Cost-Effectiveness Analysis of Transanal Irrigation for Managing Neurogenic Bowel Dysfunction in Japan

Neurogenic bowel dysfunction (NBD) is a common sequela in Spinal Cord Injury (SCI) patients. Bowel dysfunction symptoms have a significant negative impact on quality of life (QOL) and are often socially disabling. Transanal irrigation (TAI) is a bowel management procedure that significantly mitigates NBD symptoms in patients refractory to standard bowel care (SBC) by reducing the incidence of fecal incontinence, ameliorating constipation, and improving QOL. TAI devices are used across many countries such as the United Kingdom, Germany, and France, and introduction of the devices is being considered in Japan. In this context, a cost-effectiveness analysis specific to Japanese settings is relevant.

To analyze the cost-effectiveness of TAI for bowel management of SCI patients with NBD in a Japanese clinical setting.

A modified version of a previously developed and published Markov model was used to evaluate the cost-effectiveness of TAI. In the model, SCI patients using TAI due to NBD were compared with SCI patients not responding to TAI and continuing with SBC. Quality-adjusted Life Years (QALYs) were used as the primary effectiveness measure, and the analysis was conducted from the payer's perspective.

The model predicts a lifetime incremental cost of TAI to be 3 198 687 yen compared with SBC. TAI provided an additional 0.8 QALY, which leads to an incremental cost-effectiveness ratio (ICER) of TAI vs SBC of 4 016 287 yen/QALY.

An ICER of 4 million yen falls within the range of reported willingness to pay (WTP) per QALY gain (5-6.7 million yen) in Japan, and TAI is therefore found to be a cost-effective treatment strategy compared to SBC. The result should be further corroborated in future Japanese trials of TAI.