
Methods: We developed a decisionanalytic Markov model to simulate lifetime costs and survival for 65yearold men with <4cm unilateral renal cell carcinoma. Two treatment strategies were considered: RFA and NSS. The model incorporates tumor presence, treatments, success rates (local control), costs, complications, and outcomes. The impact of changes in treatment effectiveness, cost, and other key parameters on results was addressed by reevaluating outcomes as these parameters were varied. Threshold analysis was performed to determine the annual probability of postRFA local recurrence below which NSS would not be “costeffective” using a $75,000/QALY willingnesstopay threshold.
Results: Under base case assumptions, NSS was more effective and expensive than RFA. NSS had an incremental costeffectiveness ratio of $148,000/QALY relative to RFA, exceeding assumed societal willingness to pay. Below an annual postRFA local recurrence probability of 0.0043 (0.43%), RFA was preferred over NSS at the assumed willingnesstopay threshold. At this recurrence probability, RFA and NSS groups had life expectancies of 9.63 and 9.66 QALYs, and lifetime costs of $116,000 and $119,000, respectively. The annual postNSS local recurrence probability used in the model was 0.0037 (0.37%). Results were robust to changes in most model parameters, but sensitive to NSS and RFA shortterm costs (including number of RFA sessions required for tumor ablation), postNSS local recurrence, and patient age.
Conclusions: RFA is preferred over NSS for treatment of small renal cell carcinoma given an assumed societal willingnesstopay threshold of $75,000/QALY, and provided the annual postRFA local recurrence probability is below 0.0043 (0.43%). Shortterm costs, postNSS recurrence, and patient age also impact the relative costeffectiveness of each strategy.
See more of Poster Session I
See more of The 28th Annual Meeting of the Society for Medical Decision Making (October 1518, 2006)