PMID- 17136968
OWN - NLM
STAT- MEDLINE
DCOM- 20070222
LR  - 20191110
IS  - 1541-2555 (Print)
IS  - 1541-2563 (Linking)
VI  - 2
IP  - 1
DP  - 2005 Mar
TI  - The minimally clinically important difference in generic utility-based measures.
PG  - 91-7
AB  - PURPOSE: To evaluate the use of utility-based generic quality of life measures 
      for establishing the minimally clinically important difference (MCID). 
      BACKGROUND: Utility-based quality of life measures place levels of wellness on a 
      continuum anchored by death (0.00) and optimum function (1.00). Preference 
      measurement studies are used to define the meaning of points along the continuum. 
      Health states that differ by less than 0.03 units cannot be discriminated by 
      panels of judges as different from one another. Thus, 0.03 is a reasonable MCID 
      for these measures. METHOD: Three published studies of patients with Chronic 
      Obstructive Pulmonary Disease (COPD) reported data on the Quality of Well-being 
      Scale (QWB) before and after pulmonary rehabilitation. One of the studies also 
      randomly assigned patients to lung volume reduction surgery or to maximal medical 
      therapy. These patients were followed for an average of 29 months. RESULTS: All 
      three evaluations of pulmonary rehabilitation showed changes on the QWB in excess 
      of the proposed 0.03 MCID. QWB changes for patients assigned to lung volume 
      reduction surgery were close to the MCID threshold at one year but grew stronger 
      in subsequent years. Using Norman's 0.50 standard deviation method, all three 
      estimates of rehabilitation effectiveness and the outcomes one year following 
      surgery fall below the MCID. CONCLUSION: Different methods for estimating MCID 
      lead to different conclusions about the meaning of quality of life changes 
      following pulmonary rehabilitation and lung volume reduction surgery. The 
      preference scaling system in generic utility-based quality of life measures 
      provides a metric that is directly interpretable and avoids many of the 
      criticisms of MCID measures. The method is sensitive enough to suggest clinically 
      meaningful benefits of rehabilitation and surgery. Further, quality adjusted life 
      years offer a valuable metric for policy analysis. Utility-based measures of 
      health related quality of life should gain greater use in COPD outcomes research.
FAU - Kaplan, Robert M
AU  - Kaplan RM
AD  - Department of Health Services, UCLA School of Public Health, PO Box 951772, Room 
      31-293C CHS, Los Angeles, California 90095-1772, USA. rmkaplan@ucla.edu
LA  - eng
PT  - Journal Article
PL  - England
TA  - COPD
JT  - COPD
JID - 101211769
SB  - IM
MH  - Aged
MH  - Data Interpretation, Statistical
MH  - Female
MH  - Humans
MH  - Male
MH  - Pulmonary Disease, Chronic Obstructive/*diagnosis/*therapy
MH  - *Quality of Life
MH  - *Surveys and Questionnaires
MH  - Treatment Outcome
EDAT- 2006/12/02 09:00
MHDA- 2007/02/23 09:00
CRDT- 2006/12/02 09:00
PHST- 2006/12/02 09:00 [pubmed]
PHST- 2007/02/23 09:00 [medline]
PHST- 2006/12/02 09:00 [entrez]
AID - 10.1081/copd-200052090 [doi]
PST - ppublish
SO  - COPD. 2005 Mar;2(1):91-7. doi: 10.1081/copd-200052090.