Validation of a questionnaire measuring the regulation of autonomic function

BACKGROUND To broaden the range of outcomes that we can measure for patients undergoing treatment for oncological and other chronic conditions, we aimed to validate a questionnaire measuring self-reported autonomic regulation (aR), i.e. to characterise a subject's autonomic functioning by questions on sleeping and waking, vertigo, morningness-eveningness, thermoregulation, perspiration, bowel movements and digestion. METHODS We administered the questionnaire to 440 participants (female symbol: N = 316, male symbol: N = 124): 95 patients with breast cancer, 49 with colorectal cancer, 60 with diabetes mellitus, 39 with coronary heart disease, 28 with rheumatological conditions, 32 with Hashimoto's disease, 22 with multiple morbidities and 115 healthy people. We administered the questionnaire a second time to 50.2% of the participants. External convergence criteria included the German version of the Hospital Anxiety and Depression Scale (HADS-D), a short questionnaire on morningness-eveningness, the Herdecke Quality of Life Questionnaire (HLQ) and a short version questionnaire on self-regulation. RESULTS A principal component analysis yielded a three dimensional 18-item inventory of aR. The subscales orthostatic-circulatory, rest/activity and digestive regulation had internal consistency (Cronbach-alpha: ralpha = 0.65 - 0.75) and test-retest reliability (rrt = 0.70 - 85). AR was negatively associated with anxiety, depression, and dysmenorrhoea but positively correlated to HLQ, self-regulation and in part to morningness (except digestive aR) (0.49 - 0.13, all p < 0.05). CONCLUSION An internal validation of the long-version scale of aR yielded consistent relationships with health versus illness, quality of life and personality. Further studies are required to clarify the issues of external validity, clinical and physiological relevance.