Table 1. Contextual details of studies included in the meta-analysis.

In the study by Dales 2010, number of events were estimated from mean daily values (1.549 and 0.754) and the study period (2001–2005). Both short-term and long-term effects of air pollution were analyzed by Shih (2011). HES, Hospital Episode Statistics in England and Wales; WHI, the Women’s Health Initiative (WHI) Hormone Therapy trials; ARIC, the Atherosclerosis Risk in Communities study; DVT, deep vein thrombosis; PE, pulmonary embolism; NA, not available.