[Development of a short-form self-report measure to assess relaxation effects].

The present study aimed to develop a short-form self-report measure to assess relaxation effects (S-MARE). Participants (N = 190) responded to a questionnaire comprised of 45 items assessing relaxation and non-relaxation based on the Relaxation Inventory (Crist et al., 1989). Exploratory factor analysis identified three factors: physiological tension, psychological relaxation, and anxiety. Each factor was related to 5 items and each had an acceptable Cronbach's coefficient (alpha = .93, .94, and .85). S-MARE scores pre- and post- relaxation instruction were significantly correlated with the Emotional Relaxation Scale (Tokuda, 2011) (r = .446) and with State Anxiety (r = -.531) (N = 172). There was a significant correlation between the amplitude of the high frequency component of heart rate variability during relaxation instruction and physiological tension scores on the S-MARE (r = .456-.474, N = 24). These results confirmed the reliability and validity of the S-MARE in terms of physiological correlation with cardiac parasympathetic tone, suggesting that the S-MARE is a valid measure of relaxation effects.