Table 1.
Model Input Parameters: Costs of Procedures and Probabilities, (95% Confidence Interval) and [Range Tested]
| Parameters | Distribution | Data Source | Reference | |||
|---|---|---|---|---|---|---|
| Cost Estimate * | CPT code | Costs, $ | ||||
| Initial Gastroenterology Office Consultation | 99205 | 199 [150 to 250] | Gamma | Medicare | [13] | |
| Follow-up Gastroenterology Office Consultation | 99215 | 140 [100 to 180] | Gamma | Medicare | [13] | |
| Upper Gastrointestinal Endoscopy and Colonoscopy, with Biopsy † | 43235 and 45380 | 1171 [700 to 2000] | Gamma | Medicare | [13] | |
| Surgical Pathology (x5) | 88305 | 529 [400 to 650] | Gamma | Medicare | [13] | |
| Fecal Calprotectin Assay | 83993 | 28 [15 to 50] | Gamma | Medicare | [13] | |
| Probability Estimate | Adult, % | Children, % | ||||
| Sensitivity | ||||||
| FC, Overall | 93 (85 to 97) | 92 (84 to 96) |  |
Lognormal, correlated with corresponding specificity | Meta-analysis | [18] |
| FC, Low Cut-off Point (50ug/g) | 95 (87 to 98) | 95 (83 to 99) | Meta-analysis ‡ | [18] | ||
| FC, High Cut-off Point (100ug/g) | 87 (77 to 93) | 85 (75 to 91) | Meta-analysis ‡ | [18] | ||
| Endoscopy and Colonoscopy with Histology | 100 | 100 | Not parameterized | Assumed | - | |
| Specificity | ||||||
| FC, Overall | 96 (89 to 99) | 76 (62 to 86) |  |
Lognormal, correlated with corresponding sensitivity | Meta-analysis | [18] |
| FC, Low Cut-off Point (50ug/g) | 85 (65 to 95) | 70 (61 to 78) | Meta-analysis ‡ | [18] | ||
| FC, High Cut-off Point (100ug/g) | 97 (94 to 99) | 80 (66 to 89) | Meta-analysis ‡ | [18] | ||
| Endoscopy and Colonoscopy with Histology | 100 | 100 | Not parameterized | Assumed | - | |
| Proportion of True Positive IBDs among Suspected | ||||||
| IBD Patients | 32 [18 to 49] | 61 [50 to 72] | Beta | Meta-analysis | [18] | |
| Non-IBD Patients with Persistent Symptoms | 60 [41 to 76] | 35 [22 to 50] | Beta | Expert opinion** | [19] | |
based on the 2012 American Medical Association Current Procedural Terminology code book and the 2012 Medicare Fee Schedule
includes facility fee for colonoscopy ($378) and for upper gastrointestinal endoscopy ($341), physician reimbursement for colonoscopy ($264) and for upper gastrointestinal endoscopy ($148) and anesthesia fee ($132); assume no bundling discount for facility fee and physician reimbursement and 30% patients receiving anesthesia
derived from the summary ROC curves in [9]. Selection of points on summary ROC curve was based on expert's judgment and consulted with eight other gastroenterologists
based on study by Dubinsky et al [19] and adjusted for poll result from 4 pediatric and 5 adult gastroenterologists