ATLANTA?Each pack of cigarettes sold in the United States costs the nation $7 in medical care and lost productivity, the government said Thursday.

The study by the Centers for Disease Control and Prevention put the nation’s total cost of smoking at $3,391 a year for every smoker, or $157.7 billion. Health experts had previously estimated $96 billion.

Americans buy about 22 billion packs of cigarettes annually. The CDC study is the first to establish a per-pack cost to the nation.

The agency estimated the nation’s smoking-related medical costs at $3.45 per pack, and said job productivity lost due to smoking deaths amounted to $3.73 per pack, for a total of $7.18.

The average cost of a pack of cigarettes in 1999 was $2.92.

The agency also reported that smoking results in about 440,000 deaths a year in the United States, up from the government’s previous figure of 430,000, established in the early 1990s.