Modelling local uncertainty in relations between birth weight and air quality within an urban area: combining geographically weighted regression with geostatistical simulation.

In this study, we combine known methods to present a new approach to assess local distributions of estimated parameters measuring associations between air quality and birth weight in the urban area of Sines (Portugal). To model exposure and capture short-distance variations in air quality, we use a Regression Kriging estimator combining air quality point data with land use auxiliary data. To assess uncertainty of exposure, the Kriging estimator is incorporated in a sequential Gaussian simulation algorithm (sGs) providing a set of simulated exposure maps with similar spatial structural dependence and statistical properties of observed data. Following the completion of the simulation runs, we fit a geographically weighted generalized linear model (GWGLM) for each mother's place of residence, using observed health data and simulated exposure data, and repeat this procedure for each simulated map. Once the fit of GWGLM with all exposure maps is finished, we take the distribution of local estimated parameters measuring associations between exposure and birth weight, thus providing a measure of uncertainty in the local estimates. Results reveal that the distribution of local parameters did not vary substantially. Combining both methods (GWGLM and sGs), however, we are able to incorporate local uncertainty on the estimated associations providing an additional tool for analysis of the impacts of place in health.

A coregionalization model can assist specification of Geographically Weighted Poisson Regression: Application to an ecological study.

The geographical distribution of health outcomes is influenced by socio-economic and environmental factors operating on different spatial scales. Geographical variations in relationships can be revealed with semi-parametric Geographically Weighted Poisson Regression (sGWPR), a model that can combine both geographically varying and geographically constant parameters. To decide whether a parameter should vary geographically, two models are compared: one in which all parameters are allowed to vary geographically and one in which all except the parameter being evaluated are allowed to vary geographically. The model with the lower corrected Akaike Information Criterion (AICc) is selected. Delivering model selection exclusively according to the AICc might hide important details in spatial variations of associations. We propose assisting the decision by using a Linear Model of Coregionalization (LMC). Here we show how LMC can refine sGWPR on ecological associations between socio-economic and environmental variables and low birth weight outcomes in the west-north-central region of Portugal.

Sexual Dysfunction in Breast Cancer Survivors: Cross-Cultural Adaptation of the Sexual Activity Questionnaire for Use in Portugal.

INTRODUCTION: The increasing survivor population of breast cancer has shifted research and practice interests into the impacts of the disease and treatment in quality of life aspects. The lack of tools available in Portuguese to objectively evaluate sexual function led to the development of this study, which aimed to cross-culturally adapt and validate the Sexual Activity Questionnaire for use in Portugal. MATERIAL AND METHODS: The questionnaire was translated and back-translated, refined following face-to-face interviews with seven breast cancer survivors, and then self-administered by a larger sample at baseline and a fortnight later to test validity and reliability. RESULTS: Following cognitive debriefing (n = 7), minor changes were made and the Sexual Activity Questionnaire was then tested with 134 breast cancer survivors. A 3-factor structure explained 75.5% of the variance, comprising the Pleasure, Habit and Discomfort scales, all yielding good internal consistency (Cronbach's α > 0.70). Concurrent validity with the FACt-An and the BCPT checklist was good (Spearman's r > 0.65; p-value < 0.001) and reliability acceptable (Cohen's k > 0.444). The Sexual Activity Questionnaire allowed the identification of 23.9% of sexually inactive women, for whom the main reasons were lack of interest or motivation and not having a partner. DISCUSSION: Patient-reported outcomes led to a more comprehensive and improved approach to cancer, tackling areas previously abandoned. Future research should focus on the validation of this scale in samples with different characteristics and even in the overall population to enable generalizability of the findings. CONCLUSION: The adapted Sexual Activity Questionnaire is a valid tool for assessing sexual function in breast cancer survivors in Portugal.

Introdução: A crescente população de sobreviventes de cancro da mama tem redireccionado o interesse investigacional e prático para o impacto da doença e do seu tratamento nas várias áreas da qualidade de vida. A falta de questionários para avaliar de forma objectiva a disfunção sexual conduziu à necessidade de adaptar e validar culturalmente o Sexual Activity Questionnaire para utilização em Portugal. Material e Métodos: O Sexual Activity Questionnaire foi traduzido e retrovertido, sua versão de consenso refinada após teste de compreensão, e subsequentemente auto-administrado a uma amostra alargada de sobreviventes de cancro da mama em dois momentos, espaçados 15 dias, para julgar a sua validade e fiabilidade. Resultados: Após alterações minor à versão de consenso, o Sexual Activity Questionnaire foi aplicado a 134 doentes. Obteve-se uma estrutura de três factores (75,5% da variância), compreendendo as escalas do Prazer, Hábito e Desconforto, todas com boa consistência interna (α de Cronbach > 0,70), boa validade concorrente com o FACt-An e a checklist BCPT (r de Spearman > 0,65; p-value < 0,001) e estabilidade temporal aceitável (k de Cohen > 0,44). Foi identificada inactividade sexual em 23,9% das mulheres, devido a falta de interesse ou ao facto de não ter parceiro. Discussão: Os dados reportados pelos doentes conduziram a alterações nos cuidados prestados, que passaram a contemplar a oncosexologia. Estudos futuros deverão focar-se na aplicabilidade deste questionário a amostras com diferentes características e mesmo à população global, para se poderem generalizar os resultados. Conclusão: A versão obtida do Sexual Activity Questionnaire é válida para avaliar a função sexual em sobreviventes de cancro da mama em Portugal.