PRAGMATIC RANDOMISED TRIAL OF LOW VERSUS HIGH VOLUME INITIATED TRANSANAL IRRIGATION THERAPY IN ADULTS WITH CHRONIC CONSTIPATION: A FEASIBILITY STUDY

Abstract

Background
Chronic Constipation (CC) is common in adults. The effect of symptoms on quality-of-life (QOL) is significant. Trans-anal irrigation therapy has become a widely-used treatment despite a lack of robust evidence. A randomised comparison of two different methods of irrigation (the CapaCiTY 02 study) will provide valuable evidence of superiority of one system over the other. This study aims to evaluate the feasibility of conducting CapaCiTY 02. Data presented are interim findings from a single study site nested within the large multi-centre CapaCiTY 02 study.

Methods
This study was a mixed methods study involving a) a systematic review and meta-analysis of current literature data for trans-anal irrigation in chronic constipation, b) a randomised controlled trial, and c) a qualitative study of the patient experience. Participants in the trial were randomised to either high volume (HV) or low volume (LV) irrigation and underwent standardised physiological investigations. Data from the first 10 months of data collection at the Durham site were used for the feasibility study. Data were collected according to a standardised outcomes framework. The primary outcome was reduction in PAC-QOL, measured at 3 months. Qualitative interviews using a phenomenological framework were undertaken to explore the nature of the participants’ lived experience of irrigation. Descriptive analysis of data enabled assessment of study feasibility.

Results
The meta-analysis of seven eligible studies reported a positive response to treatment rate of 50.4%. Trial recruitment nationally was slower than anticipated. However the recruitment rate at the Durham site met the target for individual sites. A total of 19 participants were recruited at Durham, of whom 11 reached the primary outcome visit (3 months). The overall reduction in mean PAC-QOL at three months was 0.39 (SD 0.44), with a difference between groups of 0.04. Some outcome data were incompletely recorded. Of the 19 participants, 5 (29%) discontinued treatment, after a mean time of 51 days (SD 35.2). Qualitative interviews (n=5 at 3 months, n=3 at 6 months) identified important themes regarding participants’ experiences of irrigation training and home use.

Discussion
Collaboration between participating sites, combined with protocol amendments, has allowed measures to be taken to improve recruitment and recording of outcomes. This study demonstrates that the proposed methodology is feasible and acceptable to a majority of patients. The qualitative study provided a broader context to the quantitative study findings.