[Predictors of efficacy of biofeedback therapy in patients with chronic constipation]

To explore the anorectal physiology, psychological state, quality of life, lifestyle of patients with chronic constipation (CC) and evaluate the factors which potentially predict the efficacy of biofeedback therapy (BF).

Seventy CC patients receiving BF training were enrolled in this study. Anorectal physiology, Zung's Self-Rating Depression Scale (SDS), Zung's Self-Rating Anxiety Scale (SAS) and Chinese version of the MOS 36-item short form healthy survey (SF-36), lifestyle scale were recorded before BF training. A bowel symptom measurement including five major symptoms was recorded before and after BF training. The improvement in the symptom score was considered as criteria of clinical efficacy of BF therapy. Thirty-two possible influencing factors of efficacy of BF therapy were selected. Univariate analysis and multivariate analysis were conducted to assess the independent predictors.

The results of univariate analysis showed that efficacy of BF therapy was positively correlated to the role physical (r = 0.256, P = 0.031), negatively correlated to the score of SDS (r = -0.315, P = 0.007) and the first sensation threshold (r = -0.278, P = 0.020). The multivariate analysis showed the score of SDS (β = -0.263, P = 0.033) and the first sensation volume (β = -0.281, P = 0.013) were the independent predicator of efficacy of BF therapy.

CC patients who tended to depression state and rectal hyposensitivity have poor response to BF therapy. To treat these patients purposely could optimize the efficacy of BF therapy.