Urban environment and health: a cross-sectional multiregional project based on population health surveys in Spain (DAS-EP project) - study protocol.

INTRODUCTION: The European Environment Agency estimates that 75% of the European population lives in cities. Despite the many advantages of city life, the risks and challenges to health arising from urbanisation need to be addressed in order to tackle the growing burden of disease and health inequalities in cities. This study, Urban environment and health: a cross-sectional multiregional project based on population health surveys in Spain (DAS-EP project), aims to investigate the complex association between the urban environmental exposures (UrbEEs) and health. METHODS AND ANALYSIS: DAS-EP is a Spanish multiregional cross-sectional project that combines population health surveys (PHS) and geographical information systems (GIS) allowing to collect rich individual-level data from 17 000 adult citizens participating in the PHS conducted in the autonomous regions of the Basque Country, Andalusia, and the Valencian Community, and the city of Barcelona in the years 2021-2023. This study focuses on the population living in cities or metropolitan areas with more than 100 000 inhabitants. UrbEEs are described by objective estimates at participants' home addresses by GIS, and subjective indicators present in PHS. The health outcomes included in the PHS and selected for this study are self-perceived health (general and mental), prevalence of chronic mental disorders, health-related quality of life, consumption of medication for common mental disorders and sleep quality. We aim to further understand the direct and indirect effects between UrbEEs and health, as well as to estimate the impact at the population level, taking respondents' sociodemographic and socioeconomic characteristics, and lifestyle into consideration. ETHICS AND DISSEMINATION: The study was approved by the regional Research Ethics Committee of the Basque Country (Ethics Committee for Research Involving Medicinal Products in the Basque Country; PI2022138), Andalusia (Biomedical Research Ethics Committee of the Province of Granada; 2078-N-22), Barcelona (CEIC-PSMar; 2022/10667) and the Valencian Community (Ethics Committee for Clinical Research of the Directorate General of Public Health and Center for Advanced Research in Public Health; 20221125/04). The results will be communicated to the general population, health professionals, and institutions through conferences, reports and scientific articles.

Health literacy: association with socioeconomic determinants and the use of health services in Spain.

Background: Health literacy (HL) is the set of social and cognitive skills that determine person's level of motivation and the ability to access, understand and use information to promote and maintain good health. The aim of this study is to assess the level of health literacy, and to analyze its relationship with sociodemographic variables, state of health, and use of health services in the population aged 15 and over in the Valencian Community (Spain). Methods: Cross-sectional study based on a sample of 5,485 subjects participating in the Health Survey of the Valencia Community. The HLS-EU-Q16 was used. As outcome variables we considered HL categorized into 2 levels: Inadequate or Problematic HL and Sufficient HL and the standardized literacy index. Prevalence rates and HL means were estimated and OR were calculated to analyze the association between variables. Results: A total of 12.8% of the subjects surveyed presented an inadequate or problematic degree of HL. This percentage was higher in people >85 years (63.1%), with a low level of education (46.5%), in retired people (27.4%) or in other work situations (25.0%), in foreigners (18.1%), in low-income people (16.2%), with a perception of poor health status (26.9%), chronic disease (18.5%) or with activity limitations (56.4% severe, 19.7% not severe). Significant differences were found. With the exception of chronic disease, all the variables analyzed were associated with HL. Low HL was associated with a lower consumption of medicines, a greater use of health services, general medical consultations, poorer knowledge of new health technologies and fewer preventive health visits. Conclusion: The percentage of inadequate or problematic HL was globally not very high, but certain population subgroups notably presented a high degree of inadequate or problematic HL. Raising the HL level of such groups should be regarded as a priority. HL was shown to be associated with the service use and new health technology use. Enhancing the population's HL should lead to the following: a greater probability of adopting preventive practices; improving the use of the health system; and boosting people's abilities to manage and to improve their own health.

Construction of an individual socioeconomic status index for analysing inequalities in colorectal cancer screening.

OBJECTIVE: To construct an individual socioeconomic status index (ISESI) with information available in the Population Information System of the Region of Valencia, Spain, and use it to analyse inequalities in a colorectal cancer screening programme (CRCSP). METHODS: Cross-sectional study of men and women aged between 50 and 75 at the time of the study (2020) that were selected from the target population of the Region of Valencia CRCSP. (study sample 1,150,684). First, a multiple correspondence analysis was performed to aggregate information from the Population Information System of the Region of Valencia into an ISESI. Second, data from the 2016 Region of Valencia Health Survey were used for validation, and finally the relationship between CRCSP participation and the ISESI was analysed by logistic regression models. RESULTS: The variables included in the index were nationality, employment status, disability, healthcare coverage, risk of vulnerability and family size. The most important categories for determining the highest socioeconomic status were being employed and not being at risk of social vulnerability, and being unemployed and at risk of social vulnerability for determining the lowest socioeconomic status. Index validation demonstrated internal and external coherence for measuring socioeconomic status. The relationship between CRCSP participation and the ISESI categorised by quartile (Q) showed that Q4 (the lowest socioeconomic status) was less likely to participate OR = 0.769 (0.757-0.782) than Q1 (the highest socioeconomic status), and the opposite was found for Q2 OR = 1.368 (1.347-1.390) and Q3 OR = 1.156 (1.137-1.175). CONCLUSIONS: An ISESI was constructed and validated using Population Information System data and made it possible to evaluate inequalities in colorectal cancer screening.

Alfabetización en salud: propiedades psicométricas del cuestionario HLS-EU-Q16 / Health literacy: psychometric behaviour of the HLS-EU-Q16 questionnaire

OBJETIVO: Describir las propiedades psicométricas y el nivel de comprensión del cuestionario de alfabetización en salud HLS-EU-Q16 en español, implementado en la Encuesta de Salud de la Comunitat Valenciana de 2016. MÉTODO: Estudio descriptivo transversal para describir la comprensión, la fiabilidad, la estructura y la consistencia interna del cuestionario sobre la muestra de 5485 sujetos, de 15 o más años de edad, participantes en la encuesta. RESULTADOS: Los porcentajes de comprensión sin mucha dificultad fueron elevados. La fiabilidad fue alta (coeficiente de correlación intraclase: 0,923; kappa: 0,814). El análisis factorial sugirió una estructura unifactorial (79,1% de variabilidad explicada por el factor común), con altas cargas factoriales. La consistencia fue alta (alfa de Cronbach: 0,982). CONCLUSIONES: El HLS-EU-Q16 en español es un instrumento breve, adecuado y válido para medir el nivel de alfabetización en salud de la población

OBJECTIVE: To describe the psychometric properties and the level of understanding of the health literacy questionnaire HLS-EU-Q16 in Spanish, implemented in the Health Survey of the Valencian Region (Spain) of 2016. METHOD: Descriptive cross-sectional study to describe understanding, reliability, structure and internal consistency of the questionnaire on a sample of 5485 subjects, aged 15 or over, who participated in the survey. RESULTS: The percentages of understanding without much difficulty were high. Reliability was high (intraclass correlation coefficient:.923; kappa:.814). The factorial analysis suggested a unifactorial structure (79.1% of variability explained by the common factor), with high factorial loads. The consistency was high (Cronbach's alpha: 0.982). CONCLUSIONS: The HLS-EU-Q16 in Spanish is a short, adequate and valid instrument to measure the level of health literacy in the population

[Health literacy: psychometric behaviour of the HLS-EU-Q16 questionnaire]. / Alfabetización en salud: propiedades psicométricas del cuestionario HLS-EU-Q16.

OBJECTIVE: To describe the psychometric properties and the level of understanding of the health literacy questionnaire HLS-EU-Q16 in Spanish, implemented in the Health Survey of the Valencian Region (Spain) of 2016. METHOD: Descriptive cross-sectional study to describe understanding, reliability, structure and internal consistency of the questionnaire on a sample of 5485 subjects, aged 15 or over, who participated in the survey. RESULTS: The percentages of understanding without much difficulty were high. Reliability was high (intraclass correlation coefficient:.923; kappa:.814). The factorial analysis suggested a unifactorial structure (79.1% of variability explained by the common factor), with high factorial loads. The consistency was high (Cronbach's alpha: 0.982). CONCLUSIONS: The HLS-EU-Q16 in Spanish is a short, adequate and valid instrument to measure the level of health literacy in the population.

Contribution of the Economic Crisis to the Risk Increase of Poor Mental Health in a Region of Spain.

Previous research suggests that the economic crisis can affect mental health. The purpose of this study was to analyse the association of risk of poor mental health with various socioeconomic, demographic, health, quality of life, and social support variables; and to evaluate the contribution of socioeconomic variables most affected by the beginning of the economic crisis (employment situation and income) on the changes in the prevalence of the risk of poor mental health between 2005 and 2010. A study of prevalence evolution in adult population residents of the Valencian Community in the Spanish Mediterranean was conducted. We studied 5781 subjects in 2005 and 3479 in 2010. Logistic regression models have been adjusted to analyse the association between variables. A standardisation procedure was carried out to evaluate which part of the changes in overall prevalence could be attributed to variations in the population structure by age, sex, employment status, and income between the years under study. The prevalence of GHQ+ increased from 2005 to 2010, in both men and women. Several variables were closely associated with the risk of poor mental health (sex, age, country of birth, number of nonmental chronic diseases, social support, disability, cohabitation in couple, employment status, and income). The changes produced as a result of the onset of the economic crisis in income and unemployment (increase in low income and in unemployment rates) contributed to the increase of poor mental health risk. This could confirm the sensitivity of mental health to the economic deterioration caused by the crisis.

Self-rated health and hospital services use in the Spanish National Health System: a longitudinal study.

BACKGROUND: Self-rated health is a subjective measure that has been related to indicators such as mortality, morbidity, functional capacity, and the use of health services. In Spain, there are few longitudinal studies associating self-rated health with hospital services use. The purpose of this study is to analyze the association between self-rated health and socioeconomic, demographic, and health variables, and the use of hospital services among the general population in the Region of Valencia, Spain. METHODS: Longitudinal study of 5,275 adults who were included in the 2005 Region of Valencia Health Survey and linked to the Minimum Hospital Data Set between 2006 and 2009. Logistic regression models were used to calculate the odds ratios between use of hospital services and self-rated health, sex, age, educational level, employment status, income, country of birth, chronic conditions, disability and previous use of hospital services. RESULTS: By the end of a 4-year follow-up period, 1,184 participants (22.4%) had used hospital services. Use of hospital services was associated with poor self-rated health among both men and women. In men, it was also associated with unemployment, low income, and the presence of a chronic disease. In women, it was associated with low educational level, the presence of a disability, previous hospital services use, and the presence of chronic disease. Interactions were detected between self-rated health and chronic disease in men and between self-rated health and educational level in women. CONCLUSIONS: Self-rated health acts as a predictor of hospital services use. Various health and socioeconomic variables provide additional predictive capacity. Interactions were detected between self-rated health and other variables that may reflect different complex predictive models, by gender.

Exposure to elevated temperatures and risk of preterm birth in Valencia, Spain.

BACKGROUND: Prematurity is the second-leading cause of death in children under the age of 5 worldwide. It is predicted that the future climate will have more intense, longer lasting and frequent extreme heat episodes, and so the temperature effect on the risk of preterm birth is generating considerable interest in the public health field. Our aim was to explore the potential short-term effects of elevated temperatures on the risk of preterm birth in Valencia (Spain). METHODS: All singleton natural births born in the metropolitan area of Valencia during the warm season (May-September, 2006-2010) were included (N=20,148). We applied time-series quasi-Poisson generalized additive models to evaluate the risk of preterm birth at different maximum apparent and minimum temperature values (50th, 90th and 99th percentiles of the warm season) up to 3 weeks before delivery (reference: overall annual median value). In addition, three temperature-interval-specific estimates were obtained for changes between each of these temperature values. We took into account the pregnancies at risk adjusted by the gestational age distribution of the set in each day. We used distributed-lag non-linear models with a flexible function in the shape of the relationship and lag structure. RESULTS: Risk of preterm birth increased up to 20% when maximum apparent temperature exceeded the 90th percentile two days before delivery and 5% when minimum temperature rose to the 90th percentile in the last week. Differences between interval-specific risk estimates across lags were observed. CONCLUSION: Exposure to elevated temperatures was associated with an increased risk of preterm birth in the following three weeks.

Uneven chances of breastfeeding in Spain.

BACKGROUND: No large scale studies on breastfeeding onset patterns have been carried out in Spain. This work aims to explore the prevalence and the risk factors for not initiating breastfeeding in hospitals from Catalonia (CAT) and Valencia (V), two regions accounting approximately for 30% of the annual births in Spain. METHODS: The prevalence of not initiating breastfeeding was calculated by maternal/neonatal characteristics and type of hospital, and logistic regression models were used to estimate crude and adjusted risks of not breastfeeding in each region. RESULTS: Prevalence of breastfeeding initiation was 81.7% and 82.5% in Catalonia and Valencia, respectively. We identified conspicuous regional differences in the adjusted-risk of not breastfeeding, especially for multiple [CAT = 3.12 (95% CI: 2.93, 3.31), V = 2.44 (95% CI: 2.23, 2.67)] and preterm and low birth weight deliveries [very preterm and very low birth weight: CAT = 7.61 (95% CI: 6.50, 8.92), V = 4.03 (95% CI: 3.13, 5.19); moderate preterm and moderate low birth weight: CAT = 4.28 (95% CI: 4.01, 4.57), V = 2.55 (95% CI:2.34, 2.79)]. CONCLUSIONS: Our results suggest the existence of regional variations in breastfeeding initiation in Spain. Taking into account the known short and long-term benefits of breastfeeding it is recommended that further research should explore these differences in order to prevent potential inequities in neonatal, child and adult health.

Differences in preterm and low birth weight deliveries between spanish and immigrant women: influence of the prenatal care received.

OBJECTIVES: To compare the risk of preterm and low birth weight among newborns from native and immigrant women and to assess the role of prenatal care in the association between the ethnic origin of the women and their reproductive outcomes. METHODS: Cross-sectional study of 21,708 women giving birth between 1997 and 2008 in a region of Spain. Multinomial logistic regression models were adjusted to evaluate associations between mother's area of origin and adverse reproductive outcomes and to assess the role of prenatal care in the occurrence of adverse reproductive results. RESULTS: Our results indicate a worse prenatal control in immigrants than in natives. Very preterm birth (VPTB) and very low birth weight (VLBW) were greater among immigrants (odds ratio [OR], 1.78; 95% confidence interval [95% CI], 1.14-2.79 for VPTB and OR, 1.73; 95% CI, 0.89-3.33 for VLBW) but after adjustment for prenatal care the differences were substantially reduced (OR, 1.43; 95% CI 0.85-2.42 for VPTB and OR 1.15; 95% CI 0.53-2.52 for VLBW). CONCLUSIONS: Given the positive impact of prenatal care on reproductive results, strategies to improve it among immigrant women should be implemented. The difference found in the direction of the association between area of origin and different categories of low birth weight and preterm suggest that very and moderate categories should be analyzed separately in immigrant studies.

Caesarean section rates in immigrant and native women in Spain: the importance of geographical origin and type of hospital for delivery.

BACKGROUND: Spain has become a principal destination for immigrants and delivery is the major reason for hospitalization in this population. However, research about inequities between native and immigrant women regarding the quality of the care received during pregnancy and delivery is still scarce. One of the indicators used to evaluate the quality of the obstetric care is the rate of caesarean sections (CSs). METHODS: A cross-sectional study of 215 379 single deliveries from Spanish and immigrant women from Latin America, East Europe and Maghreb was carried out in Spain in 2005-06. Prevalence of CS according to maternal and neonatal characteristics was calculated by geographical origin. Two associations were explored by means of multiple logistic regression analysis. First, the association between geographical origin and the risk of CS in public or private hospitals separately, and, second, the risk of CS for women from the same geographical origin depending on whether they delivered at public or private hospitals. RESULTS: Overall, the risk of CS was lower for immigrants as a whole than for native women (odds ratio (OR) = 0.83 95% confidence interval (CI) = 0.80-0.85), but the risk varied markedly by area of origin, being higher for Latin Americans (OR = 1.09 95% CI = 1.05-1.13) and lower for East Europeans (OR = 0.61 95% CI = 0.57-0.66) and Maghrebians (OR = 0.60 95% CI =0.57-0.63). Public hospitals followed the overall pattern of risk. CS risk was higher in private than in public hospitals for all groups. However, the increase in risk was higher for immigrant than for natives. CONCLUSION: Immigrants in Spain are a heterogeneous population regarding the risk of CS. Geographical origin and type of hospital are key aspects underlying such a risk.

Indicadores de salud reproductiva y perinatal en mujeres inmigrantes y autóctonas residentes en Cataluña y en la Comunitat Valenciana (2005–2006) / Reproductive and perinatal health indicators in immigrant and Spanish-born women in Catalonia and Valencia (2005–2006)

ObjetivosDeterminar la prevalencia de nacimientos de madres adolescentes, de prematuridad y de bajo peso al nacer en mujeres españolas e inmigrantes originarias de Latinoamérica, Europa del Este, Magreb y África Subsahariana, residentes en Cataluña y en la Comunitat Valenciana, durante los años 2005 y 2006.MétodosA partir de los datos proporcionados por los registros de metabolopatías de ambas comunidades autónomas, se obtuvieron las proporciones y sus respectivos intervalos de confianza al 95% de: 1) madres menores de 20 años, 2) neonatos prematuros (<37 semanas) y muy prematuros (<32 semanas), y 3) neonatos con bajo peso al nacer (<2500g) y muy bajo peso al nacer (<1500g), diferenciando siempre nacimientos de madre autóctona o inmigrante de los principales colectivos (Latinoamérica, Europa del Este, Magreb y Subsahara). La comparación de las proporciones entre inmigrantes y españolas se realizó mediante la prueba de ji al cuadrado.ResultadosLa prevalencia de nacimientos de madre adolescente fue entre tres y cinco veces mayor en inmigrantes que en mujeres españolas, presentando las europeas del este la prevalencia más elevada. La prevalencia de nacidos prematuros, muy prematuros y con muy bajo peso fue mayor en las mujeres procedentes de Europa del Este que en las españolas. Del mismo modo, las subsaharianas presentaron una mayor prevalencia de prematuridad y bajo peso extremos que las autóctonas.ConclusionesTodas las regiones geográficas en estudio presentaron una mayor prevalencia de nacimientos de madre adolescente que las españolas. Las mujeres subsaharianas y las de Europa del Este presentaron las mayores tasas de bajo peso y prematuridad(AU)

ObjectivesTo determine the prevalence of teenage maternity, preterm birth and low birth weight in Spanish and immigrant mothers from Latin America, eastern Europe, Maghreb and sub-Saharan Africa resident in Catalonia and Valencia from 2005 and 2006.MethodsUsing data from congenital metabolic disorders registers in both regions, proportions and 95% confidence intervals were obtained for the following: 1) mothers aged less than 20 years; 2) preterm (<37 weeks) and very preterm (<32 weeks) births; and 3) low birth weight (<2500g) and very low birth weight (<1500g) neonates. The calculations were performed for mothers from each of the geographical areas of origin (Spain, Latin America, Eastern Europe, Maghreb and Sub-Sahara). These proportions were compared in Spanish-born and immigrant women and the significance of differences was assessed using chi-squared tests.ResultsThe prevalence of teenage mothers was between three and five times higher in immigrants than in Spanish women, the highest rate being found in women from eastern Europe. Preterm births, very preterm births and very low birth weight were more frequent in eastern European women than in Spanish women. The prevalence of prematurity and very low birth weight was higher in sub-Saharan mothers than in Spanish women.ConclusionsThe number of births in teenage mothers was higher in immigrant mothers from all origins than in Spanish women. The highest rates of low birth weight and preterm births were found in women from eastern Europe and sub-Saharan Africa(AU)

Calidad de los datos utilizados para el cálculo de indicadores de salud reproductiva y perinatal en población autóctona e inmigrante / Quality of data used to calculate reproductive and perinatal health indicators in native and migrant populations

ObjetivosEvaluar la calidad de los datos sobre nacimientos recogidos en el Movimiento Natural de la Población (MNP) y en los registros de metabolopatías para el cálculo de indicadores de salud reproductiva y perinatal.MétodosComparación entre registros acerca de 1) número total de nacimientos de madre residente en Cataluña y Comunitat Valenciana registrados durante 2005–2006, 2) grado de cumplimentación de los datos sobre origen geográfico de la madre, y 3) grado de cumplimentación de la edad materna, peso al nacer y edad gestacional según el origen de la madre.ResultadosLos registros de metabolopatías recogen de forma exhaustiva los nacimientos registrados en el MNP. El grado de cumplimentación de los datos sobre el origen y la edad materna fue algo menor en los registros de metabolopatías, aunque la proporción de nacimientos según el origen de la madre fue muy similar a la del MNP, así como la media de edad materna según el origen. El grado de cumplimentación de los datos sobre peso al nacer y edad gestacional según el origen materno fue muy inferior en el MNP, especialmente entre los nacimientos de madre inmigrante registrados en Cataluña.ConclusionesNuestros resultados sugieren una limitación en la calidad de los datos sobre edad gestacional y peso al nacer del MNP, sobre todo de cara al cálculo y la comparación de indicadores de prematuridad y bajo peso al nacer en población autóctona e inmigrante. A la vez, apoyan la utilidad de los registros de metabolopatías como fuente para el cálculo diferencial de tales indicadores(AU)

ObjectiveTo assess the quality of data on births in the Natural Population Movement (NPM) and congenital metabolic disorders registers with regard to calculation of reproductive and perinatal health indicators.MethodsThe following comparisons between registers were made: (1) the total number of births to mothers living in Catalonia and Valencia from 2005 to 2006, (2) the percentage of missing data on the mother's geographical origin, (3) the percentage of missing data on the mother's age and the infant’s birthweight and gestational age according to maternal origin.ResultsThe congenital metabolic disorders registers exhaustively collected the total number of births gathered in the NPM. The percentages of missing data on material origin and age were higher in the congenital metabolic disorders registers, although the proportion of births by maternal origin and the mean maternal age in each ethnic group was fairly similar to that in the NPM. The percentages of missing data on birthweight and gestational age were much higher in the NPM data than in the congenital metabolic disorders registers, especially among births registered in Catalonia and births to foreign mothers.ConclusionsOur results suggest some limitations in the quality of the data on gestational age and birthweight provided by NPM data, especially for comparisons of preterm and low birthweight indicators in the Spanish-born and immigrant populations. Moreover, the results point to the quality of the congenital metabolic disorders registers as a source to compare reproductive and perinatal health indicators(AU)

[Reproductive and perinatal health indicators in immigrant and Spanish-born women in Catalonia and Valencia (2005-2006)]. / Indicadores de salud reproductiva y perinatal en mujeres inmigrantes y autóctonas residentes en Cataluña y en la Comunitat Valenciana (2005-2006).

OBJECTIVES: To determine the prevalence of teenage maternity, preterm birth and low birth weight in Spanish and immigrant mothers from Latin America, eastern Europe, Maghreb and sub-Saharan Africa resident in Catalonia and Valencia from 2005 and 2006. METHODS: Using data from congenital metabolic disorders registers in both regions, proportions and 95% confidence intervals were obtained for the following: 1) mothers aged less than 20 years; 2) preterm (<37 weeks) and very preterm (<32 weeks) births; and 3) low birth weight (<2500g) and very low birth weight (<1500g) neonates. The calculations were performed for mothers from each of the geographical areas of origin (Spain, Latin America, Eastern Europe, Maghreb and Sub-Sahara). These proportions were compared in Spanish-born and immigrant women and the significance of differences was assessed using chi-squared tests. RESULTS: The prevalence of teenage mothers was between three and five times higher in immigrants than in Spanish women, the highest rate being found in women from eastern Europe. Preterm births, very preterm births and very low birth weight were more frequent in eastern European women than in Spanish women. The prevalence of prematurity and very low birth weight was higher in sub-Saharan mothers than in Spanish women. CONCLUSIONS: The number of births in teenage mothers was higher in immigrant mothers from all origins than in Spanish women. The highest rates of low birth weight and preterm births were found in women from eastern Europe and sub-Saharan Africa.

[Quality of data used to calculate reproductive and perinatal health indicators in native and migrant populations]. / Calidad de los datos utilizados para el cálculo de indicadores de salud reproductiva y perinatal en población autóctona e inmigrante.

OBJECTIVE: To assess the quality of data on births in the Natural Population Movement (NPM) and congenital metabolic disorders registers with regard to calculation of reproductive and perinatal health indicators. METHODS: The following comparisons between registers were made: (1) the total number of births to mothers living in Catalonia and Valencia from 2005 to 2006, (2) the percentage of missing data on the mother's geographical origin, (3) the percentage of missing data on the mother's age and the infant's birthweight and gestational age according to maternal origin. RESULTS: The congenital metabolic disorders registers exhaustively collected the total number of births gathered in the NPM. The percentages of missing data on material origin and age were higher in the congenital metabolic disorders registers, although the proportion of births by maternal origin and the mean maternal age in each ethnic group was fairly similar to that in the NPM. The percentages of missing data on birthweight and gestational age were much higher in the NPM data than in the congenital metabolic disorders registers, especially among births registered in Catalonia and births to foreign mothers. CONCLUSIONS: Our results suggest some limitations in the quality of the data on gestational age and birthweight provided by NPM data, especially for comparisons of preterm and low birthweight indicators in the Spanish-born and immigrant populations. Moreover, the results point to the quality of the congenital metabolic disorders registers as a source to compare reproductive and perinatal health indicators.