Table 1 Input parameters used in the model and their sampling distribution for the probabilistic sensitivity analysis
Parameter | Mean (SE) | Distribution | Source |
|---|---|---|---|
Clinical Parameters | |||
 Baseline Transitional Probabilities | |||
  DFS ➔ CHF | 0.0053 (0.0024) | Beta | Buendia et al., 2013 [31] |
  DFS ➔ Recurrence | 0.0294 (0.0029) | Beta | |
  DFS ➔ Metastasis | 0.0785 (0.0140) | Beta | |
  DFS ➔ Death | 0.0020 (0.0001) | Beta | |
  CHF ➔ Recurrence | 0.0294 (0.0029) | Beta | |
  CHF ➔ Metastasis | 0.0785 (0.0140) | Beta | |
  CHF ➔ Death | 0.1500 (0.0153) | Beta | Dokainish et al., 2017 [52] |
  Recurrence ➔ Metastasis | 0.0785 (0.0140) | Beta | Buendia et al., 2013 [31] |
  Recurrence ➔ Death | 0.2950 (0.2066) | Beta | |
  Metastasis ➔ Death | 0. 0.2950 (0.2066) | Beta | |
 Relative treatment efficacy of adjuvant trastuzumab therapy | |||
  Pooled hazard ratio for DFS | 0.65 (0.0825) | Log-Normal | Genuino et al., 2019 [40] |
  Pooled hazard ratio for OS | 0.67 (0.0493) | Log-Normal | |
  Pooled risk ratio for CHF | 3.97 (0.2240) | Log-Normal | |
 Epidemiological Data | |||
  5 – year prevalence of Breast Cancer in the Philippines | 64,046 prevalent cases | – | WHO GLOBOCAN, 2012 [8] |
  Incidence of Breast Cancer in the Philippines | 21,057 new cases | – | Estimated based on the 2015 new cases (Philippine Cancer Facts and Estimates, 2015 [2]) adjusted to 2017 values by applying the incidence rate calculated using the total population for 2015 [53] and 2017 [54] |
  Percentage of HER2-positivity of breast cancer in the Philippines | 23.17% | – | DOH Breast Cancer and Control Program, 2013 [7] |
  Estimated percentage of early-stage HER2-positive breast cancer cases in the Philippines | 80% | – | DOH Breast Cancer and Control Program, 2013 [7] |
Cost Parameters | |||
 DMC of adjuvant trastuzumab therapy for the intervention cohort (per patient per treatment course) – Drugs, CT administration, cardiac function assessment | PHP 1076607 (54929) | Gamma | DOH Philippines -Pharmaceutical Division, 2018 [47] Philippine Health Insurance Corporation, 2013 [44] |
 DMC of adjuvant CT for the control cohort (per patient per treatment course) – Drugs, CT administration, cardiac function assessment | PHP 194900 (9944) | Gamma | |
 DNMC of adjuvant treatment for intervention cohort | PHP 9432 (481) | Gamma | Riewpaiboon, 2014 [49] |
 DNMC adjuvant treatment for control cohort | PHP 3494 (178) | Gamma | |
 DMC at DFS state - imaging, labs, visits/consultation | PHP 9493 (484) | Gamma | Wong, 2018 [45] |
 DNMC at DFS state | PHP 1747 (80) | Gamma | Riewpaiboon, 2014 [49] |
 DMC at CHF state -hospital admission, echocardiography, drugs, cardiac monitoring | PHP 3400 (1602) | Gamma | Philippine Health Insurance Corporation, 2013 [44] |
 DNMC at CHF state | PHP 1049 [48] | Gamma | Riewpaiboon, 2014 [49] |
 DMC at Local Recurrence state (first year) – work-up, radiotherapy, CT drugs, CT administration | PHP 567156 (3061) | Gamma | DOH Philippines, 2018 [46] Philippine Health Insurance Corporation, 2013 [44] |
 DNMC at Local Recurrence state (first year) | PHP 8166 (1488) | Gamma | Riewpaiboon, 2014 [49] |
 DMC at Local Recurrence state (after first year) - CT drugs, CT administration | PHP 182437 (15513) | Gamma | DOH Philippines, 2018 [46] Philippine Health Insurance Corporation, 2013 [44] |
 DNMC at Local Recurrence state (after first year) | PHP 17817 (178) | Gamma | Riewpaiboon, 2014 [49] |
 DMC at Local Recurrence state (after first year) – CT drugs and administration | PHP 516904 (26373) | Gamma | DOH Philippines, 2018 [46] Philippine Health Insurance Corporation, 2013 [44] |
 DNMC at Local Recurrence state (after first year) | PHP 5939 (273) | Gamma | Riewpaiboon, 2014 [49] |
 DMC at Distant Metastasis state (first year) - work-up, radiotherapy, CT drugs, CT administration, palliative care drugs | PHP 956172 (48784) | Gamma | DOH Philippines, 2018 [46] Philippine Health Insurance Corporation, 2013 [44] |
 DNMC at Distant Metastasis state (first year) | PHP 10131 (465) | Gamma | Riewpaiboon, 2014 [49] |
 DMC at Distant Metastasis state (after first year) – CT drugs and administration, palliative care drugs | PHP 1666816 (59531) | Gamma | DOH Philippines, 2018 [46] Philippine Health Insurance Corporation, 2013 [44] |
 DNMC at Distant Metastasis state (after first year) | PHP 5939 (273) | Gamma | Riewpaiboon, 2014 [49] |
Utility Parameters | |||
 DFS | 0.8320 (0.0084) | Beta | Ahn et al., 2014 [41] |
 CHF | 0.6700 (272.71) | Beta | |
 Recurrence | 0.8280 (0.0262) | Beta | |
 Metastasis | 0.7620 (0.0262) | Beta | |