Medical researchers use both randomised clinical trials and observational studies to test the effectiveness and safety of medical treatments. In randomised control trials, patients are allocated to receive the study drug or a comparator by a computer programme based on random chance alone. This process is designed to minimise differences between the two groups. Data is collected outside of the normal treatment setting through a combination of clinical measurements and questionnaires. Observational studies compare patients prescribed different treatments in the real world, often using routinely collected healthcare data. Statistical methodologies are used to minimise bias caused by differences in patients who receive different treatments. In the ideal world, clinical trial and observational methodologies would be combined in pragmatic clinical trials where patients are randomised to treatment within the normal clinical environment. Data would be collected in everyday clinical care.
The Clinical Practice Research Datalink (CPRD) provides a suitable environment in which to conduct pragmatic clinical trials for diseases that are treated by General Practitioners. These include the long term respiratory condition, Chronic Obstructive Pulmonary Disease (COPD). This feasibility study will use anonymised data to count and describe patients with COPD who might be eligible for future pragmatic clinical trials.
The purpose of this study is to provide the descriptive data necessary for an initial assessment of the potential to conduct future point of care randomised trials in COPD in CPRD practices. We will estimate the number of patients actively enrolled at CPRD practices on July 1st 2016, describe the patient characteristics and estimate the frequency of treatment change in the 6 months prior to the index date as a proxy for understanding how frequently patients will reach clinical equipoise and be eligible for recruitment into a clinical trial. In a cohort of COPD patients who were actively registered in CPRD practices on July 1, 2011 (and whose practice still contributed to CPRD on July 1, 2016), we will describe the distribution of follow-up time, reasons for loss to follow-up and mortality rates for the COPD patients using crude Kaplan Meier curves. Analyses will be conducted separately for practices using the different GP software systems (Vision and EMIS). Additional analyses will be conducted for ‘research active’ practices, patients who are eligible for linkage with secondary care data, COPD patients with spirometry measurements in their record and patients with a change in maintenance therapy.
Jeanne Pimenta - Chief Investigator - BioMarin Pharmaceutical Inc.
Jeanne Pimenta - Corresponding Applicant - BioMarin Pharmaceutical Inc.
Achim Wolf - Collaborator - CPRD
Anna Higgins - Collaborator - Not from an Organisation
Daniel Dedman - Collaborator - CPRD
Jennifer Campbell - Collaborator - CPRD
Jennifer Quint - Collaborator - Imperial College London
John Logie - Collaborator - GlaxoSmithKline Research & Development Limited (UK)
Rachael Williams - Collaborator - CPRD
Sarah Landis - Chief Investigator - BioMarin Pharmaceutical Inc.
Helen Strongman - Corresponding Applicant - London School of Hygiene & Tropical Medicine ( LSHTM )
Mark Wright - Collaborator - CPRD
Mugdha Gokhale - Collaborator - GlaxoSmithKline - UK
HES Admitted Patient Care;Practice Level Index of Multiple Deprivation