Long-term opioid therapy in chronic non-cancer pain. Prevalence, signs of opioid use disorder and methods for tapering in a tertiary pain unit setting.

This thesis strives to describe or answer the following questions in a chronic non-cancer pain population visiting Smärtrehabilitering Skånes Universitetsjukhus Lund during the period 2015-2020 either as participants at a single visit for pain assessment, participants in multidisciplinary pain rehabilitation program or participants in a randomized controlled study:
Paper 1. Description of a randomized controlled study (RCT) on tapering opioids, TOPIO. https://clinicaltrials.gov/ct2/show/NCT03485430 The RCT aims to assess:
a. Efficiency of a structured intervention in causing stable reductions of opioid consumption in a population with long-term non-malignant pain.
b. Effects on pain, pain cognitions, physical and mental health, life quality and functioning by opioid tapering.
c. If prognostic factors for outcome can be identified.
Paper 2. A cross-sectional study describing the prescription patterns of opioid use among patients with complex chronic pain conditions attending a multidisciplinary assessment during 2015-2017.
Paper 3. Case-control study. The outcome of multidisciplinary pain rehabilitation in relation to opioid exposure at baseline is assessed in a case-control study. Does opioid exposure predict rehabilitation outcome? The result of tapering in connection to pain-rehabilitation program is also examined in a subgroup analysis among opioid exposed. A successful tapering is defined as a reduction of dispensed opioids to 50% or less than at baseline.
Paper 4. A cross-sectional study describing the prescription patterns of opioid use and signs of opioid use disorder among patients with complex chronic pain receiving prescriptions of opioids due to chronic pain. To what extent is signs of opioid use disorder observed by pain physicians at the time of assessment? Is there a fair correlation in the measurement of milligram morphine equivalent dose per day (MME/day) between data reported by patients as daily dose opioids in relation to data of dispensed opioids registered in Swedish Prescribed Drug Register (SPDR) with MME/day calculated as an average of all dispensations during a 90-days period?
Main databases are: From Swedish Prescribed Drug Register (SPDR) exposure to dispensed opioids is extracted and data concerning the pain condition, physical and mental health and demographics are collected from Swedish Quality Registry for Pain Rehabilitation (SQRP).