Americans are smoking fewer cigarettes, but the use of other forms of combustible tobacco has jumped dramatically, the CDC is reporting.

Over a 12-year period, total consumption of cigarettes fell 32.8%, the agency reported in the Aug. 3 issue of Morbidity and Mortality Weekly Report.

But over the same time, the use of pipe tobacco and large cigars skyrocketed, by factors of 5.82 and 3.33 respectively, the agency reported.

Overall, the agency found, smoking registered a steady decline – adding up to 27.5% over the whole study period -- but the decline in cigarette consumption was partly offset by an increase in the use of other forms of smokable tobacco, which more than doubled from 2000 through 2011.

The consumption estimates come from an analysis of excise tax information from the Treasury Department's Alcohol and Tobacco Tax and Trade Bureau. Using monthly tax data, the CDC researchers estimated the per unit consumption of each type of product.

To allow comparisons with pipe tobacco and roll-your-own tobacco, the agency converted the data from pounds of tobacco to a per-cigarette equivalent, in which 0.0325 oz. of tobacco equals one cigarette.

Over the study period, the agency found:

Total consumption of all combustible tobacco fell from 450.7 billion cigarette equivalents in 2000 to 326.6 in 2011, or 27.8%.

Per capita consumption fell from 2,148 cigarette equivalents to 1,374, a 36% decrease.

Total cigarette consumption fell from 435.6 billion in 2000 to 292.8 billion in 2011, a 32.8% decrease, while per capita cigarette consumption decreased 40.7%, from 2,076 to 1,232 over the same period.

On the other hand, total consumption of non-cigarette combustible forms of tobacco grew from 15.2 billion cigarette equivalents in 2000 to 33.8 billion in 2011, a 2.23-fold rise, and over the same time per capita consumption increased from 72 to 142, a 96.9% increase.

The increase in non-cigarette combustible tobacco use was mainly driven by increases in the use of pipe tobacco and large cigars, the agency found, probably because of tax changes that favored those products.

For instance, cigarette equivalent consumption of roll-your-own tobacco fell 56.3% over the study period, but pipe tobacco use rose by a factor of 5.82.

The largest changes took place from 2008 through 2011 – a period when tax changes made pipe tobacco relatively less expensive than roll-your own tobacco, the CDC reported.

During those years, roll-your-own consumption fell from 10.7 billion cigarette equivalents to 2.6 billion, down 75.7%, and pipe tobacco use increased from 2.6 billion cigarette equivalents to 17.5 billion, a 6.73-fold increase.

The agency also noted large changes in the use of small and large cigars.

Small cigars, defined as weighing no more than 3 pounds for 1,000 cigars, are often nearly indistinguishable from cigarettes. Large cigars must weigh more than 3 pounds per 1,000.

From 2000 through 2011, the use of small cigars fell 65% and consumption of large cigars rose by a factor of 3.33.

Again, the largest changes took place from 2008 through 2011: small cigar use fell from 5.9 billion to 0.8 billion, dropping 86.4%, while the consumption of large cigars rose by a factor of 2.26, from 5.7 billion to 12.9 billion.

"The rise in cigar smoking, which other studies show is a growing problem among youth and young adults, is cause for alarm," said Tim McAfee, MD director of CDC's Office on Smoking and Health and one of the report's authors.

The authors cautioned that the numbers only reflect legal sales and use of tobacco; illicit, untaxed tobacco would not be captured in the analysis.