Cost-effectiveness of denosumab for high-risk postmenopausal women with osteoporosis in Thailand

Figures & data

Figure 1. Structure of Markov cohort model.

Table 1. Fracture incidence per patient-year in Thailand.

Age	Fracture type
	Hip	Vertebral	Wrist
50	0.0003	0.0274	0.0018
55	0.0003	0.0274	0.0032
60	0.0008	0.0373	0.0033
65	0.0015	0.0373	0.0034
70	0.0039	0.0461	0.0036
75	0.0079	0.0461	0.0033
80	0.0124	0.0461	0.0038
>85	0.0141	0.0461	0.0042

Sources: Jitapunkul et al., Wongtriratanachai et al. and Health Intervention Technology Assessment Program (HITAP) Ministry of Public Health [7,44,46].

Table 2. Summary of costs.

Direct fracture-related medical costs
Type of fracture	Cost (THB)	Source
First year of fracture
Hip	54,245	[51]
Vertebral	38,305	[51]
Wrist	28,885	[52]
Second and subsequent years
Hip	1,756	Calculated based on expert’s opinion
Vertebral	1,756	Calculated based on expert’s opinion
Cost item	Unit cost (THB)	Source
DXA scan	2000	[52]
Physician visit	314	[45,52]
IV injection	32	[45,53]
Nurse visit	0	[43,44]
Direct non-medical	2,929	[25]
Informal care	72,150	[24]
Denosumab, annual cost	25,550	[54]
Alendronate, annual cost	4,570	[54]

Abbreviations. DXA, dual energy x-ray absorptiometry; IV, intravenous; THB, Thai Baht. Costs expressed in 2018 values.

Table 3. Summary of utility estimates.

Age	Utility	Source
50	0.94	[28]
60	0.91	[28]
70	0.91	[28]
80	0.88	[28]
Fracture type/period	Utility estimate	Source
First year after fracture
Hip fracture	0.797	[29]
Clinical vertebral fracture	0.720	[29]
Wrist fracture	0.956	[27]
Second and following years after fracture^a
Hip fracture	0.899	[29]
Clinical vertebral fracture	0.931	[29]

^aWrist fractures were assumed to only have an impact on quality of life during the first year.

Table 4. Treatment efficacy: relative risk of fracture (treatment versus placebo).

	Hip fractures RR (95% CI)	Vertebral fractures RR (95% CI)	Wrist fractures RR (95% CI)
Alendronate	0.65 (0.41–1.03)	0.56 (0.46–0.69)	0.81 (0.37–1.80)
Denosumab	0.61 (0.37–0.98)	0.33 (0.26–0.41)	0.84 (0.64–1.11)

Source: random effects meta-analysis [30].

Table 5. Treatment persistence estimates.

Treatment	Time (in months)						Source
	6	12	18	24	36	60
Denosumab	1.00	0.78 [0.73; 0.81]	0.68 [0.65; 0.70]	0.57 [0.52; 0.63]	NA	NA	[55]
Alendronate	0.53 [0.52; 0.53]	0.41 [0.41; 0.42]	NA	NA	0.25 [0.24; 0.25]	0.17 [0.17; 0.17]	[54]

Abbreviation. NA, not available.

Table 6. Costs and fracture results for base-case model^a.

	Denosumab	No pharmacologic treatment	Alendronate	Denosumab versus no pharmacologic treatment	Denosumab versus alendronate
Direct fracture-related medical cost (THB)	93,039	104,894	99,430	−11,856	−6,391
Hospitalization cost	24,693	28,666	26,953	−3,973	−2,260
Long- term care cost	26,301	27,419	26,585	−1,118	−284
Outpatient cost	42,045	48,810	45,892	−6,765	−3,848
Direct fracture-related non- medical and informal care costs (THB)	55,233	64,531	60,502	−9,298	−5,269
Intervention cost (THB)	64,424	0	10,171	64,424	54,252
Drug cost	59,187	0	6,810	59,187	52,378
Treatment management	5,236	0	3,362	5,236	1,875
10-year fracture incidence per 10,000
Hip fractures	0.10	0.11	0.10	−0.009	−0.003
Vertebral fractures	1.07	1.39	1.25	−0.317	−0.181
Wrist fractures	0.03	0.03	0.03	0.005	0.004

Costs expressed in 2018 values.

^aPostmenopausal women age ≥65 years with a femoral neck T-score of ≤−2.5 and history of vertebral fracture.

Table 7. Costs and fracture results for scenario model: total PMO population^a.

	Denosumab	No pharmacologic treatment	Alendronate	Denosumab versus no pharmacologic treatment	Denosumab versus alendronate
Direct fracture-related medical cost (THB)	83,585	91,715	87,991	−8,130	−4,406
Hospitalization cost	22,255	25,074	23,853	−2,819	−1,598
Long-term care cost	23,438	23,948	23,524	−510	−86
Outpatient cost	37,893	42,693	40,614	−4,801	−2,722
Direct fracture-related non-medical and informal care costs (THB)	48,553	54,776	52,051	−6,213	−3,498
Intervention cost (THB)	64,492	0	10,191	64,492	54,301
Drug cost	59,250	0	6,823	59,250	52,427
Treatment management	5,242	0	3,368	5,242	1,874
10-year fracture incidence per 10,000
Hip fractures	0.04	0.05	0.05	−0.005	−0.002
Vertebral fractures	0.75	0.96	0.87	−0.215	−0.122
Wrist fractures	0.04	0.03	0.03	0.003	0.003

Costs expressed in 2018 values.

^aPostmenopausal women with osteoporosis age 60 years or older with a femoral neck T-score of ≤−2.5 and a 23.6% prevalence of vertebral fracture.

Table 8. Incremental cost-effectiveness estimate.

	Denosumab	No treatment	Alendronate	Denosumab versus no pharmacologic treatment	Denosumab versus alendronate
Population: age ≥65 years, T-score ≤−2.5, and with history of vertebral fracture
Total cost	212,695	169,425	170,103	43,270	42,592
LY	14.49	14.07	14.24	0.415	0.248
QALY	9.523	9.161	9.309	0.362	0.214
Cost/ LY	–	–	–	152,674	252,557
Cost/ QALY				119,575	199,186
Population: age ≥60 years, T-score ≤−2.5, and with 23.6% vertebral fracture prevalence
Total cost	196,630	146,481	150,234	50,149	46,396
LY	13.122	12.859	12.968	0.263	0.154
QALY	11.268	10.942	11.078	0.326	0.190
Cost/ LY	–	–	–	190,721	301,290
Cost/ QALY	–	–	–	153,879	243,983

Abbreviations. LY, Life years; QALY, quality-adjusted life years.

Figure 2. Probabilistic sensitivity analysis: (a) denosumab vs. alendronate and no pharmacologic treatment in high-risk patients: (b) denosumab vs. no pharmacologic treatment in high-risk patients. Abbreviation. WTP: willingness to pay. Postmenopausal women age ≥ 65 years with a femoral neck T-score of ≤−2.5 and history of vertebral fracture.

Figure 3. One-way sensitivity analysis: (a) denosumab vs. no pharmacological treatment in high-risk patients: (b) denosumab vs. alendronate in high-risk patients.

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