Background and aims:
Interdisciplinary multimodal pain therapy (IMPT) is a bio-psycho-social intervention to treat chronic non-cancer pain. To solve the problem of heterogeneity in outcome measurement in effectiveness studies of IMPT the VAPAIN initiative recommended domains for the develop-ment of a core outcome set (COS).
Aim of the present study is to identify valid instruments suitable for application in this COS being used in effectiveness studies of IMPT. In order to rate the suitability of existing and well-established instruments (German versions of: CESD, CPAQ, CPGQ, CSQ, FABQ, SF-36, NRS, PCS, PDI) for the COS their psychometric property (responsiveness) was examined in the target population. 
Methods:
The examination was conducted with secondary data (n=282) of instruments being used for routine record keeping at the Comprehensive Pain Center in Dresden, Germany. All instru-ments presenting a significant and clinically relevant change (pre/post intervention) were in-cluded as factors in a regression analysis to detect the impact on subjectively experienced therapy success (Global Rating Scale, GRS).
Results:
None of the tested instruments fulfilled the conditions required for a regression analysis. Only two (sub)scales (SF-36BodilyPain, NRS) presented a significant difference in changes (pre/post) between populations with positive and negative experienced therapy success.
Conclusions:
To identify valid instruments for measuring the domains recommended by the VAPAIN initia-tive further evaluation studies of existing instruments with construct specific data collection regarding change should be considered. If no valid instruments can be identified the devel-opment of new instruments taking the specificity of the target population and intervention in-to account should be considered.

EVALUATION OF APPLICABILITY OF WELL-ESTABLISHED MEASUREMENT INSTRUMENTS IN INTERDISCIPLINARY MULTIMODAL PAIN THERAPY: INVESTIGATION OF THE INTERNATIONAL CONSENTED VAPAIN RECOMMENDATIONS