RESUMO
OBJECTIVE: To estimate the minimal clinically important difference (MCID) of the frequency of bowel movement for the patients with chronic severe functional constipation treated with acupuncture so as to provide the evidence for the clinical decision. METHODS: In this study, 813 patients with chronic severe functional constipation treated with acupuncture in two previous randomized controlled trials were included. Through the anchor-based method (anchored by the item 28 "satisfaction with previous treatment" of the patient assessment of constipation-quality of life [PAC-QOL]) and the distribution-based method, the MCID of the weekly frequency of complete spontaneous bowel movement (CSBM) and spontaneous bowel movement (SBM) was analyzed statistically in the patients. RESULTS: The MCID of the mean weekly frequency of CSBM and SBM was 1.3 times and 1.6 times in patients with chronic severe functional constipation treated with acupuncture, respectively. CONCLUSION: The mean increase of the weekly CSMB is ≥ 1.3 times and that of SBM is ≥ 1.6 times after treatment when compared with the baseline respectively, suggesting the clinical significance.