Operative and consultative proportions of neurosurgical disease worldwide: estimation from the surgeon perspective.

OBJECTIVEThe global magnitude of neurosurgical disease is unknown. The authors sought to estimate the surgical and consultative proportion of diseases commonly encountered by neurosurgeons, as well as surgeon case volume and perceived workload.METHODSAn electronic survey was sent to 193 neurosurgeons previously identified via a global surgeon mapping initiative. The survey consisted of three sections aimed at quantifying surgical incidence of neurological disease, consultation incidence, and surgeon demographic data. Surgeons were asked to estimate the proportion of 11 neurological disorders that, in an ideal world, would indicate either neurosurgical operation or neurosurgical consultation. Respondent surgeons indicated their confidence level in each estimate. Demographic and surgical practice characteristics-including case volume and perceived workload-were also captured.RESULTSEighty-five neurosurgeons from 57 countries, representing all WHO regions and World Bank income levels, completed the survey. Neurological conditions estimated to warrant neurosurgical consultation with the highest frequency were brain tumors (96%), spinal tumors (95%), hydrocephalus (94%), and neural tube defects (92%), whereas stroke (54%), central nervous system infection (58%), and epilepsy (40%) carried the lowest frequency. Similarly, surgery was deemed necessary for an average of 88% cases of hydrocephalus, 82% of spinal tumors and neural tube defects, and 78% of brain tumors. Degenerative spine disease (42%), stroke (31%), and epilepsy (24%) were found to warrant surgical intervention less frequently. Confidence levels were consistently high among respondents (lower quartile > 70/100 for 90% of questions), and estimates did not vary significantly across WHO regions or among income levels. Surgeons reported performing a mean of 245 cases annually (median 190). On a 100-point scale indicating a surgeon's perceived workload (0-not busy, 100-overworked), respondents selected a mean workload of 75 (median 79).CONCLUSIONSWith a high level of confidence and strong concordance, neurosurgeons estimated that the vast majority of patients with central nervous system tumors, hydrocephalus, or neural tube defects mandate neurosurgical involvement. A significant proportion of other common neurological diseases, such as traumatic brain and spinal injury, vascular anomalies, and degenerative spine disease, demand the attention of a neurosurgeon-whether via operative intervention or expert counsel. These estimates facilitate measurement of the expected annual volume of neurosurgical disease globally.