Statistical considerations for use of composite health-related quality-of-life scores in randomized trials Journal Article
| Author: | Vickers, A. J. |
| Article Title: | Statistical considerations for use of composite health-related quality-of-life scores in randomized trials |
| Abstract: | Background: Quality of life instruments are frequently used as outcomes in randomized trials. Instruments that consist of several subscales present researchers with a choice of whether to combine some or all scales into a single composite score. There may be several clinically and scientifically reasonable alternative combinations of subscales for the primary outcome measure. Major findings: The statistical efficiency of different combinations of subscales depends on the relative effect size of the intervention on each subscale and the correlation between the subscales. Simple equations can be derived for determining the relative statistical efficiency of each clinically reasonable combination of subscales. Hypothetical scenarios show that the number of patients needed in a clinical trial can be twice as great for some combinations of subscales as for others. Conclusions: There are often compelling clinical or scientific reasons to use a particular subscale or composite in a randomized trial. In the case where a number of different alternatives would be reasonable, statistical efficiency can help guide the choice of endpoint. |
| Keywords: | treatment outcome; functional assessment; clinical trial; research design; quality of life; statistics; questionnaires; questionnaire; sickness impact profile; correlation analysis; statistical analysis; data interpretation, statistical; pilot projects; randomized controlled trials; outcomes research; rating scale; emotion; randomization; social aspect; physical capacity; support group; sample size; models, psychological; hypothesis; cancer; humans; human; priority journal; article; functional assessment of cancer therapy scale |
| Journal Title: | Quality of Life Research |
| Volume: | 13 |
| Issue: | 4 |
| ISSN: | 0962-9343 |
| Publisher: | Springer |
| Date Published: | 2004-05-01 |
| Start Page: | 717 |
| End Page: | 723 |
| Language: | English |
| DOI: | 10.1023/B:QURE.0000021686.47079.0d |
| PROVIDER: | scopus |
| PMCID: | PMC2613680 |
| PUBMED: | 15129882 |
| DOI/URL: | |
| Notes: | Qual. Life Res. -- Cited By (since 1996):15 -- Export Date: 16 June 2014 -- CODEN: QLREE -- Source: Scopus |
