This study adds to the evidence that the Quality of Outcomes Framework (QOF) is a "truly equitable public health intervention", says the author of an accompanying editorial.
High blood pressure is the single most important risk factor for developing heart disease and adds significantly to the gap in life expectancy between deprived and affluent areas. Studies have shown that successful blood pressure control could prevent 43 000 strokes and 83 000 cases of heart disease in the UK each year, but this is less likely to be achieved in socially deprived areas.
The QOF was introduced in 2004 to improve standards of primary care by linking financial incentives to 135 performance indicators for all general practitioners in the UK. It includes the target of blood pressure monitoring of all primary care patients older than 45 years annually, and meeting blood pressure control targets in patients with chronic diseases such as hypertension and diabetes.
In the first year of its implementation (2004-5) practices in socially deprived areas reported lower achievement scores (6.1% of the total QOF score) and therefore less financial reward than the more affluent areas, but by year 2 the gap had reduced to 2.9%.
Dr Mark Ashworth and colleagues from Kings College London, report on the data from the first three years (2004-7) of the QOF's implementation, including more than 8515 (97%) of practices in England involving 53 million people. They examined the effect of social deprivation on the achievement of blood pressure targets between general practices in deprived and less deprived communities in England.
The authors found that blood pressure recording increased from 82.3% (52.8 m) of adults in 2005 to 88.3% (53.2m) in 2007, and that the gap between median blood pressure recording levels narrowed from 1.7% to 0.2% between practices in the most deprived and least deprived areas.
Over the past decade, data has shown steady improvements in population blood pressure control, but the findings of this study show a rapid improvement in the last three years.
In addition, the achievement of blood pressure targets for the five chronic diseases improved substantially, particularly in diabetics in the most deprived practices, which improved by over 10%, with over 79% achieving target blood pressure levels by 2007.
The study shows that performance indicators linked to financial incentives result in improved achievement of targets, which at the same time narrows health inequalities, conclude the authors.
"Perhaps the greatest contribution that the QOF has made to changing practice will therefore be the largely unintended consequence of generating more equitable healthcare", says Professor Helen Lester from the National Primary Care Research and Development Centre in an accompanying editorial.
This study and other evidence suggests that pay per performance schemes should be designed with health inequalities in mind, she concludes.