2.2 Effectiveness and quality of life
Based on the study by Brandt et al. there was no significant difference in median OS between NAC and AC. So, we assumed that the OS (9.1 years) and quality of life (QOL) during the progression-free survival stage were equal. The parameters like probabilities of AE and complications, are also based on the published results in this study, which are listed in Table 1. As data for postoperative death couldn’t be sourced, 30-day mortality and 90-day mortality information was integrated into postoperative complication mortality. Based on this study, the patients treated with neoadjuvant chemotherapy all received the lung cancer surgery, and the patients treated with surgery as the initial therapy, all received the adjuvant chemotherapy. In considering chemotherapy tolerance, we take the proportion of grade 3 and 4 AE as the input parameter. There were no deaths for chemotherapy and AE.
Quality of life was estimated using standard health utility weights. The utility weights of stable disease and progressive-free disease were calculated according to published study[22][24]. As there is a shortage of quality of life studies in the case of lung cancer surgery complications, we use the utility value of pneumothorax in the study of Handorf et al [24] as the 3 and 4 grade complication utility weights. The average utility weight of every treatment procedure was shown in 2, and the time frames of each treatment are based on the study of Dendulur et al [21] and Lugg et al [25]. In the model, the treatment of patients with 3 or 4 grade AE will add 0.73 months to basic time of surgery and chemotherapy, while treatment of those with 3 or 4 grade complication will add 0.5 months. The utility weight of patients with 3 or 4 grade AE and complication were 0.45. The utility weight during the time 6 months after initial treatment remained unchanged.