Tables
- Table 1
Summary of commonly used anchor-based methods
Method Explanation Comment Jaeschke Mean (Cfollow-up−Cbaseline) Regression to the mean Mean change, Redelmeier Mean (Cfollow-up−Cbaseline)–Mean (Ufollow-up−Ubaseline) Regression to the mean Receiver operating curve Cut-off point where sensitivity+specificity is maximised between changed and unchanged Non-parametric
Random sample variation
Change analysed separately for worsening and improvementRegression modelling Transition variable# as independent or dependent variable Control for confounding and effect modification Cfollow-up: follow-up score of patients who are changed based on response to anchor; Cbaseline: baseline score of patients who are changed based on response to anchor; Ufollow-up: follow-up score of patients who are unchanged based on response to anchor; Ubaseline: baseline score of patients who are unchanged based on response to anchor. #: transition variable (usually coded as 1 if changed based on response to anchor or 0 if unchanged based on anchor).
- Table 2
Summary of MCID values of physiological and patient-reported outcome measures in patients with IPF
Variable Author [ref.] Time period weeks Sample size (disease severity) Anchors Distribution method used Improvement or deterioration MCID value FVC % pred Du Bois [14] 48 1156 (mild-to-moderate) SF-2
Hospitalisation
DeathYes Both 2–6% 6MWD m Du Bois [18] 48 826 (mild-to-moderate) Hospitalisation
DeathYes Both 24–45# Nathan [19] 48 338 (mild-to-moderate) Hospitalisation
DeathYes Both 21.7–37.0# Swigris [20] 52 123 (mild-to-moderate) FVC
SGRQYes Both 28 ISW m Nolan [37] 8 77 patients¶ GRCQ Yes Improvement 31–46# Total SGRQ Swigris [22] 26 129 (mild-to-moderate) FVC TDI Yes Both 7 (5–10)+ Swigris [23] 52 1061 (mild-to-moderate) FVC
UCSD SOBQ
PGI-CYes Both 4–5 SGRQ-I Prior [24] 52 124 (mild-to-moderate) FVC
DLCO
6MWD
GRCS
UCSD SOBQ
SGRQNo Improvement 3.9 Deterioration 4.9 UCSD SOBQ Swigris [25] 24 180 (severe) SGRQ-A Yes Both 8 (5–11)+ SF-36 Swigris [22] 26 129 (mild-to-moderate) FVC Yes Both 3 (MCS) TDI 3 (PCS) Witt [27] § 258¶ 6MWD
FVC
DLCOYes Both 6 (MCS) 5 (PCS) KBILD Prior [24] 52 124 (mild-to-moderate) FVC
DLCO
6MWD
GRCS
UCSD SOBQ
SGRQNo Improvement 4.7 Deterioration 2.7 SGRQ-I: SGRQ for patients with IPF; SF-36: Short-Form Health Survey 36; SF-2: health transition question in SF-36 questionnaire; GRCQ: Global Rating of Change Questionnaire; TDI: Transition Dyspnea Index; PGI-C: Patient's Global Impression of Change; DLCO: diffusing capacity of the lung for carbon monoxide; GRCS: Global Rating of Change Scales; SGRQ-A: SGRQ activity domain; MCS: mental component score; PCS: physical component score. #: range; ¶: no set inclusion criteria based on disease severity; +: point estimate (range); §: no a priori follow-up time.