Impact of a national guideline for the management of peripheral arterial disease on revascularization rates in England: interrupted time series analysis.

Background: A national guideline on peripheral arterial disease management in England was issued in August 2012. The impact on revascularization rates was examined and variation with socioeconomic deprivation assessed.

Methods: Annual hospital admissions for England over 10 years (2008-2009 to 2017-2018) were examined using interrupted time series analysis. A pragmatic approach was used to classify admissions for revascularization into moderate and severe categories.

Results: There were 309 839 admissions (56% for moderate peripheral arterial disease), with an overall annual admission rate for revascularization of 86 per 100 000 population aged 25+ years. The rate for moderate peripheral arterial disease marginally increased by 0.29 per 100 000 per year (95% c.i. -0.22 to 0.80) from 2008-2009 to 2012-2013. Following guideline introduction, this rate decreased. The equivalent for severe peripheral arterial disease increased by 1.33 per 100 000 (0.78 to 1.88). Following guideline introduction, this rate plateaued. The change in rate (slope) for moderate peripheral arterial disease of -2.81 per 100 000 per year (-3.52 to -2.10) after guideline introduction was greater than the change in rate for severe peripheral arterial disease of -1.95 per 100 000 per year (-2.73 to -1.17). For moderate peripheral arterial disease, the annual rate in the most socioeconomically deprived category was 15.6 per 100 000 lower in 2017-2018 compared with 2012-2013 (24.3% decrease). The impact progressively diminished with decreasing deprivation. In the least deprived category, the reduction was 5.2 per 100 000 (12.9% decrease). For severe peripheral arterial disease, the decrease was 1.2 per 100 000 (3.1% reduction) with no consistent variation in relation to deprivation.

Conclusion: Introduction of the national peripheral arterial disease management guideline in England was associated with a reduction in admission rates for revascularization, especially for moderate peripheral arterial disease, with greater reduction in rates for moderate peripheral arterial disease in more socioeconomically deprived areas. Association, however, does not necessarily imply causation and alternative explanations cannot be ruled out.