Walgreens (NYSE: WAG) (Nasdaq: WAG) had December sales of $6.71 billion, a decrease of 4.0 percent from $6.99 billion for the same month in fiscal 2012. Total front-end sales decreased 1.3 percent compared with the same month in fiscal 2012, while comparable store front-end sales decreased 2.3 percent. Customer traffic in comparable stores decreased 4.0 percent while basket size increased 1.7 percent. Prescriptions filled at comparable stores decreased by 2.3 percent in December and were flat on a day-fall adjusted (DFA) basis. This year’s December had one additional Sunday and Monday and one fewer Thursday and Friday compared with December 2011, negatively impacting prescriptions filled in comparable stores by 2.3 percentage points. DFA prescriptions filled at comparable stores were positively impacted by 1.4 percentage points due to the higher incidence of flu in this year’s December and 0.7 percentage point due to more flu shots administered in the month. Click here for a graph showing the trend of comparable prescriptions filled adjusted for day fall and flu impacts. December pharmacy sales decreased 4.9 percent, while comparable store pharmacy sales decreased 8.9 percent and by a day-fall adjusted (DFA) 6.6 percent. Calendar day shifts negatively impacted pharmacy sales in comparable stores by 2.3 percentage points. DFA comparable store pharmacy sales were negatively impacted by 5.7 percentage points due to generic drug introductions in the last 12 months. Pharmacy sales accounted for 56.7 percent of total sales for the month. Flu shots administered at pharmacies and clinics season-to-date were nearly 5.5 million versus approximately 5.3 million last year. Sales in comparable stores decreased by 6.1 percent in December. Calendar day shifts negatively impacted total comparable sales by 1.3 percentage points, while generic drug introductions in the last 12 months negatively impacted total comparable sales by 3.2 percentage points. Registrations for Walgreens Balance™ Rewards loyalty program, which launched in September, totaled nearly 49 million through December.