Deconstructing the smoking-preeclampsia paradox through a counterfactual framework.

Although smoking during pregnancy may lead to many adverse outcomes, numerous studies have reported a paradoxical inverse association between maternal cigarette smoking during pregnancy and preeclampsia. Using a counterfactual framework we aimed to explore the structure of this paradox as being a consequence of selection bias. Using a case-control study nested in the Icelandic Birth Registry (1309 women), we show how this selection bias can be explored and corrected for. Cases were defined as any case of pregnancy induced hypertension or preeclampsia occurring after 20 weeks' gestation and controls as normotensive mothers who gave birth in the same year. First, we used directed acyclic graphs to illustrate the common bias structure. Second, we used classical logistic regression and mediation analytic methods for dichotomous outcomes to explore the structure of the bias. Lastly, we performed both deterministic and probabilistic sensitivity analysis to estimate the amount of bias due to an uncontrolled confounder and corrected for it. The biased effect of smoking was estimated to reduce the odds of preeclampsia by 28 % (OR 0.72, 95 %CI 0.52, 0.99) and after stratification by gestational age at delivery ( 1, revealing the structure of the paradox. The bias-adjusted estimation of the smoking effect on preeclampsia showed an OR of 1.22 (95 %CI 0.41, 6.53). The smoking-preeclampsia paradox appears to be an example of (1) selection bias most likely caused by studying cases prevalent at birth rather than all incident cases from conception in a pregnancy cohort, (2) omitting important confounders associated with both smoking and preeclampsia (preventing the outcome to develop) and (3) controlling for a collider (gestation weeks at delivery). Future studies need to consider these aspects when studying and interpreting the association between smoking and pregnancy outcomes

Early Life Residence, Fish Consumption, and Risk of Breast Cancer.

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/Open To access publisher's full text version of this article click on the hyperlink at the bottom of the pageBackground: Little is known about fish intake throughout the life course and the risk of breast cancer.Methods: We used data on the first residence of 9,340 women born 1908 to 1935 in the Reykjavik Study as well as food frequency data for different periods of life from a subgroup of the cohort entering the Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study (n = 2,882).Results: During a mean follow-up of 27.3 years, 744 women were diagnosed with breast cancer in the Reykjavik Study. An inverse association of breast cancer was observed among women who lived through the puberty period in coastal villages, compared with women residing in the capital area [HR, 0.78; 95% confidence interval (CI), 0.61-0.99]. In the subgroup analysis of this Icelandic population, generally characterized by high fish intake, we found an indication of lower risk of breast cancer among women with high fish consumption (more than 4 portions per week) in adolescence (HR, 0.71; 95% CI, 0.44-1.13) and midlife (HR, 0.46; 95% CI, 0.22-0.97), compared with low consumers (2 portions per week or less). No association was found for fish liver oil consumption in any time period, which could be due to lack of a reference group with low omega-3 fatty acids intake in the study group.Conclusions: Our findings suggest that very high fish consumption in early to midlife may be associated with a reduced risk of breast cancer.Impact: Very high fish consumption in early adulthood to midlife may be associated with decreased risk of breast cancer. Cancer Epidemiol Biomarkers Prev; 26(3); 346-54. ©2016 AACR.NIH Intramural Research Program of the National Institute on Aging Icelandic Heart Association Icelandic Parliament Icelandic Centre for Research, RANNIS Public Health Fund of the Icelandic Directorate of Healt

Effects of yoga practice on stress-related symptoms in the aftermath of an earthquake: A community-based controlled trial.

To access publisher's full text version of this article click on the hyperlink at the bottom of the pageTo evaluate the effect of an integrated hatha yoga practice on perceived stress and stress-related symptoms in the aftermath of an earthquake.Inhabitants, aged 20-67 years, from highly exposed earthquake areas of two villages in South Iceland were offered to participate in a yoga program subsequent to an earthquake. Sixty-six individuals were self-selected into the study and divided by residential convenience into an experimental group (n=31) and a waiting list control group (n=35).The yoga program was conducted twice a week for six weeks, in normal situations among the inhabitants in the community.Several validated questionnaires assessing stress and stress-related symptoms, posttraumatic symptoms, depression, anxiety and health related quality of life were administered at pre- and post-intervention.Multivariate analysis of variance (MANOVA) revealed differences between the experimental group and waiting list control group on sleep quality (p=.03) and social relations (p=.04). These differences did not prevail at Bonferroni correction for multiple testing (at alpha level of .005). Participants in both groups showed significant improvements in stress and some stress-related symptoms such as sleep, concentration, well-being, quality of life, depression and anxiety from pre- to post-intervention.The data from this small study show no statistically significant improvement of an integrated hatha yoga program above and beyond waiting list control, following exposure to an earthquake. However, the observed trend toward improved sleep quality and social relations deserve further exploration in larger effectiveness studies on the impact of Hatha yoga on recovery after natural disaster.Icelandic Nurse's Associatio

Regional differences in mortality, hospital discharges and primary care contacts for cardiovascular disease.

To access publisher's full text version of this article click on the hyperlink belowSurveillance of geographical variations in cardiovascular health is important in order to achieve the objectives of reducing regional health disparities. We aimed to explore differences in cardiovascular disease (CVD) mortality and prevalence of CVD diagnoses made in primary and in-patient care, as well as risk factor distribution by geographic regions (urban/rural) in Iceland.From nationwide health registers, we obtained data on CVD mortalities ( N = 7113), primary healthcare CVD contacts ( N = 58,246) and hospital CVD discharges ( N = 14,039), as well as data on CVD risk factors from a national health survey ( N = 5909; response rate 60.3%). Age-standardised annual mortality, primary healthcare contact and hospital discharge rates due to CVD were calculated per 100,000 population inside (urban) and outside (rural) the Capital Area (CA). Logistic regression was used to explore regional differences in CVD risk factors.We observed slightly higher total CVD mortality rates among women outside compared to inside the CA (Standardised Rate Ratio (SRR) 1.06 (95% confidence interval (CI) 1.05-1.07)), particularly due to atrial fibrillation (SRR 1.47 (95% CI 1.46-1.48)), heart failure (SRR 1.29 (95% CI 1.27-1.31)) and ischemic heart disease (SRR 1.11 (95% CI 1.10-1.12)), while reduced mortality risk for cerebrovascular disease (SRR 0.81 (95% CI 0.80-0.83)). The rates of hospital discharges and primary care contacts for these diseases, as well as prevalence of several modifiable risk factors, were generally higher outside the CA, particularly among women.The higher prevalence of modifiable risk factors and CVD in rural areas, especially among women, calls for refined treatment and health-promoting efforts in rural areas.Rannis - Icelandic Centre for Researc

Number of visits to the emergency department and risk of suicide: a population-based case-control study.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.The aim was to study whether number of visits to emergency department (ED) is associated with suicide, taking into consideration known risk factors.This is a population-based case-control study nested in a cohort. Computerized database on attendees to ED (during 2002-2008) was record linked to nation-wide death registry to identify 152 cases, and randomly selected 1520 controls. The study was confined to patients attending the ED, who were subsequently discharged, and not admitted to hospital ward. Odds ratio (OR) and 95% confidence intervals (CI) of suicide risk according to number of visits (logistic regression) adjusted for age, gender, mental and behavioral disorders, non-causative diagnosis, and drug poisonings.Suicide cases had on average attended the ED four times, while controls attended twice. The OR for attendance due to mental and behavioral disorders was 3.08 (95% CI 1.61-5.88), 1.60 (95% CI 1.06-2.43) for non-causative diagnosis, and 5.08 (95% CI 1.69-15.25) for poisoning. The ORs increased gradually with increasing number of visits. Adjusted for age, gender, and the above mentioned diagnoses, the OR for three attendances was 2.17, for five attendances 2.60, for seven attendances 5.97, and for nine attendances 12.18 compared with those who had one visit.Number of visits to the ED is an independent risk factor for suicide adjusted for other known and important risk factors. The prevalence of four or more visits was 40% among cases compared with 10% among controls. This new risk factor may open new venues for suicide prevention.Landspitali University Hospital Research Fund 311055-224

Maternal geographic residence, local health service supply and birth outcomes.

To access publisher's full text version of this article click on the hyperlink at the bottom of the pageTo describe pregnancy complications, mode of delivery and neonatal outcomes by mother's residence.Register-based cohort study.Geographical regions of Iceland.Live singleton births from 1 January 2000 to 31 December 2009 (n = 40 982) and stillbirths ≥22 weeks or weighing ≥500 g (n = 145).Logistic regression was used to explore differences in outcomes by area of residence while controlling for potential confounders. Maternal residence was classified according to distance from Capital Area and availability of local health services.Preterm birth, low birthweight, perinatal death, gestational diabetes and hypertension.Of the 40 982 infants of the study population 26 255 (64.1%) were born to mothers residing in the Capital Area and 14 727 (35.9%) to mothers living outside the Capital Area. Infants outside the Capital Area were more likely to have been delivered by cesarean section (adjusted odds ratio 1.28; 95% CI 1.21-1.36). A lower prevalence of gestational diabetes (adjusted odds ratio 0.68; 95% CI 0.59-0.78), hypertension (adjusted odds ratio 0.82; 95% CI 0.71-0.94) as well as congenital malformations (adjusted odds ratio 0.55; 95% CI 0.48-0.63) was observed outside the Capital Area. We observed neither differences in mean birthweight, gestation length nor rate of preterm birth or low birthweight across Capital Area and non-Capital Area. The odds of perinatal deaths were significantly higher (adjusted odds ratio 1.87; 95% CI 1.18-2.95) outside the Capital Area in the second half of the study period.Lower prevalence of gestational diabetes and hypertension outside the Capital Area may be an indication of underreporting and/or lower diagnostic activity.Rannis - the Icelandic Centre for Research R10-0008 201

Self-injury in youths who lost a parent to cancer: nationwide study of the impact of family-related and health-care-related factors

Background: Self-injury, a manifestation of severe psychological distress, is increased in cancer-bereaved youths. Little is known about the potential influence on the risk for self-injury of factors that could be clinically relevant to and modifiable by the health-care professionals involved in the care of the dying parent. Methods: In a nationwide population-based anonymous study, 622 (73.1%) youths (aged 18-26) who, 6 to 9 years earlier at ages 13 to 16, had lost a parent to cancer answered study-specific questions about self-injury and factors related to the family and parental health care. Results: Univariable analyses showed that the risk for self-injury was increased among cancer-bereaved youths who reported poor family cohesion the years before (relative risk [RR], 3.4, 95% confidence interval [CI], 2.5-4.6) and after the loss (RR, 3.3, 95% CI, 2.4-4.4), distrust in the health care provided to the dying parent (RR, 1.7, 95% CI, 1.2-2.4), perceiving poor health-care efforts to cure the parent (RR 1.5, 95% CI, 1.1-2.1) and poor efforts to prevent suffering (RR, 1.6, 95% CI, 1.1-2.4), that at least one of their parents had been depressed or had troubles in life (RR, 1.5, CI, 1.1-2.1) and believing 3 days before the loss that the treatment would probably cure the parent (RR, 1.6, CI, 1.1-2.3). In the total multivariable models, only poor family cohesion before and after the loss remained statistically significantly associated with self-injury. Conclusion: Poor family cohesion before and after the loss of a parent to cancer is associated with an increased risk of self-injury in teenage children. Copyright (C) 2014 John Wiley & Sons, Ltd

Increased attendance rates and altered characteristics of sexual violence.

To access publisher full text version of this article. Please click on the hyperlink in Additional Links field.OBJECTIVE: To study the attendance rates and characteristics of sexual violence presented at emergency services for rape victims, over a 10-year period. DESIGN: Incidence study. SETTING: Rape Trauma Service, within an emergency department at a tertiary referral university hospital. POPULATION. The total female population in Iceland. METHODS: Medical records on visits were reviewed and systematically coded. Annual attendance rates were calculated over time as number of visits per 10 000 female inhabitants aged 13-49 years. Characteristics of sexual violence, perpetrators and victims were compared between 1998-2002 and 2003-2007. MAIN OUTCOME MEASURES: Annual attendance rates and characteristics of sexual violence. RESULTS: Of 1153 visits, 828 (71.8%) were due to severe sexual violence (penetration). Annual attendance rates of all sexual violence increased from 12.5 to 16.9 per 10 000 women aged 13-49 (p<0.01). Attendance rates due to severe sexual violence increased specifically among women aged 18-25 (p<0.01). The proportion of assaults involving multiple perpetrators increased from 13.9% in 1998-2002 to 18.9% in 2003-2007 (p=0.05). With time, a higher proportion of victims had seriously impaired consciousness due to alcohol consumption (p<0.01) and had used illegal drugs prior to assault (p<0.05). CONCLUSIONS: The findings point towards an increase in women's visits to specialized emergency services for rape victims, particularly in the age group 18-25 years. The increased role of multiple perpetrators, alcohol and illicit drugs in sexual violence calls for further attention.Landspitali University Hospital, Mar Kristjansson Science Project Fund, University of Iceland, Icelandic Nurses Association

Body Mass Index, Smoking and Hypertensive Disorders during Pregnancy: A Population Based Case-Control Study

While obesity is an indicated risk factor for hypertensive disorders of pregnancy, smoking during pregnancy has been shown to be inversely associated with the development of preeclampsia and gestational hypertension. The purpose of this study was to investigate the combined effects of high body mass index and smoking on hypertensive disorders during pregnancy. This was a case-control study based on national registers, nested within all pregnancies in Iceland 1989–2004, resulting in birth at the Landspitali University Hospital. Cases (n = 500) were matched 1:2 with women without a hypertensive diagnosis who gave birth in the same year. Body mass index (kg/m2) was based on height and weight at 10–15 weeks of pregnancy. We used logistic regression models to calculate odds ratios and corresponding 95% confidence intervals as measures of association, adjusting for potential confounders and tested for additive and multiplicative interactions of body mass index and smoking. Women’s body mass index during early pregnancy was positively associated with each hypertensive outcome. Compared with normal weight women, the multivariable adjusted odds ratio for any hypertensive disorder was 1.8 (95% confidence interval, 1.3–2.3) for overweight women and 3.1 (95% confidence interval, 2.2–4.3) for obese women. The odds ratio for any hypertensive disorder with obesity was 3.9 (95% confidence interval 1.8–8.6) among smokers and 3.0 (95% confidence interval 2.1–4.3) among non-smokers. The effect estimates for hypertensive disorders with high body mass index appeared more pronounced among smokers than non-smokers, although the observed difference was not statistically significant. Our findings may help elucidate the complicated interplay of these lifestyle-related factors with the hypertensive disorders during pregnancy

Risk factors and health during pregnancy among women previously exposed to sexual violence.

To access publisher's full text version of this article click on the hyperlink at the bottom of the pageTo determine whether women exposed to sexual violence in adolescence or adulthood are at increased risk of adverse maternal characteristics during subsequent pregnancies.Register-based cohort study.Iceland.We identified 586 women who attended a Rape Trauma Service (RTS) between 1993 and 2008 and all subsequent births of these women up to April 2011 (n = 915). These pregnancies were compared with 1641 randomly selected pregnancies of women who had not attended the RTS and who gave birth during the same calendar month.Information on maternal smoking, body mass index and illicit drug use was obtained from maternal charts. We used Poisson regression to obtain multivariable adjusted relative risks (aRR) with 95% CI contrasting prevalence of outcomes in the two groups.Characteristics and risk factors during pregnancy, including maternal smoking, body mass index, weight gain during pregnancy, illicit drug use.Compared with unexposed women, sexually assaulted women were younger and more often primiparous in subsequent pregnancy, more likely not to be employed (7.8% vs. 4.3%; aRR 2.42, 95% CI 1.49-3.94), not cohabiting (45.6% vs. 14.2%; aRR 2.15, 95% CI 1.75-2.65), smokers (45.4% vs. 13.5%; aRR 2.68, 95% CI 2.25-3.20), and more likely to have used illicit drugs during pregnancy (3.4% vs. 0.4%; aRR 6.27, 95% CI 2.13-18.43). Exposed primiparas were more likely to be obese (15.5% vs. 12.3%; aRR 1.56, 95% CI 1.15-2.12).Women with a history of sexual violence are more likely to have risk factors during pregnancy that may affect maternal health and fetal development.Icelandic Research Fund for Graduate Students (Rannis) Landspitali University Hospital Research Fun