Table 3– Minimal important difference (MID) of 6-min walk distance (6MWD) and maximal cycle exercise capacity (MCEC)
Method used6MWD mMCEC W
 SGRQ total score#24.6 (23.4–25.7)3.3 (3.0–3.5)
  SGRQ impact#18.9 (18.1–20.1)2.2 (2.0–2.4)
 SGRQ activities#24.2 (23.4–25.4)3.2 (3.0–3.4)
 SOBQ total score26.4 (25.4–27.4)3.2 (3.0 –3.4)
 Cohen's effect size26.85.5
 Empirical rule effect size25.75.3
  • Data are presented as MID (95% CI) or MID. All regression equations multiplied by -1 to facilitate interpretation (improvements of St George's Respiratory Questionnaire (SGRQ) and University of California San Diego Shortness of Breath Questionnaire (SOBQ) if change score is negative). sem: standard error of measurement. #: MID 4 points; : MID 5 points.