Total U.S. prescription drug spending climbed more than 3% last year, propelled in part by fewer patent expirations that would have allowed for cheaper generic alternatives, according to the data firm IMS Health.

Prescription spending reached $329.2 billion in 2013 after declining 1% the year before. IMS health said price hikes, expensive new drugs and greater use of the health care system also led to the spending rise, which it detailed in a report Tuesday.

Fewer patent expirations, however, were the largest factor. The expiration of U.S. patents protecting blockbuster drugs like the cholesterol fighter Lipitor has led to a spike in generic drug use in recent years, but that wave is starting to wane.

IMS Health also noted that 36 new treatments entered the market last year, including 10 for cancer. That also includes drugs for hepatitis C, multiple sclerosis and diabetes.

New, innovative drugs often come with high price tags, like the $1,000-a-pill price set by drugmaker Gilead Sciences for its hepatitis C treatment Sovaldi.

Drugmakers have said the high cost of treatments like Sovaldi can be recouped over time, as fewer patients suffer expensive complications for their conditions.

IMS Health also said price hikes for branded drugs added more than $4 billion in spending growth last year, and the overall spending per person rose about 1%.