Healthcare is now mentioned by 21% of voters as one of the top two election issues, up from 17% in August and just 10% in June.

Healthcare issues have become the fourth most important among voter concerns, behind the war in Iraq, terrorism and the economy, according to new voter opinion polls published in Thursday’s New England Journal of Medicine.

The study identifies older Americans as the voters most concerned about healthcare issues; 3% of the voters surveyed mention Medicare specifically.

The study, conducted by researchers at the Harvard School of Public Health and the Kaiser Family Foundation, compares 10 telephone surveys and three exit polls from past elections with 22 current national opinion surveys, nine of which were conducted by phone.