Influence of educational level on the prevalence of risk behaviors during the perinatal period. / Influencia del nivel de estudios en la prevalencia de conductas de riesgo durante el periodo perinatal.

The objective of this work was to assess changes during pregnancy and after childbirth in diet, consumption of tobacco, electronic cigarettes, cannabis, alcohol use and exposure to environmental tobacco smoke depending on the mother's educational level.A cross-sectional study was carried out whose target population was 18,822 Galician women aged 18-49 who gave birth between September 2015 and August 2016, and their 19,204 live-born children. A descriptive analysis was performed, and the prevalence of different behaviors was estimated at three time points - pre-pregnancy, pregnancy and after childbirth - depending on the mother's educational level. Percentages of change were calculated.Information was obtained from 6,436 women. Regardless of the educational level, during pregnancy there was an improvement in the different lifestyles. In the first months after childbirth, lifestyles worsened, except for exposure to environmental tobacco smoke and the use of electronic cigarettes. Most of the risk behaviors showed a gradient depending on the educational level; thus, the lower the educational level, the higher the prevalence of risk behaviors.In general, during pregnancy all women adopted healthier lifestyles that they abandoned in the months following childbirth. Women with a lower level of education showed a higher prevalence of risk behaviors, both in the period prior to pregnancy, as well as during pregnancy and after childbirth.

El objetivo de este trabajo fue valorar cambios durante el embarazo y tras el parto en la dieta, consumo de tabaco, cigarrillos electrónicos, alcohol, cannabis y exposición al humo ambiental de tabaco en función del nivel de estudios de la madre. Para ello, se llevó a cabo un estudio transversal cuya población objetivo fueron 18.822 mujeres gallegas de 18-49 años que dieron a luz entre septiembre 2015 y agosto 2016, y sus 19.204 hijos/as nacidos vivos. Se realizó un análisis descriptivo y se estimó la prevalencia de diferentes conductas en tres momentos temporales ­pre-embarazo, embarazo y tras el parto­ en función del nivel de estudios de la madre. Se calcularon los porcentajes de cambio. Se obtuvo información de 6.436 mujeres. Con independencia del nivel de estudios, durante el embarazo se produce una mejora en los diferentes estilos de vida. En los primeros meses tras el parto los estilos de vida empeoran, con excepción de la exposición al humo ambiental de tabaco y el consumo de cigarrillos electrónicos. La mayoría de las conductas de riesgo muestran un gradiente dependiente del nivel educativo; así, a menor nivel educativo, mayor es la prevalencia de conductas de riesgo. En general, durante el embarazo todas las mujeres adoptan estilos de vida más saludables que abandonan en los meses siguientes al parto. Las mujeres con menor nivel de estudios muestran una mayor prevalencia de conductas de riesgo, tanto en el periodo previo al embarazo, como en el embarazo y tras el parto.

[Assessment of exposure to seconhand smoke in health surveys in Spain]. / La valoración de la exposición al humo ambiental de tabaco en las encuestas de salud de España.

OBJECTIVE: To describe the questions used to assess exposure to secondhand smoke (SHS) in Spanish health surveys. METHOD: Extraction and analysis of the literals of the questions on SHS in the health surveys in Spain identified on the website of the Ministry of Health, the National Plan on Drugs and Health Departments of the autonomous communities. RESULTS: Three nationwide surveys assessed SHS exposure, with variability in questions, responses, and recall periods. Catalonia in 2022, and Galicia and the Basque Country in 2018, assessed exposure in detail. CONCLUSIONS: Questions assessing self-reported exposure to SHS are survey-dependent. There is a need for a set of questions to assess exposure in a homogeneous way in health surveys.

Analysis of Diagnostic Delay and its Impact on Lung Cancer Survival: Results From the Spanish Thoracic Tumor Registry.

BACKGROUND: Early detection is crucial to improve lung cancer survival rates. Delays in diagnosis might negatively impact the prognosis of the disease. This study aims to analyze the diagnostic delay in lung cancer patients and describe if there is an association between delay and survival. METHODS: The data source used was the Thoracic Tumor Registry of the Spanish Lung Cancer Group. This analysis was restricted to lung cancer cases with information on the first date of consultation by symptoms and date of diagnosis. The delay was calculated as the number of days between the two dates. A descriptive analysis was performed, and ordinal logistic regressions were fitted with delay as the dependent variable. Kaplan-Meier survival analysis and Cox regression were performed. RESULTS: 22,755 lung cancer cases were included. Never smokers were 1.16 (95%CI: 1.06-1.27) times more likely to register longer delay than smokers. Stage 0-I-II cases had a 3.09 (95%CI: 2.88-3.32) higher risk of longer delay compared to III-IV stages. Overall, 5-year survival rate after diagnosis was 23.64% (95%CI: 22.88-24.41). In those categorized as having the shortest delay 5-year survival was 17.67% (95%CI: 16.31-19.07) and in the extreme delay it was 32.98% (95%CI: 31.28-34.69) (p<0.001). Adjusted mortality risk was higher in those with the shortest delay (HR 1.36, CI95%: 1.30-1.43) in comparison with the extreme delay. CONCLUSIONS: Diagnostic delay is short among Spanish lung cancer patients, indicating a relatively quick diagnostic process. Extreme delays appear to be associated with higher survival rates, possibly attributed to slow-growing tumors, earlier stage at diagnosis or basically the natural history of this disease.

Impact of the use of small-area models on estimation of attributable mortality at a regional level.

The objective of this study is to assess the impact of applying prevalences derived from a small-area model at a regional level on smoking-attributable mortality (SAM). A prevalence-dependent method was used to estimate SAM. Prevalences of tobacco use were derived from a small-area model. SAM and population attributable fraction (PAF) estimates were compared against those calculated by pooling data from three national health surveys conducted in Spain (2011-2014-2017). We calculated the relative changes between the two estimates and assessed the width of the 95% CI of the PAF. Applying surveys-based prevalences, tobacco use was estimated to cause 53 825 (95% CI: 53 182-54 342) deaths in Spain in 2017, a figure 3.8% lower obtained with the small-area model prevalences. The lowest relative change was observed in the Castile-La Mancha region (1.1%) and the highest in Navarre (14.1%). The median relative change between regions was higher for women (26.1%), population aged ≥65 years (6.6%), and cardiometabolic diseases (9.0%). The differences between PAF by cause of death were never greater than 2%. Overall, the differences between estimates of SAM, PAF, and confidence interval width are small when using prevalences from both sources. Having these data available by region will allow decision-makers to implement smoking control measures based on more accurate data.

Time Dependence Between Tobacco Consumption and Lung Cancer Mortality in Spain.

OBJECTIVES: Lung cancer is the leading cause of cancer death and the second most common cancer in both sexes worldwide, with tobacco being its main risk factor. The aim of this study is to establish the temporal relationship between smoking prevalence and lung cancer mortality in Spain. METHODS: To model the time dependence between smoking prevalence and lung cancer mortality, a distributed lag non-linear model was applied adjusting for sex, age, year of mortality and population at risk. Smoking prevalence data from 1991-2020 were used. Considering a maximum lag of 25 years, mortality data from 2016-2020 were included. The effect of prevalence on mortality for each lag is presented in terms of relative risk (RR). To identify the lag at which smoking prevalence has the greatest effect on mortality, the RR of the different lags were compared. RESULTS: The optimal lag observed between smoking prevalence and lung cancer mortality in Spain was 15 years. The maximum RR was 2.9 (95%CI: 2.0-4.3) for a prevalence of 71% and a 15-year lag. The RR was 1.8 for a prevalence of 33%, an approximate median value between 1991-2020, and a 15-year lag. CONCLUSIONS: In Spain, lung cancer mortality is affected by smoking prevalence 15 years prior. Knowing the evolution of the smoking prevalence series in a country and establishing a lag time is essential to predict how lung cancer incidence and mortality will evolve.

Perception of pregnant individuals, health providers and decision makers on interventions to cease substance consumption during pregnancy: a qualitative study.

BACKGROUND: Despite multiple recommendations and strategies implemented at a national and international level, cigarette smoking, alcohol consumption, and cannabis use during pregnancy remains high in most countries. The objective of this study was to examine key stakeholders' perception of the treatment interventions adopted in Spain, to identify political, organizational and personal factors associated with successful implementation, and to propose strategies for improvement. METHODS: A qualitative study with a phenomenological approach was conducted in 2022. The target groups were: (1) clinical decision makers in the field of addiction science, (2) health professionals who carry out treatment interventions, and (3) pregnant individuals who use tobacco, alcohol or cannabis. Two focus groups and eight in-depth interviews were conducted, recorded, and transcribed. Exploratory analysis and inductive open coding was performed, codes were merged into categories, and subcategories were identified. RESULTS: The analysis resulted in 10 subcategories which were further merged into three main categories: (1) Degree of adoption and utility of treatment interventions implemented; (2) Needs and demands with respect to the organization of treatment interventions; and, (3) Personal barriers to and facilitators for treatment. Respondents reported that despite multiple national and regional cessation initiatives, treatment interventions were rarely adopted in clinical practice. Health care administrators demanded reliable records to quantify substance use for better planning of activities. Health care professionals advocated for additional time and training and both echoed the importance of integrating cessation interventions into routine prenatal care and creating in-house specialized units. The difficulty in quitting, lack of awareness of risk for foetus and child and the controversial advice were identified as barriers by pregnant individuals. CONCLUSIONS: Consistent with previous work, this study found that cessation strategies implemented by the health authorities are not effective if they are not accompanied by organizational and behavioral changes. The current study identifies a set of factors that could be pivotal in ensuring the success of treatment interventions targeting tobacco, alcohol and cannabis use among pregnant individuals.

Mortality attributable to secondhand smoke exposure in the autonomous communities of Spain.

INTRODUCTION AND OBJECTIVES: Exposure to secondhand smoke (SHS) causes cardiovascular disease, respiratory disease, and cancer. The aim of this study was to estimate the mortality attributed to SHS in people aged ≥ 35 years in Spain and its autonomous communities (AC) by sex from 2016 to 2021. METHODS: Estimates of SHS-attributable mortality were calculated by applying the prevalence-dependent method where SHS exposure was derived from the adjustment of small-area models and based on the calculation of population-attributed fractions. Sex, age group, AC, and cause of death (ischemic heart disease and lung cancer) were included. The estimates of attributed mortality are presented with their 95% confidence interval (95%CI). Crude and age-standardized rates were estimated for each sex and AC. RESULTS: From 2016 to 2021, SHS exposure caused 4,970 (95%CI, 4,787-5,387) deaths, representing 1.6% of total mortality for ischemic heart disease and lung cancer. The burden of attributed mortality differed widely among the AC, with Andalusia having the highest burden of attributed mortality (crude rate: 46.6 deaths per 100 000 population in men and 17.0/100 000 in women). In all the AC, the main cause of death in both sexes was ischemic heart disease. The highest burden of mortality was observed in nonsmokers. CONCLUSIONS: The burden of SHS-attributable mortality was high and varied geographically. The results of this study should be considered to advance tobacco control legislation in Spain.

Evolution and characteristics of studies estimating attributable mortality to second-hand smoke: a systematic review.

BACKGROUND: Several studies have estimated the impact of second-hand smoke (SHS) exposure on mortality in the population of different countries. This study aimed to identify and describe studies that have estimated the attributable mortality (AM) associated with SHS exposure in the adult population. METHODS: A literature search was conducted in MEDLINE, EMBASE, Cochrane Library and CINAHL databases up to January 2023. Studies that estimated the AM associated with SHS exposure in the adult population and used a prevalence-dependent method were included. The main characteristics of the studies and their results were described. RESULTS: Fifty-three studies were included. Most of them were conducted in North America (n = 13), Europe (n = 14) and China (n = 6) and included lung cancer (n = 46) or ischaemic heart disease (n = 22) as causes of death. There was considerable variety in the population under study regarding the relationship with tobacco: non-smokers (n = 30); never-smokers (n = 9); both non and never-smokers (n = 2); the whole population (n = 1) and not known (n = 11). The age at which AM was estimated also varied between studies, ranging from 15 to 40 years and older. CONCLUSIONS: Studies estimating AM associated with SHS exposure are heterogeneous in terms of the causes of death studied, the age at which mortality is attributed, or the population to which mortality referred: consensus should be reached. Despite their importance, studies assessing AM to SHS are infrequent in low- and middle-income countries.

Occupational exposure to endotoxins and small cell lung cancer: a systematic review with meta-analysis.

The relationship of occupational exposure to endotoxins with different histologic subtypes of lung cancer has not been established. Our objective was to conduct a systematic review with meta-analysis to assess the effect of exposure to endotoxins on the development of small cell lung cancer (SCLC). A bibliographic search was conducted using MEDLINE, Embase, CENTRAL, and Web of Science databases until December 2022, including all cohort and/or case-control studies that examined occupational exposure to endotoxins and SCLC. Risk of bias was assessed using the U.S. Office of Health Assessment and Translation tool. A random effects model was applied, publication bias were assessed, and a sensitivity analysis was conducted. Four papers were selected for meta-analysis purposes. A total of 144 incident cases of SCLC and 897 population or hospital controls were included. Occupational exposure to endotoxins was considered for textile/leather industry and agricultural sector workers exposed to endotoxins originating from wool, cotton, or leather dust. Except for one study, all investigations were classified as having a low probability of risk of biases. The results of the meta-analysis were not statistically significant (pooled OR: 0.86; 95% CI:0.69-1.08). In addition, neither between-study heterogeneity (I2=0%;p=0.92) nor publication bias was observed (p=0.49). The results of the sensitivity analysis, after including five studies that assessed the risk of SCLC among textile industry and crop/livestock farm workers (not specifically exposed to endotoxins), showed a negative statistically non-significant association and low between-study heterogeneity (pooled OR: 0.90; 95% CI:0.79-1.02; I2=22%;p=0.23). Subjects exposed to occupational exposure to endotoxins seem to exhibit a negative association with the development of SCLC, although the results are not conclusive.

Antibiotic consumption in the first months of life: A cross-sectional study.

INTRODUCTION: The factors and patterns associated with antibiotic consumption in infants are unclear. Our aim was to assess the cumulative incidence of antibiotic consumption from birth to 16 months and identify factors associated with antibiotic consumption among infants aged 4-16 months. MATERIAL AND METHODS: We conducted a cross-sectional study in 2016 in a sample of 18 882 women from Galicia, Spain, who had given birth to a live child between September 1, 2015 and August 31, 2016. We calculated the cumulative incidence of antibiotic consumption based on maternal reports regarding the infant's consumption from birth to 14 months obtained through interviews; we did not estimate consumption at ages 15 and 16 months due to the small sample size. To assess which factors were associated with antibiotic consumption, we carried out a nested case-control study matching cases and controls for birth month on a 1:1 ratio. RESULTS: The cumulative incidence of antibiotic consumption among infants aged 0-14 months increased from 7.5% to 66.0%. The case-control study included data for 1852 cases and 1852 controls. Daycare attendance (OR: 3.8 [95% CI: 3.2-4.6]), having older siblings (OR: 1.8 [95% CI: 1.6-2.1]), health care visits to private clinics (OR: 1.6 [95% CI: 1.4-2.0]), and passive smoking (OR: 1.3 [95% CI: 1.1-1.6]) were associated with an increased probability of antibiotic consumption. Maternal age between 30-39 years or 40 years and over at the time of birth was associated with a decreased probability of antibiotic consumption (OR: 0.8 [95% CI, 0.7-1.0] and OR: 0.6 [95% CI: 0.5-0.8], respectively). CONCLUSIONS: Some of the factors associated with antibiotic consumption in infants are modifiable and should be considered in the development of public health measures aimed at reducing antibiotic consumption.

Comparison of Clinical and Genetic Characteristics Between Younger and Older Lung Cancer Patients.

INTRODUCTION: The aim of this study was to analyze the clinical and genetic characteristics of young lung cancer cases, and to compare them with those of older cases. METHODS: We used the Thoracic Tumors Registry (TTR) as a data source representative of lung cancer cases diagnosed in Spain, and included all cases registered until 9/01/2023 which had information on age at diagnosis or the data needed to calculate it. We performed a descriptive statistical analysis and fitted logistic regressions to analyze how different characteristics influenced being a younger lung cancer patient. RESULTS: A total of 26,336 subjects were included. Lung cancer cases <50 years old had a higher probability of being women (OR: 1.38; 95% CI: 1.21-1.57), being in stage III or IV (OR: 1.32; 95% CI: 1.08-1.62), not having comorbidities (OR: 5.21; 95% CI: 4.59-5.91), presenting with symptoms at diagnosis (OR: 1.53; 95% CI: 1.29-1.81), and having ALK translocation (OR: 7.61; 95% CI: 1.25-46.32) and HER2 mutation (OR: 5.71; 95% CI: 1.34-24.33), compared with subjects ≥50 years. Among subjects <35 years old (n=61), our study observed a higher proportion of women (59.0% vs. 26.6%; p<0.001), never smokers (45.8% vs. 10.3%; p<0.001), no comorbidities (21.3% vs. 74.0%; p<0.001); ALK translocation (33.3% vs. 4.4%; p<0.001) and ROS1 mutation (14.3% vs. 2.3%; p=0.01), compared with subjects ≥35 years. CONCLUSIONS: Lung cancer displays differences by age at diagnosis which may have important implications for its clinical management.

Addressing lung cancer screening eligibility in Spain using 2013 and 2021 US Preventive Service Task Force criteria: cross-sectional study.

Objectives: The aim of the study was to ascertain the percentage of Spanish lung cancer cases that would fulfil the lung cancer screening inclusion criteria recommended by the United States Preventive Service Task Force (USPSTF) in 2013 and 2021. Methods: A cross-sectional study was carried out. All lung cancer cases registered in the Thoracic Tumor Registry with data on date of birth, date of diagnosis, smoking habit, number of pack-years and time elapsed since smoking cessation were included. Results: The study included 15 006 patients diagnosed with lung cancer in Spain between 2016 and 2022. Eligibility to participate in screening increased from 53.7% to 63.5% (an increase of 9.8%) according to the 2013 and 2021 recommendations, respectively. The percentage of eligible men rose by 9.2 percentage points with the 2021 versus 2013 recommendations, whereas this rise was 11.5 percentage points in women. Under the 2021 recommendations, 36.6% of women and 5.3% of men would not have fulfilled the screening inclusion criteria due to being never-smokers; 14.9% of women and 11.0% of men would not have fulfilled the age criterion; and 27.0% of ex-smokers among women compared to 35.6% among men would not have been eligible due to >15 years having elapsed since smoking cessation. Conclusions: In Spain, over one-third of lung cancer cases could not be detected through screening, by virtue of not meeting the most recent inclusion criteria stated by the USPSTF. The degree of fulfilment in a potential nationwide screening programme should be analysed, with the aim of establishing inclusion criteria in line with each country's context.

Occupational exposure to respirable crystalline silica and lung cancer: a systematic review of cut-off points.

BACKGROUND: Respirable crystalline silica (RCS) is associated with the development of lung cancer. However, there is uncertainty around the exposure threshold at which exposure to RCS may pose a clear risk for the development of lung cancer. The objective of this study was to review the cut-off points at which the risk of mortality or incidence of lung cancer due to occupational exposure to RCS becomes evident through a systematic review. METHODS: We conducted a search in PubMed, including cohort and case-control studies which assessed various categories of RCS exposure. A search was also conducted on the webpages of institutional organizations. A qualitative data synthesis was performed. RESULTS: Twenty studies were included. Studies that assessed lung cancer mortality and incidence displayed wide variability both in RCS exposure categories and related risks. Although most studies found no significant association for RCS exposure categories, it appears to be a low risk of lung cancer for mean concentrations of less than 0.07mg/m3. Regulatory agencies set annual RCS exposure limits ranging from 0.025mg/m3 through 0.1mg/m3. CONCLUSIONS: There is a wide degree of heterogeneity in RCS exposure categories, with most studies observing no significant risk of lung cancer for the lowest exposure categories. Cut-off points differ between agencies but are nonetheless very similar and do not exceed 0.1mg/m3.

Radon exposure and its influencing factors across 3,140 workplaces in Spain.

Indoor radon exposure increases the risk of lung cancer. Radon concentration in workplaces is regulated in EU countries, including Spain, based on a reference level of 300 Bq/m3. The objective of this study is to describe workplace radon exposure in Spain and its influencing factors. To do this, we collected long-term radon measurements with alpha track detectors in 3140 workplaces mainly located in radon prone areas. Radon concentration exceeded 300 Bq/m3 in 1 out of 5 workplaces. Median radon concentration was 107 Bq/m3 in radon prone areas, 28 Bq/m3 off radon prone areas, and 101 Bq/m3 globally for the complete sample. Our results indicate that excessive radon concentrations can be expected in radon prone areas at all floor levels, especially below ground. Floor level, working sector, and location significantly influence radon concentration. The highest radon concentrations were found in the Education & Culture sector, comprising schools, universities, libraries, or cultural centers. These results indicate that radon should no longer be considered a risk for marginal occupations, but a risk everyone has if located in a radon prone area. Immediate action, including radon testing and mitigation, is needed to protect workers in Spain against radon exposure. This is already mandatory since EU regulation for radon has been recently transposed in Spain. Competent authorities should enforce this regulation without further delay, and employers must address their responsibility and communicate with workers about this risk.

Validation of a small-area model for estimation of smoking prevalence at a subnational level.

INTRODUCTION: Small-area estimation methods are an alternative to direct survey-based estimates in cases where a survey's sample size does not suffice to ensure representativeness. Nevertheless, the information yielded by small-area estimation methods must be validated. The objective of this study was thus to validate a small-area model. METHODS: The prevalence of smokers, ex-smokers, and never smokers by sex and age group (15-34, 35-54, 55-64, 65-74, ≥75 years) was calculated in two Spanish Autonomous Regions (ARs) by applying a weighted ratio estimator (direct estimator) to data from representative surveys. These estimates were compared against those obtained with a small-area model applied to another survey, specifically the Spanish National Health Survey, which did not guarantee representativeness for these two ARs by sex and age. To evaluate the concordance of the estimates, we calculated the intraclass correlation coefficient (ICC) and the 95% confidence intervals of the differences between estimates. To assess the precision of the estimates, the coefficients of variation were obtained. RESULTS: In all cases, the ICC was ≥0.87, indicating good concordance between the direct and small-area model estimates. Slightly more than eight in ten 95% confidence intervals for the differences between estimates included zero. In all cases, the coefficient of variation of the small-area model was <30%, indicating a good degree of precision in the estimates. CONCLUSIONS: The small-area model applied to national survey data yields valid estimates of smoking prevalence by sex and age group at the AR level. These models could thus be applied to a single year's data from a national survey, which does not guarantee regional representativeness, to characterize various risk factors in a population at a subnational level.

An overview on the relationship between residential radon and lung cancer: what we know and future research.

We aim to provide an overview of the research available on indoor radon and lung cancer, with a special focus on Spanish investigations. Early studies on underground miners established the link between radon and lung cancer, which was later confirmed for the general population by residential case-control studies. Spain contributed with extensive evidence, including 5 multicentric, hospital-based, case-control studies in the last 30 years, exploring diverse aspects, such as radon's effect on never-smokers, molecular pathways linking radon exposure to lung cancer risk, survival rates, mortality burden, and occupational exposure. There is a well-established causal association between radon with lung cancer. Despite pioneering research performed in our country by the Galician Radon Laboratory, particularly on driver genes, the evidence on the potential molecular pathways which makes radon a carcinogen is sparse. Also, relevant questions on the potential association of radon exposure with the induction of other diseases are still pending.

Asbestos exposure and small cell lung cancer: Systematic review and meta-analysis.

Asbestos is a mineral that is carcinogenic to humans. Its use has been banned in many occidental countries yet it is still produced in the United States, and materials that contain asbestos remain in many occupational settings and indoor environments. Even though asbestos carcinogenicity is well known, there is scant literature on its specific effects regarding small cell lung cancer (SCLC). We therefore conducted a systematic review and meta-analysis to determine SCLC risk among workers exposed to asbestos. A systematic search of the literature was conducted to identify studies which reported occupational exposure to asbestos and SCLC-related deaths and/or incidence. We identified seven case-control studies that included 3,231 SCLC cases; four studies reported smoking-adjusted risks. A significantly increased risk of SCLC (pooled OR 1.89; 95% CI, 1.25-2.86) was observed on pooling studies on men (six studies) that displayed moderate heterogeneity (I2 = 46.0%). Overall, our synthesis suggests that occupational exposure to asbestos significantly increases the risk of SCLC on men.

Small-area models to assess the geographical distribution of tobacco consumption by sex and age in Spain.

INTRODUCTION: Complete and accurate data on smoking prevalence at a local level would enable health authorities to plan context-dependent smoking interventions. However, national health surveys do not generally provide direct estimates of smoking prevalence by sex and age groups at the subnational level. This study uses a small-area model-based methodology to obtain precise estimations of smoking prevalence by sex, age group and region, from a population-based survey. METHODS: The areas targeted for analysis consisted of 180 groups based on a combination of sex, age group (15-34, 35-54, 55-64, 65-74, and ≥75 years), and Autonomous Region. Data on tobacco use came from the 2017 Spanish National Health Survey (2017 SNHS). In each of the 180 groups, we estimated the prevalence of smokers (S), ex-smokers (ExS) and never smokers (NS), as well as their coefficients of variation (CV), using a weighted ratio estimator (direct estimator) and a multinomial logistic model with random area effects. RESULTS: When smoking prevalence was estimated using the small-area model, the precision of direct estimates improved; the CV of S and ExS decreased on average by 26%, and those of NS by 25%. The range of S prevalence was 11-46% in men and 4-37% in women, excluding the group aged ≥75 years. CONCLUSIONS: This study proposes a methodology for obtaining reliable estimates of smoking prevalence in groups or areas not covered in the survey design. The model applied is a good alternative for enhancing the precision of estimates at a detailed level, at a much lower cost than that involved in conducting large-scale surveys. This method could be easily integrated into routine data processing of population health surveys. Having such estimates directly after completing a health survey would help characterize the tobacco epidemic and/or any other risk factor more precisely.

Clinical characteristics of chronic obstructive pulmonary disease in never-smokers: A systematic review.

INTRODUCTION: Chronic Obstructive Pulmonary Disease (COPD) is the third cause of death worldwide. While tobacco smoking is a key risk factor, COPD also occurs in never-smokers (NS). However, available evidence on risk factors, clinical characteristics, and natural history of the disease in NS is scarce. Here, we perform a systematic review of the literature to better describe the characteristics of COPD in NS. METHODS: We searched different databases following the PRISMA guidelines with explicit inclusion and exclusion criteria. A purpose-designed quality scale was applied to the studies included in the analysis. It was not possible to pool the results due to the high heterogeneity of the studies included. RESULTS: A total of 17 studies that met the selection criteria were included, albeit only 2 of them studied NS exclusively. The total number of participants in these studies were 57,146 subjects, 25,047 of whom were NS and 2,655 of the latter had NS-COPD. Compared to COPD in smokers, COPD in NS is more frequent in women and older ages, and is associated with a slightly higher prevalence of comorbidities. There are not enough studies to understand if COPD progression and clinical symptoms in NS are different to that of ever-smokers. CONCLUSIONS: There is a significant knowledge gap on COPD in NS. Given that COPD in NS account for about a third of all COPD patients in the world, particularly in low-middle income countries, and the decrease in tobacco consumption in high income countries, understanding COPD in NS constitutes a public-health priority.