Impact of age on the recovery of six-minute walking distance after lung cancer surgery: a retrospective cohort study

Purpose: The aim was to investigate the relationship of age for recovery of six-minute walking distance (6MWD), pulmonary function, and health-related quality of life (HRQOL) after lung cancer surgery. Methods: Primary outcome was the 6MWD recovery until 6 months after surgery. Secondary outcome was the recoveries of forced expiratory volume in 1 s (FEV₁) and HRQOL until 6 months after surgery. Linear mixed-effects model was used to estimate the association of age to the outcomes. Results: A total of 311 lung cancer patients were included. All the 6MWD, FEV₁, and HRQOL decreased after surgery (− 32 m, − 0.39L, and − 2 scores, respectively, p = 0.027—p < 0.001). While 6MWD increased every month after surgery (5 m/month, 95% confidence interval (CI); 4–7, p < 0.001), the recovery decreased, as the age increased 1 standard deviation (SD) (i.e., 9 years) (− 2 m/month; 95% CI − 3 to − 1, p < 0.001). While FEV₁ increased every month after surgery (0.03 L/month; 95% CI 0.02–0.03, p < 0.001), the recovery increased, as the age increased by 1 SD (0.01 L/month; 95% CI 0.00–0.01, p = 0.003), which was opposite to the 6MWD recovery. While the postoperative HRQOL recovered every month (2 score/month; 95% CI 1–2, p < 0.001), there was no significant association between the recovery and age (0 score/month; 95% CI − 1 to 0, p = 0.5). Conclusions: The 6MWD recovery delayed in elderly patients, which was not related to their FEV₁-and HRQOL recoveries. Postoperative walking training would be important for the elderly lung cancer patients.