Applying measures of discriminatory accuracy to revisit traditional risk factors for being small for gestational age in Sweden: a national cross-sectional study.

Small for gestational age (SGA) is considered as an indicator of intrauterine growth restriction, and multiple maternal and newborn characteristics have been identified as risk factors for SGA. This knowledge is mainly based on measures of average association (ie, OR) that quantify differences in average risk between exposed and unexposed groups. Nevertheless, average associations do not assess the discriminatory accuracy of the risk factors (ie, its ability to discriminate the babies who will develop SGA from those that will not). Therefore, applying measures of discriminatory accuracy rather than measures of association only, our study revisits known risk factors of SGA and discusses their role from a public health perspective

Psychological distress by age at migration and duration of residence in Sweden

Migrants suffer from worse psychological health than natives in many countries, yet the extent to which this varies by age at migration and duration of residence in the receiving context remains unexplored in Sweden. Drawing on a life course approach, we investigate differences in psychological distress by age at migration and duration of residence in working-age migrants to Sweden, and examine the role of various social determinants of health in explaining these differences relative to Swedish-born. Using pooled cross-sectional data from the 2011/2015 Health on Equal Terms survey in Västra Götaland Region, Sweden (n = 58,428), we applied logistic regression analysis to calculate predicted probabilities and average marginal effects (AME) of migrant status, by age at migration and duration of residence, on psychological distress. Analyses were stratified by sex and region of origin and controlled for indicators of socioeconomic status (SES), social cohesion, and discrimination to assess their potential contribution to differences in migrants' and natives' psychological distress. All migrants except men from OECD-predominant regions had a greater probability of psychological distress than Swedish-born (ranging from AME 0.031 [95% Confidence Interval or CI 0.000–0.062] for OECD women to AME 0.115 [95% CI 0.074–0.156] for non-OECD men). Marginal effects of migration status on psychological distress probabilities generally increased with age at migration and duration of residence. Differences between migrants and natives were largely attenuated after controlling for social determinants, the greatest contribution coming from inequalities in social cohesion, followed by inequalities in discrimination and SES. Our results suggest a relative health advantage of early-life compared to later-life migration, albeit with worse outcomes with longer residence in Sweden. The predominance of integration opportunities in childhood strengthens calls for supportive policies to assist older migrants' integration directly upon arrival, which may ultimately improve their psychological wellbeing

Effects of non-health-targeted policies on migrant health: a systematic review and meta-analysis

Background: Government policies can strongly influence migrants' health. Using a Health in All Policies approach, we systematically reviewed evidence on the impact of public policies outside of the health-care system on migrant health. Methods: We searched the PubMed, Embase, and Web of Science databases from Jan 1, 2000, to Sept 1, 2017, for quantitative studies comparing the health effects of non-health-targeted public policies on migrants with those on a relevant comparison population. We searched for articles written in English, Swedish, Danish, Norwegian, Finnish, French, Spanish, or Portuguese. Qualitative studies and grey literature were excluded. We evaluated policy effects by migration stage (entry, integration, and exit) and by health outcome using narrative synthesis (all included studies) and random-effects meta-analysis (all studies whose results were amenable to statistical pooling). We summarised meta-analysis outcomes as standardised mean difference (SMD, 95% CI) or odds ratio (OR, 95% CI). To assess certainty, we created tables containing a summary of the findings according to the Grading of Recommendations Assessment, Development, and Evaluation. Our study was registered with PROSPERO, number CRD42017076104. Findings: We identified 43 243 potentially eligible records. 46 articles were narratively synthesised and 19 contributed to the meta-analysis. All studies were published in high-income countries and examined policies of entry (nine articles) and integration (37 articles). Restrictive entry policies (eg, temporary visa status, detention) were associated with poor mental health (SMD 0·44, 95% CI 0·13–0·75; I2=92·1%). In the integration phase, restrictive policies in general, and specifically regarding welfare eligibility and documentation requirements, were found to increase odds of poor self-rated health (OR 1·67, 95% CI 1·35–1·98; I2=82·0%) and mortality (1·38, 1·10–1·65; I2=98·9%). Restricted eligibility for welfare support decreased the odds of general health-care service use (0·92, 0·85–0·98; I2=0·0%), but did not reduce public health insurance coverage (0·89, 0·71–1·07; I2=99·4%), nor markedly affect proportions of people without health insurance (1·06, 0·90–1·21; I2=54·9%). Interpretation: Restrictive entry and integration policies are linked to poor migrant health outcomes in high-income countries. Efforts to improve the health of migrants would benefit from adopting a Health in All Policies perspective

Qué es lo que importa del peso al nacer: la paradoja epidemiológica en la población inmigrada de la Comunidad de Madrid

La tesis se adentra en un debate internacional conocido en la literatura con el nombre de “paradoja epidemiológica”. Con este término se resume un conjunto de evidencias, encontradas en países de larga trayectoria migratoria, que muestran similares o mejores indicadores de salud en la población inmigrante en comparación a la población de acogida. Y esto, pese a que provienen de contextos socioeconómicamente más desfavorecidos y que experimentan desventajas sociales en el país de acogida. El estudio centra su atención en una manifestación concreta de la paradoja epidemiológica que afecta a los resultados reproductivos: “la paradoja del bajo peso al nacer”. El objetivo del este trabajo es explorar en qué medida dicha ventaja es producto de un efecto artificial producido por algunas decisiones metodológicas derivadas tanto de la conceptualización del peso al nacer como indicador de salud (desde un punto de vista teórico y de medición), así como de la naturaleza de los datos estudiados (estadísticas vitales)

Calidad de los datos del Instituto Nacional de Estadística para la elaboración de los indicadores de salud perinatal: pequeño y grande para su edad gestacional

Background: Relative measures of birthweight (small and large-for-gestational age, SGA-LGA) are increasingly preferred to absolute measures (low birthweight, macrosomia). In this study we assess whether the national vital statistics provided by the Spanish National Statistical Institute (INE) reliably estimate SGA and LGA. Also, we will assess whether missing data (selection) and misreported information (bias) are systematically associated with parental socioeconomic information. Methods: We linked the information on 6,339 births at the Hospital Clínico San Carlos of Madrid (2005-06) with the vital statistics records (successful for the 95% of the observation). Validity measures and concordance were estimated for low birthweight (LBW, 2500 gr), macrosomia (4500 gr), SGA (10th percentile) and LGA (>90 percentile). Logistic regressions were fitted. Results: The prevalence estimated with the hospital data were: LBW (6%), macrosomia (0.5%) SGA (1%) and LGA (15%) and, with the data from INE: 5% 0.5% 2% 12% respectively. Kappa statistics: LBW (83%), macrosomia (79%), PEG (24%) and LGA (82%). Missing and misreported data vary with parental nationality and their situation in the labor market (OR between 1.5 y 2.2). Conclusions: Vital statistics overestimate the prevalence of SGA and underestimate the prevalence of LGA. The concordance between the sources is very good for low birthweight, macrosomia and LGA, and moderately good for SGA. Both missing and misreported birthweight and gestational age are associated with parental socioeconomic characteristics.Fundamentos: Los indicadores perinatales de peso relativo como pequeño y grande para la edad gestacional (PEG, GEG) son preferibles frente a medidas de peso absolutas (bajo peso, macrosomia). El objetivo de esta investigación fue evaluar si los datos del Instituto Nacional de Estadística (INE) tienen la fiabilidad suficiente para estimar indicadores de peso relativo y si la calidad de la información que comunican los progenitores varía según sus características sociodemográficas. Métodos: Se comparó la información de 6.339 nacimientos del Hospital Clínico San Carlos de Madrid (2005-06) con el registro de nacimientos del INE (con un éxito del 95%). Se evaluaron medidas de validación y acuerdo para los indicadores de bajo peso (BP 2500 gr), macrosomia (4.500 gr), PEG (percentil 10) y GEG (percentil 90). Se realizó un análisis de regresión logísticas Resultados: Las prevalencias estimadas con los datos del hospital fueron: BP (6%), macrosomia (0,5%) PEG (1%) y GEG (15%) y con datos del INE: 5% 0,5% 2% 12%, respectivamente. La especificidad: 80%, 78%, 24%, 82%. El estadístico Kappa: BP (83%), macrosomia (79%), PEG (24%) y GEG (82%). La omisión e incorrecta declaración varió según la nacionalidad y la situación laboral de los padres (OR entre 1,5 y 2,2). Conclusiones: El INE sobreestimaría la prevalencia de PEG e infraestimaría la de GEG. El acuerdo entre las fuentes es muy bueno para BP, macrosomia y GEG y moderadamente bueno para PEG. Tanto la omisión como los errores en la declaración del peso y la edad gestacional varían en función de las características sociodemográficas de los padres

Notas acerca del movimiento natural de la población para el estudio de la salud perinatal

El movimiento natural de la población, publicado por el Instituto Nacional de Estadística (INE), constituye una fuente de enorme importancia para el estudio de la salud perinatal en el ámbito nacional. Sin embargo, se desconocen las características de la recogida de la información que afectan a la calidad y la interpretación de los estudios epidemiológicos que utilizan esta fuente. El objetivo de este estudio es dar a conocer cómo se recoge la información y algunos problemas asociados. Este trabajo es el resultado de un análisis de las notas metodológicas del INE y de la información recogida de primera mano en hospitales de Madrid, en el Registro Civil central de Madrid y en el Instituto de Estadística de Madrid (IEM). Es necesaria una mayor integración entre las instituciones involucradas para mejorar la calidad de las estadísticas de nacimientos y muertes fetales tardías

The effect of Swedish snuff (snus) on offspring birthweight: a sibling analysis.

Current observational evidence indicates that maternal smoking during pregnancy is associated with reduced birthweight in offspring. However, less is known about the effect of smokeless tobacco on birthweight and about the possible mechanisms involved in this relationship. This paper studies the effect of Swedish smokeless tobacco (snus) on offspring birthweight comparing the results obtained from a conventional linear regression analysis and from a quasi-experimental sibling design using a multilevel linear regression analysis. From the Swedish Medical Birth Register, we investigated 604,804 singletons born between 2002 and 2010. From them, we isolated 8,861 siblings from 4,104 mothers with discrepant snus-use habits (i.e., women who had at least one pregnancy during which they used snus and at least one other pregnancy in which they did not). The conventional analysis shows that continuous snus use throughout the pregnancy reduces birthweight in 47 g while quitting or relapsing snus has a minor and statistically non-significant effect (-6 g and -4 g, respectively). However, using a sibling analysis the effect observed for mothers who continue to use snus during pregnancy is less intense than that observed with previous conventional analyses (-20 g), and this effect is not statistically significant. Sibling analysis shows that quitting or relapsing snus use after the first trimester slightly reduces birthweight (14 g). However, this small change is not statistically significant. The sibling analysis provides strong causal evidence indicating that exposure to snus during pregnancy has a minor effect on birthweight reduction. Our findings provide a new piece of causal evidence concerning the effect of tobacco on birthweight and support the hypothesis that the harmful effect of smoking on birthweight is not mainly due to nicotine

Revisiting the effect of maternal smoking during pregnancy on offspring birthweight: a quasi-experimental sibling analysis in Sweden.

Maternal smoking during pregnancy (SDP) seems associated with reduced birthweight in the offspring. This observation, however, is based on conventional epidemiological analyses, and it might be confounded by unobserved maternal characteristics related to both smoking habits and offspring birth weight. Therefore, we apply a quasi-experimental sibling analysis to revisit previous findings. Using the Swedish Medical Birth Register, we identified 677,922 singletons born between 2002 and 2010 from native Swedish mothers. From this population, we isolated 62,941 siblings from 28,768 mothers with discrepant habits of SDP. We applied conventional and mother-specific multilevel linear regression models to investigate the association between maternal SDP and offspring birthweight. Depending on the mother was light or heavy smoker and the timing of exposition during pregnancy (i.e., first or third trimester), the effect of smoking on birthweight reduction was between 6 and 78 g less marked in the sibling analysis than in the conventional analysis. Sibling analysis showed that continuous smoking reduces birthweight by 162 grams for mothers who were light smokers (1 to 9 cigarettes per day) and 226 g on average for those who were heavy smokers throughout the pregnancy in comparison to non-smoker mothers. Quitting smoking during pregnancy partly counteracted the smoking-related birthweight reduction by 1 to 29 g, and a subsequent smoking relapse during pregnancy reduced birthweight by 77 to 83 g. The sibling analysis provides strong evidence that maternal SDP reduces offspring birthweight, though this reduction was not as great as that observed in the conventional analysis. Our findings support public health interventions aimed to prevent SDP and to persuade those who already smoke to quit and not relapse throughout the pregnancy. Besides, further analyses are needed in order to explain the mechanisms through which smoking reduces birthweight and to identify other maternal characteristics that are common causes of both birthweight reduction and maternal smoking

Acculturation or unequal assimilation? : Smoking during pregnancy and duration of residence among migrants in Sweden

A growing corpus of evidence reveals that smoking patterns of migrant women tend to converge with that of the host population over time (‘acculturation paradox’). In this paper we aim to adopt a health equity perspective by studying the extent to which this pattern reflects a convergence with the group of natives who are more socioeconomically disadvantaged. Using population-based registers, we study 1,194,296 women who gave birth in Sweden between 1991 and 2012. Using logistic regression, we estimated odds ratios to assess the effect of duration of residence on the association between smoking during pregnancy and women's origin (classified according to inequality-adjusted Human Development Index (iHDI) of the country of birth). Sibling information and multilevel models were used to assess the extent to which our results might be affected by the cross-sectional nature of the data. Smoking during pregnancy increases with duration of residence among migrants from all levels of iHDI to such an extent that they tend to converge or increase in relation to the levels of the Swedish population with low education and low income, leaving behind the native population with high education and income. The results are robust to possible selection bias related to the cross-sectional nature of the data. Ourfindings indicate the need of a health equity perspective and suggest the use of ‘unequal assimilation’ rather than ‘acculturation paradox’ as a more suitable framework to interpret these findings

Characteristics of the children and the children's mothers in the two samples.

<p>Characteristics of the children and the children's mothers in the two samples.</p