Maria Antònia Barceló

Spatial variability in mortality inequalities, socioeconomic deprivation, and air pollution in small areas of the Barcelona Metropolitan Region, Spain

BACKGROUND There is evidence that geographic variability of social health inequalities continues to exist even after individual risk factors have been taken into account. However, relatively few studies have examined the contribution of exposure to air pollutants to those inequalities. OBJECTIVES To study the geographic variability of inequalities in mortality and their associations with socioeconomic and environmental inequalities in small areas of the metropolitan of Barcelona during the period 1994 to 2003. METHODS As in the MEDEA Project, the small area unit was the census tract. Study population consisted of the residents of the metropolitan area of Barcelona. Response variables were all-cause and specific-cause standardized mortality ratio (SMR). Explanatory variables were deprivation index, summarizing socioeconomic variables of the census tracts, and estimates of air pollutant exposures. Bayesian hierarchical models were used in order to reduce the extra variability when using SMR and to assess associations between mortality and deprivation and air pollution. RESULTS Statistically significant associations with deprivation were found for the causes of death related to consumption of tobacco and alcohol for men and, besides lung cancer, diet-related causes for women. Statistically significant pollution coefficients were only found in the metropolitan area of Barcelona and in men. A positive interaction between pollutants and the deprivation index was statistically significant for respiratory mortality and PM(10), and ischemic disease mortality and NO(2), both for men. CONCLUSIONS We found deprivation to be associated in a statistically significant way with the geographical variation in mortality in the census tracts of the metropolitan area of Barcelona, in the period 1994 to 2003. Those air pollutants more directly related with traffic modify some of these associations.

Development of an automated system to classify retinal vessels into arteries and veins

There are some evidence of the association between the calibre of the retinal blood vessels and hypertension. Computer-assisted procedures have been proposed to measure the calibre of retinal blood vessels from high-resolution photopraphs. Most of them are in fact semi-automatic. Our objective in this paper is twofold, to develop a totally automated system to classify retinal vessels into arteries and veins and to compare the measurements of the arteriolar-to-venular diameter ratio (AVR) computed from the system with those computed from observers. Our classification method consists of four steps. First, we obtain the vascular tree structure using a segmentation algorithm. Then, we extract the profiles. After that, we select the best feature vectors to distinguish between veins and arteries. Finally, we use a clustering algorithm to classify each detected vessel as an artery or a vein. Our results show that compared with an observer-based method, our method achieves high sensitivity and specificity in the automated detection of retinal arteries and veins. In addition the system is robust enough independently of the radii finally chosen, which makes it more trustworthy in its clinical application. We conclude that the system represents an automatic method of detecting arteries and veins to measure the calibre of retinal microcirculation across digital pictures of the eye fundus.

Area deprivation and mortality in the provincial capital cities of Andalusia and Catalonia (Spain)

Objective: To study the linkage between material deprivation and mortality from all causes, for men and women separately, in the capital cities of the provinces in Andalusia and Catalonia (Spain). Methods: A small-area ecological study was devised using the census section as the unit for analysis. 188 983 Deaths occurring in the capital cities of the Andalusian provinces and 109 478 deaths recorded in the Catalan capital cities were examined. Principal components factorial analysis was used to devise a material deprivation index comprising the percentage of manual labourers, unemployment and illiteracy. A hierarchical Bayesian model was used to study the relationship between mortality and area deprivation. Main results: In most cities, results show an increased male mortality risk in the most deprived areas in relation to the least depressed. In Andalusia, the relative risks between the highest and lowest deprivation decile ranged from 1.24 (Malaga) to 1.40 (Granada), with 95% credibility intervals showing a significant excess risk. In Catalonia, relative risks ranged between 1.08 (Girona) and 1.50 (Tarragona). No evidence was found for an excess of female mortality in most deprived areas in either of the autonomous communities. Conclusions: Within cities, gender-related differences were revealed when deprivation was correlated geographically with mortality rates. These differences were found from an ecological perspective. Further research is needed in order to validate these results from an individual approach. The idea to be analysed is to identify those factors that explain these differences at an individual level.

Improving retinal artery and vein classification by means of a minimal path approach

This paper describes a technique for the retinal vessel classification into artery and vein categories from fundus images within a framework to compute the arteriovenous ratio. This measure is used to assess the patient condition, mainly in hypertension and it is computed as the ratio between artery and vein widths. To this end, the vessels are segmented and measured in several circumferences concentric to the optic nerve. The resulting vessel segments at each radius are classified as artery or vein independently. After that, a tracking procedure joins vessel segments in different radii that belong to the same vessel. Finally, a voting system is applied to obtain the final class of the whole vessel. The methodology has been tested in a data set of 100 images labeled manually by two medical experts and a classification rate of over 87.68 % has been obtained.

Long term effects of traffic noise on mortality in the city of Barcelona, 2004–2007

Numerous studies showing statistically significant associations between environmental noise and adverse health effects already exist for short-term (over one day at most) and long-term (over a year or more) noise exposure, both for morbidity and (albeit to a lesser extent) mortality. Recently, several studies have shown this association to be independent from confounders, mainly those of air pollutants. However, what has not been addressed is the problem of misalignment (i.e. the exposure data locations and health outcomes have different spatial locations). Without any explicit control of such misalignment inference is seriously compromised. Our objective is to assess the long-term effects of traffic noise on mortality in the city of Barcelona (Spain) during 2004-2007. We take into account the control of confounding, for both air pollution and socioeconomic factors at a contextual level and, in particular, we explicitly address the problem of misalignment. We employed a case-control design with individual data. We used deaths resulting from myocardial infarction, hypertension, or Type II diabetes mellitus in Barcelona between 2004 and 2007 as cases for the study, while for controls we used deaths (likewise in Barcelona and over the same period of time) resulting from AIDS or external causes (e.g. accidental falls, accidental poisoning by psychotropic drugs, drugs of abuse, suicide and self-harm, or injuries resulting from motor vehicle accidents). The controls were matched with the cases by sex and age. We used the annual average equivalent A-weighted sound pressure levels for daytime (7-21h), evening-time (21-23h) and night-time (23-7h), and controlled for the following confounders: i) air pollutants (NO2, PM10 and benzene), ii) material deprivation (at a census tract level) and iii) land use and other spatial variables. We explicitly controlled for heterogeneity (uneven distribution of both response and environmental exposures within an area), spatial dependency (of the observations of the response variables), temporal trends (long-term behaviour of the response variables) and spatial misalignment (between response and environmental exposure locations). We used a fully Bayesian method, through the Integrated Nested Laplace Approximation (INLA). Specifically, we plugged the whole model for the exposure into the health model and obtained a linear predictor defined on the entire spatial domain. Separate analyses were carried out for men and for women. After adjusting for confounders, we found that traffic noise was associated with myocardial infarction mortality along with Type II diabetes mellitus in men (in both cases, odds ratios (OR) were around 1.02) and mortality from hypertension in women (ORs around 1.01). Nevertheless, only in the case of hypertension in women, does the association remain statistically significant for all age groups considered (all ages, ≥65 years and ≥75 years).

Accurately estimating breast cancer survival in Spain: cross-matching local cancer registries with the National Death Index

OBJECTIVES To assess the impact of using data from the National Death Index (NDI) of Spain to estimate breast cancer survival rates among residents of Girona and Zaragoza diagnosed in 1995-1999. METHODS This was an observational, longitudinal epidemiologic study, using two population-based cancer registries. Data collected were of female residents of Girona or Zaragoza who had been diagnosed with breast cancer in 1995-1999. Observed and relative 5-year survival rates were estimated, first using the information available from the Girona and Zaragoza cancer registries, and then with the inclusion of NDI data. The 5-year relative survival rate and corresponding 95% Confidence Intervals were estimated using the Hakulinen method. The Kaplan-Maier method and Log Rank test were used to compare survival curves. RESULTS No statistically significant difference in survival curves was observed in Girona for the data obtained before and after cross-matching with the NDI. However, there was a significant difference in Zaragoza. A comparison of the relative survival rates of each of the two registries before NDI cross-matching showed differences of 3.9% (5-year) and 16.1% (10-year) between the two, whereas after the cross-match, the difference was only 0.5% (5-year) and 1.2% (10-year). CONCLUSIONS In Spain it is imperative that there be systematic use of NDI data to supplement cancer registries, so that comparisons of relative survival rates between registries can be improved.

El proyecto Emecas: protocolo del estudio multicéntrico en España de los efectos a corto plazo de la contaminación atmosférica sobre la salud

El proyecto EMECAM constato el efecto a corto plazo de la contaminacion atmosferica sobre la mortalidad en 14 ciudades espanolas entre 1990 y 1995. El Estudio Multicentrico Espanol de Contaminacion Atmosferica y Salud (EMECAS) amplia estos objetivos incorporando al analisis datos de morbilidad hospitalaria, utiliza informacion mas reciente y suma un total de 16 ciudades. Se trata de un estudio ecologico de series temporales, siendo las variables respuesta las defunciones diarias y los ingresos hospitalarios urgentes por enfermedades del aparato circulatorio y enfermedades respiratorias en los residentes de cada ciudad. Contaminantes analizados: particulas en suspension, SO2, NO2, CO y O3. Variables de control: meteorologicas, de calendario, estacionalidad y tendencia e incidencia de gripe. Analisis estadistico: estimacion de la asociacion en cada ciudad mediante la construccion de modelos de regresion de Poisson aditivos generalizados, y meta-analisis para la obtencion de estimadores conjuntos. Los niveles medios de contaminantes se situaron por debajo de los establecidos por la normativa actual para el dioxido de azufre, el monoxido de carbono y el ozono. Los valores de NO2 y PM10 se situaron alrededor de los establecidos en la normativa (40 µg/m³). Se trata del primer estudio de la relacion entre contaminacion atmosferica y morbilidad en un conjunto de ciudades espanolas. Los niveles de contaminantes estudiados son moderados para algunos contaminantes, aunque en otros, especialmente NO2 y particulas, podrian representar un problema para el cumplimiento de la normativa vigente.

Assessment of self‐monitoring of blood pressure in the diagnosis of isolated clinic hypertension

Background. There are no studies assessing cardiovascular morbidity/mortality in patients with isolated clinical hypertension (ICH) with self‐blood pressure monitoring (SBPM). Objectives. To determine the value of SBPM in the diagnosis of ICH. Methods. Cohort study. New hypertensive and normotensive patients 15–75 years, without cardiovascular events history. Variables. Oriented anamnesis hypertension; blood pressure measurements (BP): clinical BP, SBPM and ambulatory BP monitoring (ABPM); evaluation of target organ damage (TOD); electrocardiogram; retinography and microalbuminuria (MA). Results. One hundred and thirty‐five patients, 95 hypertensive (62.1% males; mean age 59.08±16.8 years), 40 normotensive (37.5% males; mean age 56.32±10.22 years). BP measurements (mmHg) in normotensives vs hypertensives: clinical BP, 125.36/76.74 vs 149.81/87.86 mmHg (p<0.0001) and SBPM, 114.90/69.96 vs 142.06/86.31 (p<0.0001). Twenty‐four‐hour ABPM: 135.41/81.74. Prevalence of TOD in hypertensive: 23.10% left ventricular hypertrophy (LVH), 8.42% haemorrhage or exudates, 3.15% MA; 30.53% of hypertensives had ICH. The BP measurements in ICH vs sustained hypertension (SH): clinic BP, 149.88/86.34 vs 152.51/89.55 (p>0.10); SBPM: 147.895/88.95 vs 128.17/79 (p<0.0001) and ABPM, 141.72/88.22 vs 131.66/80 (p = 0.053 for systolic). TOD in SH vs ICH: LVH, 24.6% vs 19.2% (p = 0.814); exudates or haemorrhages, 7.7% vs 9.8% (p = 0.580). The risk of an occurrence of any TOD in ICH patients is lower for 125/80 (OR = 2.5). Conclusions. VAMPAHICA will provide information about value of SBPM in the diagnosis of ICH. Advanced retinopathy is relative frequent in ICH patients. If TOD is accepted as a surrogate endpoint, the diagnostic values of ICH will be probably decreased.

Treatment efficacy of anti-hypertensive drugs in monotherapy or combination: ATOM systematic review and meta-analysis of randomized clinical trials according to PRISMA statement.

Background:The relative efficacy of antihypertensive drugs/combinations is not well known. Identifying the most effective ones and the patients’ characteristics associated with best performance of the drugs will improve management of hypertensive patients. Objective:To assess the blood pressure (BP) reduction attributed to antihypertensive drugs and identify characteristics associated with BP decrease. Data sources:MEDLINE, Cochrane Central Register of Controlled Trials from inception through July 2012 and selected papers. Study eligibility criteria:Double-blind, randomized clinical trials whose main result was the reduction in BP by antihypertensive treatment, with study population ≥50 or ≥25 if the study was a crossover, follow-up of at least 8 weeks, and available required data. Study appraisal and synthesis methods:Study data were independently extracted by multiple observers and introduced in an electronic database. Inconsistencies were resolved by discussion and referral back to the original articles. Meta-analysis was performed according to PRISMA statement and using a Bayesian framework. Main Outcome(s) and Measure(s):Mean decrease in systolic (SBP) and diastolic blood pressure (DBP) achieved by each drug or combination. Results:Two hundred eight trials including 94,305 patients were identified. In monotherapy, most drugs achieved 10 to 15 mm Hg SBP and 8 to 10 mm Hg DBP decreases.Olmesartan/amlodipine, olmesartan/hydrochlorothiazide, felodipine/metoprolol, and valsartan/hydrochlorothiazide were the combinations leading to the greatest mean SBP reductions (>20 mm Hg). Female sex and body mass index >25 kg/m2 were associated with more pronounced SBP and DBP reductions, whereas Afro-American ethnicity was associated with BP reductions smaller than the median. Results were adjusted by study duration, cardiovascular disease, and diabetes mellitus. Still, the estimation was performed using the mean administered doses, which do not exactly match those of the available drug formats. Limitations:Data corresponded to those obtained in each of the included trials; the analysis of the combinations was limited to the most recent ones; estimations were performed using the mean administered doses. Conclusions and implications:Certain drug combinations achieve BP reductions ranging from 20 to 25/10 to 15 mm Hg. Sex, ethnicity, and obesity are associated with antihypertensive response. This information can contribute to better selection of the antihypertensive drug, depending on the magnitude of pretreatment BP elevation. Guidelines should be revised.

Effects of deprivation on the geographical variability of larynx cancer incidence in men, Girona (Spain) 1994-2004.

OBJECTIVE To assess the association between the incidence of larynx cancer and socioeconomic conditions in the province of Girona from a spatial viewpoint. MATERIALS AND METHODS Incidence cases of larynx cancer (CL) in 1994-2004 were provided by the Girona Cancer Registry. A census tract (CT) was assigned to all patients. Socioeconomic data were extracted from the 2001 Census. A deprivation index for each CT was obtained by principal component analysis, using four socioeconomic indicators. The standardised incidence ratio (SIR) was calculated using the CL incidence rates in the men of the province of Girona assuming a Poisson distribution. Relative risk was obtained applying the Besag, York and Mollié model. The deprivation index was introduced into the model and was categorised in quartiles. RESULTS Four hundred and seventy-six incident cases in men were registered. CTs in the lowest deprivation index had a lower risk of larynx cancer, with a risk increase in the higher quartiles. In the highest quartile it was 1.91 times greater than in the lowest. This association was significant when the whole province was considered. DISCUSSION The deprivation index explains only part of the geographical variability of CL incidence. Other risk factors without spatial structure may contribute to this explaination.