The Canterbury Ileal Pouch-Anal Anastomosis Study

Abstract

Background and aim: Inflammatory bowel disease (IBD) is an increasingly prevalent chronic disease, frequently with an early age of onset and no cure. It is important to ascertain which treatments are effective and cost-effective, in order to optimise treatment and rationalise use of resources. One of the treatments for IBD is surgery, commonly restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA). This study aimed to collect information regarding complications, outcomes, quality of life, disability and cost information of all IPAA patients in the Canterbury region, New Zealand, which will enable comparison to be made to international research and provide crucial information to aid treatment decisions.

Method: This population study aimed to recruit all patients with IPAA performed between 1984 to 2013 in the Canterbury region, New Zealand, and collected information on demographics, indications, complications, functional outcomes, quality of life (QoL), disability and direct and indirect costs. Data was sourced from hospitals and primary care facilities. Further information was gathered from participants who completed the Short-Form 36 Questionnaire (SF36), the Inflammatory Bowel Disease Questionnaire (IBDQ), the Inflammatory Bowel Disease Disability Index (IBD-DI) and the Indirect Costs Questionnaire through structured interviews and online questionnaires.

Results: In total there were 136 IPAA patients; 95 were eligible for the study after review (mean follow up of 11.5 years). Eighty-six completed the SF36, 81 completed the IBDQ, and 84 completed the IBD-DI. Twenty-four percent of patients had at least one early complication and 77% had at least one late complication. The average IBD-DI score was -1.0, which showed less disability than a cohort of UC patients on medical therapy in Sydney (p value = 0.04). The IBDQ and IBD-DI were highly correlated (r = 0.84, p value <0.01). The annual average direct costs were NZD$930.42, and the average indirect costs in the last 12 months were NZD$3,825.38. Lower QoL and disability were found in those who had their position affected at work (p values <0.01) and those who had more than 100 days off work in the last year (p value <0.01 for QoL and p value = 0.012 for disability). Lower QoL and disability were associated with higher indirect and total costs (p value <0.01).

Discussion and conclusion: The IPAA patients in Canterbury, New Zealand, had a higher rate of late complications than the average rate observed internationally (2), likely due to more complete data collection from multiple sources. The quality of life in the Canterbury cohort was comparable to international data (4-8). Perioperative complications and high costs of care were associated with higher levels of disability. The Canterbury IPAA recipients experienced less disability than medically managed UC patients in Sydney. Indirect costs accounted for 80% of total costs, and should not be underestimated.