Feeling better versus feeling good: interpreting pain relief using minimal clinically important differences and patient acceptable symptom states for patients who underwent lung cancer surgery

Abstract Purpose Selection of thresholds for pain relief remains empirical and controversial. This study aimed to demonstrate the performance of two mostly used concepts, MCID and PASS, in interpreting perioperative recovery in patients undergoing VATS for lung cancer. Methods Patients undergoing VATS were asked to report their pain score daily on a 0–10 scale using PSA-Lung, a validated PRO tool for perioperative symptom measurement. If patients reported a pain score above 3 on the first day post-surgery, pain relief were defined either by MCID (feeling better) or PASS (feeling good) Factors associated with pain relief defined by those two thresholds were analyzed via cox regression models. Median days of pain relief were illustrated using K-M curves. Results Among 881 patients with POD1 pain ≥ 4, 805(91.37%) achieved ‘feeling better', and 775 (87.97%)achieved 'feeling good'(P < 0.05). Cox regression analysis showed that CCI scores ([HR]1.234,95%CI 1.022–1.490, P < 0.05) were associated with "feeling better" and single-port thoracoscopic surgery ([HR]1.192,95%CI1.017-1.397, P < 0.05) and no postoperative complications ([HR] 1.316, 95% CI 1.123–1.543) were associated with "feeling good". Using the log-rank test, we identified that patients with better CCI scores needed 4 days (95% CI = 4–5) to "feel better" whereas those with lower CCI scores needed 5 (95%CI = 3–7). Patients undergoing single-port thoracoscopic surgery required 6 days (95% CI = 5–6) to achieve a "feeling good" state compared to 7 days(95%CI = 6–8)for patients undergoing multi-port thoracoscopic surgery (all P < 0.05). Conclusion Responders, defined using the MCID and PASS, had similar rates of postoperative pain relief. However, the low agreement between responders and the unique predictors of responders suggests distinct underlying mechanisms and diverse potential applications of these two therapies.