Fig. 1Simplified schematic of the structure of the Korean adaptation of economic model. rhTSH, recombinant human thyroid stimulating hormone.
Fig. 2Quality-adjusted life year (QALY) weights as used in the economic model. rhTSH, recombinant human thyroid stimulating hormone.
Table 1Duration of Health States Applied to the Economic Model
Health state |
Exogenously-stimulated (rhTSH) |
Endogenously-stimulated (hypothyroid) |
Pre-ablation |
1 week |
Between 2 and 7 weeks (refer to Table 2) |
Ablation |
1 week |
1 week |
Initial post-ablation period |
4 weeks |
4 weeks |
Second post-ablation period |
4 weeks |
4 weeks |
Patient recovered (well state) |
Remainder of the model (7 weeks per patient) |
Remainder of the model (average 3.6 weeks per patient)a
|
Table 2Distribution of Time Spent between Thyroidectomy and Ablation in the Endogenously-Stimulated Patient Group
Duration of time between thyroidectomy and ablation |
Proportion of patients as estimated by the expert opinion survey, % |
Transition probability used in the model of a patient in the pre-ablation state moving to the ablation state, %a
|
Less than 3 weeksb
|
0 |
0 |
3 weeks |
0.3 |
0.3 |
4 weeks |
72.42 |
72.64 |
5 weeks |
13.64 |
50.00 |
6 weeks |
13.64 |
100 |
Greater than 6 weeksc
|
0 |
100 |
Table 3Duration of Time Spent It the Radioprotective Ward for Endogenously-Stimulated (Recombinant Human Thyroid Stimulating Hormone) Patients
Duration |
Proportion of patients, % |
Expected duration, days |
Less than 1 day |
0 |
- |
2 days |
5.70 |
- |
3 days |
91.30 |
- |
4 days |
3.00 |
- |
5 days |
0 |
- |
Average expected duration |
- |
2.97 |
Table 4Unit Costs Incorporated into the Economic Evaluation
Resource |
Unit cost, ₩ |
Source |
Ablative dose of radioiodine (I131) to treat thyroid cancer (post-thyroidectomy) |
387,890 |
Korean Health Insurance Review Agency (HIRA) |
Whole body scan using radioiodine |
113,680 |
HIRA |
One day of hospitalization (inpatient) for patients receiving radioiodine ablation |
216,550 |
HIRA |
Visit to specialist (radiation oncologist) |
17,400 |
HIRA |
Visit to practice nurse |
1,290 |
HIRA |
Thyroid stimulating hormone quantification test |
19,750 |
HIRA |
Serum thyroglobulin count |
17,200 |
HIRA |
Thyroglobulin antibody test |
14,870 |
HIRA |
Weekly T4 drug cost |
306 |
HIRA, based on 125 µg daily dose at ₩35/100 µg |
Weekly T3 drug cost |
966 |
HIRA, based on 60 µg daily dose at ₩46/20 µg |
Recombinant human thyroid stimulating hormone (2-vial kit of Thyrogen) |
1,219,000 |
Genzyme |
Table 5Costs Applied to Each Treatment Arm
|
Unit cost, ₩ |
Total cost per health state (₩), exogenous stimulated (rhTSH) arm |
Total cost per health state (₩), endogenous stimulated (hypothyroid) arm |
Pre-ablation |
|
|
|
T4 therapy (daily cost) |
44 |
306 |
(-) |
TSH testing (including TSH measurement, thyroglobulin count and antigen test) |
51,820 |
51,820 |
51,820 |
2×Specialist visits |
17,400 |
34,800 |
34,800 |
1×Nurse visit (first rhTSH administration) |
1,290 |
1,290 |
(-) |
1×Nurse visit (second rhTSH administration) |
1,290 |
1,290 |
(-) |
T3 therapy (daily cost) |
138 |
(-) |
1,932 |
1×Specialist visit for hypothyroidism symptom management |
17,400 |
(-) |
261 |
rhTSH (Thyrogen) |
1,219,000 |
1,219,000 |
(-) |
Ablation |
|
|
|
Ablative dose of radioiodine (100 mCi) |
387,890 |
387,890 |
387,890 |
T4 therapy (daily cost) |
44 |
306 |
(-) |
Hospital stay (1.85 days vs. 2.97 days) |
216,550 |
400,617 |
643,153 |
2×Specialist visits |
17,400 |
17,400 |
34,800 |
Whole body scan using radioiodine |
113,680 |
113,680 |
113,680 |
Post-ablation |
|
|
|
T4 therapy (daily cost) |
44 |
2,450 |
2,450 |
Hospital day |
17,400 |
17,400 |
17,400 |
Well |
|
|
|
T4 therapy (daily cost) |
44 |
2,144 |
1,102 |
Total cost over the duration of the model |
- |
2,250,393 |
1,289,288 |
Table 6Base Case Analysis
Parameter |
Exogenously-stimulated (rhTSH) |
Endogenously-stimulated (hypothyroid) |
Incremental difference |
Cost per patient over the course of the model, ₩ |
2,250,393 |
1,289,288 |
961,105 |
QALYs per patient over the course of the model |
0.281 |
0.245 |
0.036 |
ICER, ₩/QALY |
- |
- |
26,697,361 |
Table 7Sensitivity Analysis
Model |
Incremental cost, ₩ |
Incremental QALY |
ICER, ₩/QALY |
Inclusion of indirect costs (i.e., loss of productivity) |
848,173 |
0.036 |
23,560,361 |
Assume no difference in the time spent in the radioprotective ward (i.e., 2.97 days in both arms) |
1,220,736 |
0.036 |
33,909,333 |
Increasing the duration of the pre-ablation health state in the exogenously-stimulated arm to 2 weeks (base case: 1 week) |
977,424 |
0.030 |
32,580,800 |
Reducing the incremental utility difference in the pre-ablation health state by 50% (i.e., increasing the utility of hypothyroidism from 0.548-0.631) |
977,118 |
0.029 |
33,693,724 |