The cost-effectiveness of onabotulinumtoxinA for the prophylaxis of headache in adults with chronic migraine in the UK

Figures & data

Figure 1. Markov-state transition diagram.

Figure 2. Visual representation of transition probabilities: 30% negative stopping rule.

Table 1. Utility values for onabotulinumtoxinA and placebo across health states and patient populations.

Headache days per	OnabotulinumtoxinA			Placebo
28 days	n	Mean	SE	n	Mean	SE
Whole population
0–3	94	0.746	0.004	65	0.724	0.006
4–9	160	0.719	0.002	129	0.658	0.003
10–14	105	0.652	0.003	126	0.62	0.003
15–19	85	0.602	0.004	96	0.568	0.003
20–23	41	0.515	0.006	52	0.558	0.005
24–28	43	0.601	0.007	76	0.479	0.003
1 or more prior prophylactic treatment
0–3	49	0.740	0.000	27	0.678	0.001
4–9	94	0.712	0.000	76	0.645	0.000
10–14	66	0.645	0.000	79	0.590	0.000
15–19	49	0.572	0.000	68	0.563	0.000
20–23	25	0.499	0.002	37	0.575	0.001
24–28	28	0.528	0.001	60	0.474	0.000
3 or more prior prophylactic treatments
0–3	24	0.691	0.028	13	0.669	0.053
4–9	45	0.699	0.018	40	0.638	0.022
10–14	36	0.635	0.024	44	0.565	0.024
15–19	26	0.561	0.028	36	0.550	0.037
20–23	18	0.462	0.054	21	0.597	0.036
24–28	15	0.501	0.054	41	0.461	0.036

All values generated from trial populations using the algorithm in Gillard et al.26

Table 2. Resource use and costs by health state (per 12-week model cycle).

Health state	GP visits		ED visits		Hospitalisation		Triptan usage		Cost per 12-week cycle
	Number	Subtotal	Number	Subtotal	Number	Subtotal	Number	Subtotal
0–3 migraines per 28 days	0.69	£22.08	0.10	£7.73	0.03	£17.51	1.88	£6.30	£53.62
4–9 migraines per 28 days	0.69	£22.08	0.10	£7.73	0.03	£17.51	5.07	£16.98	£64.31
10–14 migraines per 28 days	0.69	£22.08	0.10	£7.73	0.03	£17.51	5.07	£16.98	£64.31
15–19 migraines per 28 days	2.07	£66.24	0.41	£31.71	0.09	£52.53	7.29	£24.42	£174.90
20–23 migraines per 28 days	2.07	£66.24	0.41	£31.71	0.09	£52.53	7.29	£24.42	£174.90
24+ migraines per 28 days	2.07	£66.24	0.41	£31.71	0.09	£52.53	7.29	£24.42	£174.90

GP, general practitioner; ED, emergency department

Table 3. Base case results—disaggregated costs and QALYs.

Costs (discounted)	Drug cost	Administration cost	GP visits	Hospitalisations	A&E visits	Triptan treatments	Total cost
Placebo	–	£634	£371	£294	£165	£166	£1630
OnabotulinumtoxinA	£1314	£807	£327	£259	£141	£149	£2997
Change	£1488	£1488	−£44	−£35	−£24	−£18	£1367
Life years (undiscounted)	0–3 HA per 28 days	4–9 HA per 28 days	10–14 HA per 28 days	15–19 HA per 28 days	20–24 HA per 28 days	24+ HA per 28 days	Total life years
Placebo	0.25	0.46	0.39	0.43	0.24	0.29	2.06
OnabotulinumtoxinA	0.49	0.53	0.32	0.33	0.19	0.19	2.06
Change	0.23	0.08	−0.07	−0.09	−0.05	−0.09	0.00
QALYs (discounted)	0–3 HA per 28 days	4–9 HA per 28 days	10–14 HA per 28 days	15–19 HA per 28 days	20–24 HA per 28 days	24+ HA per 28 days	Total QALYs
Placebo	0.17	0.29	0.24	0.24	0.13	0.13	1.20
OnabotulinumtoxinA	0.35	0.36	0.20	0.19	0.10	0.10	1.30
Change	0.17	0.07	−0.04	−0.05	−0.03	−0.04	0.09
Incremental cost effectiveness ratio							£15,028

GP, General practitioner; A&E, Accident & Emergency; HA, Headaches; QALY, Quality Adjusted Life Year.

Table 4. Base case results and sensitivity analyses.

	Totals		Discounted totals		Incremental costs	Incremental QALYs	ICER
	Costs	QALYs	Costs	QALYs
Base case results (all patients, 30% negative stopping rule)
Placebo	£1680	1.24	£1630	1.20
OnabotulinumtoxinA	£3077	1.34	£2997	1.30	£1367	0.09	£15,028
Secondary analysis: 1 or more prior prophylactic treatments, 30% negative stopping rule
Placebo	£1743	1.20	£1691	1.17
OnabotulinumtoxinA	£3104	1.30	£3024	1.26	£1332	0.09	£14,273
Secondary analysis: 3 or more prior prophylactic treatments, 30% negative stopping rule
Placebo	£1765	1.17	£1712	1.13
OnabotulinumtoxinA	£3070	1.24	£2990	1.21	£1278	0.07	£17,212
No negative stopping rules
Placebo	£1680	1.24	£1630	1.20
OnabotulinumtoxinA	£3596	1.36	£3498	1.31	£1868	0.11	£17,190
0% negative stopping rule (i.e. patients must not deteriorate in the first 2 cycles)
Placebo	£1680	1.24	£1630	1.20
OnabotulinumtoxinA	£3444	1.35	£3351	1.31	£1721	0.10	£16,456
50% negative stopping rule
Placebo	£1680	1.24	£1630	1.20
OnabotulinumtoxinA	£2860	1.32	£2788	1.28	£1158	0.08	£15,127
No positive stopping rule
Placebo	£1680	1.24	£1630	1.20
OnabotulinumtoxinA	£3245	1.34	£3158	1.29	£1527	0.09	£16,967
100% of episodic patients cease treatment
Placebo	£1680	1.24	£1630	1.20
OnabotulinumtoxinA	£2544	1.34	£2488	1.30	£858	0.09	£9141
OnabotulinumtoxinA and placebo utilities the same per health state
Placebo	£1680	1.28	£1630	1.24
OnabotulinumtoxinA	£3077	1.33	£2997	1.29	£1367	0.05	£29,157
Placebo does not impact number of headache days
Placebo	£2211	1.13	£2143	1.09
OnabotulinumtoxinA	£3132	1.32	£3050	1.28	£907	0.18	£4945
Lost workplace productivity costs included
Placebo	£5204	1.24	£5055	1.20
OnabotulinumtoxinA	£6071	1.34	£5912	1.30	£857	0.09	£9422

ICER, incremental cost-effectiveness ratio; QALY, quality-adjusted life year.

Figure 3. Patient distribution over 20-year time horizon, onabotulinumtoxinA and placebo. HA, headache.

Figure 4. Probabilistic sensitivity analysis: cost-effectiveness plane, 5000 simulations. QALY, Quality--adjusted life year.

Gillard PJ, Devine B, Varon SF, et al. Mapping from disease-specific measures to health-state utility values in individuals with migraine. Value Health 2012;15:485-94

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