Table 1.
Model parameters, baseline values, ranges, and distribution for sensitivity analyses.
| Parameters | Base Case Value | Range | Reference | Distribution | |
|---|---|---|---|---|---|
| Minimum | Maximum | ||||
| Clinical effectiveness [15] | |||||
| HR for OS (atezo + bev vs.sorafenib) | 0.58 | 0.42 | 0.79 | [15] | Normal |
| HR for PFS (atezo + bev vs. sorafenib) | 0.59 | 0.47 | 0.76 | [15] | Normal |
| Weibull OS model with sorafenib | λ = 0.027, γ = 1.286 |
- | - | [15] | - |
| Weibull PFS model with sorafenib | λ = 0.093, γ = 1.312 |
- | - | [15] | - |
| Background mortality rate | Age-specific | ||||
| Rate of treatment discontinuation due to AEs [15] | |||||
| Atezo + Bev | 0.07 | 0.056 | 0.084 | [15] | Binomial |
| Sorafenib | 0.10 | 0.08 | 0.12 | [15] | Binomial |
| Proportion of patients with grade 3–4 AEs [15] | |||||
| Atezo + Bev | |||||
| Diarrhea | 0.018 | 0.014 | 0.022 | [15] | Binomial |
| Hand–foot syndrome | 0.0 | 0.0 | 0.0 | [15] | Binomial |
| Hypertension | 0.152 | 0.122 | 0.182 | [15] | Binomial |
| Increased bilirubin | 0.024 | 0.019 | 0.029 | [15] | Binomial |
| Sorafenib | |||||
| Diarrhea | 0.051 | 0.041 | 0.061 | [15] | Binomial |
| Hand–foot syndrome | 0.083 | 0.066 | 0.1 | [15] | Binomial |
| Hypertension | 0.122 | 0.098 | 0.146 | [15] | Binomial |
| Increased bilirubin | 0.064 | 0.051 | 0.077 | [15] | Binomial |
| Patient weight, kg | 70 | 40 | 200 | [42] | Triangular |
| Cost parameters, USD * | |||||
| Atezolizumab (1200 mg) (fixed) (every 3 weeks) | 9419.16 | 7535.33 | 11,302.99 | [4,5] | Triangular |
| Bevacizumab (15 mg/kg) (every 3 weeks) | 117.60 | 94.08 | 141.12 | [34,35,36] | Triangular |
| Sorafenib (every 3 weeks) | 14,609.28 | 11,687.42 | 17,531.14 | [34,35,36] | Triangular |
| Drug administration (every 3 weeks) | 435.04 | 348.03 | 522.05 | [34,35,36] | Triangular |
| CT imaging (every 6 weeks) | 1543 | 1235 | 1852 | [35] | Triangular |
| Other care (every week) | 174.5 | 139.6 | 209.4 | [20] | Triangular |
| In-patient EOL care | 7360.16 | 6208.85 | 9313.77 | [31] | Triangular |
| Post-progression therapy cost per cycle in atezo + bev | 4612.66 | 3690.13 | 5535.20 | [15] | Triangular |
| Post-progression therapy cost per cycle in sorafenib | 4825.93 | 3860.74 | 5791.11 | [15] | Triangular |
| Societal costs, USD * | |||||
| Caregiver (every 3 weeks) | 382.21 | 305.77 | 458.65 | [43] | Triangular |
| Patient time | 896.2 | 716.96 | 1075.44 | [43,44] | Triangular |
| Parking/meals/travel | 329.5 | 263.6 | 395.4 | [43,45] | Triangular |
| Management of Grade 3–4 AEs, USD * | |||||
| Diarrhea | 88.38 | 70.70 | 106.05 | [38,39,40,41] | Triangular |
| Hand–foot syndrome | 145.65 | 116.51 | 174.78 | [38,39,40,41] | Triangular |
| Hypertension | 64.01 | 51.21 | 76.81 | [38,39,40,41] | Triangular |
| Increased bilirubin | 0 | 0 | 0 | Estimates | Triangular |
| Utilities and dis-utilities | |||||
| In atezo–bev first-line therapy | 0.78 | 0.624 | 0.936 | [31] | Triangular |
| In sorafenib first-line therapy | 0.78 | 0.624 | 0.936 | [21] | Triangular |
| In second-line therapy | 0.68 | 0.54 | 0.82 | [21] | Triangular |
| Dis-utilities | |||||
| Diarrhea | −0.103 | −0.082 | −0.123 | [46] | Triangular |
| Hand–foot syndrome | −0.116 | −0.093 | −0.139 | [46] | Triangular |
| Hypertension | −0 | −0 | −0 | [46] | Triangular |
| Increased bilirubin | −0 | −0 | −0 | [46] | Triangular |
Abbreviations: atezo, atezolizumab; bev, bevacizumab; OS, overall survival; PFS, progression-free survival; AE, adverse event; CT, computed tomography; DM, diabetics mellitus; EOL, end-of-life; HR, hazard ratio. * Adjustment of the costs for inflation to reflect the 2020 USD value, using the US consumer price index.