The payments are meant to compensate practices for extra work associated with their patient population.
But responses from 1,871 GPs to a survey posted out in February 2004 by researchers from the University of York found that working hours were ‘perversely negatively associated’ with additional needs payments.
Other weighting factors, for example, age and sex were all positively associated with GPs workload.
Lead researcher Professor Hugh Gravelle said: ‘Our finding that GPs in practices with higher additional needs payments work fewer hours suggests that the formula needs revising.’
The DoH is reviewing the global sum formula and has commissioned research to report by the summer.
However, GPC negotiator Dr Stewart Drage said that the majority of pay weighting was based on age and sex.
He said that more work was needed to assess the link between workload and additional needs payments.
‘You have to look beyond GP hours to see practice workload,’ he said.
Last week GP reported that researchers had found that the average male full-time GP was working a 50-hour week.