Economic burden of refractory chronic spontaneous urticaria on Kuwait’s health system

Figures & data

Table 1 Cost analysis

Item	Before use of omalizumab			After use of omalizumab			Budget impact
	Number of units	Unit cost, USD	Total cost, USD	Number of units	Unit cost, USD	Cost of adding omalizumab, USD
Diagnostics
ANA	1,293	1.32	1,707	1,293	1.32	1,707
TSH	1,293	3.3	4,267	1,293	3.3	4,267
FT4	1,293	1.32	1,707	1,293	1.32	1,707
Total IgE	1,293	1.32	1,707	1,293	1.32	1,707
Anti-TPO	1,293	9.9	12,801	1,293	9.9	12,801
ATA	1,293	53.42	69,072	1,293	53.42	69,072
Anti-ENA	1,293	9.9	12,801	1,293	9.9	12,801
Total cost			104,062			104,062	0
Conventional drug therapy
NSAa	1,887,780	0.12	226,534	250,755	0.12	30,091	−196,443
Montelukastb	409,176	0.10	40,918	0	0.10	0	−40,918
Ranitidinec	943,890	0.01	9,439	0	0.01	0	−9,439
Steroidsd	354,760	0.02	7,095	8,600	0.02	172	−6,923
Total cost			283,986			30,263	−253,723
Omalizumab				31,032	495.21	15,367,357	15,367,357
Outpatient visit
Urticaria exacerbationse	77,400	37.97	2,938,878	8,280	37.97	314,392	−2,624,486
Angioedema exacerbationsf	1,792	37.97	68,042	129	37.97	4,898	−63,144
			3,006,920			319,290	−2,687,630
Angioedema ER visitsg	1,406	181.91	255,765	42	181.91	7,640	−248,125
Total cost			3,650,733			15,828,612	+12,177,879

Notes:

a Total tablets before: 1,293 pts ×365 days × four tablets per day =1,887,780; after: (345 pts ×365 days × one tablet/day) + (171 pts ×365 days × two tablets per day) =250,755 tablets;

b total tablets before: 1,121 pts ×365 days × one tablet per day =409,176;

c total tablets before: 1,293 pts ×365 days × two tablets per day =943,890;

d total tablets before: (42 pts × four attacks per year ×40 tablets per attack) + (86 pts × five attacks per year ×40 tablets per attack) + (387 pts × six attacks per year × 40 tablets per attack) + (345 pts × seven attacks per year ×40 tablets per attack) + (345 pts × eight attacks per year ×40 tablets per attack) + (86 pts × nine attacks per year ×40 tablets per attack) =354,760; after: 215 pts × one attack per year ×40 tablets per attack =8,600;

e total visits before: (42 pts × two visits per month ×12 months =1,008) + (603 pts × four visits per month ×12 months = 28,944) + (603 pts × six visits per month ×12 months = 43,416) + (42 pts × eight visits per month ×12 months =4,032) =77,400 visits; after: 345 pts × two visits per month ×12 months =8,280 visits;

f total angioedema visits before: (42 pts × three visits per year =126) + (42 pts × four visits per year =168) + (86 pts × five visits per year =430) + (129 pts × six visits per year =774) + (42 pts × seven visits per year =294) =1,792; after: 129 pts × one visit per year =129;

g total ER visits before: (42 pts × two visits per year =84) + (215 pts × four visits per year =860) + (42 pts × five visits per year =210) + (42 pts × six visits per year =252) =1,406; after: 42 pts × one visit per year =42.

Abbreviations: USD, US dollars; ANA, antinuclear antibody; TSH, thyroid stimulating hormone; FT4, free thyroxine; IgE, immunoglobulin E; TPO, thyroid peroxidase; ATA, anti-thyroglobulin antibody; ENA, extractable nuclear antigen; ER, emergency room; NSA, sedating antihistamine; pts, patients.

Table 2 One-way sensitivity analysis: effect of varying the price of each cost component by ±25% on total costs of treating CSU

Cost component	± Change in total treatment costs, USD
	±25% change in price		±25% change in utilization
	Before	After	Before	After
Omalizumab	NAa	3,840,210	NAa	NAb
Outpatient visits	751,334	79,781	751,334	79,781
Conventional drugs	69,845	7,491	12,220	7,491
ER visits	63,914	1,911	63,914	1,911
Diagnostic tests	26,007	26,007	NAb	NAb

Notes:

a Omalizumab was not used in the “Before” period.

b All patients were given diagnostic testing and, in the “After” period, omalizumab; so it was not relevant to vary utilization of these factors.

Abbreviations: CSU, chronic spontaneous urticaria; USD, US dollars; ER, emergency room; NA, not applicable.