title: Comparison of amlodipine/valsartan/hydrochlorothiazide single pill combination and free combination: adherence, persistence, healthcare utilization and costs.
abstract: OBJECTIVE
  To determine whether amlodipine/valsartan/hydrochlorothiazide single pill combination (SPC) is associated with improved persistence, adherence and reduced healthcare utilization and costs compared to the corresponding free combination (FC).
  
  
  METHODS
  Adult (≥18 years) patients covered by commercial and Medicare Supplemental insurance in the Truven MarketScan database with hypertension (HTN) diagnosis between October 2009 and December 2011 were included. At least two filled prescriptions for the SPC cohort or two periods of minimum 15 days of concurrent use of amlodipine, valsartan and hydrochlorothiazide (HCT) for the FC cohort were required. Cohorts were propensity score matched (PSM) to balance on important confounders. Outcomes included: 1) adherence (proportion of days covered [PDC] and medication possession ratio [MPR]); 2) persistence (treatment gap >30 days); 3) all-cause and HTN-specific healthcare utilization and costs at 12 months.
  
  
  RESULTS
  After cohort matching with PSM, patients taking SPC (N = 9221) exhibited better outcomes than FC (N = 1884): higher mean adherence (85.7% vs. 77.0%), mean PDC (73.8% vs. 60.6%) and persistence (46.8% vs. 23.6%) (all p < 0.0001). Patients taking SPC were associated with higher odds of persistence (OR: 3.51; 95% CI: 3.08-4.02), MPR ≥80% (OR: 2.72; 95% CI: 2.40-3.08) and PDC ≥80% (OR: 2.88; 95% CI: 2.55-3.26). After PSM, the SPC cohort exhibited statistically significantly lower mean number of resource utilization events compared to FC. Patients in the SPC cohort also had a statistically significantly (p < 0.05) lower percentage of patients with ≥1 all-cause hospitalization (15.0% vs. 18.2%), ≥1 all-cause emergency room (ER) visits (25.7 vs. 31.4%), and ≥1 ER HTN-specific visits (9.7% vs. 14.1%). The costs incurred by SPC cohort patients were 2.8% to 41.7% numerically lower than the FC cohort, statistically significant for all-cause ER costs ($430.6 vs. $549.5, p < 0.05).
  
  
  CONCLUSIONS
  Real-world data indicate an association of the amlodipine/valsartan/HCT SPC with improved adherence and persistence vs. FC with no difference in overall healthcare or hypertension specific costs between the cohorts.
authors.affiliation: a a Janssen Latin America , Buenos Aires , Argentina.
authors.forename: G
authors.initials: G
authors.lastname: Machnicki
authors.affiliation: b b Novartis Pharma AG , Basel , Switzerland.
authors.forename: S H
authors.initials: SH
authors.lastname: Ong
authors.affiliation: c c Novartis Pharma Co. Ltd , Shanghai , China.
authors.forename: W
authors.initials: W
authors.lastname: Chen
authors.affiliation: c c Novartis Pharma Co. Ltd , Shanghai , China.
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Wei
authors.affiliation: d d Novartis Pharmaceuticals Corporation , East Hanover , NJ , USA.
authors.forename: K H
authors.initials: KH
authors.lastname: Kahler
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017311:Amlodipine / Q000008:administration & dosage*; D000959:Antihypertensive Agents / Q000008:administration & dosage*; D015331:Cohort Studies; D004338:Drug Combinations; D005260:Female; D006760:Hospitalization; D006801:Humans; D006852:Hydrochlorothiazide / Q000008:administration & dosage*; D006973:Hypertension / Q000188:drug therapy; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D010342:Patient Acceptance of Health Care; D012189:Retrospective Studies; D000068756:Valsartan / Q000008:administration & dosage*
chemical_list: D000959:Antihypertensive Agents; D004338:Drug Combinations; D006852:Hydrochlorothiazide; D017311:Amlodipine; D000068756:Valsartan
keywords: Adherence; Costs; Healthcare utilization; Hypertension; Persistence; Single pill combination