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

Abstract

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. Primary outcome was the 6MWD recovery until 6months after surgery. Secondary outcome was the recoveries of forced expiratory volume in 1s (FEV1) and HRQOL until 6months after surgery. Linear mixed-effects model was used to estimate the association of age to the outcomes. A total of 311 lung cancer patients were included. All the 6MWD, FEV1, and HRQOL decreased after surgery (-32m, -0.39L, and -2 scores, respectively, p = 0.027-p < 0.001). While 6MWD increased every month after surgery (5m/month, 95% confidence interval (CI); 4-7, p < 0.001), the recovery decreased, as the age increased 1 standard deviation (SD) (i.e., 9years) (-2m/month; 95% CI -3 to -1, p < 0.001). While FEV1 increased every month after surgery (0.03L/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). 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.