The GP Patient Survey is a reliable and valid way of providing financial incentives to doctors, and there is little evidence to support concerns that it has led to unfair payments, according to new research published on bmj.com today.
Results of the survey were published in July 2009 and patients generally reported positive experiences and high levels of satisfaction with their general practices.
But many GPs and practice managers argued that insufficient patients were surveyed in some practices, and that the poor response rate meant that the survey results were biased.
To explore this further, a team of researchers led by Professor Martin Roland at the University of Cambridge and Professor John Campbell at Peninsula Medical School assessed the robustness of patient responses to the survey.
The overall response rate was 38.2% (2.2 million responses). In line with many other surveys, men, young people, and people living in deprived areas were less likely to respond.
But the researchers found little evidence that this would result in any systematic disadvantage to practices with either low or high response rates for the questions linked to payments.
The two questions on access to care (PE7 and PE8), which triggered payments to GPs, were reliable measures of practice performance, they say.
In total, 97% of practices achieved the 90% threshold for reliability for these two questions. For the 3% of practices with insufficient responses needed to meet this threshold, the authors suggest that larger numbers of patients from these practices should be sampled in future rounds of the survey.
"This study suggests that the current survey procedures result in reliable and valid survey estimates of performance at the practice level on the pay for performance items which we examined", write the authors.
"Furthermore," they say, "there is little evidence to support the concern of some GPs that low response rates and selective non-response bias have led to systematic unfairness in payments attached to questionnaire scores."
They also say that the study provides lessons for the UK and for other countries considering the use of patient experience as part of pay-for-performance schemes.
They conclude: "Patient reported measures of quality are an important aspect of care, and the GP Patient Survey represents a major opportunity to improve care on a national scale.
"Nonetheless, additional refinements of the measurement or compensation process and ongoing dialogue with practising doctors will be essential if the survey is to play an important role in improving in patient experience in the UK."