Suchergebnisse

"Kreuter and Peng open Part III, an the statistical framework, with a discussion of the new statistical challenges associated with inference in the context of big data. They begin by noting that reliable statistical inference requires an understanding of the data-generating process. That process is not well understood in the case of big data, so it is important that researchers be given access to the source data so that coverage and quality issues can be identified and addressed. Standard statistical disclosure limitations are unlikely to work, because an important feature of big data is the ability to examine different, targeted populations, which often have unique and easily re-identifiable characteristics." (Text excerpt, IAB-Doku) ((en))

Severe air pollution episodes in Europe and the USA in the early- to mid-twentieth century caused large health impacts, spurring national legislation. Similarly severe episodes currently affect developing regions, as exemplified by a particularly extreme episode in January 2013 in Beijing, China. We investigated associations between this episode and medical visits at a Beijing hospital. We obtained fine particulate matter (PM(2.5)) measurements from the US State Department's Embassy monitor and daily counts of all-cause, cardiovascular, and respiratory emergency visits, and outpatient visits from a nearby hospital in the Liufang Nanli community. We analyzed whether risks increased during this episode (with daily PM(2.5) ≥ 350 μg/m(3)) using generalized linear modeling, controlling for potential confounders. The episode brought exceptionally high PM2.5 (peak daily average, 569 μg/m(3)). Risk increased during the episode for all-cause (relative risk 1.29 [95% CI 1.13, 1.46]), cardiovascular (1.55 [0.90, 2.68]) and respiratory (1.33 [1.10, 1.62]) emergency medical visits, and respiratory outpatient visits (1.16 [1.00, 1.33]). Relative risks of all-cause (0.95 [0.82, 1.10]) and cardiovascular (0.83 [0.67, 1.02]) outpatient visits were not statistically significant. Results were robust to modeling choices and episode definitions. This episode was extraordinarily severe, with maximum daily PM(2.5) concentration nearly 22-fold above the World Health Organization guideline. During the episode, risk increased for all-cause, cardiovascular, and respiratory emergency medical visits, and respiratory outpatient visits, consistent with previous US-based research. However, no association was found for all-cause or cardiovascular outpatient visits. China-based studies like this one provide critical evidence in developing efforts regarding air pollution remediation in China.