Copyright ©ERS Journals Ltd 2006 The effect of tiotropium on exacerbations and airflow in patients with COPD1 Groupe Hôspitalier Cochin, Assistance Publique Hôpitaux de Paris, Faculté Cochin Port-Royal, Université Paris, Paris, and 2 Boehringer Ingelheim France, Reims, France. CORRESPONDENCE: D. Dusser, Service de Pneumologie, Hôpital Cochin, 27 Rue du Faubourg Saint Jacques, 75679 Paris, Cedex 14, France. Fax: 33 146338253. E-mail: daniel.dusser{at}cch.aphp.fr Keywords: Chronic obstructive pulmonary disease, exacerbations, health resource utilisation, peak expiratory flow, tiotropium
Received: May 30, 2005
This randomised, double-blind, parallel-group, 1-yr study compared the effect of tiotropium 18 µg once daily (n = 500) and placebo (n = 510) on exacerbations, associated health resource use (HRU) and airflow limitation in chronic obstructive pulmonary disease (COPD) patients.
The mean±SD number of exacerbations during the past year was 2.14±1.40, the mean weekly morning peak expiratory flow (PEF) was 259.6±96.1 L·min1 and the mean forced expiratory volume in one second (FEV1) was 1.37±0.45 L. Tiotropium significantly delayed the time to first exacerbation by In conclusion, tiotropium reduced exacerbations and associated health resource use, and improved airflow over 1 yr in chronic obstructive pulmonary disease patients. Exacerbations of chronic obstructive pulmonary disease (COPD) are a major cause of morbidity and mortality 1. They are caused or triggered by a variety of factors, including bacteria, viruses and air pollution 2, and are characterised by acute worsening of symptoms, increased airway inflammation and deterioration of respiratory function 1. As well as the burden to the patient, additional medication and/or hospitalisation for exacerbations add to the financial cost of treating COPD 3. In addition, frequent exacerbations are associated with impaired health-related quality of life (HRQL) and a more rapid decline in lung function over time 46. Interventions that reduce the severity or frequency of exacerbations and associated healthcare resource utilisation (HRU) should have a significant impact on both the patient's HRQL and the cost of treatment. Physiological changes (e.g. decreases in peak expiratory flow (PEF) and forced expiratory volume in one second (FEV1)) immediately prior to an exacerbation are generally small and are not useful in predicting exacerbations 1, 4. However, improved knowledge of the time course and duration of these physiological changes during an exacerbation could facilitate the administration of appropriate and timely care in the community and thus avoid hospital admissions. Several studies have shown that maintenance treatment with long-acting bronchodilators (anticholinergics and ß2-agonists) may provide a protective effect against exacerbations 7. Tiotropium is a once-daily anticholinergic bronchodilator that has been shown to improve FEV1, forced vital capacity (FVC), lung volumes, dyspnoea, HRQL and exercise capacity 812. It has also been shown to reduce the incidence of exacerbations and delay the time to first exacerbation compared with either ipratropium or placebo 810. In these studies, however, exacerbations were collected as adverse events. As a different approach, the present authors chose to solicit exacerbation data explicitly by the protocol, using a graded definition that included symptom and treatment intervention elements, and allowed sophisticated differentiation between the various severities of exacerbations. A recent prospectively designed trial has shown that tiotropium reduces exacerbations in patients with moderate-to-severe COPD 13. However, this trial was restricted to a predominantly male sample study with severe-to-very severe COPD and the follow-up period was only 6 months. Moreover, the various severities of exacerbations were not differentiated. Results from previous trials have also shown that tiotropium reduced HRU compared with placebo and ipratropium, as indicated by reductions in the number of hospital admissions, days in hospital, unscheduled visits to healthcare providers and concomitant medication use 810, 1316. However, it is valuable to evaluate the impact of bronchodilators on HRU outcomes in single healthcare settings directly, rather than extrapolating data from multinational trials. The objective of this analysis was to investigate the effects of tiotropium on the incidence of exacerbations, HRU and airflow limitation in patients with COPD in France. The relationship between PEF and exacerbations was also examined.
Study design This was a 1-yr, multicentre, double-blind, parallel-group study comparing the effect of tiotropium and placebo on exacerbations and associated HRU, and on airflow limitation. The trial (study protocol number 0205.214, assigned by Boehringer Ingelheim, Reims, France) was performed at 177 centres in France. An Institutional Review Board (the Comité Consultatif pour la Protection des Personnes dans les Recherches Biomédicales, Hôpital Cochin, Paris, France) approved the study protocol and all participants gave written, informed consent.
Patients
Study protocol
Detailed information on exacerbations of COPD, hospital admissions due to a COPD exacerbation, concomitant medications and non-scheduled contacts with physicians were collected at randomisation (day 1) as well as after 6, 12, 24, 36 and 48 weeks of treatment. HRU data specifically related to COPD were collected on a separate page of the case report form. An exacerbation was defined as the onset of at least one clinical descriptor (worsening of dyspnoea, cough or sputum production; appearance of purulent sputum; fever (>38°C); appearance of new chest radiograph abnormality) lasting In order to compare the results of this study more directly with those from previous exacerbation trials, a post hoc analysis was conducted, which used a more generalised classification of exacerbation severity based on HRU and treatment use. A severe exacerbation was classified as one requiring hospitalisation. A moderate exacerbation was defined as one requiring treatment with systemic steroids and/or antibiotics. All remaining events were classified as mild exacerbations. Each patient performed daily PEF measurements in the morning prior to inhalation of the study drug and recorded the highest of three readings graphically on their diary card. They also recorded the number of puffs of "as-needed" rescue medication used in their diary and their respiratory condition using a graduated numerical scale (0: poor; 10: excellent). Patients were instructed to contact the investigator immediately if they experienced a negative change in their condition, and adequate treatment was prescribed if the investigator considered the patient to be having an exacerbation. Spirometric tests were conducted at each clinic visit. FEV1, FVC, SVC and inspiratory capacity (IC) were recorded 30 min prior to dosing. All spirometric tests were conducted in triplicate and the highest measurements were used in subsequent analyses. Adverse events were monitored throughout the treatment period.
Statistical analysis The percentages of patients with one or more COPD exacerbation or hospital admission due to a COPD exacerbation over the 1-yr study period were analysed using Fisher's exact test. The number of COPD exacerbations, exacerbation days, hospital admissions, hospital days, physician visits, phone calls, oral steroid courses and antibiotic courses were analysed using the WilcoxonMannWhitney test. The duration of oral steroid and antibiotic courses were also analysed using the WilcoxonMannWhitney test. The time to first COPD exacerbation was analysed using the log-rank test. The percentage of patients requiring additional respiratory medication during an exacerbation was analysed using the Chi-squared test. Statistical significance was considered to be p<0.05. Summary data are expressed as mean±SE, unless otherwise stated. Prior to calculating descriptive statistics per group, quantitative descriptors of events were divided by the treatment exposure for each patient (and expressed as events per patient per yr by applying a multiplication factor of 365.25). A sample size of 459 patients per group was calculated as adequate to detect a difference of 15 L·min1 in mean weekly morning PEF based on an SD of 70 L·min1. To ensure adequate safety exposure, a sample size of 1,000 patients (500 patients per group) was selected.
A total of 1,010 patients from 177 centres in France were randomised and treated, with 500 receiving tiotropium and 510 receiving placebo. More patients in the tiotropium group completed the trial than those in the placebo group (76.6% versus 71.2%). The two treatment groups were well matched at baseline (table 1
Exacerbations The proportion of patients experiencing one or more exacerbation during the 1-yr treatment period was significantly lower in the tiotropium group than in the placebo group (17% reduction; p<0.01) (fig. 1a 100 days compared with placebo (p<0.001; fig. 2
Severe exacerbations were observed in only 104 cases (85 of which fulfilled the hospitalisation criteria and 19, the arterial blood gas criteria). A sensitivity analysis for moderate and severe exacerbations was conducted. Tiotropium reduced the proportion of patients experiencing one or more moderate-to-severe exacerbation (by 30%; p<0.0001), and decreased the number of both moderate-to-severe exacerbations (by 36%; p<0.0001) and moderate-to-severe exacerbation days (by 34%; p<0.0001) compared with placebo (fig. 1
The post hoc analysis, using a more generalised classification of exacerbations, revealed similar results (table 2
Compared with placebo, tiotropium reduced the number of exacerbations, irrespective of COPD severity (based on FEV1 % pred) at baseline (table 3
Healthcare resource utilisation This study was not powered to detect a reduction in hospitalisations due to COPD exacerbations. However, compared with placebo, tiotropium resulted in numerically fewer hospitalisations and hospital days caused by COPD, but the differences between the groups were not statistically significant (table 4
Morning PEF and respiratory condition score were analysed for 15 days prior to, and for 8 weeks after, an exacerbation. Baseline PEF was defined as the mean morning PEF from day 28 to 14 prior to the start of the first exacerbation. Morning PEF declined rapidly 34 days prior to the reported start of an exacerbation in both the tiotropium and placebo groups (fig. 3a 4 weeks after the start of the exacerbation in both groups. Baseline respiratory condition score was defined as the mean daily score from day -28 to -14 prior to the start of the first exacerbation. Similarly, respiratory condition score declined rapidly in the week preceding the exacerbation in both groups (fig. 3b
Peak expiratory flow and spirometry Weekly morning PEF was significantly higher in the tiotropium group compared with the placebo group from week 1 until the end of the study (p<0.0001 for all weekly intervals). The mean difference between the groups over the 1-yr study period was 25 L·min1. At the end of the treatment period, tiotropium improved trough FEV1 by 0.12±0.02 L (p<0.0001), FVC by 0.17±0.03 L (p<0.0001), SVC by 0.17±0.03 L (p<0.0001) and IC by 0.14±0.04 L (p<0.001) compared with placebo.
Use of rescue medication
Respiratory condition score
Adverse events
The goals of maintenance therapy in COPD include the relief of symptoms and the reduction of the number of exacerbations 18. Exacerbations, especially those resulting in hospitalisation, are the main cost driver in COPD and frequent exacerbations are associated with impaired health status and a more rapid decline in lung function over time 46. This 1-yr study found that maintenance treatment with once-daily tiotropium 18 µg reduced exacerbations and associated HRU, and improved airflow limitation compared with placebo. As this study was conducted in a single healthcare system, any potential bias due to combining data from different systems was avoided. Surprisingly, relatively few females were included in this trial (13%); however, this is probably a French phenomenon as a similar male:female ratio was observed in a recent randomised controlled trial 19 and in a "real world" study of patients with COPD in France 20. Prevention and more effective treatment of exacerbations of COPD are the desirable outcomes, as the economic and social burden of exacerbations is extremely high. In this study, tiotropium significantly delayed the time to first exacerbation, reduced the proportion of patients experiencing an exacerbation and decreased the number of both exacerbations and exacerbation days compared with placebo. Patients enrolled in clinical trials may experience fewer exacerbations than usual as any deterioration in their condition may be detected and treated sooner. However, the rate of exacerbations was comparable in the placebo group with the year before trial entry and during the trial (2.12 and 2.41 events per yr, respectively). Previous observations from long-term studies have shown that tiotropium significantly reduced the number of exacerbations and delayed the time to first exacerbation, compared with placebo or ipratropium 810. Whereas in these former studies exacerbations were captured as adverse events, this study solicited exacerbation data using a grading system distinguishing events by severity. The overall incidence of exacerbations in this trial was higher compared with these previous studies (2.0 versus 0.81.3 exacerbations per patient per year) 810. This is probably because only patients with at least one exacerbation in the previous year were eligible to enrol in the study. As the number of exacerbations in the previous year predicts exacerbation frequency 6, the patients enrolled in this trial may have been more prone to exacerbations than those in the previous studies.
Another potential reason for this finding is that the definition of an exacerbation used in this study differs somewhat from that reported in earlier publications, since the minimum duration of worsened symptoms was In order to compare the results of this study more directly with those from previous exacerbation trials, a post hoc analysis was conducted, which used a more generalised classification of exacerbation severity based on HRU and treatment use. Using this classification, tiotropium significantly reduced both the proportion of patients experiencing a moderate-to-severe exacerbation and the number of moderate-to-severe exacerbations compared with placebo.
Tiotropium also reduced the number of exacerbations, irrespective of COPD severity (based on FEV1) at baseline. Furthermore, tiotropium lowered the number of exacerbations in patients who had frequent exacerbations in the previous year and in those receiving ICS during the trial. The improvement with tiotropium did not reach statistical significance in patients who had infrequent exacerbations in the previous year and in those not receiving ICS during the trial, but the study was not adequately powered to detect these differences. However, the results indicate that treatment with tiotropium is beneficial even in patients with less severe COPD (FEV1 >50% pred), as well as patients with more severe disease (FEV1 The mechanisms by which tiotropium reduces exacerbations remain to be identified. Tiotropium may have a direct anti-inflammatory effect 22. Alternatively, the reduction in exacerbations may be explained, in part, by the sustained bronchodilation and consequent reduction in lung hyperinflation afforded by maintenance tiotropium treatment. Airflow limitation (the most prominent physiological impairment in COPD) causes hyperinflation when there is insufficient expiratory time for adequate lung emptying. This causes the patient to feel dyspnoeic very quickly when the respiration rate is increased, for example, during exercise or an exacerbation. In this study, treatment with tiotropium led to significant improvements in PEF, FEV1, FVC, SVC and IC compared with placebo. These findings confirm previous observations from large-scale studies demonstrating that tiotropium provided significant improvements in airflow and lung volume parameters 812. The present authors propose that the sustained reduction in hyperinflation (as indicated by a significant reduction in IC) may allow patients to withstand an insult for longer before experiencing intolerable dyspnoea (a key symptom during an exacerbation 23). In other words, whereas patients may previously have perceived an acute deterioration in their condition as an exacerbation, after recalibration of their operating lung volumes with tiotropium treatment, their symptoms become better tolerated.
Improved knowledge of the time course and duration of physiological changes during an exacerbation would facilitate the administration of appropriate and timely care. In this study, PEF declined A reduction in the frequency of exacerbations or in the time to exacerbation is likely to reduce HRU, which, in turn, should reduce the cost of COPD management. In the present study, tiotropium significantly reduced HRU, as indicated by a significant decrease in the use of concomitant respiratory medication, antibiotics and oral steroids, as well as the number of unscheduled physician contacts. The inclusion criteria in this study were such that HRU focused mainly on outpatient treatment. Nevertheless, patients treated with tiotropium had numerically fewer hospitalisations and hospital days compared with those treated with placebo. Although the differences between groups were not statistically significant, the results are in agreement with those from previous studies, which have shown that tiotropium significantly delayed the time to first hospitalisation compared with ipratropium 9, and reduced the number of both hospitalisations and hospitalisation days compared with placebo 8, 9. As hospitalisation is a large contributor to the cost of COPD, the addition of tiotropium to usual care therapy may reduce the economic burden of this disease (excluding the acquisition cost of the drug) 14. Reducing physician visits and the use of concomitant medications are also of economic benefit. In conclusion, this study found that, compared with placebo, administration of tiotropium 18 µg once daily for 48 weeks reduced the frequency of exacerbations, with concomitant benefits in healthcare resource utilisation and improved airflow limitation. The beneficial effect of treatment with tiotropium was observed irrespective of inhaled corticosteroid use during the trial, chronic obstructive pulmonary disease severity and exacerbation history at baseline.
The authors gratefully acknowledge the provision of medical writing services from PAREXEL MMS. The MISTRAL (Mesure de l'Influence de Spiriva® sur les Troubles Respiratoires Aigus à Long terme) study group is made up of the following investigators located in France. Abbeville: O. Leleu; Agen: G. Esculpavit; Aix Les Bains: O. Deschamps; Albi: B. Carme, J-J. Innocenti, F. Malaquin; Amboise: B. Lemmens; Amiens: V. Dinnoo; Angers: P. Moneger, L. Savary, R. Thuilier; Annecy: Y. Maria; Annonay: P. Gaillot; Antibes: J-M. Chavaillon, L. Lerousseau; Aubagne, Marseille: G. Thomas, D. Chollet; Aubergenville: P. Chaumier, C. Guelaud; Auch: J-C. Bersia; Auxerre: M. Piffoux; Avrillé: N. Tolstuchow; Barbezieux: R. Meunier; Beausoleil: F. Bonnaud Belfort: D. El Baz, B. Richaud-Thiriez; Beziers: G. Durand, J-P. Dussol, J-C. Severac, M. Terol; Bobigny: F. Girard, D. Valeyre, H. Nunes; Bois Guillaume: J-F. Muir, A. Cuvelier; Bordeaux: J-M. Dupis, I. Hamy Marthan, P. Henrion, J. Vergeret; Boulogne Billancourt: J-F. Foult; Bourges: F. Bonte, J-C. Dassonneville, G. Adam, G. Desrivot, A. Levy, M. Mornet; Bourgoin-Jallieu: J-F. Bessonnat, J. Brunel-Crova; Bry Sur Marne: A. Bedin; Caen: P. Guillais, A. Guillo Lohan; Caluire: G. Chatte, M. Colas; Cambrai: S. Beaujot; Carcassonne: P. Chr. Carre, R. Perisse; Carpentras: M. Dedieu; Chalon Sur Saone: O. Jarry; Chambery: G. Gaudilliere; Chateauroux: O. Chauvin-Veron; Chauny: L. Bernabeu; Chevilly La Rue: M. Angebault, J-P. Homasson; Cholet: N. Grunchec, D. Krai, P. Masson-Maury; Clermont Ferrand: D. Caillaud; Colmar: M. Schaller; Cornebarrieu: P. Mourlanette, P. Debove; Courbevoie: V. Davy, C. Marie-Laure Debin; Dole: G. Sfeir; Douai: F. Pagnier, P. De Tauriac, A. Kaluzy; Dunkerque: C. Deroubaix, B. Mellin, G. Trochu; Eaubonne: P. Dournovo, S. Remili; Epernay: E. Bongrain, M. Carbonnelle; Ermont: M. Monchatre; Grasse: P. Dugue, M. Gomez-Figueredo, M-C. Dumon, B. Fouquert-Gau; Grenoble: J. Girey-Rannaud, M. Kuentz-Rousseaux, C. Grange, L. Chavez, B. Hamm, D. Rigaud, P. Satre; Guise: S. Kuissu; Hagondange: J-M. Zordan; Henain Beaumont: E. Fournier, R. Roboubi; Langon: G. Fadlallah; La Rochelle: C. Gendreau; La Roche Sur Yon: O. Maurisset; La Teste: D. Boz, M. Denis; Le Cannet: C. Tabutin; Le Chesnay: R. Azarian, C. Camus-Cartraud, P. Kasparian, J-F. Le Calvez, P. Petitpretz; Le Mans: S. Girard, F-X. Lebas, I. Simon, F. Goupil, M. Pottier; Le Plessis Robinson: P. Herve; Libourne: B. Le Brozec, Y. Plantard; Lille: A-B. Tonnel, A. Scherperel, T. Perez, I. Tillie-Leblond, C. Deswarte-Antonius, J-J. Lafitte, C. Croxo, E. Dansin, P. Delecluse, P. Ramon; Limoges: G. Michel, P. Bourras, B. Wendling, F. Bonnaud, F. Vincent, B. Melloni, A. Vergnenegre, B. Eichler, F. Touraine; Lomme: A. Darras; Longjumeau: P. Assouline, A. Kabbani, G. Oliviero; Lorient: J-Y. Rigault; Lunel: C. Paillarguelo; Luneville: F. Chiny; Lyon: J-C. Guerin, A. Agresti, P. Nesme, M. Germain, P. Hyvernat, A. Penet, J-Y. Bayle, R. Ferrenq-Dubost; Marseille: H. Pegliasco, D. Charpin, M. Gouitaa; Martigues: H. Jullian; Maxeville: J-F. Bic, G. Issartel, L. Moreau; Metz: P. Zuck, G. Peiffer, M. Boukhana; Millau: F. Tronc; Montargis: C. Artigas, M. Daher; Montauban: B. Denis, F. Tirouvanziam; Montbeliard: C. Bertin, V. Robert; Mont De Marsan: B. Etcheverry; Montfermeil: Cyril Maurer, J. Piquet; Montigny Les Metz: D. Muller; Montivilliers: Chr. Dominique Guyonnaud, J. Quieffin; Montpellier: P. Chanez, L. Meziane, R. Clavel, P. Michel Coulet; Moulins: P. Duband; Nanterre: C. Appere, I. Caby, M. Saillour; Nantes: H-P. Audouin, S. Boutet Madrange, D. Payerne, J-Y. Jasnot; Narbonne: M. Benosmane, A. Fraisse, F. Trigui; Nevers: D. Herman, B. Meunier; Nice: A. Bettendorf, C. Perrin, B. Blaive, C. Clary, F. Lemoigne, I. Nicole, R. Tamisier, F. Macone, L. Limouse, B. Pigearias, B. Bugnas; Nimes: H. Faucal, O. Benezet, J. Dupouy, M. Yacono, M. Taulelle; Niort: D. Dutartre; Nogent Le Rotrou: P. Vivet; Noisy Le Sec: R. Kamte Yowou; Ollioules: P. Greillier, B. Terol, C. Pacchioni, J-J. Roujon, P. Salletaz, J-L. Vialla; Orleans: J. Durieu, A. Perche; Pamiers: J. Dakhil; Paris: D. Dusser, L. Tecucianu, N. Dufeu, T. Bui-Quang, M. Aubier, L. Hafi, F. Gagnadoux, M-L. Debin, G. Huchon, A. Mounejdi, J-C. Pujet, T. Baleyte Desfemmes; Perigueux: J-Y. Delhoume, F. Raad; Perpignan: B. Lirsac, M. Verdier, C. Sevette; Pierre Benite: F. Gormand, Y. Pacheco, S. Najda, R. Harf, S. Jerome; Poitiers: F. Caron, J-C. Meurice; Rambouillet: Y. Jerzy Scholz; Rang Du Fliers: M. Awad, C. Aron; Reims: J-B. Jouet, F. Masure, F. Passemard; Remiremont Cedex: Z. Bavelele, A. Kheir; Rennes: P. Delaval, C. Belleguic, B. Desrues, G. Le Garff, H. Lena; Romans Sur Isere: P. Gil; Rouen: G. Nouvet, S. Bota, J-B. Auliac, B. Melen, P. Denis; Saint Denis De La Reunion: F. Paganin, M-F. Angelini; Saintes: P. Bellvert; Saint Jean De Luz: J. Saint-Pie; Saint Martin Boulogne: P-A. Maignan; Saint Pierre: C. Arvin-Berod, P. Poubeau; Saint Quentin: T. Fontaine, H. Kafe, P. Rohart; Salon De Provence: B. Hugues; Saumur: B. Thomas; Selesta: S. Taieb; Sete: A. Rigaud; Soissons: A. Ittah, D. Proisy; St Aubin Les Elbeuf: P. David, C. Vincent; St Brieuc: P. Bihet; St Denis: D. Penaud; St Die: E. Marangoni; St Etienne: D. Mounier; Ste Feyre: S. Jeandeau; St Laurent Du Var: G. René Boyer; St Nazaire: X. D'arco, J. Garnier, E. Michaud, A. Berthier; Tarbes: A. Prud'homme, J. Courdeau-Laborie, J-A. Silvani; Tergnier: M. Monsigny; Thionville: Y. Bassegoda, A. Beraud, J. Duc, D. Logros, A. Plaindoux; Toul: M-A. Vincent; Toulouse: C. Aldegheri, C. Raspaud, D. Giamarchi, C. Hermant, M. Krempf, H. Perelroizen, P. Bernard; Tours: J-P. Maffre; Troyes: J-P. Hurdebourcq; Tulle: J-L. Bouyer; Vandoeuvre: X. Feintrenie, B. Mouget, J-M. Polu; Vendome: S. Hourie; Verdun: J-C. Cornu; Villefranche Sur Saône: L. Falchero; Villeneuve Sur Lot: A. Razafimdramboa; Voiron: M-H. Laussedat.
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