A study of the impact of VNS on health care utilisation in England

• Compares hospital activity before and after VNS therapy for epilepsy using HES data.
• VNS reduces length of hospital stay and increases elective care.
• The impact on A&E attendance is equivocal.
• VNS requires increased outpatient activity.

PurposeTo compare hospital service use before and after VNS therapy implantation in a sample of drug-resistant people with epilepsy.MethodThe before and after study was performed using anonymised Hospital Episode Statistics (HES) data from one year before to 3 years after implantation in 321 patients from data collected between April 2009 to July 2011. Episodes relating to out-patient clinic, Accident and Emergency (A&E) department attendance, hospital admissions and length of stay were collected and compared. Descriptive statistics are used to summarise patient demographics, patient pathways and resource usage before and after VNS implantation. Means and proportions were reported on continuous variables, proportion and frequency on categorical variables. Trends of activity over time were determined using before and after VNS comparisons and tested with the Wilcoxon Signed-rank (WSR) test.ResultsThe summary statistics indicate a drop in resource use in terms of in-patient bed-days (21% decrease), elective in-patient episodes (7% decrease) and non-elective in-patient episodes (14% decrease). There was an increase in the quarterly average out-patient appointments by 12%. The A&E attendance outcome recorded a mean increase in quarterly attendances of 9% but a slight decrease when subject to a signed rank test. These contradictory results should therefore be treated with caution.ConclusionVNS Therapy may be associated with an overall reduction in health service resource use.