The number of providers that perform enough non-elective neurosurgical procedures over 3-year and 5-year periods to detect statistical outliers if the 30-day mortality rate is double the national average
| Non-elective neurosurgery | National average mortality rate for non-elective neurosurgery (%) | Average annual no of procedures per surgeon/hospital (n) | Minimum sample size (80% power) (n) | Surgeons/hospitals achieving or exceeding minimum sample size | |
| 3 years (n, %) | 5 years (n, %) | ||||
| Surgeons | |||||
| I. All procedures and major procedures | |||||
| All procedures | 6.1 | 51 | 149 | 149/353 (42.2) | 234/370 (63.2) |
| Major procedures | 6.6 | 47 | 137 | 143/349 (41.0) | 229/364 (62.9) |
| Hospitals | |||||
| I. All procedures and major procedures | |||||
| All procedures | 6.1 | 770 | 149 | 24/24 (100) | 24/24 (100) |
| Major procedures | 6.6 | 702 | 137 | 24/24 (100) | 24/24 (100) |
| II. Cranial and spinal procedures | |||||
| Cranial surgery | 8.4 | 495 | 105 | 24/24 (100) | 24/24 (100) |
| Spinal surgery | 1.6 | 162 | 617 | 9/24 (37.5) | 19/24 (79.2) |
| III. Subspecialty procedures | |||||
| Trauma | 11.0 | 112 | 77 | 23/24 (95.8) | 24/24 (100) |
| General neurosurgery | 7.6 | 110 | 118 | 24/24 (100) | 24/24 (100) |
| Functional | 3.4 | 7 | 282 | 0/24 (0) | 0/24 (0) |
| Neuro-oncology | 5.7 | 66 | 160 | 16/24 (66.7) | 23/24 (95.8) |
| All CSF procedures | 10.7 | 109 | 79 | 24/24 (100) | 24/24 (100) |
| CSF shunt procedures | 3.0 | 63 | 317 | 0/24 (0) | 12/24 (50.0) |
| Skull base | 2.3 | 15 | 412 | 0/24 (0) | 0/24 (0) |
| Neurovascular | 6.7 | 91 | 136 | 20/24 (83.3) | 24/24 (100) |
| Simple spine | 1.2 | 116 | 811 | 0/24 (0) | 8/24 (33.3) |
| Complex spine | 2.5 | 43 | 388 | 0/24 (0) | 1/24 (4.2) |
| Intradural spine | 2.6 | 10 | 366 | 0/24 (0) | 0/24 (0) |
CSF, cerebrospinal fluid.