Cost-effectiveness analysis of oxycodone with naloxone versus oxycodone alone for the management of moderate-to-severe pain in patients with opioid-induced constipation in Canada

Background:
Approximately 20–30% of Canadians suffer from chronic pain. Guidelines for the management of chronic pain support the use of controlled-release (CR) opioids to treat chronic pain. Although effective in managing chronic pain, oxycodone is associated with high rates of opioid-induced constipation (OIC). The cost-effectiveness of a combination of oxycodone for the management of pain and naloxone for the relief of OIC has not previously been evaluated for Canada.
Methods:
A decision analytic model was developed to estimate the cost-utility of combination oxycodone/naloxone compared to oxycodone alone in four populations. Drug costs for managing pain and healthcare costs related to managing OIC were included in the analysis and the primary measure of effectiveness was quality adjusted life years (QALYs) derived from OIC rates observed in clinical trials. The analysis was conducted from a healthcare system perspective, used a 1-year time horizon, and results were expressed in 2015 Canadian dollars.
Results:
In all four patient populations, there was a trade-off between slightly higher total expected costs for Targin treated patients compared to oxycodone treated patients, but also improved clinical benefits in terms of reduced OIC, which resulted in higher QALYs for patients. Although analgesic costs were found to be slightly higher for Targin treated patients, Targin also resulted in cost offsets to the healthcare system in terms of less rescue laxative drug use and other resources required for the management of OIC. The resulting 1-year cost-utility of Targin compared to oxycodone ranged from $2178–$7732 per QALY gained in the base case analysis, and it was found that these cost-utility results remained robust and at low values throughout a series of one-way deterministic analyses of uncertainty.
Conclusion:
The clinical effectiveness of oxycodone/naloxone in managing pain and OIC compared to CR oxycodone alone resulted in low cost-utility estimates.

研究背景：
约20%~30%的加拿大人遭受慢性疼痛困扰。慢性疼痛管理指南支持使用控释（CR）阿片类药物治疗慢性疼痛。羟考酮虽可有效缓解慢性疼痛，但伴随较高的阿片类药物诱发便秘（OIC）发生率。此前尚未针对加拿大人群评估羟考酮镇痛联合纳洛酮缓解OIC的成本效益。
研究方法：
本研究构建决策分析模型，以评估羟考酮/纳洛酮复方制剂相较于单用羟考酮在四类人群中的成本效用。分析纳入疼痛管理的药物成本及与OIC管理相关的医疗成本，主要疗效指标为从临床试验观察到的OIC发生率推导得到的质量调整生命年（QALYs）。本分析从医疗体系视角出发，采用1年时间跨度，结果以2015年加元计价。
研究结果：
在全部四类患者人群中，与单用羟考酮治疗的患者相比，Targin治疗患者的总预期成本略高于单用羟考酮治疗的患者，但临床获益也有所改善——OIC发生率降低，这使得患者的QALYs更高。尽管Targin治疗患者的镇痛药物成本略高，但Targin同时可通过减少救援性泻药使用及OIC管理所需的其他医疗资源，为医疗体系带来成本节约。基准病例分析显示，Targin相较于单用羟考酮的1年成本效用为每获得1个QALY需2178~7732加元；且在一系列单因素确定性不确定性分析中，该成本效用结果始终稳健且处于较低水平。
研究结论：
相较于单用控释羟考酮，羟考酮/纳洛酮复方在镇痛及缓解OIC方面的临床有效性使其具有较低的成本效用估值。