New oncology drug approvals in the United States outpaced European approvals by 33 percent between 2000 and 2011, according to a new study by the Tufts Center for the Study of Drug Development.

Another study finding: Oncology drug prices in Europe, on average, are 9 percent lower than prices in the United States.

But what is not clear from the study is whether greater access to oncology drugs leads to better outcomes, said Joshua P. Cohen, the research assistant professor at Tufts who conducted the analysis.

‘Although more oncology drugs are available in the US, and the costs for a higher share of them are reimbursed, the evidence-based approach adopted by European systems have improved the affordability of drugs in Europe that are considered to be cost-effective,’’ Cohen said in a statement.