BACKGROUND: Use of non-nucleoside reverse transcriptase inhibitors (NNRTIs) such as rilpivirine and efavirenz in treatment-naive HIV-1 patients can be associated with the development of central nervous system side-effects, rash and lipid elevations. Resource utilisation and costs associated with managing adverse events (AEs) are, therefore, key factors in assessing the cost-effectiveness of treatment.
METHODS: A Delphi approach was used to estimate the healthcare resources used in the management of AEs in current practice in the United Kingdom. Responses from 64 British healthcare professionals working in HIV were collated and distributed to all respondents for review and validation. Costs were then calculated by multiplying the proportion of patients requiring each resource (GP visit, specialist visit, tests/monitoring, hospitalisation, drug costs) by the number of units of each resource used and its associated 2010 unit cost. Costs were then summed across each AE, by grade, to estimate total cost for each grade of AE (Division of AIDS, 2009).
RESULTS: Estimates derived from the Delphi panel suggest that the management of rash, dizziness, abnormal dreams and lipid elevations have a considerable resource impact. Based on the incidence of AEs for rilpivirinebased and efavirenz-based regimens reported in the pooled ECHO and THRIVE trials during the first 48 weeks of treatment, mean costs associated with the management of AEs in treatment-naive HIV-1 patients were £49.25 in the rilpivirine-treated group versus £122.92 in the efavirenz-treated group. The cost per patient of managing these AE in England has been estimated at: AE Grade Estimated mean cost (95% CI) Rash 2 £124 (75–187) 3 £736 (524–980) 4 £1,494 (1,232–1,784) Dizziness 2 £85 (52–127) 3 £369 (222–548) 4 £1,092 (847–1,366) Abnormal dreams 2 £29 (18–41) 3 £67 (44–94) Triglyceride levels 3 £358 (273–444) 4 £491 (376–606)
CONCLUSION: The costs of managing AEs associated with NNRTIs are considerable and rise with the severity of the AE. Given that rilpivirine has better tolerability profile compared with efavirenz, it is anticipated that the resource impact and cost of managing AEs will be lower in patients receiving rilpivirine than in those receiving efavirenz.
