The Neurosurgical National Audit Programme (NNAP) was established by the Society of British Neurological Surgeons (SBNS) in 2013 as part of a major quality improvement initiative. The programme aims to support neurosurgical units in the UK and Ireland to improve patient care, outcomes, safety, and experience by providing high quality, robust audit data that is analysed and presented in a consistent and clinically relevant way.

Reponen et al. recorded outcome event rates and categorized them according to British Neurosurgical National Audit Programme (NNAP), American National Surgical Quality Improvement Program (NSQIP), and American National Neurosurgery Quality and Outcomes Database (N2QOD) to assess the applicability of these programs for quality benchmarking and estimated sample sizes required for reliable quality comparisons.

The rate of in-hospital major and minor morbidity was 18.7% and 38.0%, respectively, and 30-d mortality rate was 2.4%. The NSQIP criteria identified 96.2% of major but only 38.4% of minor complications. N2QOD performed better, but almost one-fourth (23.2%) of all patients with adverse outcomes, mostly minor, went unnoticed. For NNAP, a sample size of over 4200 patients per surgeon is required to detect a 50.0% increase in mortality rates between surgeons. The sample size required for reliable comparisons between the rates of complications exceeds 600 patients per center per year.

The implemented benchmarking programs in the United Kingdom and the United States fail to identify a considerable number of complications in a high-volume center. Health care policymakers should be cautious as outcome comparisons between most centers and individual surgeons are questionable if based on the programs ¹⁾.