Healthcare resource utilization associated with ivacaftor use in patients with cystic fibrosis

Figures & data

Figure 1. CONSORT diagram showing patient selection. IP, inpatient; OP, outpatient; CF, cystic fibrosis.

Table 1. Baseline demographic characteristics.

Demographic characteristic	n = 79
Age, mean (SD)	20.8 (11.8)
Age group, n (%)
6–11	19 (24.1)
12–17	22 (27.8)
18–34	27 (34.2)
35–54	11 (13.9)
55+	— (0.0)
Female, n (%)	43 (54.4)
Health plan type, n (%)
Health maintenance organization (HMO)	12 (15.2)
Preferred provider organization (PPO)	48 (60.8)
Point of service (including ‘with capitation’) (POS)	8 (10.1)
Other/unknown*	11 (13.9)
Geographic region, n (%)
Northeast	29 (36.7)
North Central	20 (25.3)
South	13 (16.5)
West	16 (20.3)
Unknown/missing data	1 (1.3)

SD, standard deviation.

* Includes patients insured under exclusive provider organizations, consumer-driven health plans, high-deductible health plans, and those with unknown or missing data.

Table 2. Clinical characteristics and medications within the 12-month pre-index period.

Clinical characteristic	n = 79
Respiratory diagnosis,* n (%)
Aspergillosis	3 (3.8)
Asthma	17 (21.5)
Bronchiectasis	17 (21.5)
Cough	19 (24.1)
Nasal polyp	4 (5.1)
Pulmonary infection	22 (27.8)
Pseudomonas	11 (13.9)
Non-Pseudomonas	20 (25.3)
Sinusitis	28 (35.4)
GI/hepatic diagnosis,* n (%)
Biliary tract disorder	1 (1.3)
GERD	14 (17.7)
Intestinal obstruction	2 (2.5)
Malabsorption	15 (19.0)
Nausea/vomiting	3 (3.8)
Pancreatitis	1 (1.3)
Pancreatic insufficiency†	66 (83.5)
Other diagnosis,* n (%)
Depression	1 (1.3)
Diabetes, type I	5 (6.3)
Diabetes, type II	8 (10.1)
Hypertension	2 (3.5)
Renal insufficiency	1 (1.3)
Medication,‡ n (%)
Airway clearance	61 (77.2)
Anti-allergy	15 (19.0)
Anti-asthma	66 (83.5)
Antibiotic	75 (94.9)
Anti-depressant/anti-anxiety	5 (6.3)
Anti-inflammatory	8 (10.1)
Birth control	6 (7.6)
Endocrine	12 (15.2)
Pancreatic enzymes	66 (83.5)
Gastrointestinal	39 (49.4)
Nutrition	21 (26.6)
Pain relief	8 (10.1)
Dornase alfa	58 (73.4)
Tobramycin inhalation solution	34 (43.0)
Other	10 (12.6)

GI, gastrointestinal; GERD, gastroesophageal reflux disease; NDC, National Drug Code.

* Clinical characteristics as identified by primary or secondary ICD-9 diagnosis code on any claim generated during the pre-index period.

† Reported based on prescription claims for pancreatic enzymes during the pre-index period.

‡ Medications as identified by a NDC code on any claim generated during the pre-index period.

Table 3. Healthcare resource utilization.

Healthcare resource utilization	Pre-index	Post-index	p-value
Patients with an all-cause inpatient admission, n (%)	26 (32.9)	13 (16.5)	0.021
Number of admissions among all patients, mean (SD)	0.5 (1.0)	0.3 (0.9)	0.055
Number of admissions among patients with an admission, mean (SD)	1.6 (1.1)	1.9 (1.4)	0.175
Average total hospital days per patient, mean (SD)	13.1 (17.9)	12.8 (14.8)	0.846
Patients with inpatient admissions with admitting diagnosis of CF, n (%)	15 (19.0)	5 (6.3)	0.041
Number of admissions among all patients, mean (SD)	0.3 (0.7)	0.1 (0.3)	0.017
Number of admissions among patients with an admission, mean (SD)	1.6 (0.9)	1.2 (0.4)	—**
Average total hospital days per patient, mean (SD)	13.8 (14.2)	7.8 (5.2)	—**
Number of all-cause outpatient claims per patient, mean (SD)	52.8 (68.6)	47.5 (68.9)	0.155
Number of all-cause outpatient office visits per patient, mean (SD)	8.8 (7.3)	8.2 (7.2)	0.266
Number of CF-related outpatient claims per patient*, mean (SD)	36.1 (46.3)	31.5 (48.9)	0.124
Number of CF-related outpatient office visits, mean (SD)	5.4 (3.9)	4.7 (4.2)	0.111
Number of pulmonary function tests per patient, n (%)	75 (94.9)	74 (93.7)	1.000

SD, standard deviation; CF, cystic fibrosis.

* All outpatient services include physician office and other visits, as well as services such as laboratory and radiology (i.e. all outpatient services excluding emergency room visits).

** No patient with a pre-index admission had a post-index admission and visa versa.

Table 4. Ivacaftor treatment characteristics during the post-index period.

Treatment characteristics	n = 79
Number of ivacaftor claims per patient, mean (SD)	8.8 (3.6)
MPR,* mean (SD)	0.8 (0.3)
Patients with single-month supply claims,† mean (SD)	0.8 (0.3)
Patients with multi-month supply claims,‡ mean (SD)	0.9 (0.2)
MPR >0.80, n (%)	58 (73.4)

SD, standard deviation; MPR, medication possession ratio.

* MPR was calculated as the sum of the day’s supply as listed on each adjudicated ivacaftor claim divided by the total number of days in the post index period (365).

† n = 63 for patients with average day’s supply between 28–35.

‡ n = 16 for patients with average day’s supply between 51–90.

Figure 2. Medication possession ratio by deciles. MPR, medication possession ratio; total days supplied from all ivacaftor refills divided by 365 days of the post-index period.