Distribución espacial de la tuberculosis en España mediante métodos geoestadísticos / Space distribution of tuberculosis in Spain by geostatistical methods

Fundamentos: La incidencia de tuberculosis (TB) se haasociado a factores, epidemiológicos y sociales. En España, laTB es una enfermedad de declaración obligatoria e individualizada.Las tasas de TB respiratoria experimentan un descensoconstante en los últimos años. El objetivo es valorar la asociaciónentre la morbilidad por TB respiratoria y variables socioeconómicasy epidemiológicas así como su distribución espacialmediante métodos geoestadísticos.Método: Las tasas de incidencia se estandarizaron poredad y sexo con datos de la Red Nacional de Vigilancia (2006).Las variables socioeconómicas incluidas son: condiciónsocioeconómica, nivel de estudios, tasa de hacinamiento, densidadde población, tasa de inmigración estandarizada porsexo, tasa de analfabetismo, tasa de paro, gasto medio en eurospor persona. Las variables epidemiológicas incluidas han sidola tasa de SIDA y la tasa de incidencia de gripe. Se realizó unanálisis multivariable mediante un Modelo Lineal Generalizadopoisson. Se aplicó la técnica geoestadística Cokringingajustada por las variables estadísticamente significativas paraver la distribución espacial de riesgo.Resultados: Las variables estadísticamente significativasson la tasa de hacinamiento, tasa de inmigración, tasa de analfabetismo,tasa de paro, gasto medio euros por persona, tasa degripe y tasa de sida. La técnica geoestadística muestra unavariabilidad espacial del riesgo y una concentración del riesgoen el noroeste y sureste de la península.Conclusiones: Los resultados permiten afirmar que elmétodo Cokriging es una herramienta útil para representar ladistribución espacial del riesgo. Existe asociación entre variablessocioeconómicas , epidemiológicas y TB en España(AU)

Background: Tuberculosis incidence has been associatedwith many factors, both epidemiological and social. In Spain,tuberculosis is a statutorily notifiable disease requiringindividualised reporting. During the last few years rates ofrespiratory tuberculosis show a steady decline. This study soughtto assess respiratory tuberculosis morbidity and mortality inassociation to socio-economic and epidemiological covariatesand estimate its spatial distribution across the country, using geostatisticalmethods.Methods: Respiratory tuberculosis incidence rates werestandardised by age and sex with the data of the NationalEpidemiological Surveillance Network (RENAVE, RedNacional de Vigilancia Epidemiológica) for 2006. Thefollowing socio-economic variables were included in thestudy: socio-economic status, educational level, overcrowdingrate, population density, standardised immigration rate by sex,unemployment rate and average spending per person in euros.The epidemiological variables included were, such as, AIDSrate and the influenza incidence rate. To assess the associationof covariables a multivariate analysis was performed using aGeneralised Linear Model assuming Poisson distribution. Thegoestatistical method Co-kriging was adjusted with thesignificant variables to built the spatial distribution of risk.Results: The statistically significant covariates wereovercrowding rate, standardised immigration rate by sex,educational level, unemployment rate, average spending perperson in euros, AIDS rate and the influenza incidence rate. Thegeostatistical method shows spatial variability of the risk withhigher risks in the northwest and southeast of the peninsula.Conclusion: Results prove that the Co-kriging method is auseful tool to show the spatial distribution of risk. Alternatively,tuberculosis is associated with both social and epidemiologicalcovariates(AU)

[Space distribution of tuberculosis in Spain by geostatistical methods]. / Distribución espacial de la tuberculosis en España mediante métodos geoestadísticos.

BACKGROUND: Tuberculosis incidence has been associated with many factors, both epidemiological and social. In Spain, tuberculosis is a statutorily notifiable disease requiring individualised reporting. During the last few years rates of respiratory tuberculosis show a steady decline. This study sought to assess respiratory tuberculosis morbidity and mortality in association to socio-economic and epidemiological covariates and estimate its spatial distribution across the country, using geo-statistical methods. METHODS: Respiratory tuberculosis incidence rates were standardised by age and sex with the data of the National Epidemiological Surveillance Network (RENAVE, Red Nacional de Vigilancia Epidemiológica) for 2006. The following socio-economic variables were included in the study: socio-economic status, educational level, overcrowding rate, population density, standardised immigration rate by sex, unemployment rate and average spending per person in euros. The epidemiological variables included were, such as, AIDS rate and the influenza incidence rate. To assess the association of covariables a multivariate analysis was performed using a Generalised Linear Model assuming Poisson distribution. The goestatistical method co-kriging was adjusted with the significant variables to built the spatial distribution of risk. RESULTS: The statistically significant covariates were overcrowding rate, standardised immigration rate by sex, educational level, unemployment rate, average spending per person in euros, AIDS rate and the influenza incidence rate. The geostatistical method shows spatial variability of the risk with higher risks in the northwest and southeast of the peninsula. CONCLUSION: Results prove that the co-kriging method is a useful tool to show the spatial distribution of risk. Alternatively, tuberculosis is associated with both social and epidemiological covariates.