A cost utilization analysis of intrathecal therapy for refractory cancer pain: identifying factors associated with...

Intrathecal therapy (ITT) for cancer pain is characterized by high initial cost followed by low maintenance costs. Non-ITT pain management is associated with steadily increasing cumulative cost that can equal the cost of ITT over time. The intent of this modeling project is to identify factors associated with relatively rapid achievement of cost-benefit with ITT.

A retrospective chart review was performed on 36 patients with cancer pain who underwent ITT and survived beyond 4 weeks.

Data on the cost of conventional opioid therapy prior to ITT and at 4-6 weeks were collected and projected over time. ITT costs included all intrathecal pump implantation and maintenance costs. Pre-ITT opioid regimens were stratified into high-cost conventional (HCC-high-dose, nongeneric, or use of intravenous patient-controlled analgesia, N = 12) and low-cost conventional (low-dose or generic, N = 24) regimens.

The median daily cost of opioid medications pre-ITT was $21.26 (25th-75th percentile $10.31-78.85, range 0-$971.97) vs $0 (25th-75th percentile $0-0.70), P = 0.007, post-ITT. In the HCC group, the median daily cost was $172.47 (25th-75th percentile $67.29-406.20). The median daily cost of ITT medications was $16.01 (25th-75th percentile $9.52-23.23).When these data were used to model costs over the long term, including pump implantation costs, cost-benefit for all patients compared with conventional therapy was predicted at 344 months but at 7.4 months in the HCC group. Seven patients (19%) achieved cost equivalence within 6 months and three of these within the first 3 months.

In selected patients on high-cost opioid regimens, ITT may become cost-beneficial within 6 months. Factors associated with earlier attainment of ITT cost-benefit include the use of parenteral therapy, high-dose opioids, and the use of nongeneric opioid products.