Participating centers were educational, community-based, inpatient, or freestanding outpatient dialysis centers. There were no significant distinctions between your two treatment groups at baseline with respect to demographic characteristics, relevant health background, or features of the arteriovenous gain access to graft, with the exception of a higher incidence of axillary venous anastomosis in the balloon-angioplasty group. Nor have there been significant differences between your two groups with regards to the nature or prevalence of abnormalities resulting in the intervention in the arteriovenous access graft. The three most typical triggers for intervention were clinical variables, elevated venous pressure during dialysis, and detection of decreased blood circulation.The reduction in the U.S. Business principally relates to lower revenues from INRatio sales also to lower pain administration revenues in our Toxicology business. Net product and solutions revenue from our Health Information Solutions segment was $34.7 million in the fourth quarter of 2014, in comparison to $30.8 million in the fourth quarter of 2013, reflecting growth inside our Alere Home Monitoring individual self-testing services from $25.5 million in the fourth quarter of 2013 to $30.0 million in the fourth quarter of 2014. Gross margin was 46.5 percent of net revenue in the fourth quarter of 2014, compared to 50.8 percent in the fourth quarter of 2013. Non-GAAP altered gross margins, which exclude from cost of net income amortization of acquisition-related intangibles, stock-based compensation expense, restructuring charges, and noncash charges associated with obtained inventory, was 50.0 percent of non-GAAP adjusted net revenue in the fourth one fourth of 2014, compared to 53.6 percent in the fourth quarter of 2013 and 49.8 percent in the third quarter of 2014.