Transanal Irrigation vs. Conservative Bowel Management
Christensen and colleagues (2009; Europe) developed a study to determine the cost effectiveness of transanal irrigation compared to conservative bowel management. Costs were obtained from a randomized clinical trial and represented the average time between bowel management procedures (2 days). Costs included the labour costs related to the interventions (including leakage costs), and costs related to the product, urinary tract infections and lost wages due to time spent on bowel management. The effectiveness measure for this model was the St Mark’s fecal incontinence score and the Cleveland Clinic constipation scoring system. At 10 weeks all effectiveness measures had significantly lower (better) scores for all three for transanal irrigation. Overall costs were €1 less for transanal irrigation over the two days of bowel management compared to conservative bowel management. As a sensitivity analysis, the authors observed that caregiver time would have to be increased 26%, transanal irrigation time increased 12% or patient time on bowel management increased 10% before transanal irrigation becomes more expensive than conservative bowel management. The conclusion from this study was that transanal irrigation is a dominant strategy compared to conservative bowel management. This treatment was both less costly and had better outcomes. The authors also mention that their results were robust after conducting the sensitivity analyses. It was noted that presenting costs for only a 2-day period was a limiting factor in their study; consequently, it is difficult to determine whether transanal irrigation will remain less costly than conservative bowel management over the long-term.
The conclusion that transanal irrigation is the dominant strategy should be viewed with caution given that the difference in cost was €1 over a 2-day timeframe. Study limitations include a very short timeframe where costs were captured and a small cohort. Uncertainty was also not explored in this study and thus it is difficult to know how robust the results truly are.
In a separate study Emmanuel and colleagues examined the cost effectiveness of trans-anal irrigation for individuals with neurogenic bowel dysfunction and on an ineffective standard bowel program (i.e., persons who had poor outcomes with standard bowel care) (Emmanuel et al. 2016). This study was from the perspective of the National Healthcare Service (NHS) in the UK and used a Markov model to estimate costs and outcomes over a lifetime time horizon. Model inputs were mainly based on data from three UK hospital clinics and supplemented by published literature. The primary outcome was cost per QALY. Results showed an increase in QALY for the transanal irrigation cohort of 0.40 compared to continuing the standard bowel program. There was also an estimated £21,768 cost savings with the transanal irrigation program. These results were robust even when considering the uncertainty. The utility values and number of times transanal irrigation is used per week were the most sensitive model inputs. The conclusions of this study are that transanal irrigation is a cost saving and improves quality of life for individuals with neurogenic bowel dysfunction and have failed standard bowel program.
