Health economic impact of early versus delayed treatment of herpes simplex virus encephalitis in the UK

Abstract

Objective: Thanks to the introduction of recent national guidelines for treating herpes simplex virus (HSV) encephalitis, health outcomes have improved. This paper evaluates the health system costs and the health-related quality of life implications of these guidelines.

Design and setting: A sub-analysis of data from a prospective, multi-centre, observational cohort ENCEPH-UK study conducted across 29 hospitals in the UK from 2012 to 2015.

Study participants: Data for patients aged ≥16 years with a confirmed HSV encephalitis diagnosis admitted for treatment with aciclovir were collected at discharge, 3 and 12 months.

Primary and secondary outcome measures: Patient health outcomes were measured by the Glasgow outcome score (GOS), modified ranking score (mRS) and the EuroQoL; healthcare costs were estimated per patient at discharge from hospital and at 12 months follow-up. In addition, Quality Adjusted Life Years (QALYs) were calculated from the EQ-5D utility scores. Cost-utility analysis was performed using the NHS and Social Care perspective.

Results: A total of 49 patients were included; 35 were treated within 48 hours, 'early' (median (IQR) 8.25 [3.7-20.5]) and 14 were treated after 48 hours 'delayed' (median (IQR) 93.9 [66.7-100.1]). At discharge, 30 (86%) in the early treatment group had a good mRS outcome score (0-3) compared with 4 (29%) in the delayed group. According to GOS, 10 (29%) had a good recovery in the early treatment group, but only 1 (7%) in the delayed group. EQ-5D-3L utility value at discharge was significantly higher for early treatment (0.609 vs 0.221, p<0.000). After adjusting for age and symptom duration at admission, early treatment incurred a lower average cost at discharge, £23,086 (95% CI: £15,186 to £30,987) vs £42,405 (95% CI: £25,457 to £59,354) [p<0.04]. A -£20,218 (95% CI: -£52,173 to £11,783) cost difference was observed at the 12- month follow-up post discharge.

Conclusions: This study suggests that early treatment may be associated with better health outcomes and reduced patient healthcare costs, with a potential for savings to the NHS with faster treatment.

Keywords: HEALTH ECONOMICS; Health economics; Infectious disease/HIV; Quality of Life.

Figure 1. Cost Effectiveness Plane