Original ArticlesDo Individualized Medication Effectiveness Tests (N-of-1 Trials) Change Clinical Decisions About Which Drugs to Use for Osteoarthritis and Chronic Pain?Nikles, C. Jane1*; Yelland, Michael1; Glasziou, Paul P.2; Del Mar, Chris3 Author Information 1Discipline of General Practice, The University of Queensland, Herston, Queensland, Australia; 2Department of Primary Health Care, Centre for Evidence-Based Practice, Oxford University, Oxford, United Kingdom; 3Bond University, Gold Coast, Queensland, Australia. Statement of competing interests: General Practice Evaluation Program and the Department of Health and Aged Care provided funding but had no involvement in any facet of the research. GlaxoSmithKline provided medication and placebos and funding; participated in initial planning discussions; and viewed the manuscript prior to publication but had no involvement in the collection, analysis, or interpretation of data, writing the report, or the decision to submit the final manuscript for publication. In the past 5 years, Paul Glasziou has received reimbursement for attending a symposium and a fee for speaking as well as funds for research and a member of staff. Michael Yelland and Chris Del Mar have received funds for research. Jane Nikles was a member of staff partly supported by these funds. Contributors: Jane Nikles set up and coordinated the chronic pain IMET and the IMET project, collected some data, conducted data analysis, and drafted and finalized the paper. Michael Yelland provided clinical input, assisted with design of questionnaires, took overall responsibility for the chronic pain IMET, and had input in writing the paper. Chris Del Mar obtained the original grant, provided clinical input, assisted with design of questionnaires, and had input in writing the paper. Paul Glasziou obtained the original grant, provided clinical input, assisted with design of questionnaires, took overall responsibility for IMET project, and had input in writing the paper. Alexandra Clavarino assisted with design of questionnaires. Dr. Chris Poulos and Dr. Lisa Sherry provided support and help in recruiting patients. Cate Duggan, Tina Janamian, Peter Coxeter, Cate Del Mar, Sharyn Herzig, Julie King, Jacob Carter, Donna-Marie Preston, Robyn Brown, and Norma McNairn collected the data. Guarantor: C. Jane Nikles. *Address for correspondence: Discipline of General Practice, The University of Queensland, Herston Road, Herston, Queensland, Australia, 4006. E-mail: [email protected] American Journal of Therapeutics: January 2005 - Volume 12 - Issue 1 - p 92-97 Buy Abstract To assess the impact of individualized medication effectiveness tests (IMETs, or n-of-1 trials), on patients' short-term decision making about medications for chronic pain. Survey evaluation of patients undergoing a double-blind, crossover comparison of drug versus placebo, drug versus drug, or drug versus drug combination using paracetamol and ibuprofen in 3 pairs of treatment periods, randomized within pairs. General practice patients (supplemented by a few from 2 tertiary pain clinics) with either chronic pain (≥3 months), or osteoarthritis (with pain for ≥1 month) severe enough to warrant consideration of long-term nonsteroidal antiinflammatory drug (NSAID) use but for whom there was doubt about the efficacy of NSAID or alternative. Pain and stiffness in sites nominated by the patient, global pain, use of escape analgesia, and side effects. Of 116 IMETs started, 71 were completed. Drug management changed for 46 of 71 (65%). The most common change was to add paracetamol or to substitute the NSAID or COX-2 inhibitor with paracetamol (25 of 71 patients and 54% of changes). Of the 37 who were using NSAIDs or COX-2 inhibitors before the IMET, 12 (32%) ceased these afterward. Paracetamol was as effective or more effective than ibuprofen in 37 (68%) of the 54 IMETs directly comparing these drugs. IMETs provide useful information for clinical decisions. Paracetamol continues to be useful for patients with chronic pain whose optimal drug choice is in doubt. Our results provide a new (individual) perspective on the well-known recommendation for paracetamol as first-line treatment for chronic pain and demonstrate that it is feasible to provide IMETs nationally by mail and telephone. © 2005 Lippincott Williams & Wilkins, Inc.