University of Manchester researchers have found a huge variation in how long patients are signed off work by GPs.
Researchers surveyed 113 GPs within one health trust, looking at sickness certification practices after surgery or a heart attack. They found just one in 20 GPs followed government advice on sickness leave.
GPs differed widely in how long they thought patients should be signed off for, reports the BBC. For hernia operations, some GPs recommended four to six weeks off work, while others recommended one to two weeks.
One-third of GPs suggested heart attack patients should be off work longer than the four to six weeks recommended by the Department for Work and Pensions.
The survey found that almost two-thirds of GPs had not been trained in sickness certification. Those who had, received an average of four hours' training.
Study leader Dr Richard Roope said that the inconsistency found was unsurprising, given the lack of training.
The government is currently working to replace sicknotes with 'fit notes', which would involve GPs outlining what work their patients were fit for.