However, full-time female GPs work just over 43 hours a week on average, about 1.5 hours less than women in other professional occupations, and roughly an hour less than female managers.
Part-time male GPs work around 34 hours a week, compared to 29 for part-time female GPs, according to the study.
Male GPs were on call for nearly 15 hours a week if full-time, or eight hours if part-time. Female GPs were on call for around 12.5 hours full-time and 7.5 hours if part-time.
The results are based on responses from 1,871 GPs to a survey carried out in February 2004 by the University of York.
The new GMS contract began in April 2004, allowing GPs to opt out of out-of-hours. But many GPs report that the quality framework and enhanced services have added to their workload.
Derbyshire LMC secretary Dr John Grenville said many GPs worked more than 50 hours.
‘It sounds low to me. People may be under-reporting how much work they take home.'
He said the results showing that women worked for fewer hours were odd: ‘It's not something that I recognise.'
The survey found that female GPs with children reduced their hours more than men. Female GPs with children aged over 18 years worked the same number of hours as men.