Fluticasone propionate-salmeterol versus inhaled corticosteroids plus montelukast: outcomes study in pediatric patients with asthma

Figures & data

Table 1 Demographic and clinical characteristics of study sample at baseline

	Fluticasone propionate-salmeterol (n = 2231)		ICS + montelukast (n = 770)		Total (n = 3001)
Demographics
Age, year, mean (SD)	8.7a	(1.9)	6.2	(2.1)	8.0	(2.2)
Female (n, %)	871	39.0%	301	39.1%	1172	39.1%
Comorbidity
Charlson index in pre-index period (mean, SD)	1.1	(0.6)	1.2	(0.8)	1.1	(0.7)
Concomitant AR	991	44.4%	368	47.8%	1359	45.3%
Number of classes of AR medicationsb (mean, SD)	1.1	(0.9)	1.1	(0.9)	1.1	(0.9)
Asthma severity in pre-index period
Presence of SABA use, n (%)	1330	59.6%	487	63.3%	1817	60.6%
Number of SABA canisters, mean (SD)	1.4	(1.7)	0.7	(1.1)	1.3	(1.6)
Presence of OCS use, n (%)	482a	21.6%	312	40.5%	794	26.5%
Number of OCS prescriptions, mean (SD)	1.5	(0.9)	1.7	(1.1)	1.6	(1.0)
Presence of ICS use, n (%)	120a	5.4%	115	14.9%	235	7.8%
Number of ICS canisters, mean (SD)	2.1	(1.8)	2.7	(2.3)	2.4	(2.1)
Patients with respiratory-related hospitalization or ED, n (%)	266a	11.9%	174	22.6%	440	14.7%
Number of hospitalizations/ED visits for respiratory-related conditions, mean (SD)	0.2	(0.5)	0.3	(0.7)	0.2	(0.5)
Total medical costs for respiratory-related conditions, mean (SD)	$992a	($4291)	$1785	($4919)	$1196	($4473)
Pharmacy costs for asthma medications, mean (SD)	$90a	($186)	$194	($418)	$117	($269)

Notes:

a P < 0.05 when compared with ICS + montelukast; based on Chi-square test or t-test;

b mean computed among those with a diagnosis of allergic rhinitis.

Abbreviations: AR, allergic rhinitis; ED, emergency department; ICS, inhaled corticosteroid; OCS, oral corticosteroid; SABA, short-acting beta agonist; SD, standard deviation.

Table 2 Demographic and clinical characteristics of matched study sample at baseline

Characteristics	Fluticasone propionate-salmeterol (n = 747)		ICS + montelukast (n = 747)		Total (n = 1494)
Demographics
Age, years, mean, (SD)	8.5a	(1.9)	6.2	(2.1)	7.4	(2.3)
Female, n (%)	293	39.2%	292	39.1%	585	39.2%
Comorbidity
Charlson index in pre-index period, mean (SD)	1.1	(0.6)	1.2	(0.8)	1.1	(0.7)
Concomitant AR	314a	42.0%	358	47.9%	672	45.0%
Number of classes of AR medicationsb (mean, SD)	0.8	(0.8)	0.8	(0.9)	0.8	(0.9)
Asthma severity in pre-index period
Presence of SABA use, n (%)	502	67.2%	466	62.4%	968	64.8%
Number of SABA canisters, mean (SD)	1.0	(1.5)	0.4	(0.9)	0.7	(1.3)
Presence of OCS use, n (%)	289	38.7%	289	38.7%	578	38.7%
Number of OCS prescriptions, mean (SD)	0.6	(0.9)	0.7	(1.1)	0.6	(1.0)
Presence of ICS use, n (%)	92	12.3%	92	12.3%	184	12.3%
Number of ICS canisters, mean (SD)	0.3	(1.0)	0.3	(1.2)	0.3	(1.1)
Patients with respiratory-related hospitalization or ER, n (%)	165	22.1%	165	22.1%	330	22.1%
Number of hospital/ED visits for respiratory-related conditions, mean (SD)	0.3	(0.6)	0.3	(0.7)	0.3	(0.7)
Total medical costs for respiratory-related conditions, mean (SD)	$1522	($4993)	$1757	($4937)	$1640	($4965)
Pharmacy costs for asthma medications, mean (SD)	$140	($254)	$169	($363)	$155	($314)

Notes:

a P < 0.05 when compared with ICS + montelukast;

b mean computed among those with a diagnosis of allergic rhinitis.

Abbreviations: AR, allergic rhinitis; ED, emergency department; ICS, inhaled corticosteroid; OCS, oral corticosteroid; SABA, short-acting beta agonist; SD, standard deviation.

Figure 1 Time to first asthma related hospitalization for each cohort over the follow-up period.

Abbreviation: ICS, inhaled corticosteroid.

Figure 2 Time to first combined asthma related hospitalization or emergency room visit for each cohort over the follow-up period.

Abbreviations: ICS, inhaled corticosteroid; ER, emergency room.

Table 3 Adjusted average asthma-related monthly costs

Outcome, mean (95% CI)	Fluticasone propionate-salmeterol (n = 747)	ICS + montelukast (n = 747)	Difference (CI difference)*
Total	$165 ($61, $467)	$316 ($129, $814)	$151 ($67, $346)
Medical	$57 ($1, $1232)	$121 ($4, $1980)	$64 ($3, $748)

Notes:

* P < 0.05 based on a gamma-distributed generalized linear model with a log-link function controlling for patient age, Charlson comorbidity index, geographic location, gender, presence of allergic rhinitis, number of canisters of inhaled short-acting beta-agonists, oral corticosteroid prescription count, ICS prescription count, and number of hospitalizations/ED visits.

Abbreviations: CI, confidence interval; ICS, inhaled corticosteroid.

Table S1A Results of Cox proportional hazards model: time to asthma-related hospitalization

Variable	HR	95% CI		P value
Fluticasone-salmeterol (1 = yes)	0.039	0.004	0.428	0.0080
Age (continuous)	1.159	0.826	1.625	0.3939
Male (1 = yes)	0.479	0.119	1.930	0.3003
Midwest region* (1 = yes)	4.703	0.502	44.096	0.1752
South region* (1 = yes)	6.467	0.391	106.867	0.1921
Charlson index in pre-index period (continuous)	1.672	1.149	2.432	0.0072
Presence of allergic rhinitis (1 = yes)	1.312	0.329	5.236	0.7002
Number of SABA canisters (continuous)	1.540	1.029	2.305	0.0358
Number of OCS prescriptions (continuous)	1.026	0.644	1.632	0.9153
Number of ICS canisters (continuous)	0.964	0.543	1.710	0.8999
Number of hospital/ED visits for respiratory-related conditions (continuous)	1.640	1.001	2.687	0.0497

Note:

* Reference group, East region.

Abbreviations: ED, emergency department; ICS, inhaled corticosteroid; OCS, oral corticosteroid; SABA, short-acting beta agonist; CI, confidence interval; HR, hazards ratio.

Table S1B Results of Cox proportional hazards model: time to asthma-related hospitalization/emergency department visit

Variable	HR	95% CI		P value
Fluticasone/salmeterol (1 = yes)	0.441	0.225	0.864	0.0169
Age (continuous)	1.050	0.906	1.216	0.5170
Male (1 = yes)	0.707	0.404	1.237	0.2248
Midwest region* (1 = yes)	1.321	0.633	2.755	0.4580
South region* (1 = yes)	1.752	0.647	4.743	0.2700
Charlson index in pre-index period (continuous)	1.294	0.970	1.725	0.0792
Presence of allergic rhinitis (1 = yes)	1.104	0.622	1.962	0.7346
Number of SABA canisters (continuous)	1.210	1.016	1.440	0.0324
Number of OCS prescriptions (continuous)	0.957	0.756	1.212	0.7150
Number of ICS canisters (continuous)	0.884	0.671	1.164	0.3796
Number of hospital/ED visits for respiratory-related conditions (continuous)	1.792	1.421	2.259	<0.0001

Note:

* Reference group, East region.

Abbreviations: ED, emergency department; ICS, inhaled corticosteroid; OCS, oral corticosteroid; SABA, short-acting beta agonist; CI, confidence interval; HR, hazards ratio.

Table S2A Results of cost model: asthma-related total costs

Variable	Parameter estimate	95% CI		P value
Fluticasone-salmeterol (1 = yes)	−0.6474	−0.7401	−0.5546	<0.0001
Age (continuous)	0.0118	−0.0099	0.0335	0.2864
Male (1 = yes)	−0.0392	−0.1213	0.0429	0.3489
Midwest region* (1 = yes)	0.0815	−0.0132	0.1761	0.0917
South region* (1 = yes)	−0.07	−0.2107	0.0707	0.3295
Charlson index in pre-index period (continuous)	0.1703	0.1238	0.2169	<0.0001
Presence of allergic rhinitis (1 = yes)	0.0798	−0.001	0.1606	0.0528
Number of SABA canisters (continuous)	0.0278	−0.0104	0.066	0.1544
Number of OCS prescriptions (continuous)	0.0287	−0.0189	0.0763	0.2377
Number of ICS canisters (continuous)	0.0013	−0.0406	0.0432	0.9525
Number of hospital/ED visits for respiratory-related conditions (continuous)	0.2097	0.1414	0.2779	<0.0001
Respiratory-related medical costs (natural log)	0.0519	0.0311	0.0728	<0.0001
Asthma-related pharmacy costs (natural log)	0.0027	−0.0203	0.0257	0.8185

Note:

* Reference group, East region.

Abbreviations: ED, emergency department; ICS, inhaled corticosteroid; OCS, oral corticosteroid; SABA, short-acting beta agonist; CI, confidence interval; HR, hazards ratio.

Table S2B Results of cost model: asthma-related medical costs

Variable	Parameter estimate	95% CI		P value
Fluticasone-salmeterol (1 = yes)	−0.6675	−0.8566	−0.4783	<0.0001
Age (continuous)	0.0622	0.0170	0.1075	0.0071
Male (1 = yes)	−0.2849	−0.4582	−0.1117	0.0013
Midwest region* (1 = yes)	0.0881	−0.1113	0.2875	0.3864
South region* (1 = yes)	0.0970	−0.2215	0.4155	0.5505
Charlson index in pre-index period (continuous)	0.3038	0.2104	0.3972	<0.0001
Presence of allergic rhinitis (1 = yes)	0.0609	−0.1100	0.2319	0.4849
Number of SABA canisters (continuous)	0.0306	−0.0624	0.1235	0.5192
Number of OCS prescriptions (continuous)	−0.0079	−0.1073	0.0916	0.8767
Number of ICS canisters (continuous)	0.0041	−0.1002	0.1083	0.9388
Number of hospital/ED visits for respiratory-related conditions (continuous)	0.4177	0.2786	0.5568	<0.0001
Respiratory-related medical costs (natural log)	0.1075	0.0632	0.1518	<0.0001
Asthma-related pharmacy costs (natural log)	0.0091	−0.0412	0.0594	0.7227

Note:

* Reference group, East region.

Abbreviations: ED, emergency department; ICS, inhaled corticosteroid; OCS, oral corticosteroid; SABA, short-acting beta agonist; CI, confidence interval; HR, hazards ratio.