The cost-effectiveness of somatropin treatment for short children born small for gestational age (SGA) and children with growth hormone deficiency (GHD) in Sweden

Figures & data

Table 1. Patient demographics.

	Patient level data for:
	SGA Mean (SD)	GHD Mean (SD)
Start of treatment
Patient numbers	19	5,491
Chronological age	6.98 (2.24)	10.00 (1.80)
GH dose (mg/kg/day)	0.034 (0.20)*	0.023 (0.20)
Weight (kg)	17.00 (5.10)	28.60 (9.10)
Height (cm)	108.53 (13.19)	NA
Height (SDS)	−3.12 (0.70)	−2.90 (0.80)
End of treatment or near adult height
Chronological age (years)	16.43 (1.19)	15.10 (1.80)
Weight (kg)	48.00 (8.40)	44.40 (8.40)
Height (cm)	167.87 (6.81)	NA
Height (SDS)	−1.14 (0.65)	−1.50 (0.80)

NA, not available.

*Although the licensed dose of somatropin is 0.033 mg/kg/day the average daily dose in the trial was 0.034 mg/kg/day.

Table 2. The increase in patient's weight and age over the course of somatropin treatment¹⁷.

Age	Weight during treatment (kg)Mean (SD)
6	15.20 (0.00)
7	17.00 (5.10)
8	20.50 (6.10)
9	23.80 (7.10)
10	28.60 (9.10)
11	32.80 (10.20)
12	37.90 (10.80)
13	41.10 (9.60)
14	43.60 (10.10)
15	44.40 (8.70)
16	48.00 (8.40)
17	53.70 (8.40)

Table 3. Utility scores associated with height SDS categories¹².

Height SDS group*	Utility score
	Mean	SD
< −3.000	0.687	0.287
−3.000 to −2.501	0.744	0.279
−2.501 to −2.001	0.801	0.261
−2.000 to −1.501	0.819	0.244
−1.500 to −1.001	0.831	0.244
−1.000 to −0.501	0.850	0.234
−0.500 to −0.001	0.864	0.223
0.000 to 0.499	0.881	0.201

*A negative figure represents a height below the mean of the normal population.

Table 4. Variables used in the univariate and probabilistic sensitivity analyses.

Variable	Current value	Lower value	Upper value	Reference
Time of height benefit	2nd year	First year	Benefit achieved over treatment duration	van Pareren, et al 200319
Cost per mg	234 SEK	230 SEK	239 SEK	Source: FASS (Unit cost of Norditropin)30
Discount rate: costs	3.00%	0.00%	5.00%	Swedish Pharmaceutical Benefits Board20
Discount rate: outcomes	3.00%	0.00%	5.00%
Compliance	90.00%	81.00%	100.00%	Lustig 200431
Weight factor	100%	80%	120%	The average weight per patient by age, from the van Pareren et al19 study was used in the model to calculate the appropriate dosage. However, for simplicity all weight values were varied by this factor
Endocrinologist visits – year 1	3.00	0.00	3.00	Bryant et al 200222
Endocrinologist visits – year n	3.00	0.00	3.00
Endocrinologist visits – final year	4.00	0.00	4.00
Cost per endocrinologist visit	2,945 SEK	0 SEK	3,240 SEK	http://www.externt9.lul.se/svn/akademiska09.xls 200929
Start age – SGA	6.98	5.97	7.98	Bannink et al 200716
Start Height (SDS) – SGA	−3.12	−3.43	−2.80
End of treatment age – SGA	16.43	15.89	16.96
Near adult height (SDS) – SGA	−1.14	−1.44	−0.85
Start age – GHD	10.00	9.00	11.00	GHD meta-analysis
Start Height (SDS) – GHD	−2.90	−2.61	−3.19
End of treatment age – GHD	15.10	13.59	16.61
Near adult height (SDS) – GHD	−1.50	−1.35	−1.65
Utility: < 3.000	0.687	0.631	0.742	Christensen et al 200712
Utility: −3.000 to −2.501	0.744	0.701	0.787
Utility: −2.501 to −2.001	0.801	0.775	0.827
Utility: −2.000 to −1.501	0.819	0.802	0.837
Utility: −1.500 to −1.001	0.831	0.817	0.846
Utility: −1.000 to −0.501	0.850	0.838	0.863
Utility: −0.500 to −0.001	0.864	0.853	0.875
Utility: 0.000 to 0.499	0.881	0.870	0.892
Utility: 0.500 to 0.999	0.887	0.874	0.900
Utility: 1.000 to 1.499	0.889	0.873	0.905
Utility: 1.500 to 1.999	0.899	0.877	0.920

Table 5. Base-case results: per-patient costs and benefits associated with somatropin therapy.

	SGA		GHD
	Untreated	Treated	Untreated	Treated
Drug acquisition cost	—	764,357 SEK (892,933 SEK)	—	372,949 SEK (404,050 SEK)
Clinician visit costs	51,750 SEK (58,900 SEK)	79,882 SEK (91,295 SEK)	32,864 SEK (35,340 SEK)	51,837 SEK (55,955 SEK)
Total costs	51,750 SEK (58,900 SEK)	844,240 SEK (984,288 SEK)	32,864 SEK (35,340 SEK)	424,786 SEK (460,005 SEK)
QALYs	21.58 (53.51)	24.88 (61.47)	20.92 (49.62)	24.17 (57.52)
Cost /QALY (compared with untreated)	—	240,831 SEK (116,242 SEK)	—	120,494 SEK (53,733 SEK)

Values presented are discounted. Undiscounted values are presented in parentheses.

Figure 1. A cost-effectiveness acceptability curve (CEAC) for somatropin compared with no treatment, highlighting the probability that somatropin treatment will be cost-effective at the given cost-effectiveness threshold.

Novo Nordisk Limited. GHRETARD/BPD/14-20-21/NL clinical trial. Unpublished data 2007

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Christensen TL, Djurhuus CB, Clayton P, An evaluation of the relationship between adult height and health-related quality of life in the general UK population. Clin Endocrinol 2007;67:407-12.

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