Cyclooxygenase-2 Inhibitors (COX-2) are drugs which are used to treat pain and inflammation. They have been found to prevent the development of a certain type of brain tumour, the so-called glioma, in experiments performed on cells. Whether these drugs also may reduce the likelihood of glioma developing in humans is unknown.
We propose to conduct a study using the U.K.-based Clinical Practice Research Datalink (CPRD) to compare use of these pain reducing drugs among patients with a glioma diagnosis and among patients without a diagnosis of glioma. Patients with glioma will be individuals younger than 90 years of age with a first-time diagnosis of glioma between 1995 and 2015. We will identify ten patients without glioma from the same general practice and compare these patients to those with a diagnosis of glioma. Patients without glioma will be of the same age, sex and have been registered for the same number of years at the practice.
We propose to conduct a 1:10 matched case-control analysis using the CPRD to test the hypothesis that use of COX-2 inhibitors is associated with decreased risk of glioma. We will conduct conditional logistic regression analyses to determine relative risks, estimated as odds ratios (ORs) with 95% confidence intervals (CIs) of glioma in relation to use of COX-2 inhibitors. Analyses will be adjusted for various potential confounding variables and only variables altering the risk of glioma by >10% will be included in the final multivariate analysis. The effects of exposure to COX-2 inhibitors will be compared to the effects of other non-selective NSAIDs (diclofenac, ibuprofen, naproxen, and aspirin) and non-NSAID analgesics (paracetamol, opioids). We will shift the date of diagnosis backward in time by one year for cases and controls. Missing data will be included in a separate category in the logistic regression model.
Health Outcomes to be Measured: