Main Article Content
Administrative database, inhaled corticosteroids, persistence, adherence, private drug insurance
Despite important differences in reimbursement procedures between private and public drug insurance plans in Quebec (Canada), no study has evaluated the impact of the type of drug insurance on the use of essential medications such as inhaled corticosteroids (ICS). The lack of data might be attributable, at least in part, to the absence of a provincial medication database for patients with private drug insurance.
To compare patient’s adherence and persistence to ICS between Quebec residents (Canada) with private and public drug insurance.
A matched cohort design with patients selected from the database of the Régie de l’assurance maladie du Québec (RAMQ) and from reMed, a database that we have put in place for Quebec residents covered by a private drug insurance, was used. ICS users with private drug insurance were selected from reMed between 2008 and 2010 and matched to ICS users with public drug insurance selected from the RAMQ database. Patient’s adherence, measured with the proportion of prescribed days covered (PPDC) and persistence over one year, was compared between patients privately and publicly insured using linear regression and Cox regression models.
This study included 330 and 1,109 ICS users with private and public drug insurance, respectively. Patients privately insured were significantly less adherent than patients publicly insured (adjusted mean difference of PPDC: -9.7%; 95% CI: -13.2% to -6.5%). Moreover, patients privately insured were found to be 52% more likely to stop ICS during the first year than patients publicly insured (adjusted HR=1.5; 95% CI: 1.2 to 2.0).
Although adherence and persistence were rather low in both groups, patients with public drug insurance appeared to have greater adherence and persistence to ICS than patients with private drug insurance. Differences in reimbursement policies might explain the observed differences.
2. Bateman ED, Hurd SS, Barnes PJ, et al. Global strategy for asthma management and prevention: GINA executive summary. Eur Respir J 2008;31:143-178.
3. Lougheed MD, Lemiere C, Dell SD, et al. Canadian Thoracic Society Asthma Management Continuum--2010 Consensus Summary for children six years of age and over, and adults. Can Respir J 2010;17:15-24.
4. Reddel HK, Taylor DR, Bateman ED, et al. An official American Thoracic Society/European Respiratory Society statement: asthma control and exacerbations: standardizing endpoints for clinical asthma trials and clinical practice. Am J Respir Crit Care Med 2009;180:59-99.
5. Blais L, Kettani FZ, Beauchesne MF, Lemiere C, Perreault S, Forget A. New measure of adherence adjusted for prescription patterns: the case of adults with asthma treated with inhaled corticosteroid monotherapy. Ann Pharmacother 2011;45:335-341.
6. Bukstein DA, Henk HJ, Luskin AT. A comparison of asthma-related expenditures for patients started on montelukast versus fluticasone propionate as monotherapy. Clin Ther 2001;23:1589-1600.
7. Delea TE, Hagiwara M, Stanford RH, Stempel DA. Effects of fluticasone propionate/salmeterol combination on asthma-related health care resource utilization and costs and adherence in children and adults with asthma. Clin Ther 2008;30:560-571.
8. Ivanova JI, Birnbaum HG, Hsieh M, et al. Adherence to inhaled corticosteroid use and local adverse events in persistent asthma. Am J Manag Care 2008;14:801-809.
9. Stempel DA, Mauskopf J, McLaughlin T, Yazdani C, Stanford RH. Comparison of asthma costs in patients starting fluticasone propionate compared to patients starting montelukast. Respir Med 2001;95:227-234.
10. Williams LK, Pladevall M, Xi H, et al. Relationship between adherence to inhaled corticosteroids and poor outcomes among adults with asthma. J Allergy Clin Immunol 2004;114:1288-1293.
11. Williams LK, Peterson EL, Wells K, et al. A cluster-randomized trial to provide clinicians inhaled corticosteroid adherence information for their patients with asthma. J Allergy Clin Immunol 2010; 126:225-31, 231.
12. Breekveldt-Postma NS, Gerrits CM, Lammers JW, Raaijmakers JA, Herings RM. Persistence with inhaled corticosteroid therapy in daily practice. Respir Med 2004;98:752-759.
13. Cramer JA, Bradley-Kennedy C, Scalera A. Treatment persistence and compliance with medications for chronic obstructive pulmonary disease. Can Respir J 2007;14:25-29.
14. Dorais M, Blais L, Chabot I, LeLorier J. Treatment persistence with leukotriene receptor antagonists and inhaled corticosteroids. J Asthma 2005;42:385-393.
15. Marceau C, Lemiere C, Berbiche D, Perreault S, Blais L. Persistence, adherence, and effectiveness of combination therapy among adult patients with asthma. J Allergy Clin Immunol 2006;118: 574-581.
16. Rand C, Bilderback A, Schiller K, Edelman JM, Hustad CM, Zeiger RS. Adherence with montelukast or fluticasone in a long-term clinical trial: results from the mild asthma montelukast versus inhaled corticosteroid trial. J Allergy Clin Immunol 2007;119:916-923.
17. Institut de la statistique du Québec (ISQ). Population du Québec, 1971-2012. Statistique Canada, Estimation de la population, 2012 (Accessed February 4, 2010 http://www.stat.gouv.qc.ca/donstat/societe/demo graphie/struc_poplt/qc_1971-20xx.htm).
18. Régie de l'assurance maladie du Québec. Statistiques annuelles RAMQ - 2009. Tableau AM.6. Régie de l'assurance maladie du Québec, 2009. Available from: https://www.prod.ramq.gouv.qc.ca/IST/CD/CD F_DifsnInfoStats/CDF1_CnsulInfoStatsCNC_iu t/RappPDF.aspx?TypeImpression=pdf&NomPd f=CCB3R01A_AM06_2009_0_O.PDF
19. Goldman D, Joyce G, Zheng Y. Prescription drug cost sharing association with medication and medical utilization and spending and health. JAMA 2007;298:61-69.
20. Rice T, Lavarreda SA, Ponce NA, Brown ER. The impact of private and public health insurance on medication use for adults with chronic diseases. Medical Care Research and Review 2005;62: 231-249.
21. Tamblyn R, Lavoie G, Petrella L, Monette J. The use of prescription claims databases in pharmacoepidemiological research: the accuracy and comprehensiveness of the prescription claims database in Quebec. J Clin Epidemiol 1995;48:999-1009.
22. Pilote L, Lavoie F, Ho V, Eisenberg MJ. Changes in the treatment and outcomes of acute myocardial infarction in Quebec, 1988-1995. CMAJ 2000;163:31-36.
23. Martel MJ, Rey E, Beauchesne MF, et al. Use of inhaled corticosteroids during pregnancy and risk of pregnancy induced hypertension: nested case-control study. BMJ 2005;330:230.
24. WHO Collaborating Centre for Drug Statistics Methodology. Guidelines for ATC classification and DDD assignment 2011. 14th ed ed. Oslo, Norway: WHO Collaborating Centre for Drug Statistics Methodology; 2010.
25. Health Canada. Drug Product Database. Drugs and Health Products, Health Canada, 2010 (Accessed April 4, 2010 http://www.hcsc. gc.ca/dhpmps/ prodpharma/databasdon/index-eng.php).
26. Régie de l'assurance maladie du Québec. Amount to pay for prescription drugs. Régie de l'assurance maladie du Québec, 2011 (Accessed April 15, 2011 http://www.ramq.gouv.qc.ca/en/citoyens/assuran cemedicaments/regimesprives/lescouts_contribu tionannuellemaximale.shtml).
27. Hess LM, Raebel MA, Conner DA, Malone DC. Measurement of adherence in pharmacy administrative databases: a proposal for standard definitions and preferred measures. Ann Pharmacother 2006;40:1280-1288.
28. Greenland S. Modeling and variable selection in epidemiologic analysis. Am J Public Health 1989;79:340-349.
29. Rothman KJ, Greenland S, Last TL. Modern epidemiology. 3rd ed ed. Philadelphia: Wolters Kluwer LippincottWilliams &Wilkins; 2008.
30. CYR MC, Blais L, Beauchesne MF, et al. The use of prescribed medications among residents of Quebec covered by a private drug insurance plan: results from the reMed pilot study. Pharmacoepidemiol Drug Saf 2009;18:184.
31. Bernèche F, Dumitru V. Données sociale du Québec, Chapitre 2 Santé: perceptions et comportements. Satistique Canada, Enquête sur la santé dans les collectivités canadiennes, cycle 3 1 (2005-2006), Fichier de microdonnées à grande diffusion(FMGD) Compilation Institut de la statistque du Québec (ISQ), 2009. Available from: http://www.stat.gouv.qc.ca/publications/conditio ns/pdf2009/donn_sociale09c2.pdf
32. Indice de masse corporelle (norme internationale), population de 20 à 64 ans excluant les femmes enceintes, Québec et régions sociosanitaires. Satistique Canada, Enquête sur la santé dans les collectivités canadiennes, cycle 3 1 (2005-2006), Fichier de microdonnées à grande diffusion(FMGD) Compilation Institut de la statistque du Québec (ISQ), 2008. Available from: http://www.bdso.gouv.qc.ca/pls/ken/p_afch_tabl _clie?p_no_client_cie=FR&p_param_id_raprt=9 08
33. ESI Canada. ESI Canada 2007 Drug Trend Report. ESI CANADA, 2008. Available from: http://www.esicanada. com/aboutus/outcomes/2008/ESI_Canad a_2007_Drug_Trend_Report.pdf
34. ESI Canada. Health Newsflash-Therapeutic Class Ranking (Top 100 Ranked by Claim Cost) Prescriptions filled from 01/2006 through 12/2006 compared to 01/2007 through 12/2007 Quebec. No. 2. 2008.10. Available from: http://www.esicanada. com/aboutus/news/health_newsflashes/V olume_10_Issue2_TherapyClasses_Qc.pdf
35. Janson SL, Earnest G, Wong KP, Blanc PD. Predictors of asthma medication nonadherence. Heart Lung 2008;37:211-218.
36. Lynd LD, Guh DP, Pare PD, Anis AH. Patterns of inhaled asthma medication use: a 3-year longitudinal analysis of prescription claims data from British Columbia, Canada. Chest 2002;122: 1973-1981.