Back to Search
Start Over
Weight-for-age z-score as a proxy marker for diarrhoea in epidemiological studies.
- Source :
- Journal of Epidemiology & Community Health; Dec2010, Vol. 64 Issue 12, p1074-1079, 6p, 2 Charts, 4 Graphs
- Publication Year :
- 2010
-
Abstract
- Background The validity of unblinded randomised trials testing interventions against diarrhoea is severely compromised by the potential for bias. Objective proxy markers for diarrhoea not relying on self-report are needed to assess the effect of interventions that cannot be blinded. Short-term changes in weight-for-age z-score (WAZ) may (due to catch-up growth) not be a clinically important marker for nutritional status. However, even a transient decrease in WAZ could indicate recent diarrhoea, and be interpreted as the effect of an intervention. Methods Using data from two large vitamin A trials from Ghana and Brazil, the immediate effect of the cumulative diarrhoea occurrence over 14 and 28 day time windows on WAZ was explored. Results A very strong linear association was found between the number of days with diarrhoea over the last 14-28 days and WAZ. In both trials, differences in diarrhoea between the trial arms were associated with corresponding differences in WAZ. Conclusion Repeated WAZ measures appear to be a suitable proxy marker for diarrhoea in children, but have disadvantages in terms of specificity and study power. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 0143005X
- Volume :
- 64
- Issue :
- 12
- Database :
- Complementary Index
- Journal :
- Journal of Epidemiology & Community Health
- Publication Type :
- Academic Journal
- Accession number :
- 65968040
- Full Text :
- https://doi.org/10.1136/jech.2009.099721