Susan Chinn1. 1. Department of Public Health Sciences, King's College, Capital House, 42 Weston Street, London SE1 3QD, UK. sue.chinn@kcl.ac.uk
Abstract
BACKGROUND: There is no standardised protocol for the measurement of bronchial responsiveness. Results from different studies are difficult to compare and combine. METHODS: Analyses are divided between those of a continuous outcome, which can be directly standardised as effect size, and those based on a binary outcome. A published method is used to convert an odds ratio to equivalent effect size. RESULTS: The use of effect size allows comparison between studies using a continuous outcome but different protocols, provided the relevant standard deviation is reported. Effect size from a continuous outcome and that derived from an odds ratio from an equivalent analysis gave similar results. CONCLUSIONS: Systematic reviews which include both continuous effect estimates and odds ratios can include both in one meta-analysis, provided relevant standard deviations are published for the former. Authors are encouraged to report these in all fields in which measurement protocols vary.
BACKGROUND: There is no standardised protocol for the measurement of bronchial responsiveness. Results from different studies are difficult to compare and combine. METHODS: Analyses are divided between those of a continuous outcome, which can be directly standardised as effect size, and those based on a binary outcome. A published method is used to convert an odds ratio to equivalent effect size. RESULTS: The use of effect size allows comparison between studies using a continuous outcome but different protocols, provided the relevant standard deviation is reported. Effect size from a continuous outcome and that derived from an odds ratio from an equivalent analysis gave similar results. CONCLUSIONS: Systematic reviews which include both continuous effect estimates and odds ratios can include both in one meta-analysis, provided relevant standard deviations are published for the former. Authors are encouraged to report these in all fields in which measurement protocols vary.
Authors: M Van Den Berge; R J Meijer; H A Kerstjens; D M de Reus; G H Koëter; H F Kauffman; D S Postma Journal: Am J Respir Crit Care Med Date: 2001-06 Impact factor: 21.405
Authors: Frederieke G Schaafsma; Karyn Whelan; Allard J van der Beek; Ludeke C van der Es-Lambeek; Anneli Ojajärvi; Jos H Verbeek Journal: Cochrane Database Syst Rev Date: 2013-08-30