{
  "abstract": "Objective General practitioners may not prescribe amitriptyline for irritable bowel syndrome (IBS) despite using it for other chronic conditions. The Amitriptyline at Low-Dose and Titrated for Irritable Bowel Syndrome as Second-Line Treatment (ATLANTIS) trial found low-dose titrated amitriptyline was a safe and clinically effective second-line treatment for IBS in primary care. We undertook a prespecified cost-effectiveness analysis of ATLANTIS trial data.Design/method Complete case (CC) and a full population (FP) analysis using multiply imputed data with analyses at 6 (365 participants CC, 463 participants FP) and 12 (224 participants CC, 291 participants FP) months. As the trial was not fully randomised between 6 and 12 months, we adopted inverse probability weighting to mitigate potential impact of participants choosing to continue trial medication.Results At a 6-month time horizon, CC analysis demonstrated low-dose amitriptyline was more likely to be cost-effective than not (incremental net health benefit (NHB) 0.0029 quality-adjusted life years (QALYs)/person, low-dose amitriptyline dominant, 67.3% probability cost-effective), but not FP analysis. At 12 months, all analyses demonstrated low-dose amitriptyline was more likely to be cost-effective than not (CC: incremental NHB 0.00757 QALYs/person, low-dose amitriptyline dominant, 81.7% probability cost-effective; FP: incremental NHB 0.00388 QALYs/person, low-dose amitriptyline dominant, 68.7% probability cost-effective).Conclusion In addition to the clinical benefit, safety and acceptability of low-dose amitriptyline in patients with IBS found in the ATLANTIS trial, these results indicate this inexpensive medication is likely to be cost-effective as a second-line treatment for IBS in primary care over 12 months. This strengthens amitriptyline as a treatment option for people with ongoing IBS symptoms.Trial registration number ISRCTN48075063.",
  "authors": [
    {
      "affiliations": [
        "Leeds Institute of Health Sciences, School of Medicine, University of Leeds, Leeds, UK"
      ],
      "name": "Georgios Gkountouras"
    },
    {
      "affiliations": [
        "Leeds Gastroenterology Institute, St James’s University Hospital, Leeds, UK",
        "Leeds Institute of Medical Research at St James’s, University of Leeds, Leeds, UK"
      ],
      "name": "Alexander Charles Ford"
    },
    {
      "affiliations": [
        "Clinical Trial Research Unit,Leeds Institute of Clinical Trials Research,School of Medicine, University of Leeds, Leeds, UK"
      ],
      "name": "Alexandra Wright-Hughes"
    },
    {
      "affiliations": [
        "Leeds Institute of Health Sciences, School of Medicine, University of Leeds, Leeds, UK"
      ],
      "name": "Sarah Alderson"
    },
    {
      "affiliations": [
        "Clinical Trial Research Unit,Leeds Institute of Clinical Trials Research,School of Medicine, University of Leeds, Leeds, UK"
      ],
      "name": "Pei-Loo Ow"
    },
    {
      "affiliations": [
        "Population Health Sciences, University of Bristol, Bristol, UK"
      ],
      "name": "Matthew Ridd"
    },
    {
      "affiliations": [
        "Leeds Institute of Health Sciences, School of Medicine, University of Leeds, Leeds, UK"
      ],
      "name": "Robbie Foy"
    },
    {
      "affiliations": [
        "Centre for Clinical and Community Applications of Health Psychology, University of Southampton, Southampton, UK"
      ],
      "name": "Felicity Bishop"
    },
    {
      "affiliations": [
        "Let’sCure IBS, Leeds, UK"
      ],
      "name": "Matthew Chaddock"
    },
    {
      "affiliations": [
        "Clinical Trial Research Unit,Leeds Institute of Clinical Trials Research,School of Medicine, University of Leeds, Leeds, UK"
      ],
      "name": "Catherine Fernandez"
    },
    {
      "affiliations": [
        "Leeds Institute of Health Sciences, School of Medicine, University of Leeds, Leeds, UK"
      ],
      "name": "Elspeth Guthrie"
    },
    {
      "affiliations": [
        "Clinical Trial Research Unit,Leeds Institute of Clinical Trials Research,School of Medicine, University of Leeds, Leeds, UK"
      ],
      "name": "Delia P Muir"
    },
    {
      "affiliations": [
        "Clinical Trial Research Unit,Leeds Institute of Clinical Trials Research,School of Medicine, University of Leeds, Leeds, UK"
      ],
      "name": "Amanda Farrin"
    },
    {
      "affiliations": [
        "PCPS, University of Southampton, Southampton, UK"
      ],
      "name": "Hazel Everitt"
    },
    {
      "affiliations": [
        "Leeds Institute of Health Sciences, School of Medicine, University of Leeds, Leeds, UK"
      ],
      "name": "Daniel Howdon"
    },
    {
      "affiliations": [],
      "name": "ATLANTIS trialists"
    }
  ],
  "title": "Cost-effectiveness of low-dose amitriptyline for irritable bowel syndrome in primary care",
  "uid": "0472e3a4-6b66-50dc-8d75-44f7052e0c3d"
}