Cost Effectiveness Analysis of Instanyl for the Treatment of Breakthrough Cancer Pain (BtcP)

Background: Breakthrough cancer pain (BTcP) is a transitory exacerbation of the intensity of the pain in a patient with background pain that is well controlled by analgesic treatment (with morphine). The drugs most widely used to treat individual episodes of BTcP are the opioids. Better results can be obtained with Instanyl. So far, while several studies have proven the effectiveness of Istanyl, limited evidence is actually available on the economic affordability for a third party payer (i.e. National Healthcare Systems). In this paper we perform a cost effectiveness analysis, whose aim is to estimate the cost per Quality Adjusted Life Year (QALYs) of Istanyl compared to the use of morphine. Methods: The analysis was carried out by constructing a Markov model that simulates the natural history of a hypothetical cohort of 100 advanced cancer patients: the patients in the case arm of the study are treated with Instanyl, and those in the control arm with morphine. Consistently with the Instanyl treatment indications, the hypothesis was that patients would have a minimum of 1 to a maximum of 4 episodes of BTcP per day, and that administration of Instanyl might cause side effects which influence both cost and quality of life (QoL). Based on the data in the literature, we populated our model considering the probability of the daily frequency of episodes of BTcP and the associated probability of side effects reported in the literature. Quality of life weights were used to differentiate the health status associated to BTcP depending on whether Instanyl or placebo was used. Probabilistic sensitivity analysis was conducted to assess the variability of results associated to the variation of costs, side effects episodes, daily BTcP episodes and BTcP prevalence. Results: The results of our analysis show that the treatment of BTcP with Instanyl costs 8,893 euros with an outcome of 0.63 QALYs, whilst the treatment with morphine costs of 6,431 euros for a QALY of 0.29. These data generate an ICER of 10,140 euros/QALY. Overall, the Cost Effectiveness Acceptability Curve shows that the treatment of BTcP with Instanyl would have an 86% probability of having a cost lower of 30,000 euro/QALY. The results clearly show that Istanyl administration is a good and sustainable investment in health, despite the collateral effects and the short life expectancy of advanced cancer patients.