Modelling the economic impact of managing a chronic anal fissure with a proprietary formulation of nitroglycerin (Rectogesic) compared to lateral internal sphincterotomy in the United Kingdom

BACKGROUND AND AIMS: This study estimated the economic impact of using a proprietary formulation of 0.2% nitroglycerin (GTN) ointment (Rectogesic) compared with lateral internal sphincterotomy in the treatment of a chronic anal fissure in the United Kingdom (UK), from the perspective of the National Health Service (NHS). PATIENTS AND METHODS: Clinical and surgical outcomes attributable to managing a chronic anal fissure were obtained from published literature, supplemented with information about resource utilisation derived from interviews with a panel of colorectal surgeons and general practitioners. Using this information, a decision tree modelling the management of a chronic anal fissure by a colorectal surgeon was constructed. Unit resource costs at 1999/2000 prices were applied to the resource utilisation estimates in the model to estimate the expected NHS cost of managing a chronic anal fissure. Consensus on the information contained within the model was reached at a meeting with an expert panel comprising five of the interviewees and one other colorectal surgeon. RESULTS: The expected NHS cost of a colorectal surgeon initially managing a chronic anal fissure with GTN was estimated to be pound616, compared to pound840 when a lateral internal sphincterotomy is the first-line treatment. Moreover, the expected probability of successful healing following initial treatment with either intervention is 99-100%, taking into account all subsequent treatments. CONCLUSION: The initial use of GTN compared to lateral internal sphincterotomy to treat a chronic anal fissure affords a potential cost reduction to the NHS of pound224 per patient without any loss in effectiveness. Hence, GTN is potentially a cost-effective first-line treatment strategy for the management of a chronic anal fissure.