Updated cost-effectiveness analysis of palivizumab (Synagis) for the prophylaxis of respiratory syncytial virus in infant populations in the UK

Figures & data

Figure 1. High-risk patient populations endorsed by JCVI for palivizumab in existing guidance.³

Figure 2. Structure of model.

Table 1. Clinical and cost inputs of original Bentley et al model and the updated model.

Parameter	Data	Source in original Bentley et al. model	Updated data	Updated sources/notes
Baseline risk of hospitalization (%)
CHD infants	9.7	Feltes, 2003^21	9.7	No update
BPD infants	12.8	IMpact-RSV, 1998^20	12.8	No update
Pre-term:<29 wGA	10	MedImmune/Abbott, Data on File	10.0	Data on file now published, subgroup analysis of IMpact-RSV, Notario, 2014^45
Pre-term: 29–32 wGa	7.7	MedImmune/Abbott, Data on File	7.7	Notario, 2014^45
Pre-term: 33–35 wGa	7.7	MedImmune/Abbott, Data on File	8.2	Notario, 2014^45
Relative risk reduction of RSV hospitalization with palivizumab prophylaxis (%)
CHD infants	45.3	Feltes, 2003^21	45.3	No update
BPD infants	38.5	IMpact-RSV, 1998^20	38.5	No update
Pre-term:<29 wGA	80.4	MedImmune/Abbott, Data on File	80.4	No update Data on file now published, subgroup analysis of IMpact-RSV, Notario, 2014^45
Pre-term: 29–32 wGa	79.7	MedImmune/Abbott, Data on File	79.7	Notario, 2014^45
Pre-term: 33–35 wGa	73.2	MedImmune/Abbott, Data on File	73.2	Notario, 2014^45
Mortality rates of infants hospitalized due to RSV disease (%)
CHD infants	3.72	Wang, 2011^25	2.0	Clinician opinion, confidence intervals from REGAL (RSV Evidence-a Geographical Archive of the Literature) systematic review of 38 studies, Checchia, 2017^54

Table 2. Predicted dose of palivizumab for babies born <29 wGA, aged <6 months of age at the onset of the RSV season (October) and discharged at 36 weeks.

wGA		Birth month/maximum number of doses per baby								Total
		Apr	May	Jun	Jul	Aug	Sep	Oct	Nov
23	Max doses/baby	5	5	5	4	3	2	1	0
	Births	18	18	18	18	18	18	18	18
	Total doses	91	91	91	72	54	36	18	0	453
24	Max doses/baby	5	5	5	4	3	2	1	0
	Births	27	27	27	27	27	27	27	27
	Total doses	136	136	136	108	81	54	27	0	678
25	Max doses/baby	5	5	5	5	4	3	2	0
	Births	29	29	29	29	29	29	29	29
	Total doses	145	145	145	145	116	87	58	0	839
26	Max doses/baby	5	5	5	5	4	3	2	1
	Births	40	40	40	40	40	40	40	40
	Total doses	199	199	199	199	159	119	79	40	1,192
27	Max doses/baby	5	5	5	5	4	3	2	1
	Births	50	50	50	50	50	50	50	50
	Total doses	249	249	249	249	200	150	100	50	1,497
28	Max doses/baby	5	5	5	5	4	3	2	1
	Births	90*	90*	90*	62	62	62	62	62
	Total doses	448	448	448	309	247	185	124	62	2,271
Overall total doses										6,930
Total number of babies										1,814
Mean number of doses										3.81

*These figures are higher than for babies born in July to November since babies born April to June are not eligible for prophylaxis with palivizumab under current JCVI guidance despite having BPD.

Table 3. Summary of results per hundred infants from the base case model.

	Prophylaxis		No prophylaxis		Incremental change		Results
	Costs	QALYs	Costs	QALYs	Costs	QALYs	ICER	INMB
CHD infants	£477,336	2,505	£491,025	2,501	−£13,689	4	−£3,422 Dominant	£112,989
BPD infants	£479,657	2,523	£490,469	2,519	−£10,812	4	−£2,703 Dominant	£122,797
Premature infants without CHD or BPD aged < 6 months at the start of RSV season
<29 wGA	£254,001	2,528	£387,900	2,525	−£133,889	3	−£44,629 Dominant	£221,881
29–32 wGA	£238,551	2,528	£298,385	2,526	−£59,834	2	−£29,917 Dominant	£126,919
33–35 wGA	£263,508	2,528	£318,822	2,526	−£55,314	2	−£27,657 Dominant	£121,124

Table 4. Summary of results per hundred infants, scenario five doses of palivizumab, costs of respiratory sequelae for 2 years and a decrease in utility due to respiratory sequelae for 5 years.

	Prophylaxis		No prophylaxis		Incremental change		Results
	Costs	QALYs	Costs	QALYs	Costs	QALYs	ICER*	INMB
CHD infants	£654,317	2,505	£491,025	2,501	£163,292	4	£49,333	−£63,992
BPD infants	£595,310	2,523	£490,469	2,519	£104,841	4	£28,086	£7,144
Premature infants without CHD or BPD aged < 6 months at the start of RSV season
<29 wGA	£400,318	2,528	£387,900	2,525	£12,418	3	£4,234	£75,564
29–32 wGA	£384,868	2,528	£298,385	2,526	£86,483	2	£38,675	−£19,398
33–35 wGA	£440,489	2,528	£318,822	2,526	£122,667	2	£55,463	−£55,857

*Calculated ICER differs from Cost/QALY due to rounding error.

Table 5. Summary of results per hundred infants, scenario respiratory sequalae (costs and utilities) continue until age 7 years, 3.7 doses of palivizumab.

	Prophylaxis		No prophylaxis		Incremental change		Results
	Costs	QALYs	Costs	QALYs	Costs	QALYs	ICER	INMB
CHD infants	£480,124	2,505	£496,120	2,503	−£15,996	2	−£7,998 Dominant	£98,165
BPD infants	£483,793	2,524	£497,192	2,521	−£13,399	3	−£4,466 Dominant	£106,168
Premature infants without CHD or BPD aged < 6 months at the start of RSV season
<29 wGA	£255,047	2,528	£393,237	2,526	−£138,190	2	−£69,095 Dominant	£194,308
29–32 wGA	£239,385	2,528	£302,490	2,527	−£63,105	1	−£63,105 Dominant	£105,894
33–35 wGA	£264,685	2,528	£323,209	2,527	−£58,524	1	−£58,524 Dominant	£100,499

Table 6. Probability that palivizumab is cost-effective for different CE thresholds.

Subgroup	CE threshold £20,000	CE threshold £30,000
CHD infants	58.36%	68.08%
BPD infants	54.72%	66.04%
Premature infants without CHD or BPD aged < 6 months at the start of RSV season
<29 wGA	72.08%	75.56%
29–32 wGA	54.28%	59.58%
33–35 wGA	49.42%	53.74%

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