S. Deviation, Wilcoxon test for the difference. c Standardized Response Mean. d Effect Size. e Higher score indicates a higher level of functioning or better quality of life. f Higher score indicates more symptoms/problems

. Uwer, Responsiveness of EORTC QLQ-C30, QLQ-CR38 and FACT-C quality of life questionnaires in patients with colorectal cancer, Health and Quality of Life Outcomes, vol.9, issue.1, p.70, 2011.
DOI : 10.1007/s11136-004-2577-x
URL : https://hal.archives-ouvertes.fr/inserm-00622834

E. Qlq-cr38, Functional scales e : Body image 20 90.9 (16.3) -3.3 (14.5)

S. Deviation, b Wilcoxon test of the change. c Standardized Response Mean. d Effect Size. e Higher score indicates a higher level of functioning or better quality of life. f Higher score indicates more symptoms/problems

R. 1. Guyatt, G. Ferrans, C. Halyard, M. Revicki, D. Symonds et al., Exploration of the Value of Health-Related Quality-of-Life Information From Clinical Research and Into Clinical Practice, Mayo Clinic Proceedings, vol.82, issue.10, pp.1229-1239, 2007.
DOI : 10.4065/82.10.1229

A. Garratt, L. Schmidt, A. Mackintosh, and R. Fitzpatrick, Quality of life measurement: bibliographic study of patient assessed health outcome measures, BMJ, vol.324, issue.7351, p.1417, 2002.
DOI : 10.1136/bmj.324.7351.1417

N. Aaronson, S. Ahmedzai, B. Bergman, M. Bullinger, A. Cull et al., The European Organization for Research and Treatment of Cancer QLQ-C30: A Quality-of-Life Instrument for Use in International Clinical Trials in Oncology, JNCI Journal of the National Cancer Institute, vol.85, issue.5, pp.365-376, 1993.
DOI : 10.1093/jnci/85.5.365

D. Osoba, B. Zee, J. Pater, D. Warr, L. Kaizer et al., Psychometric properties and responsiveness of the EORTC Quality of Life Questionnaire (QLQ-C30) in patients with breast, ovarian and lung cancer, Quality of Life Research, vol.16, issue.5, pp.353-364, 1994.
DOI : 10.1007/BF00451727

M. Sprangers, A. Velde, and N. Aaronson, The construction and testing of the EORTC colorectal cancer-specific quality of life questionnaire module (QLQ-CR38), European Journal of Cancer, vol.35, issue.2, pp.238-247, 1999.
DOI : 10.1016/S0959-8049(98)00357-8

D. Cella, D. Tulsky, G. Gray, B. Sarafian, E. Linn et al., The Functional Assessment of Cancer Therapy scale: development and validation of the general measure., Journal of Clinical Oncology, vol.11, issue.3, pp.570-579, 1993.
DOI : 10.1200/JCO.1993.11.3.570

W. Ward, E. Hahn, F. Mo, L. Hernandez, D. Tulsky et al., Reliability and validity of the Functional Assessment of Cancer Therapy-Colorectal (FACT-C) quality of life instrument, Quality of Life Research, vol.8, issue.3, pp.181-195, 1999.
DOI : 10.1023/A:1008821826499

T. Conroy, M. Mercier, J. Bonneterre, E. Luporsi, J. Lefebvre et al., French version of FACT-G: validation and comparison with other cancer-specific instruments, European Journal of Cancer, vol.40, issue.15, pp.2243-2252, 2004.
DOI : 10.1016/j.ejca.2004.06.010

G. Guyatt, D. Feeny, and D. Patrick, Measuring Health-Related Quality of Life, Annals of Internal Medicine, vol.118, issue.8, pp.130-136, 1993.
DOI : 10.7326/0003-4819-118-8-199304150-00009

D. Hawley and F. Wolfe, Sensitivity to change of the Health Assessment Questionnaire (HAQ) and other clinical and health status measures in rheumatoid arthritis results of short-term clinical trials and observational studies versus long-term observational studies, Arthritis Care & Research, vol.81, issue.3, pp.130-136, 1992.
DOI : 10.1002/art.1790050304

J. Katz, M. Larson, C. Phillips, A. Fossel, and M. Liang, Comparative Measurement Sensitivity of Short and Longer Health Status Instruments, Medical Care, vol.30, issue.10, pp.917-925, 1992.
DOI : 10.1097/00005650-199210000-00004

L. Kazis, J. Anderson, and R. Meenan, Effect Sizes for Interpreting Changes in Health Status, Medical Care, vol.27, issue.Supplement, pp.178-189, 1989.
DOI : 10.1097/00005650-198903001-00015

G. Guyatt, S. Walter, and G. Norman, Measuring change over time: assessing the usefulness of evaluative instruments. JC h r o n i cD i s1987, pp.171-178

G. Guyatt, R. Deyo, M. Charlson, M. Levine, and A. Mitchell, Responsiveness and validity in health status measurement: A clarification, Journal of Clinical Epidemiology, vol.42, issue.5, pp.493-504, 2003.
DOI : 10.1016/0895-4356(89)90128-5

T. Conroy and J. Blazeby, Health-related quality of life in colorectal cancer patients, Expert Review of Anticancer Therapy, vol.3, issue.4, pp.493-504, 2003.
DOI : 10.1586/14737140.3.4.493

M. Guren, S. Dueland, E. Skovlund, S. Fossa, J. Poulsen et al., Quality of life during radiotherapy for rectal cancer, European Journal of Cancer, vol.39, issue.5, pp.587-594, 2003.
DOI : 10.1016/S0959-8049(02)00741-4

D. Osoba, G. Rodrigues, J. Myles, B. Zee, and J. Pater, Interpreting the significance of changes in health-related quality-of-life scores., Journal of Clinical Oncology, vol.16, issue.1, pp.139-144, 1998.
DOI : 10.1200/JCO.1998.16.1.139

R. Jaeschke, J. Singer, and G. Guyatt, Measurement of health status, Controlled Clinical Trials, vol.10, issue.4, pp.407-415, 1989.
DOI : 10.1016/0197-2456(89)90005-6

J. Fleiss and P. Shrout, The effects of measurement errors on some multivariate procedures., American Journal of Public Health, vol.67, issue.12, pp.1188-1191, 1977.
DOI : 10.2105/AJPH.67.12.1188

J. Cohen, Statistical Power Analysis for the Behavioural Sciences, 1977.

J. Katz, C. Phillips, A. Fossel, and M. Liang, Stability and Responsiveness of Utility Measures, Medical Care, vol.32, issue.2, pp.183-188, 1994.
DOI : 10.1097/00005650-199402000-00009

D. Beaton, C. Bombardier, J. Katz, and J. Wright, A taxonomy for responsiveness, Journal of Clinical Epidemiology, vol.54, issue.12, pp.1204-1217, 2001.
DOI : 10.1016/S0895-4356(01)00407-3

S. Wasserman and U. Bockenholt, Bootstrapping: Applications to Psychophysiology, Psychophysiology, vol.14, issue.2, pp.208-221, 1989.
DOI : 10.1037//0033-2909.101.1.136

R. Deyo, P. Diehr, and D. Patrick, Reproducibility and responsiveness of health status measures statistics and strategies for evaluation, Controlled Clinical Trials, vol.12, issue.4, pp.142-158, 1991.
DOI : 10.1016/S0197-2456(05)80019-4

C. Terwee, F. Dekker, W. Wiersinga, M. Prummel, and P. Bossuyt, On assessing responsiveness of health-related quality of life instruments: guidelines for instrument evaluation, Quality of Life Research, vol.12, issue.4, pp.349-362, 2003.
DOI : 10.1023/A:1023499322593

C. Bombardier, C. Melfi, J. Paul, R. Green, G. Hawker et al., Comparison of a generic and a disease-specific measure of pain and physical function after knee replacement surgery, Med Care, vol.33, pp.131-144, 1995.

K. Yost, D. Cella, A. Chawla, E. Holmgren, D. Eton et al., Minimally important differences were estimated for the Functional Assessment of Cancer Therapy???Colorectal (FACT-C) instrument using a combination of distribution- and anchor-based approaches, Journal of Clinical Epidemiology, vol.58, issue.12, pp.1241-1251, 2005.
DOI : 10.1016/j.jclinepi.2005.07.008

S. Gujral, T. Conroy, C. Fleissner, O. Sezer, P. King et al., Assessing quality of life in patients with colorectal cancer: An update of the EORTC quality of life questionnaire, European Journal of Cancer, vol.43, issue.10, pp.1564-1573, 2007.
DOI : 10.1016/j.ejca.2007.04.005

R. Whistance, T. Conroy, W. Chie, A. Costantini, O. Sezer et al., Clinical and psychometric validation of the EORTC QLQ-CR29 questionnaire module to assess health-related quality of life in patients with colorectal cancer, European Journal of Cancer, vol.45, issue.17, pp.3017-3026, 2009.
DOI : 10.1016/j.ejca.2009.08.014

M. Sprangers and C. Schwartz, Integrating response shift into health-related quality of life research: a theoretical model, Social Science & Medicine, vol.48, issue.11, pp.1507-1515, 1999.
DOI : 10.1016/S0277-9536(99)00045-3

M. Visser, F. Oort, and M. Sprangers, Methods to detect response shift in quality of life data: A convergent validity study, Quality of Life Research, vol.19, issue.3, pp.629-639, 2005.
DOI : 10.1007/s11136-004-2577-x