Predictive Markers of the Effects of Opioid Therapy

The overall goal of the ABILITY study is to help improve pain diagnostics and treatment by developing an implementable clinical computerised decision support system based on individual patient characteristics. The investigators hypothesize that successful pain control with opioids can be predicted before treatment initiation with advanced data analyses of data originating from pre-treatment EEG, QST and pain-related catastrophic thinking. The primary objective of this study is the identification of markers that can be used to individualize treatment recommendations, i.e. to reliably predict the response of pain to opioids. Markers are selected among the most promising data and machine-learning methods are used for the prediction. This includes determining the associations between a battery of selected pre-treatment clinical predictive markers and the analgesic effect of opioid treatment in opioid naïve chronic pain patients, including indication and responder identification. The key secondary objectives are as follows: to investigate pre-treatment clinical predictive markers as predictors of opioid treatment efficacy and effectiveness in terms of the following: * Pain intensity and unpleasantness * Use of rescue analgesics * Physical functioning * Global improvement and satisfaction with treatment