Epidemiological study assessing the treatment gaps for COPD patients managed with maintenance bronchodilators in Quebec.

Trial description: Background: Chronic Obstructive Pulmonary Disease (COPD) affects over 770,000 Canadians or 4% of those over the age of 35 years. The disease is the leading cause of all hospitalizations in Canada with direct health care costs being over 1.5 billion dollars per year (1-7). To date there is no cure for COPD and patient management is focused on managing symptoms, reducing the severity and frequency of exacerbations and improving the patient’s quality of life (8-11). For patients with mild COPD the Canadian Thoracic Society recommends initiating treatment with Short Acting Bronchodilators (SABD), including anti-cholinergics and beta-2 agonists, as required (prn) (12). For patients with moderate COPD and less than one exacerbation per year, the CTS recommends initiating treatment with LAMA or LABA monotherapy; if symptoms and disability persist treatment with LAMA + LABA is recommended; if disability and treatment persist, then treatment with LAMA + Low Dose Inhaled Corticosteroid in combination with LABA (ICS/LABA) is recommended (12). For patients with severe COPD and more than 1 exacerbation per year the CTS recommends treatment with LAMA + ICS/LABA + SABA followed by the addition of theophylline when disability and symptoms persist (8-18). Despite these recommendations, a large proportion of patients are on maintenance therapy with LAMA or LABA as monotherapy or LAMA + LABA open dual therapy without ICS. It follows that patients that have not been treated according to this recommendation may have received suboptimal care, in the context of what is currently considered best practice.Primary Objective:To describe the treatment gap, as assessed by noncompliance with current CTS guidelines, for COPD patients having had an exacerbation managed with LAMA or LABA as monotherapy or LAMA/LABA dual therapy.Study Design:This is an administrative database study using the databases of the Regie de l’assurance maladie du Quebec (RAMQ). The study sample will consist of the cohort of patients initiated on treatment for COPD with LAMA or LABA monotherapy, LAMA + LABA double therapy or LAMA + LABA + ICS/LABA triple therapy between January 1st, 2001 and December 21st, 2010. Patients will be followed to their last known claim, death or March 31, 2011.Study Population and Sampling Methods: Patients will be selected by identifying all those in the database who had at least one medical claim with a diagnosis of COPD (ICD-9: 490.xx, 491.xx, 492.xx or 496.xx) between January 01, 2001 and December 31, 2010. Datasource:This study will be conducted with the administrative databases of the RAMQ and MedEcho.Data Analysis Methods:Descriptive statistics will be produced for all relevant study variables including patient characteristics, disease parameters, treatments and outcome measures as described in previous sections. More specifically for continuous scale variables the descriptive statistics will be comprised of the mean, median, standard deviation and 95% confidence interval of the mean. For categorical scale variables frequency distributions will be produced with 95% confidence intervals of the proportion estimates. In addressing the primary objective of the study, the independent variable will be the occurrence of a COPD exacerbation and the dependent variable will the treatment received following the exacerbation. The primary objective will be addressed by describing the proportion of patients in groups A (Possible Over Treatment*), B (Appropriate Treatment), C (Appropriate Treatment) and D (Suboptimal Treatment) above but with an emphasis on the proportion of patients with one or more exacerbations that did not receive triple therapy (D/(B+D)). Ninety five percent confidence intervals will be computed for the assessment of precision. The analysis will be repeated for relevant subgroups of patients defined according to age, duration of disease, presence of comorbidities and prior treatment for COPD.*This is possible over-treatment although the use of triple therapy may be based on increased symptom severity.Sample Size and Power:The study cohort will include more than 35,000 patients. It is expected that this sample size will be sufficient to address all the study objectives with acceptable precision.Limitations:The limitations of the current study include those that are characteristic of administrative database studies the most important being: lack of clinical and laboratory data; diagnoses and treatments based on ICD codes and claims submissions; diagnosis of COPD may not be accurate in administrative databases; and, classification of appropriate treatment with triple therapy will be based on the presence of a COPD exacerbation.