Cost-effectiveness analysis of colonoscopy for screening colorectal cancer in Indonesia using Markov Model

Colorectal cancer (CRC) is one of the top three diagnosed cancers worldwide and the second leading cause of cancer-related deaths, imposing a significant economic burden. In this context, early detection is crucial for effective management. The primary detection method particularly for high-risk individuals is colonoscopy but screening has not been widely adopted and the participation rate and the colonoscopy screening compliance rate were low. Pharmacoeconomic investigations are essential for evaluating the costs and effectiveness of colonoscopy screening for colorectal cancer. Therefore, this research aimed to conduct a cost-effectiveness analysis using a Markov model for a cohort of 100,000 adults aged 45 to compare the outcomes of screened and unscreened scenarios. The Markov model developed in this study consists of three main stages: the health stage, the colorectal cancer stage, and the death stage. The parameters used in this study include the probabilities at each stage, costs, the sensitivity and specificity of colonoscopy, utilities at each stage, and the discount rate. One-way and probabilistic sensitivity analyses were conducted to address uncertainty. Meanwhile, the Incremental Cost-Effectiveness Ratio (ICER) of screening colonoscopy compared to no screening for adult patients was found to be cost-effective and valued at USD 6,191.15/QALY (Quality-adjusted Life Year). This value was significantly below the Cost-Effectiveness Threshold (CET) assumed to be USD 14,759.10. Based on the cost-effectiveness acceptability curve at a willingness to pay (WTP) threshold of USD 5,500, the probability of being cost-effective for colorectal cancer screening increased and consistently reached 100% at a WTP level of USD 9,000. Colonoscopy screening was cost-effective when analyzed using the Markov model, as suggested by ICER value exceeding three times the Gross Domestic Product (GDP) of Indonesia. Future research could explore alternative interventions, such as biennial colonoscopy, and compare the result with other screening methods.