GPs are hugely inconsistent in deciding how long people should stay off work, with some signing staff off for much greater periods of time than others.
Research by academics at the University of Manchester found wide variation in how patients were signed off by GPs.
Its survey of 113 GPs within one health trust looked at sickness certification practices after surgery or a heart attack, and found that just one in 20 followed government advice on sick leave.
For hernia operations, for example, some GPs recommended four to six weeks off work, while others recommended one to two weeks.
One-third suggested heart attack patients should be off work longer than the four to six weeks recommended by the Department for Work and Pensions.
Despite the government spending £2m piloting a three-year training programme in workplace health for GPs, which is being run by the Royal College of General Practitioners, almost two-thirds of the GPs polled said they had not been trained in sickness certification.
Those who had been trained received an average of four hours’ training, which raises questions as to how GPs will cope with the added burden of making decisions on fitness to work once the new ‘fit note’ arrives in April.
The research was published in the journal Occupational Medicine.
Study leader Dr Richard Roope said it was important that GPs understood the message that being signed off work could actually be worse for a patient than trying to get them back to work more quickly, as well as being more damaging for the employer and the economy in general.