ABSTRACT
Abstract Introduction There is a need to develop methods to evaluate public health interventions. Therefore, this work proposed an intervention analysis on time series of breast cancer mortality rates to assess the effects of an action of the Brazilian Screening Programme. Methods The analysed series was the monthly female breast cancer mortality rates from January 1996 to March 2016. The intervention was the establishment of the National Information System on Breast Cancer in June 2009. The Box-Tiao approach was used to build a Global Intervention Model (GIM) composed of a component that fits the series without the intervention, and a component that fits the effect with the intervention. The intervention's response time was estimated and used to define the length of the residual series to assess the predictive accuracy of the GIM, which was compared to a one-step-ahead forecasting approach. Results The pre-intervention period was fitted to a SARIMA (0,1,2) (1,1,1)12 model and the intervention's effect to an ARIMA (1,1,0) model. The intervention led to an increase in the mortality rates, and its response time was 24 months. The forecast error (MAPE) for the GIM was 3.14%, and for the one-step-ahead forecast it was 2.15%. Conclusion This work goes one step further in relation to the studies carried out to evaluate the Breast Cancer Screening Programme in Brazil, considering that it was possible to quantify the effects and the response time of the intervention, demonstrating the potential of the proposed method to be used to evaluate health interventions.
ABSTRACT
As lesões intraepiteliais escamosas de alto grau (HSIL) são precursoras do câncer do colo do útero, com maior risco de ocorrência e desenvolvimento em mulheres HIV+. Neste trabalho, estimamos e comparamos o desempenho do exame citológico e da captura híbrida II no rastreamento das lesões precursoras em mulheres HIV+. A população de estudo compreendeu mulheres acompanhadas na coorte prospectiva aberta do Instituto de Pesquisa Clínica Evandro Chagas da Fundação Oswaldo Cruz (IPEC/Fiocruz). A colposcopia e histologia foram consideradas conjuntamente na definição do teste de referência. O exame citológico apresentou sensibilidade de 31,8 por cento e especificidade de 95,5 por cento, enquanto a captura híbrida II apresentou maior sensibilidade (100 por cento) e menor especificidade (52 por cento). As razões de verossimilhança para o teste positivo e negativo foram estimadas em 7,1 e 0,7 para o exame citológico e em 2,1 e 0,0 para a captura híbrida II, respectivamente.
HIV-infected women are at increased risk of developing high-grade squamous intraepithelial lesions (HSIL), the precursor lesions for cervical cancer. This study estimated and compared the performance of cytology and hybrid capture II in screening for precursor lesions of cervical cancer among HIV-infected women. The study population consisted of women from the open prospective cohort at the Evandro Chagas Clinical Research Institute, Oswaldo Cruz Foundation (IPEC/Fiocruz). Colposcopy and histology were considered jointly in defining the gold standard. Cytology showed 31.8 percent sensitivity and 95.5 percent specificity, while hybrid capture II showed higher sensitivity (100 percent) and lower specificity (52 percent). The positive likelihood ratio was 7.1 for cytology and 2.1 for hybrid capture II, while the negative likelihood ratio was 0.7 for cytology and 0.0 for hybrid capture II.