Clarke H, Soneji N, Ko DT, Yun L, Wijeysundera DN Rates and risk factors for prolonged opioid use after major surgery: population based cohort study. BMJ. 2014 Feb 11;348:g1251. doi: 10.1136/bmj.g1251.
Fletcher D, Martinez V Opioid-induced hyperalgesia in patients after surgery: a systematic review and a meta-analysis. Br J Anaesth. 2014 Jun;112(6):991-1004. doi: 10.1093/bja/aeu137.
Katz J, Seltzer Z Transition from acute to chronic postsurgical pain: risk factors and protective factors. Expert Rev Neurother. 2009 May;9(5):723-44. doi: 10.1586/ern.09.20.
Portenoy R Development and testing of a neuropathic pain screening questionnaire: ID Pain. Curr Med Res Opin. 2006 Aug;22(8):1555-65. doi: 10.1185/030079906X115702.
Rampakakis E, Ste-Marie PA, Sampalis JS, Karellis A, Shir Y, Fitzcharles MA Real-life assessment of the validity of patient global impression of change in fibromyalgia. RMD Open. 2015 Sep 14;1(1):e000146. doi: 10.1136/rmdopen-2015-000146. eCollection 2015. Erratum In: RMD Open. 2015;1(1):e000146corr1.
Savage SR Long-term opioid therapy: assessment of consequences and risks. J Pain Symptom Manage. 1996 May;11(5):274-86. doi: 10.1016/0885-3924(95)00202-2.
Tan G, Jensen MP, Thornby JI, Shanti BF Validation of the Brief Pain Inventory for chronic nonmalignant pain. J Pain. 2004 Mar;5(2):133-7. doi: 10.1016/j.jpain.2003.12.005.
Wicksell RK, Renofalt J, Olsson GL, Bond FW, Melin L Avoidance and cognitive fusion--central components in pain related disability? Development and preliminary validation of the Psychological Inflexibility in Pain Scale (PIPS). Eur J Pain. 2008 May;12(4):491-500. doi: 10.1016/j.ejpain.2007.08.003. Epub 2007 Sep 20.
Ontario Transitional Pain and Opioid Safety Program: Improving Pain and Opioid Practices for Complex Chronic Pain Patients Following Surgery
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.
