The financial and service implications of splitting fixed-dose antiretroviral drugs - a case study.
In 2010/2011, regional commissioners withdrew payment for the fixed-dose combination Combivir, forcing a switch to component drugs. This was deemed clinically acceptable and annual savings of £44 k expected. We estimated the true costs of switching and examined patient outcomes. Information for 46 patients using Combivir was extracted from case notes for each clinical contact in the 12 months pre- and post-switch (clinician seen, tests, antiretrovirals). Post-switch care costs £93/patient more annually versus pre-switch (95% CI £424 to £609), yielding £4278/year more post-switch for all patients. Drug and pathology costs were more expensive post-switch and extra clinical visits required. None of these results were statistically significant. Forty-two per cent of patients switched directly or in the subsequent year to an alternative fixed-dose combination rather than generics. Costs in this group were significantly higher post-switch driven by drug cost. Six patients (13%) reported problems with the switch including confusion around dosing and new side effects. As less-expensive generic antiretroviral drugs become available, it may appear cheaper to switch from fixed-dose combinations to component drugs. However, the additional clinical costs involved may outweigh the initial cost savings of the drugs and switching may cause confusion for some patients, risking loss of adherence.
Department of Genitourinary Medicine, Nottingham University Hospitals NHS Trust, Nottingham, UK ruth.taylor@nuh.nhs.uk.
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Taylor
Department of Genitourinary Medicine, Nottingham University Hospitals NHS Trust, Nottingham, UK.
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Carlin
Independent Health Economist, London, UK.
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Sadique
Department of Genitourinary Medicine, Nottingham University Hospitals NHS Trust, Nottingham, UK.
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Ahmed
Aquarius Population Health, Bristol, UK School of Social and Community Medicine, University of Bristol, Bristol, UK.
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Adams
D000328:Adult; D000368:Aged; D019380:Anti-HIV Agents / Q000191:economics* / Q000627:therapeutic use; D003362:Cost-Benefit Analysis; D003365:Costs and Cost Analysis / Q000706:statistics & numerical data; D004338:Drug Combinations; D057915:Drug Substitution / Q000191:economics*; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000191:economics; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006801:Humans; D019259:Lamivudine / Q000191:economics* / Q000627:therapeutic use; D008297:Male; D016896:Treatment Outcome; D019562:Viral Load; D015215:Zidovudine / Q000191:economics* / Q000627:therapeutic use
D019380:Anti-HIV Agents; D004338:Drug Combinations; C109078:lamivudine, zidovudine drug combination; D019259:Lamivudine; D015215:Zidovudine
AIDS; HIV; antiretroviral therapy; combination; cost and cost analysis; drug substitution; drug therapy; drugs; generic