Cost-Effectiveness and Cost–Utility Analyses in Thailand of Continuous Intrathecal Morphine Infusion Compared with Conventional Therapy in Cancer Pain: A 10-year Multicenter Retrospective Study

Figures & data

Figure 1. Decision tree.

Improvement = pain reduction (reduce NRS), increasing functional scale (increase PPS), and quality of life (increase EQ-5D score).

Figure 2. Patient flowchart.

Table 1. Demographic data (n = 20).

Age (mean ± SD)	60.10 ± 15 years
Male: female; n (%)	10 (50):10 (50)
Body mass index (kg/m^2; mean ± SD)	21.07 (±4.38)
Type of cancer; n (%)
Gastrointestinal tract	4 (20)
Gynecological	4 (20)
Hepatobiliary	3 (15)
Lung	2 (10)
Urological	2 (10)
Other (e.g., nasal cavity, liposarcoma, chordoma, osteosarcoma)	5 (25)
Type of pain; n (%)
Nociceptive pain	7 (35)
Neuropathic pain	1 (5)
Mixed pain	12 (60)
Reasons for ITDD therapy implantation; n (%)
Inadequate pain control with conventional pain therapy	16 (80)
Intolerance of the conventional pain therapy secondary to side effects	1 (5)
Inadequate pain control and intolerable side effects	3 (15)
Type of ITDD therapy; n (%)
IT percutaneous port	15 (75)
IT programmable pump	5 (25)
Opioid consumption 1 day pre-ITDD therapy (mg MEDD), median (IQR)
IT percutaneous port	140.00 (183–115)
IT programmable pump	160 (168–128)
Survival time after ITDD implantation (days), median (IQR)
IT percutaneous port	85 (111–55)
IT programmable pump	71 (555–53)
Average	78 (121–54)

Table 2. Clinical outcomes.

			Total opioid consumption (mg MEDD), median (IQR)
Time	NRS (0–10), median (IQR)	PPS (0–100%), median (IQR)	IT port	IT pump
Pre-ITDD therapy
1 month (n = 20)	8 (8.25–7.75)	40 (50.00–30.00)	120.00 (164.00–97.5)	160.00 (168.00–130.00)
1 day (n = 20)	8 (8.50–7.00)	30 (40.00–20.00)	140.00 (183.40–115.00)	160.00 (168.00–128.00)
Post-ITDD therapy
1 month (n = 17)	5 (5.00–4.00)**	30 (40.00–30.00)	180.00 (265.20–108.00)	266.15 (331.65–213.45)
2 month (n = 15)	4 (5.00–3.50)**	30 (40.00–25.00)	213.00 (332.81–135.00)	312.30 (376.15–231.15)
3 month (n = 8)	4 (5.25–2.75)*	30 (42.50–20.00)	289.50 (358.50–233.25)	396.09 (437.99–354.20)
4 month (n = 7)	5 (6.50–3.00)*	20 (40.00–20.00)	324.00 (480.00–216.00)	396.09 (437.99–354.20)
5 month (n = 4)	3.5 (5.25–1.75)	40 (52.50–27.50)	759.00 (895.50–622.50)	396.09 (437.99–354.20)
6 month (n = 4)	4 (5.25–2.50)	35 (52.50–20.00)	765.00 (895.50–634.50)	396.15 (438.08–354.23)
7 month (n = 3)	3 (4.00–2.00)	50 (55.00–35.00)	1,092.00 (one patient)	396.15 (438.08–354.23)
8 month (n = 3)	1 (3.00–0.50)	50 (55.00–30.00)	1,182.00 (one patient)	345.00 (412.50–277.50)
9 month (n = 2)	2.5 (1.25–3.75)	55 (57.50–52.50)	(All patients receiving IT port therapy died)	345.00 (412.50–277.50)
10 month (n = 2)	2.5 (1.25–3.75)	55 (57.50–52.50)		345.00 (412.50–277.50)
11 month (n = 2)	2.5 (1.25–3.75)	55 (57.50–52.50)		345.00 (412.50–277.50)
12 month (n = 2)	4 (6.00–2.00)	50 (50.00–50.00)		380.00 (465.00–295.00)

Repeated measures analyses performed only through 4 months due to more than two-thirds missing data thereafter.

*P < .05 compared with pretreatment; **P < .01 compared with pretreatment.

Figure 3. Graph depicting median opioid consumption among patients receiving ITDD therapy.

Opioid consumption includes all routes of administration. The blue line represents the total opioid consumption of the ITDD therapy group; the median rate of increase was 1.88% per month.

Table 3. Lifetime costs of treatment: Conventional therapy vs. ITDD therapy (n = 15) after 2 months.

Costs, median (IQR)	Conventional therapy (pre-ITDD therapy)	Post-ITDD therapy
		IT port (n = 12)	IT pump (n = 3)
1. Direct medical costs (IT and non-IT medication cost)
1.1 Daily medication cost/day (US$)	6.50 (15.05–3.89)	7.43 (9.04–4.64)	1.97 (3.32–0.54)
(CA$)	8.91 (20.62–5.33)	10.18 (12.38–6.36)	2.70 (4.55–0.74)
1.2 ITDD costs
1.2.1 Fixed cost
Implantation cost/one time (US$)		2,587.18 (3,305.15–2,540.33)	15,015.24 (15,145.03–14,835.18)
(CA$)		3,544.44 (4,528.06–3,480.25)	20,570.88 (20,748.69–20,324.20)
Implantation cost/day (US$)		86.24 (110.17–84.68)	500.51 (504.83–494.51)
(until death or for 12 months) (CA$)		118.15 (150.93–116.01)	685.67 (685.70–677.48)
1.2.2 Variable costs
Refill medication cost/time (US$)		36.49 (36.60–36.33)	154.15 (154.15–152.27)
(CA$)		49.99 (50.14–49.77)	210.98 (211.19–208.61)
		(Refill 1.5 times/month)	(Refill 1 time/month)
Maintenance cost/day (US$)		1.22 (1.22–1.21)	5.14 (5.14–5.08)
(until death or for 12 months) (CA$)		1.67 (1.67–1.66)	7.04 (7.04–6.96)
2. Direct nonmedical costs
Cost of one OPD visit (US$)	18.18 (73.17–11.70)	16.79 (73.17–11.41)	9.20 (52.92–2.30)
(CA$)	24.91 (100.24–16.02)	23.00 (100.24–15.63)	12.60 (72.50–3.15)
Number of visits per month	1	1.5	1
Lifetime cost/day (US$)	0.60 (2.44–0.39)	0.84 (3.66–0.57)	0.31 (1.76–0.08)
(until death or for 12 months) (CA$)	0.82 (3.34–0.53)	1.15 (5.01–0.78)	0.42 (2.41–0.11)
3. Indirect costs
Cost of one OPD visit (US$)	0.00 (2.30–0.00)	0.00 (7.60–0.00)	0.00 (6.90–0.00)
(CA$)	0.00 (3.12–0.00)	0.00 (10.41–0.00)	0.00 (9.45–0.00)
Lifetime cost/day (US$)	0.00 (0.08–0.00)	0.00 (0.38–0.00)	0.00 (0.23–0.00)
(until death or for 12 months) (CA$)	0.00 (0.11–0.00)	0.00 (0.52–0.00)	0.00 (0.32–0.00)
Total lifetime costs/day (US$/day)	7.10	95.73	507.93
(CA$/day)	9.72	131.15	695.86

U.S. dollars in bold. ITDD implantation costs = cost of equipment (IT port with infusion pump/IT pump) and facility fees; ITDD maintenance cost = cost of refill kits and refill procedure fees; direct nonmedical costs = cost of caregivers, transportation, and meals; indirect costs = cost of patient productivity loss and caregiver productivity loss.

Figure 4. The accumulation of total costs.

The orange and blue lines represent the accumulated total costs per patient of the IT programmable pump and IT percutaneous port therapy groups, respectively. The IT therapy depiction was stopped at 8 months because all patients died. The yellow line represents the projected accumulated total costs for a conventional therapy group assuming patients had remained on their pre-ITDD analgesic regimen with projected increases by 1.88% per month, which was the actual dose increase in the ITDD group.

Table 4. Cost-effectiveness and cost–utility analyses at 2 months after ITDD therapy.

	Cost US$ (CA$)
		ITDD therapy
Outcomes	Conventional therapy	IT port (n = 12)	IT pump (n = 3)	Average (IT port and pump)
Lifetime cost per patient; US$	623.72	3789.93	16,437.78	9942.53
(CA$)	(854.50)	(5192.20)	(22,519.76)	(13,621.27)
Cost-effectiveness analysis (n = 15)
Outcomes
NRS reduction	0.00	3.67	6.00	4.13
PPS change	0.00	–10.00	26.67	–2.67
Cost-effectiveness ratio
Expressed per 1-point NRS reduction (US$)		1032.68	2739.63	2407.39
(CA$)		(1414.77)	(3753.29)	(3298.12)
Expressed per 1-point PPS change (US$)		−378.99	616.34	−3723.79
(CA$)		(−519.22)	(844.39)	(−5101.59)
ICER (compared with conventional therapy)
Expressed per 1-point NRS reduction (US$)		862.73	2635.68	2256.37
(CA$)		(1181.94)	(3610.88)	(3091.23)
Expressed per 1-point PPS change (US$)		−316.62	592.95	−3490.19
(CA$)		(−433.77)	(812.34)	(−4781.56)
Cost–utility analysis (n = 10; 9 in IT port group and 1 in IT pump group)
Utility score	0.09	0.23	0.54 (one patient)
QALD per patient	15.77	26.65	397.55
ICER (compared with conventional therapy), 1 QALD gained (US$)		259.19	39.24
(CA$)		(355.09)	(53.76)
QALY per patient	0.04	0.07	1.09
ICER (compared with conventional therapy), 1 QALY gained (US$)(CA$)		93,999.31^a (128,779.06^a)	14,269.95^a (19,549.83^a)

U.S. dollars in bold. ITDD = intrathecal drug delivery.

^aCost–utility thresholds for willingness to pay in Thailand = 160,000 Thai baht/QALY gained = US$4848 (CA$6400)/QALY gained. Negative values for cost-effectiveness ratios and ICER indicate poorer outcomes.