking photographs/videos with sexual content (3.2%); and CSA incidents involved intercourse (15.2%); and almost three-quarter of the victims of CSA in the school environment reported the incident late. This study indicates that peer perpetrators abuse younger victims and a greater proportion of male victims relative to adult perpetrators. In light of these findings, school security must be improved, especially in public schools, and trainings aimed at preventing bullying and sexual abuse (SA) should be given to all school staff, students, and parents.

Family profiles of maltreated children in Singapore: A latent class analysis.

Children who enter the child protection system often have complex family problems and have experienced early adverse experiences. Using latent class analysis, this study aimed to identify family classes of child protection cases in Singapore, to ascertain the prevalence of these family classes, and to test the association of family class membership to subsequent recurrence of harm. A sample of 440 cases who entered the Child Protective Service in Singapore was analyzed based on eight familial factors on the household and caregiver levels. A four-class solution was found to demonstrate the best fit: (a) the large household group was intergenerational and majority lived with extended family members, (b) the harsh parenting group showed high levels of parenting problems and the caregiver justifying his abuse/neglect, (c) the high criminality group had high levels of caregiver substance abuse and caregiver arrest and incarceration history, and (d) the low disadvantage group rated low on all the familial factors. A Cox Regression revealed that in comparison to the low disadvantage group, the harsh parenting group was twice as likely to have recurrence of harm. There were also differences across family classes with regard to age at entry into child protection, gender composition and abuse types. The findings and practice implications are discussed.

Psychological and Familial Factors of Depression in Relation to Adolescent Smoking Behavior.

BACKGROUND: Several common factors have been identified for smoking and depression. The The present study explores the relation of psychological and familial factors with depression, by student smoking behavior. MATERIALS AND METHODS: A total of 5500 middle- and high-school students were selected in Isfahan province in 2010. A self-administered questionnaire collected data on background characteristics, smoking status, depression, and risk factors. Univariate analysis multiple logistic regressions were conducted to compare between depressed and nondepressed people by adolescent smoking status. Odds ratios and the corresponding 95% confidence intervals (CIs) were reported. RESULTS: Fathers lower education attainment was accompanied adolescents higher depression prevalence. Parental smoking and sibling smoking increased the depression likelihood by 1.41 (95% CI: 1.18, 1.68) and 1.43 folds (95% CI: 1.04-1.94) for never-smokers. Positive attitude toward smoking increased the probability of depression by 1.18 among never-smokers. Never-smokers lacking refusal skill had 1.23 (1.03-1.47) higher chance of depression. A higher level of self-efficacy related to lower chance of depression. Taking risky behavior, increased the depression likelihood by 1.56 (95% CI: 1.29-1.89) in never-smokers, by 1.85 (95% CI: 1.37-2.44) in experimental smokers, and by 1.14 times (95% CI: 1.01-1.72) in current smokers. Family conflict increased depression chance by 2.25 times (95% CI: 1.89-2.66) in never-smokers, by 1.95 (95% CI: 1.46-2.61) in experimental smokers, and by 2.06 times (95% CI: 1.38-3.08) in current smokers. CONCLUSIONS: Targeting self-efficacy level, risky behavior, and family conflict can drop the comorbidity of smoking and depression simultaneously. This may help public health practitioners and policymakers to develop common strategies in reducing adolescents smoking and depression comorbidity.

Intimate partner violence perpetrated by young adult women against men in Ukraine: Examining individual, familial, and cultural factors.

We examined the role of financial strain, parent-to-parent violence, parent-to-child violence, emotional distress, and alcohol use in intimate partner violence perpetrated by young adult women against men in Ukraine. The moderating role of acceptability of intimate partner violence and violence-related laws and regulations was also examined. Four hundred and six full-time female university students from four universities in Ukraine participated in the study. We found that emotional distress, parent-to-parent, and parent-to-child violence mediated the link between financial strain and intimate partner violence perpetrated by women on men. However, we found limited support for the moderating role of acceptability of intimate partner violence and violence-related laws and regulations in the relationship between individual and familial factors on intimate partner violence. The findings from this investigation suggest that there is a distinct need for supporting families and individuals in dealing with issues of intimate partner violence directed by women against men in Ukraine. Aggr. Behav. 42:380-393, 2016. © 2015 Wiley Periodicals, Inc.

Pregnancy history and risk of premenopausal breast cancer-a nested case-control study.

BACKGROUND: Reproductive factors are well-known risk factors for premenopausal breast cancer (PBC). It is unknown whether these associations are modified by familial factors, including genetic and early environment factors. METHODS: Using Swedish health registries, we performed a nested case-control study with two control groups: sister controls and population controls. The study population included women with live singleton births between 1973 and 2010, who also had a full sister who gave birth during this period. All women subsequently diagnosed with PBC were selected as cases (n = 8327). Sisters with the least age difference and without PBC at the time of her sister's diagnosis were selected as sister controls. For each incident case, one population control without previous PBC was selected.The population controls were individually matched with the sister controls on year of birth. Conditional logistic regression was used to estimate associations between reproductive factors and PBC. RESULTS: Increasing parity was inversely associated with PBC using population controls, and multiparity was a risk factor using sister controls. Very preterm delivery (≤ 31 weeks) was associated with a slightly higher PBC risk using sister controls. Preeclampsia was associated with a slightly protective effect using population controls. With respect to other factors, there were no substantial differences in risks of PBC by choice of control group. CONCLUSIONS: The divergent results with regard to parity and PBC risk when using sister and population controls suggest that the influence of childbearing may be modified by genotype. Selection bias when using different control groups must also be considered.

Overweight and Obesity and Associated Factors among School-Aged Adolescents in Six Pacific Island Countries in Oceania.

The aim of this study was to assess overweight and obesity and associated factors in school-going adolescents in six Pacific Island countries in Oceania. The sample included 10,424 school-going adolescents predominantly 13-16 years old from Fiji, Kiribati, Samoa, Solomon Islands, Tonga, and Vanuatu. Bivariate and multivariable analyses were conducted to assess the relationship between dietary behaviour, substance use, physical activity, psychosocial factors, social-familial influences, and overweight or obesity. The prevalence of overweight and obesity was determined based on self-reported height and weight and the international child body mass index standards. Results indicate a prevalence of overweight or obesity of 24.3% and obesity of 6.1% in the six countries, ranging in terms of overweight or obesity and obesity from 12.0% and 0.4% in Vanuatu to 58.7% and 21.1% in Tonga, respectively. In multivariable regression analysis, being female was associated with overweight, carbonated soft drink use with obesity, sedentary behaviour with overweight or obesity, suicidal ideation with overweight, having close friends and peer support with overweight and obesity, parental or guardian supervision with overweight, and parental or guardian bonding was associated with overweight or obesity. High prevalence rates of overweight and obesity were found and several factors identified which can help guide interventions.