title: CON-COUR study: Interferential therapy in the treatment of chronic constipation in adults: study protocol for a randomized controlled trial.
abstract: BACKGROUND
  The prevalence of chronic constipation is about 15 % in Western countries with a significant impact on quality of life and health care costs. The first-line therapy, based on medical treatment combined with laxatives and dietary rules, is often disappointing. Interferential therapy is a new treatment that has demonstrated its efficiency in the treatment of chronic constipation in children and encouraging results in adults. The primary objective of this study is to assess the efficacy of interferential therapy during 8 weeks in adult patients. The secondary objectives are to assess this new and noninvasive therapy in terms of persistence of the clinical efficacy, colonic transit time, ano-rectal manometry, patient satisfaction and quality of life (QoL), and tolerance.
  
  
  METHODS
  
  
  
  METHODS
  multicenter, prospective, randomized, placebo-controlled, double blind, two-parallel groups study.
  
  
  METHODS
  nine French adult gastroenterology centers.
  
  
  METHODS
  adult patients with a history of chronic constipation refractory to medical treatment for at least 3 months. Treatment groups: (1) interferential-experimental group (effective stimulation); (2) placebo-control group (sham stimulation).
  
  
  METHODS
  1:1 allocation ratio. Evaluation times: inclusion (T0, randomization), baseline assessment (T1), start of stimulation (T2), intermediary assessment (T3, 4 weeks), end of stimulation (T4, 8 weeks), follow-up (T5 and T6, 1- and 6-month).
  
  
  METHODS
  (1) primary: short-term efficacy at T4 (treatment response defined as three or more spontaneous, complete bowel movements per week); (2) secondary: efficacy at T5 and T6, symptoms (Patient Assessment of Constipation Symptoms questionnaire), colonic transit time, anorectal manometry, patient satisfaction (analogical visual scale), patient QoL (Patient Assessment of Constipation Quality of Life Questionnaire), side/unexpected effects.
  
  
  METHODS
  200 individuals to obtain 80 % power to detect a 20 % difference in treatment response at T4 between the two groups (15 % of lost to follow-up patients expected).
  
  
  CONCLUSIONS
  The randomized, double-blind, placebo-controlled design is the most appropriate to demonstrate the efficacy of a new experimental therapeutic (Evidence-Based Medicine Working Group classification). National and international recommendations could be updated based on the findings of this study.
  
  
  BACKGROUND
  Current controlled trials NCT02381665 (registration date: February 13, 2015).
authors.affiliation: Service de Gastroentérologie, Hôpital Nord, Assistance Publique-Hôpitaux de Marseille, Marseille, France. veronique.vitton@ap-hm.fr.|Plateforme d'Interface Clinique, CRN2M, UMR 7286, Aix Marseille Université, Marseille, France. veronique.vitton@ap-hm.fr.
authors.forename: Véronique
authors.initials: V
authors.lastname: Vitton
authors.affiliation: Service de Gastroentérologie, Hôpital Nord, Assistance Publique-Hôpitaux de Marseille, Marseille, France. benezech.alban@gmail.com.
authors.forename: Alban
authors.initials: A
authors.lastname: Benezech
authors.affiliation: Unité d'expertise pharmaceutique et recherche biomédicale, AP-HM, Marseille, France. stephane.honore@ap-hm.fr.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Honoré
authors.affiliation: Direction de la Recherche, AP-HM, Marseille, France. patrick.sudour@ap-hm.fr.
authors.forename: Patrick
authors.initials: P
authors.lastname: Sudour
authors.affiliation: Centre d'Investigation Clinique 1409, AP-HM, Aix-Marseille Université, Marseille, France. nathalie.lesavre@ap-hm.fr.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Lesavre
authors.affiliation: EA3279 Self-perceived Health Assessment Research Unit and Department of Public Health, AP-HM, Aix-Marseille University, Méditerranée, 27 bd Jean Moulin, Marseille, Cedex 05, F-13385, France. pascal.auquier@univ-amu.fr.
authors.forename: Pascal
authors.initials: P
authors.lastname: Auquier
authors.affiliation: EA3279 Self-perceived Health Assessment Research Unit and Department of Public Health, AP-HM, Aix-Marseille University, Méditerranée, 27 bd Jean Moulin, Marseille, Cedex 05, F-13385, France. karine.baumstarck@univ-amu.fr.
authors.forename: Karine
authors.initials: K
authors.lastname: Baumstarck
mesh_terms: D000328:Adult; D002908:Chronic Disease; D002985:Clinical Protocols; D003106:Colon / Q000503:physiopathology*; D003248:Constipation / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology / Q000628:therapy*; D003672:Defecation; D004311:Double-Blind Method; D004599:Electric Stimulation Therapy / Q000009:adverse effects; D005260:Female; D005602:France; D005772:Gastrointestinal Transit; D006801:Humans; D008297:Male; D008365:Manometry; D017060:Patient Satisfaction; D011446:Prospective Studies; D011788:Quality of Life; D020127:Recovery of Function; D012107:Research Design; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome