[Characteristic values and test statistical goodness of the Veterans RAND 12-Item Health Survey (VR-12) in patients with chronic pain : An evaluation based on the KEDOQ pain dataset].

The Veterans RAND 12-Item Health Survey (VR-12) was added to the German Pain Questionnaire (DSF) as a self-report measure of health-related quality of life in 2016, replacing the previously used SF-12, which required a license. Both measures have 12 items and include a physical component summary (PCS) and a mental component summary (MCS). Evaluations with a larger sample on characteristic values and on the test-statistical goodness of the VR-12 in patients with chronic pain are so far missing. Data on the VR-12 and other procedures of the DSF were evaluated from 11,644 patients from 31 centers participating in KEDOQ pain. The patients filled out the DSF before starting a pain therapy treatment. Change sensitivity was determined for 565 patients for whom the VR-12 was available from a follow-up questionnaire of the DSF several months after the initial survey.The reliability (Cronbach's alpha) of the PCS was rtt = 0.78 and for the MCS rtt = 0.84. The MCS had significant relationships with the depression, anxiety and stress scales (r = -0.51 to r = -0.72), and the PCS correlated more highly with areas of pain-related impairment (r = -0.48 to r = -0.52). Patients with higher pain chronicity, those with higher pain severity, and those with evidence of high psychological distress described significantly lower health-related quality of life in PCS and MCS. The effect size (ES) of change in terms of improvement in health-related quality of life was ES = 0.33 in the MCS and ES = 0.51 in the PCS.The results are in agreement with the findings of the SF-36 and SF-12 in patient collectives with chronic pain. In summary, they show that the VR-12 is an adequate substitute for the SF-12 in the German pain questionnaire.