COST-EFFECTIVENESS ANALYSIS OF PLEURX® CATHETER VS. TALC PLEURODESIS FOR THE TREATMENT OF MALIGNANT PLEURAL EFFUSIONS: A MARKOV MODEL

Purpose: To evaluate the cost-effectiveness of treating malignant pleural effusions with the PleurX® indwelling pleural catheter versus talc pleurodesis. 

Method: We developed a Markov, state-transition model encoded as a Markov influence diagram (MID). MIDs are a new type of probabilistic graphical model that allow for an intuitive encoding of complex state-transition Markov models. Due to the short life expectancy of these patients, we used a cycle length of a week and a time horizon of two years. Patients treated with talc spend a week in hospital. PleurX® patients have the catheter placed in an outpatient setting but have to perform drainage of effusions until pleurodesis or death.  If the treatment is successful, pleurodesis is achieved in the first week for talc patients whereas for PleurX® patients, the probability of transition to pleurodesis is modeled with a Weibull distribution (median: 10 weeks). Treatment complications considered include infection and death. Death for causes other than treatment was also modeled through a Weibull distribution whose median was the life expectancy. Costs were obtained from Medicare reimbursement data whereas probabilities and utilities were obtained from the literature. In the base case we assumed a life expectancy of 6 months and for PleurX® patients, drainage sessions twice a week in the first four weeks and once a week thereafter with the assistance of a nurse for 50% of the patients. We also performed several one-way sensitivity analyses.

Result: Treatment with PleurX® is slightly more effective in the base case but not cost-effective (ICER = $101,914/QALY). However, it is cost-effective for patients whose life expectancy is 13 weeks (ICER = $49,272/QALY) or shorter, or if nurse visits are excluded. On the other hand, PleurX® is not cost-effective for higher frequencies of drainage sessions or if all patients receive nurse visits. Talc dominates PleurX® if the latter offers a quality of life lower than 0.553 during treatment.

Conclusion: The cost-effectiveness of PleurX® is strongly dependent on the expected survival of the patient, as well as on the ability and willingness of the patient to perform effusion drainage without the assistance of a nurse. A more precise measurement of the quality of life of patients with PleurX® would reduce significantly the uncertainty of these conclusions.