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Erschienen in: BMC Pulmonary Medicine 1/2016

Open Access 01.12.2016 | Research article

Effectiveness of initiating extrafine-particle versus fine-particle inhaled corticosteroids as asthma therapy in the Netherlands

verfasst von: Thys van der Molen, Dirkje S. Postma, Richard J. Martin, Ron M. C. Herings, Jetty A. Overbeek, Victoria Thomas, Cristiana Miglio, Richard Dekhuijzen, Nicolas Roche, Theresa Guilbert, Elliot Israel, Wim van Aalderen, Elizabeth V. Hillyer, Simon van Rysewyk, David B. Price

Erschienen in: BMC Pulmonary Medicine | Ausgabe 1/2016

Abstract

Background

Most randomised clinical trials typically exclude a significant proportion of asthma patients, including those at higher risk of adverse events, with comorbidities, obesity, poor inhaler technique and adherence, or smokers. However, these patients might differentially benefit from extrafine-particle inhaled corticosteroids (ICS). This matched cohort, database study, compared the effectiveness of extrafine-particle with fine-particle ICS in a real-life population initiating ICS therapy in the Netherlands.

Methods

Data were from the PHARMO Database Network, comprising pharmacy and hospital discharge records, representative of 20 % of the Dutch population. The study population included patients aged 12 − 60, with a General Practice-recorded diagnosis for asthma (International Classification of Primary Care code R96), when available, ≥2 prescriptions for asthma therapy at any time in their recorded history, and receiving first prescription of ICS therapy as either extrafine-particle (ciclesonide or hydrofluoroalkane beclomethasone dipropionate [BDP]) or fine-particle ICS (fluticasone propionate or non-extrafine-particle-BDP). Patients were matched (1:1) on relevant demographic and clinical characteristics over 1-year baseline. Primary outcomes were severe exacerbation rates, risk domain asthma control and overall asthma control during the year following first ICS prescription. Secondary outcomes, treatment stability and being prescribed higher versus lower category of short-acting β2 agonists (SABA) dose, were compared over a 1-year outcome period using conditional logistic regression models.

Results

Following matching, 1399 patients were selected in each treatment cohort (median age: 43 years; males: 34 %). Median (interquartile range) initial ICS doses (fluticasone-equivalents in μg) were 160 (160 − 320) for extrafine-particle versus 500 (250 − 500) for fine-particle ICS (p < 0.001). Following adjustment for residual confounders, matched patients prescribed extrafine-particle ICS had significantly lower rates of exacerbations (adjusted rate ratio [95 % CI], 0.59 [0.47–0.73]), and significantly higher odds of achieving asthma control and treatment stability in the year following initiation than those prescribed fine-particle ICS, and this occurred at lower prescribed doses. Patients prescribed extrafine-particle ICS had lower odds of being prescribed higher doses of SABA (0.50 [0.44–0.57]).

Conclusion

In this historical, matched study, extrafine-particle ICS was associated with better odds of asthma control than fine-particle ICS in patients prescribed their first ICS therapy in the Netherlands. Of importance, this was reached at significantly lower prescribed dose.
Hinweise

Electronic supplementary material

The online version of this article (doi:10.​1186/​s12890-016-0234-0) contains supplementary material, which is available to authorized users.
An erratum to this article can be found at http://​dx.​doi.​org/​10.​1186/​s12890-016-0270-9.

Competing interests

Thys van der Molen has received grants for research, travel, and reimbursement for presentations and advisory boards from AstraZeneca, GlaxoSmithKline, Almirall, Mundipharma, Boehringer Ingelheim, Chiesi, Teva Pharmaceuticals Europe B.V., and Novartis.
David B. Price has Board Membership with Aerocrine, Almirall, Amgen, AstraZeneca, Boehringer Ingelheim, Chiesi, Meda, Mundipharma, Napp, Novartis, and Teva Pharmaceuticals Europe B.V. Consultancy: Almirall, Amgen, AstraZeneca, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, Meda, Mundipharma, Napp, Novartis, Pfizer, Teva Pharmaceuticals Europe B.V., and Zentiva. Grants/Grants Pending with UK National Health Service, British Lung Foundation, Aerocrine, AstraZeneca, Boehringer Ingelheim, Chiesi, Eli Lilly, GlaxoSmithKline, Meda, Merck, Mundipharma, Novartis, Orion, Pfizer, Respiratory Effectiveness Group, Takeda, Teva Pharmaceuticals Europe B.V., and Zentiva. Payments for lectures/speaking: Almirall, AstraZeneca, Boehringer Ingelheim, Chiesi, Cipla, GlaxoSmithKline, Kyorin, Meda, Merck, Mundipharma, Novartis, Pfizer, SkyePharma, Takeda, and Teva Pharmaceuticals Europe B.V. Payment for manuscript preparation: Mundipharma and Teva Pharmaceuticals Europe B.V. Patents (planned, pending or issued) with AKL Ltd. Payment for the development of educational materials: GlaxoSmithKline, and Novartis. Stock/Stock options: Shares in AKL Ltd, which produces phytopharmaceuticals. Owns 80 % of Research in Real Life Ltd and its subsidiary social enterprise Optimum Patient Care. Received Payment for travel/accommodations/meeting expenses from: Aerocrine, Boehringer Ingelheim, Mundipharma, Napp, Novartis, and Teva Pharmaceuticals Europe B.V. Funding for patient enrolment or completion of research: Almirral, Chiesi, Teva Pharmaceuticals Europe B.V., and Zentiva. Peer reviewer for grant committees: Medical Research Council (2014), Efficacy and Mechanism Evaluation program (2012), HTA (2014); and received unrestricted funding for investigator-initiated studies from Aerocrine, AKL Ltd, Almirall, Boehringer Ingelheim, Chiesi, Meda, Mundipharma, Napp, Novartis, Orion, Takeda, Teva Pharmaceuticals Europe B.V., and Zentiva.
Ron M.C. Herings and Jetty A. Overbeek are employees of the PHARMO Institute for Drug Outcomes Research. This independent research institute performs financially supported studies for government and related healthcare authorities and several pharmaceutical companies.
Victoria Thomas is an employee of Research in Real-Life (RiRL). Cristiana Miglio is a former employee of Research in Real-Life, Ltd (RiRL). RiRL conducted this study. RiRL has conducted paid research in respiratory disease on behalf of the following other organizations in the past 5 years: Aerocrine, AKL Ltd, Almirall, AstraZeneca, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, Meda, Mundipharma, Napp, Novartis, Orion, Takeda, Teva Pharmaceuticals Europe B.V., and Zentiva, a Sanofi company.
Richard Dekhuijzen has received over the past 3 years’ fees for speaking, education, participation in advisory boards or consulting, from: Almirall, AstraZeneca, Boehringer Ingelheim, Chiesi, Mundipharma, Novartis, Pfizer, Teva Pharmaceuticals Europe B.V., and Zambon. Research grants: AstraZeneca, Boehringer Ingelheim, and Novartis.
Richard J. Martin has conducted consultancy work and/or received travel support and/or honoraria for attendance at advisory boards for: AstraZeneca, MedImmune, Merck, and Teva Pharmaceuticals Europe B.V. Received research grants: MedImmune, and the NHLBI. Received royalties from UpToDate.
The University of Groningen has received money for Dirkje S. Postma regarding an unrestricted educational grant for research from Astra Zeneca, and Chiesi. Travel to ERS and/or ATS has been partially funded by Astra Zeneca, Chiesi, GlaxoSmithKline, and Takeda. Fees for consultancies given to the University of Groningen from: Astra Zeneca, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, Takeda and Teva Pharmaceuticals Europe B.V. Travel and lectures in China paid by Chiesi.
Nicolas Roche has received fees over the past 3 years for speaking, education, and participation in advisory boards or consulting from: 3M, Aerocrine, Almirall, AstraZeneca, Boehringer Ingelheim, Chiesi, Cipla, GlaxoSmithKline, MSDChibret, Mundipharma, Novartis, Pfizer, Sandoz, Sanofi, Stallergenes, Takeda, and Teva Pharmaceuticals Europe B.V. Research grants from: Boehringer Ingelheim, Novartis, and Pfizer.
Theresa Guilbert has received personal fees from the American Board of Pediatrics, GlaxoSmithKline, Merck, and Regeneron Pharmaceuticals, and Sanofi. Pediatric Pulmonary Subboard, grants and personal fees from Teva Pharmaceuticals Europe B.V. Grants: Abbott Laboratories, Array Biopharma, CDC, CF Foundation Therapeutics, CompleWare Corporation, DHHS, F. Hoffman-LaRoche, Forest Research Institute, KaloBios Pharmaceuticals, Medimmune, Mylan, NIH, Roche/Genetech, Roxane Laboratories, and UW-Madison Medical and Education Research Committee, and Vertex Pharmaceuticals. Royalties from UpToDate.
Elliot Israel reports having received speaking fees over the past 3 years’ fees from Merck. Fees for consulting from AstraZeneca and Merck. Non-financial participation in Advisory Boards or consulting for Novartis (as DSMB Member). Research grants from Genentech and NIH. Writing/editorial support for manuscript preparation from RiRL. Travel grant support from RiRL and Teva Pharmaceuticals Europe B.V. Specialty Pharmaceuticals, fees for expert testimony from: Campbell, Campbell, Edwards & Conroy, Ficksman & Conley, Fox Rothschild, LLP, and Ryan Deluca, LLP. Royalties from UpToDate. Deputy Editor for the American Journal of Respiratory and Critical Care Medicine.
Wim van Aalderen is a member of the Medical Advisory Board of AstraZeneca.
Elizabeth V. Hillyer is a consultant to RiRL and has received payment for writing and editorial support to Merck.
Simon van Rysewyk is an employee of the Observational & Pragmatic Research Institute Pte Ltd, and has no competing interests to declare.

Authors’ contributions

All authors were involved in the conception or design of the study; or the acquisition, analysis, or interpretation of study data; and, drafting the study or revising it; and, giving final approval for publication. The authors are responsible for all aspects of this study. DBP led the study design process, which was guided by Steering Committee discussions. The Steering Committee was composed of study authors representing the SASG: RJM, DSP, NR, WvA, RD, and TvdM. CM and VT were responsible for the data acquisition and analyses. SvR wrote the manuscript.
Abkürzungen
EF-HFA-BDP [Qvar®]
extrafine-particle hydrofluoroalkane beclomethasone dipropionate
FP
fluticasone propionate
GERD
gastro-oesophageal reflux disease
ICS
inhaled corticosteroid
LABA
long-acting β2-agonist
LTRA
leukotriene receptor antagonist
N/A
not applicable
Non-EF-BDP
non-extrafine-particle beclomethasone dipropionate
PHARMO
PHARMO Database Network provided by the PHARMO Institute for Drug Outcomes Research (Utrecht, the Netherlands)
SABA
short-acting β2-agonist

Background

Traditional randomized controlled trials (RCT) aim to establish a clear cause-and-effect relationship between an intervention and an outcome. Although asthma RCTs have high internal validity, a problem is that they typically represent fewer than 5 % of patients with a current diagnosis of asthma [1, 2]. Patients at high risk of adverse events, with comorbid conditions such as obesity, rhinitis or smoking, or those with poor inhaler technique and adherence, are typically excluded. Real-life research can help balance the limitations of a RCT design [1]. Using real-life medical information recorded in primary care databases allows assessment of long-term outcomes in broader asthma populations cared for under usual conditions. These populations also include patients with unstable asthma often excluded from RCTs, but routinely seen by clinicians in primary care settings [3].
Traditional inhaler devices for controlling asthma symptoms produce fine particles with a mass median aerodynamic diameter (MMAD) of 2–4 μm; however, some newer pressurized metered dose inhalers (pMDI) using hydrofluoroalkane propellant generate an aerosol of smaller, extrafine-particles with an MMAD <2 μm [4, 5]. RCTs 8–12 weeks in duration have reported that extrafine-particle ICS is equally effective as fine-particle ICS in controlling asthma symptoms [6, 7]. Some patients typically excluded in these studies (see above) might differentially benefit from extrafine-particle ICS [4]. For these reasons, real-life database comparative effectiveness studies may usefully complement traditional RCTs to evaluate whether different properties of extrafine-particle and fine-particle ICS result in different effects in broader clinical populations.
Relevant real-life database studies in the UK and US show matched asthma patients prescribed extrafine-particle hydrofluoroalkane beclomethasone dipropionate (EF-HFA-BDP) for the first time had equivalent or better odds of achieving asthma control over 1 year than patients initiating fluticasone, despite being prescribed lower doses [810]. In contrast to findings from some RCTs [6, 7], these studies suggest that extrafine-particle ICS offers further clinical benefits in asthma control compared with fine-particle ICS therapy in real-life populations. To determine whether this finding can be generalized in other settings with different healthcare systems and possibly different prescribing habits, this real-life database study compared the effectiveness of initiating ICS therapy in patients with asthma in the Netherlands prescribed extrafine-particle ciclesonide or EF-HFA-BDP (Qvar®) versus fine-particle ICS fluticasone propionate or non-extrafine-particle-beclomethasone dipropionate (Non-EF-BDP). In line with previous real-life research [810], it was hypothesized that EF-ICS may be at least as effective as fine-particle ICS therapy.

Methods

Study design and data source

This was a matched cohort, database study, consisting of a baseline and outcome period. The baseline period served for patient characterization and confounder definition and was 1 year before the initiation date of ICS therapy. The outcome period was 1 year following the initiation date for evaluating the effectiveness of ICS therapy. The initiation date was the date when patients received their first prescription of extrafine-particle ICS (either ciclesonide or EF-HFA-BDP), or fine-particle ICS (either fluticasone or Non-EF-BDP). The study period was from January 1998 to December 2012.
An independent steering committee was involved in a priori development of study design, review of analyses and interpretation of results [11]. The study was registered with the European Network of Centres for Pharmacoepidemiology and Pharmacovigilance (ENCePP, study no. 8391), and conducted in accordance with the ENCePP Code of Conduct. The study design is summarized in Additional file 1: Figure S1.
Anonymous data to inform the study objectives were obtained from the PHARMO Database Network provided by the PHARMO Institute for Drug Outcomes Research (Utrecht, the Netherlands). The PHARMO Database Network comprises, among other databases, linked Outpatient Pharmacy, General Practice (GP), Hospitalization and Clinical Laboratory Register databases, and accounts for almost 3 million patients’, representative of 20 % of the Dutch population. The Outpatient Pharmacy database includes the dispensing records of more than 200 community pharmacies and is linked to hospital discharge records. Data from the PHARMO Institute were provided in accordance with Dutch privacy laws.

Study population

The study population included adult patients aged 12–60 years with evidence of asthma, defined as ≥2 prescriptions for asthma therapy at any time in their recorded history, a General Practice-recorded diagnosis for asthma (International Classification of Primary Care [ICPC] code R96), when available, and receiving continuous ICS therapy following the initiation date, defined as ≥2 ICS prescriptions during the outcome period in addition to the first prescription. Patients were excluded from the study if, at any time, they had been diagnosed with any chronic respiratory diseases other than asthma. Patients prescribed long-acting muscarinic antagonists at baseline were not excluded.

Outcomes

The rate of severe asthma exacerbations in the year following ICS therapy initiation, one of three co-primary outcomes, was defined based on the American Thoracic Society/European Respiratory Society (ATS/ERS) Task Force definition to include asthma-related hospital admissions or prescription for acute courses of oral corticosteroids. Asthma-related admissions were defined as any hospital entry for asthma or any lower respiratory reason (including lower respiratory tract infections). Acute oral corticosteroid use associated with asthma exacerbation treatment was defined as all courses that were not maintenance therapy, and/or all courses where dosing instructions suggested exacerbation treatment. Emergency department data were not included in the exacerbation definition as these data were not available in the database. Two further co-primary outcomes included risk-domain asthma control, defined as the absence of asthma-related hospital admissions and prescription for acute courses of oral corticosteroids; and overall asthma control, defined as achieved risk-domain asthma control and average daily dose of ≤200 μg salbutamol or ≤500 μg terbutaline.
Secondary outcomes were (1) treatment stability during the outcome period, defined as achieving risk-domain asthma control and no change in therapy; and (2) average daily dose of short-acting β2 agonists (SABA), defined as \( \frac{number\kern0.5em of\kern0.5em inhaler s\kern0.5em \times \kern0.5em Doses\kern0.5em per\kern0.5em inhaler}{365}\kern0.5em \times \kern0.5em strength, \) where strength is inhaler dose (μg). Change in therapy was defined as an ICS prescribed dose increase of ≥50 % or addition of new asthma therapy, including leukotriene receptor antagonists (LTRA), theophylline, or long-acting β-agonists (LABA).
Finally, two exploratory outcomes were (1) prevalence of oral candidiasis, based on the number and percentage of patients who either received a diagnosis of oral candidiasis in their hospital records, or the number and percentage of topical oral prescriptions for antifungals; and (2) hospitalization rate, defined as the number of any recorded hospital entry for asthma and/or any (asthma-related) lower respiratory reason in the year following the initiation date. All outcomes have been used in prior studies by the research group and have been described previously [810].

Statistical analysis

The database extraction and statistical analysis plan were written before any analyses were conducted [12]. All analysis was carried out using IBM SPSS Statistics version 22, Microsoft Office EXCEL 2007, and SAS version 9.3. Complete details on statistical analysis methods are in the Additional file 1: Figure S1.
Patients were exact-matched (1:1) based on key baseline demographic and clinical characteristics to ensure comparison of similar patients and to reduce potential confounders [13]. Matching criteria were informed from baseline differences between treatment cohorts as evidenced by exploratory analysis (t-test/chi square test, p < 0.05), from expert clinical advice, and from previous research experience, and included the following: sex, age, exact year of ICS therapy initiation, severe exacerbations, LABA and LTRA prescriptions, and SABA daily dose. Patients were matched sequentially on each of the selected matching criteria. Patients who did not match were excluded.
The rate of severe exacerbations in the outcome period was compared between matched treatment cohorts using a conditional Poisson regression model. The odds of achieving risk-domain asthma control and overall asthma control, and changing asthma therapy, were compared between matched treatment cohorts using a conditional binary logistic regression model. Ordinal conditional logistic regression modeling was used to analyze prescriptions of higher doses of SABA (categorized doses). The models used empirical standard errors (for more conservative confidence interval [CI] estimations) and adjustments were made for any residual non-collinear baseline confounders (Pearson and Spearman correlation coefficients, r > 0.3) and for those variables predictive of the results through full multivariable analysis (multivariable model, p ≤ 0.05). The results are expressed as adjusted rate ratios and odds ratios and 95 % confidence intervals. Number of prescriptions of antifungal medications to treat oral candidiasis, prevalence of hospitalizations, and initial ICS doses were compared between the two matched cohorts through conditional logistic regression (p < 0.05).

Results

Patient characteristics and demographics

Following 1:1 matching, 1399 patients were selected in each of the extrafine-particle ICS and fine-particle ICS cohorts (Fig. 1).
Within the extrafine-particle cohort, 712 patients (51 %) were prescribed ciclesonide, 687 (49 %) EF-HFA-BDP. Median (interquartile range [IQR]) age for patients in each of the matched cohorts was 43 years. Median (IQR) ICS doses (μg) were 160 (160–320) for the extrafine-particle cohort versus 500 (250–500) for the fine-particle cohort (p < 0.001) (fluticasone-equivalents) (Fig. 2).
The two study cohorts were similar for the study asthma control measures and prescriptions for SABA (Table 1). However, at baseline, patients in the extrafine-particle cohort received more diagnoses for rhinitis and gastro-oesophageal reflux disease, more prescriptions for acute oral corticosteroids, topical corticosteroid therapy, and had a higher prevalence of asthma-related hospital admissions, than patients in the fine-particle cohort (Table 1). For these specific variables, data were comparable within the extrafine-particle cohort for patients prescribed ciclesonide and EF-HFA-BDP (Table 1).
Table 1
Baseline demographic and clinical characteristics for 1:1 matched patients
Baseline Characteristic
Extrafine-particle ICSa (n = 1399)
Fine-particle ICSb (n = 1399)
p-value
Sex, male, n (%)c
471 (34)
471 (34)
N/A
Age, median (IQR)c
43 (32–53)
43 (32–52)
0.091
Year of initiation date, median (IQR)c
2008 (2006–2009)
2008 (2006–2009)
N/A
ICS dose prescribed on initiation date, n (%)
   
  <200μg/d, n (%)
866 (62)
218 (16)
<0.001
  201–400μg/d, n (%)
477 (34)
301 (22)
  401–800μg/d, n (%)
56 (4)
677 (48)
  801μg/d, n (%)
0 (0)
203 (15)
ICS dose on initiation date, median (IQR)
160 (160–320)
500 (250–500)
<0.001
Average ICS daily dose (μg/d, categorized EF-HFA-BDP/ciclesonide equivalent dosed)
   
  0–200μg/d, n (%)
866 (62)
218 (16)
<0.001
  201–400μg/d, n (%)
477 (34)
301 (22)
  401–800μg/d, n (%)
56 (4)
677 (48)
  801μg/d+, n (%)
0 (0)
203 (15)
Recorded comorbidity, n (%)
   
  Rhinitis diagnosis, n (%)
623 (45)
536 (38)
<0.001
  GERD diagnosis, n (%)
513 (37)
437 (31)
0.001
  Paracetamol script, n (%)
28 (2)
47 (3)
0.020
  NSAID script, n (%)
219 (16)
215 (15)
0.834
  Topical corticosteroid treatment, n (%)
433 (31)
374 (27)
0.014
  Oral candidiasis diagnosis, n (%)
14 (1)
11 (1)
0.533
  Rhinitis diagnosis, n (%)
Ciclesonide
18 (1)
N/A
N/A
EF-HFA-BDP
21 (1)
  GERD diagnosis, n (%)
Ciclesonide
0 (0)
N/A
N/A
EF-HFA-BDP
1 (1)
  Topical corticosteroid treatment, n (%)
Ciclesonide
207 (15)
N/A
N/A
EF-HFA-BDP
226 (16)
Respiratory Medications
   
Acute oral corticosteroid prescriptions, <1, n (%)
101 (7)
120 (9)
0.001
Acute oral corticosteroid prescriptions, <1, n (%)
Ciclesonide
47 (3)
N/A
N/A
EF-HFA-BDP
54 (4)
SABA daily dose, n (%)c
   
  0μg/d, n (%)
953 (68)
953 (68)
N/A
  200μg/d, n (%)
57 (4)
57 (4)
  201μg/d, n (%)
40 (3)
40 (3)
SABA prescriptions, n (%)
   
  0, n (%)c
953 (68)
953 (68)
0.251
  1, n (%)
281 (20)
267 (19)
  2+, n (%)
165 (12)
179 (13)
Prior therapy
   
  LABA, n (%)c
21 (2)
21 (2)
N/A
  LTRA, n (%)c
1 (0)
1 (0)
N/A
Asthma control
   
Risk-domain asthma control, n (%)c
1275 (91)
1275 (91)
N/A
Overall asthma control, n (%)c
1241 (89)
1241 (89)
N/A
Severe exacerbations, n (%)c
   
  0
1275 (91)
1275 (91)
N/A
  1
109 (8)
109 (8)
  2+
15 (1)
15 (1)
Asthma-related hospital admissions, n (%)
23 (2)
4 (0)
0.001
Asthma-related hospital admissions, n (%)
Ciclesonide
11 (1)
N/A
N/A
EF-HFA-BDP
12 (1)
GERD, gastro-oesophageal reflux disease; ICS, inhaled corticosteroid; LABA, long-acting β2-agonist; LTRA, leukotriene receptor antagonist; N/A: not applicable; SABA, short-acting β2-agonist; initiation date: the date when patients received their first prescription of extrafine-particle ICS (ciclesonide or EF-HFA-BDP), or fine-particle ICS (fluticasone or Non-EF-BDP)
aExtrafine-particle ICS: ciclesonide; hydrofluoroalkane beclomethasone dipropionate (EF-HFA-BDP)
bFine-particle ICS: non-extrafine-particle beclomethasone dipropionate (Non-EF-BDP); fluticasone propionate
cMatching variable
dAverage ICS daily dose calculated as [(number of inhalers * doses per inhaler / 365) * µg strength]

Outcomes

Patients who received extrafine-particle ICS had 40 % lower rates of severe exacerbations in the year following the initiation date than those receiving fine-particle ICS therapy, following adjustment for residual confounders (adjusted rate ratio [95 % CI], 0.59 [0.47–0.73]) (Fig. 3). In addition, patients in the extrafine-particle cohort had greater odds of achieving risk-domain asthma control, overall asthma control, and treatment stability, and had lower odds of being in a higher dose category of SABA (adjusted rate ratio [95 % CI], 0.50 [0.44–0.57]) (Fig. 3, Table 2).
During the outcome year, patients in the extrafine-particle cohort received fewer prescriptions for other respiratory drugs (oral corticosteroids, SABA and LABA) compared with the fine-particle cohort, although more patients in the extrafine-particle cohort were prescribed LTRAs during the outcome period than the fine-particle cohort (6 % and 3 % in extrafine-particle versus fine-particle ICS cohorts, respectively; p = 0.001) (Fig. 3, Table 2). Prescriptions of medications for treating oral candidiasis in the outcome period were not significantly different between the two study cohorts. Although patients in the extrafine-particle cohort had significantly higher asthma-related hospital admissions in baseline (Table 1), in the year following the date of first prescription of ICS therapy, this difference was not evident (Table 2).
Table 2
Outcome measures for matched groups 1 year following date of first ICS prescription
Outcome
Extrafine-particle ICSa (n = 1399)
Fine-particle ICSb (n = 1399)
p-value
Asthma control
   
Risk-domain asthma control, n (%)
1236 (88)
1129 (81)
<0.001
Overall asthma control, n (%)
1091 (78)
934 (67)
<0.001
Severe exacerbations, n (%)
   
  0, n (%)
1236 (88)
1129 (81)
<0.001
  1, n (%)
108 (8)
184 (13)
  2+, n (%)
55 (4)
86 (6)
Treatment stability, n (%)
809 (58)
560 (40)
<0.001
Prescribed average daily dose of SABA, μg/d, n (%)
   
  0 μg/d, n (%)
686 (49)
461 (33)
<0.001
  1–100 μg/d, n (%)
326 (23)
343 (25)
  101 μg/d+, n (%)
387 (28)
595 (43)
1+ prescriptions of antifungal for candidiasis, n (%)
48 (3)
45 (3)
0.753
1+ asthma-related hospital admissions, n (%)
19 (1)
16 (1)
0.613
Respiratory medications in outcome period
   
Courses of acute oral corticosteroids, n (%)
   
  0, n (%)
1246 (89)
1135 (81)
<0.001
  1, n (%)
102 (7)
182 (13)
  2+, n (%)
51 (5)
82 (6)
SABA prescriptions, n (%)
   
  0, n (%)
686 (49)
461 (33)
<0.001
  1, n (%)
245 (18)
235 (17)
  2, n (%)
180 (13)
218 (16)
  3+, n (%)
288 (21)
485 (35)
ICS prescriptions (including initial prescription)
   
  2, n (%)
0 (0)
0 (0)
0.022
  3, n (%)
462 (33)
520 (37)
  4+, n (%)
937 (67)
879 (63)
Average ICS daily dose (μg/d, fluticasone-equivalentsc)
   
  0–150 μg/d, n (%)
460 (33)
263 (19)
<0.001
  151–250 μg/d, n (%)
484 (35)
416 (30)
  251–450 μg/d, n (%)
358 (26)
401 (29)
  451 μg/d+, n (%)
97 (7)
319 (23)
Average ICS daily dose (μg/d, EF-HFA-BDP/ciclesonide equivalent dosed), median (IQR)
185 (132–290)
272 (178–410)
<0.001
Average ICS daily dose (μg/d, EF-HFA-BDP/ciclesonide equivalent dosed)
   
  0–150 μg/d, n (%)
460 (33)
263 (19)
<0.001
  151–250 μg/d, n (%)
484 (35)
416 (30)
  251–450 μg/d, n (%)
358 (26)
401 (29)
  451 μg/d+, n (%)
97 (7)
319 (23)
LABA prescriptions in outcome period
770 (55)
875 (63)
<0.001
LTRA prescriptions in outcome period
83 (6)
47 (3)
0.001
GERD gastro-oesophageal reflux disease, ICS inhaled corticosteroid, LABA long-acting β2-agonist, LTRA leukotriene receptor antagonist, N/A not applicable, SABA short-acting β2-agonist
a Extrafine-particle ICS: ciclesonide (Alvesco®); hydrofluoroalkane beclomethasone dipropionate (EF-HFA-BDP [Qvar®])
b Fine-particle ICS: non-extrafine-particle beclomethasone dipropionate (Non-EF-BDP); fluticasone propionate (FP)
c Fluticasone-equivalent dose for fine-particle ICS (FP and Non-EF-BDP) delivered via a pressurized-metered dose inhaler
d EF-HFA-BDP/ciclesonide equivalent dose for extrafine-particle ICS delivered via a pressurized-metered dose inhaler

Discussion

In this real-life population-based study, matched patients initiating extrafine-particle ICS had significantly lower rates of severe exacerbations and significantly higher odds of achieving asthma control and treatment stability than those prescribed fine-particle ICS. Notably, the prescribed doses of extrafine-particle ICS were lower than fine-particle ICS at the initiation date (median dose, 160 vs. 500 μg per day, fluticasone-equivalents). In addition, patients prescribed extrafine-particle ICS showed lower odds of being prescribed higher doses of short-acting β2 agonists. Outcome data showed no significant differences between the study cohorts for medications prescribed for treating oral candidiasis, and for asthma-related hospital admissions. These findings suggest a significant improvement in asthma control for patients prescribed extrafine-particle ICS with unstable asthma. Such patients would typically be excluded from traditional RCTs.
Possible mechanisms to account for the superior effectiveness of extrafine-particle ICS observed in this study include improved airway drug deposition and distribution, including distally in the small airways, and improved inhaler device tolerance. These are each discussed in turn below.
Aerosol particle size now appears therapeutically important for controlling asthma symptoms [14]. Evidence indicates that fine-particle ICS with a MMAD of <5 μm, but ≥2 μm, show lower total lung distribution and deposition than extrafine-particles with a MMAD <2 μm, which can deposit more in the small airways [1, 2, 15]. More effective control of small airway inflammation might contribute to improved asthma control [15].
Poor device technique by patients is a common problem observed by clinicians. Asthma control worsens as the number of mistakes in device technique increases [16]. The combination of fine-particle ICS with poor device technique can lead to some of the ICS settling in the oropharynx, resulting in side-effects such as oropharyngeal candidiasis. However, lung deposition of EF-HFA-BDP remains adequate even in patients with poor inhaler device technique [1]. This may be due to pMDI design incorporating hydrofluoroalkane propellant that produces a softer, warmer and longer duration spray. This particular method of delivery has proven more tolerant of poor inhaler technique than some metered dose inhalers emitting fine-particle ICS [1]. Tolerance to inhalation errors may in turn promote improved adherence to therapy [14].
This study has several strengths. To ensure all potentially relevant variables for characterizing patients were included, and that the key outcomes of interest could be evaluated, both the statistical analysis plan, study population and outcomes were conceived prior to any analyses [11]. Imitating traditional RCT design, the study included an initiation date marking therapy initiation. The study inclusion and exclusion criteria were selected to minimize potential confounding factors such as other asthma therapies, and to identify patients from a large clinical population receiving initial ICS therapy. Patient matching was used to adjust for demographic and clinical differences between the study cohorts. An advantage of 1-year baseline and outcome periods is that this time-period allows for natural seasonal changes in respiratory disease, and for recording infrequent clinical events such as exacerbations and asthma-related hospitalizations [11]. The results confirm both the study hypothesis and similar findings observed in real-life asthma control studies with patients in the UK and US [810]. This seems to suggest that the present findings can be extrapolated to healthcare systems and prescribing patterns in different countries. Collectively, these studies provide balance to findings reported in some RCTs that extrafine-particle ICS is only equally effective as fine-particle ICS in achieving asthma control [3, 4].
However, as with all real-life comparative database studies, this study has its limitations as well. Limitations could derive from using the PHARMO Database Network, including disease misclassification biases from the almost exclusive use of “asthma prescriptions” to individuate patients with asthma, and the impossibility to adjust for all potential confounders, such as potential confounding by severity for factors indiscernible from patient records or patient-reported outcomes. Asthma diagnosis data, defined as a General Practice recorded diagnosis for asthma (ICPC code R96), were available in the General Practice database for only 12.2 % of the study population. In addition, the results of this study only apply to healthier patients who survive at least 1 year following prescription date. Therefore, this study cannot exclude potential survivor bias [11, 13, 17].
Although specific to respiratory disease, this study could not accurately assess lung function, or symptom control. However, short-acting β2 agonist prescriptions were included in the study as a substitute for asthma symptoms in the ‘overall asthma control’ measure, because short-acting β2 agonist use reflects symptom control [18]. The control cutoff point of a mean short-acting β2 agonist use of ≥2 puffs per day corresponds to the level 2 category (2 of 4, with 1 being the best controlled) of the validated approach of Schatz et al. [18] for short-acting β2 agonist canister dispensing to assess asthma symptom control. During the study period, 1399/2981 (47 %) eligible patients initiating extrafine-particle ICS therapy were matched, and 1399/8200 (17 %) of those initiating fine-particle ICS were matched, possibly indicating that patients in neither cohort were representative of those who initiate extrafine-particle or fine-particle ICS therapy in the Netherlands. Finally, although smoking status was not reported in the study due to poor availability within the PHARMO Database Network, possible COPD patients were included (e.g., patients prescribed long-acting muscarinic agents in addition to ICS), but constituted only 1.8 % of the total study population.

Conclusions

This study in a real-life population shows that extrafine-particle ICS are associated with better asthma control and better odds of therapy stability than fine-particle ICS, at significantly lower prescribed doses, despite patients having otherwise similar baseline characteristics after exact matching. These results for a Dutch population confirm relevant real-life asthma studies conducted in the UK and US, and seem generalizable to countries with different healthcare systems and prescribing habits. The findings also provide balance to findings reported in some randomized asthma RCTs. The study applied reliable prescribing and medical information recorded in a well-maintained database for a diverse clinical population, a population including those at high risk of exacerbations, with comorbid rhinitis, smokers and non-smokers. Although patients prescribed extrafine-particle ICS showed signs of more severe asthma, they had better asthma control at lower ICS doses than patients prescribed fine-particle ICS. Additional comparative effectiveness studies are required to better understand the differential effects of extrafine-particle versus fine-particle ICS in real-life asthma patients, especially regarding possible subgroup specificities.

Acknowledgements

Gokul Gopalan (a Senior Global Medical Director [Respiratory], at Teva Pharmaceuticals, Frazer, PA, US, at the time of this study), assisted with study design.

Funding

Funds to acquire the dataset from the PHARMO Institute for Drug Outcomes Research (Utrecht, the Netherlands) were provided by RiRL. The study received institutional support from Teva Pharmaceuticals Europe B.V. Gokul Gopalan, a Senior Global Medical Director (Respiratory), at Teva Pharmaceuticals, Frazer, PA, US, at the time of this study, assisted with study design, but neither Teva Pharmaceuticals Europe B.V. nor Teva Pharmaceuticals, Frazer, PA, US, contributed, either in part or in whole, to the collection, analysis, or interpretation of study data, manuscript writing, or the decision to submit the manuscript for publication.
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://​creativecommons.​org/​licenses/​by/​4.​0/​), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://​creativecommons.​org/​publicdomain/​zero/​1.​0/​) applies to the data made available in this article, unless otherwise stated.

Competing interests

Thys van der Molen has received grants for research, travel, and reimbursement for presentations and advisory boards from AstraZeneca, GlaxoSmithKline, Almirall, Mundipharma, Boehringer Ingelheim, Chiesi, Teva Pharmaceuticals Europe B.V., and Novartis.
David B. Price has Board Membership with Aerocrine, Almirall, Amgen, AstraZeneca, Boehringer Ingelheim, Chiesi, Meda, Mundipharma, Napp, Novartis, and Teva Pharmaceuticals Europe B.V. Consultancy: Almirall, Amgen, AstraZeneca, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, Meda, Mundipharma, Napp, Novartis, Pfizer, Teva Pharmaceuticals Europe B.V., and Zentiva. Grants/Grants Pending with UK National Health Service, British Lung Foundation, Aerocrine, AstraZeneca, Boehringer Ingelheim, Chiesi, Eli Lilly, GlaxoSmithKline, Meda, Merck, Mundipharma, Novartis, Orion, Pfizer, Respiratory Effectiveness Group, Takeda, Teva Pharmaceuticals Europe B.V., and Zentiva. Payments for lectures/speaking: Almirall, AstraZeneca, Boehringer Ingelheim, Chiesi, Cipla, GlaxoSmithKline, Kyorin, Meda, Merck, Mundipharma, Novartis, Pfizer, SkyePharma, Takeda, and Teva Pharmaceuticals Europe B.V. Payment for manuscript preparation: Mundipharma and Teva Pharmaceuticals Europe B.V. Patents (planned, pending or issued) with AKL Ltd. Payment for the development of educational materials: GlaxoSmithKline, and Novartis. Stock/Stock options: Shares in AKL Ltd, which produces phytopharmaceuticals. Owns 80 % of Research in Real Life Ltd and its subsidiary social enterprise Optimum Patient Care. Received Payment for travel/accommodations/meeting expenses from: Aerocrine, Boehringer Ingelheim, Mundipharma, Napp, Novartis, and Teva Pharmaceuticals Europe B.V. Funding for patient enrolment or completion of research: Almirral, Chiesi, Teva Pharmaceuticals Europe B.V., and Zentiva. Peer reviewer for grant committees: Medical Research Council (2014), Efficacy and Mechanism Evaluation program (2012), HTA (2014); and received unrestricted funding for investigator-initiated studies from Aerocrine, AKL Ltd, Almirall, Boehringer Ingelheim, Chiesi, Meda, Mundipharma, Napp, Novartis, Orion, Takeda, Teva Pharmaceuticals Europe B.V., and Zentiva.
Ron M.C. Herings and Jetty A. Overbeek are employees of the PHARMO Institute for Drug Outcomes Research. This independent research institute performs financially supported studies for government and related healthcare authorities and several pharmaceutical companies.
Victoria Thomas is an employee of Research in Real-Life (RiRL). Cristiana Miglio is a former employee of Research in Real-Life, Ltd (RiRL). RiRL conducted this study. RiRL has conducted paid research in respiratory disease on behalf of the following other organizations in the past 5 years: Aerocrine, AKL Ltd, Almirall, AstraZeneca, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, Meda, Mundipharma, Napp, Novartis, Orion, Takeda, Teva Pharmaceuticals Europe B.V., and Zentiva, a Sanofi company.
Richard Dekhuijzen has received over the past 3 years’ fees for speaking, education, participation in advisory boards or consulting, from: Almirall, AstraZeneca, Boehringer Ingelheim, Chiesi, Mundipharma, Novartis, Pfizer, Teva Pharmaceuticals Europe B.V., and Zambon. Research grants: AstraZeneca, Boehringer Ingelheim, and Novartis.
Richard J. Martin has conducted consultancy work and/or received travel support and/or honoraria for attendance at advisory boards for: AstraZeneca, MedImmune, Merck, and Teva Pharmaceuticals Europe B.V. Received research grants: MedImmune, and the NHLBI. Received royalties from UpToDate.
The University of Groningen has received money for Dirkje S. Postma regarding an unrestricted educational grant for research from Astra Zeneca, and Chiesi. Travel to ERS and/or ATS has been partially funded by Astra Zeneca, Chiesi, GlaxoSmithKline, and Takeda. Fees for consultancies given to the University of Groningen from: Astra Zeneca, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, Takeda and Teva Pharmaceuticals Europe B.V. Travel and lectures in China paid by Chiesi.
Nicolas Roche has received fees over the past 3 years for speaking, education, and participation in advisory boards or consulting from: 3M, Aerocrine, Almirall, AstraZeneca, Boehringer Ingelheim, Chiesi, Cipla, GlaxoSmithKline, MSDChibret, Mundipharma, Novartis, Pfizer, Sandoz, Sanofi, Stallergenes, Takeda, and Teva Pharmaceuticals Europe B.V. Research grants from: Boehringer Ingelheim, Novartis, and Pfizer.
Theresa Guilbert has received personal fees from the American Board of Pediatrics, GlaxoSmithKline, Merck, and Regeneron Pharmaceuticals, and Sanofi. Pediatric Pulmonary Subboard, grants and personal fees from Teva Pharmaceuticals Europe B.V. Grants: Abbott Laboratories, Array Biopharma, CDC, CF Foundation Therapeutics, CompleWare Corporation, DHHS, F. Hoffman-LaRoche, Forest Research Institute, KaloBios Pharmaceuticals, Medimmune, Mylan, NIH, Roche/Genetech, Roxane Laboratories, and UW-Madison Medical and Education Research Committee, and Vertex Pharmaceuticals. Royalties from UpToDate.
Elliot Israel reports having received speaking fees over the past 3 years’ fees from Merck. Fees for consulting from AstraZeneca and Merck. Non-financial participation in Advisory Boards or consulting for Novartis (as DSMB Member). Research grants from Genentech and NIH. Writing/editorial support for manuscript preparation from RiRL. Travel grant support from RiRL and Teva Pharmaceuticals Europe B.V. Specialty Pharmaceuticals, fees for expert testimony from: Campbell, Campbell, Edwards & Conroy, Ficksman & Conley, Fox Rothschild, LLP, and Ryan Deluca, LLP. Royalties from UpToDate. Deputy Editor for the American Journal of Respiratory and Critical Care Medicine.
Wim van Aalderen is a member of the Medical Advisory Board of AstraZeneca.
Elizabeth V. Hillyer is a consultant to RiRL and has received payment for writing and editorial support to Merck.
Simon van Rysewyk is an employee of the Observational & Pragmatic Research Institute Pte Ltd, and has no competing interests to declare.

Authors’ contributions

All authors were involved in the conception or design of the study; or the acquisition, analysis, or interpretation of study data; and, drafting the study or revising it; and, giving final approval for publication. The authors are responsible for all aspects of this study. DBP led the study design process, which was guided by Steering Committee discussions. The Steering Committee was composed of study authors representing the SASG: RJM, DSP, NR, WvA, RD, and TvdM. CM and VT were responsible for the data acquisition and analyses. SvR wrote the manuscript.
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Metadaten
Titel
Effectiveness of initiating extrafine-particle versus fine-particle inhaled corticosteroids as asthma therapy in the Netherlands
verfasst von
Thys van der Molen
Dirkje S. Postma
Richard J. Martin
Ron M. C. Herings
Jetty A. Overbeek
Victoria Thomas
Cristiana Miglio
Richard Dekhuijzen
Nicolas Roche
Theresa Guilbert
Elliot Israel
Wim van Aalderen
Elizabeth V. Hillyer
Simon van Rysewyk
David B. Price
Publikationsdatum
01.12.2016
Verlag
BioMed Central
Erschienen in
BMC Pulmonary Medicine / Ausgabe 1/2016
Elektronische ISSN: 1471-2466
DOI
https://doi.org/10.1186/s12890-016-0234-0

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