Table 2 Probabilities, costs and utility parameters in the decision tree model
Parameter (Unit) | Base Case value | Lower Bound | Upper Bound | Source |
|---|---|---|---|---|
Annual Probability | ||||
Probability of B12 Deficiency (%) | 0.141 | 0.139 | 0.145 | [12] |
Probability of Folate Deficiency (%) | 0.273 | 0.232 | 0.318 | [19] |
Probability of Dual Deficiencies (%) | 0.092 | 0.077 | 0.103 | [20] |
Hazard Ratio for First Stroke | 0.79 | 0.68 | 0.93 | [6] |
Hazard Ratio for First Stroke for Folate-deficient Sub-population | 0.61 | 0.45 | 0.82 | [6] |
Probability of First Stroke in the Control Group for Folate-indeficient Sub-population (%) | 0.0061 | \ | \ | [6] |
Probability of First Stroke in the Control Group (%) | 0.0070 | \ | \ | [6] |
Probability of First Stroke in the Treatment Group for Folate-deficient Sub-population (%) | 0.0057 | \ | \ | [6] |
Probability of First Stroke in the Treatment Group (%) | 0.0055 | \ | \ | [6] |
Probability of Death due to Stroke in the Treatment Group (%) | 0.013 | \ | \ | [6] |
Probability of Death due to No-Stroke in the Treatment Group (%) | 0.0056 | \ | \ | [6] |
Probability of Death due to Stroke in the Control Group (%) | 0.0057 | \ | \ | [6] |
Probability of Death due to No-Stroke in the Control Group (%) | 0.0061 | \ | \ | [6] |
Probability of Severe Neuropathy in case of B12 Deficiency | 0.33 | 0.26 | 0.40 | [18] |
Probability of Neuropathy in case of B12 Deficiency | 0.063 | 0.034 | 0.098 | [18] |
Probability of Death due to Neuropathy after Stroke | 0.0073 | 0.0058 | 0.0093 | [21] |
Probability of Death due to Neuropathy after No-Stroke | 0.0343 | 0.0303 | 0.0388 | [21] |
Annual Costs | ||||
Cost of Enalapril & Folic Acid ($ Per day) | ||||
鈥僂nalapril-folic acid separate pill | 0.2417 | 0.0357 | 0.6126 | [22] |
鈥僂nalapril-folic acid combo pill | 0.7123 | 0.7034 | 0.7584 | [22] |
Cost of Vitamin Folate Screening Test ($ Per visit) | 9.3681 | 7.0261 | 11.7101 | [23] |
Cost of Vitamin B12 Screening Test ($ Per visit) | 9.3681 | 7.0261 | 11.7101 | [23] |
Cost of Vitamin B12 ($ Per period) | 11.6581 | 4.9963 | 16.6544 | [22] |
Direct Annual Medical Cost of a Stroke ($) | 1,610.35 | 1,207.76 | 2,012.94 | [2] |
Effects | ||||
Quality of Life for Stroke | 0.719 | 0.560 | 0.879 | [24闭銆赌 |
Quality of Life for No-stroke | 0.908 | 0.893 | 0.923 | [24] |
Quality of Life for Vitamin B12 Severe Neuropathy | 0.310 | 0.170 | 0.450 | [25] |
Quality of Life for Vitamin B12 Neuropathy | 0.588 | 0.200 | 0.920 | [11] |
Discount rate | ||||
Annual Discount Rate | 5% | 0 | 8% | [26] |