In last year's study, the average service time at the McDonald's drive-through studied was 188.83 seconds, compared with 129.75 for industry leader Wendy's Co.

WSJ: McDonald's Tackles Repair of 'Broken' Service

But at the same time, the health service is changing - average lengths of stay in hospitals are about one third shorter than they were 10 years ago, and there is more surgery where patients don't have to stay overnight on a ward.

BBC: Nurses warn of 'workforce crisis' in NHS

The IRS is considering coordinating standards with the Department of Labor to consider a full time employee to be a worker who is employed on average at least 30 hours of service per week.

FORBES: IRS Asks for Input on Health Care Law