Impact of participant attrition on child injury outcome estimates: a longitudinal birth cohort study in Australia

Cameron, Cate M., Osborne, Jodie M., Spinks, Anneliese B., Davey, Tamzyn M., Sipe, Neil and McClure, Roderick J. (2017) Impact of participant attrition on child injury outcome estimates: a longitudinal birth cohort study in Australia. BMJ Open, 7 6: e015584. doi:10.1136/bmjopen-2016-015584


Author Cameron, Cate M.
Osborne, Jodie M.
Spinks, Anneliese B.
Davey, Tamzyn M.
Sipe, Neil
McClure, Roderick J.
Title Impact of participant attrition on child injury outcome estimates: a longitudinal birth cohort study in Australia
Journal name BMJ Open   Check publisher's open access policy
ISSN 2044-6055
Publication date 2017-06-01
Year available 2017
Sub-type Article (original research)
DOI 10.1136/bmjopen-2016-015584
Open Access Status DOI
Volume 7
Issue 6
Start page e015584
Total pages 9
Place of publication London, United Kingdom
Publisher BMJ Group
Language eng
Abstract Longitudinal research is subject to participant attrition. Systemic differences between retained participants and those lost to attrition potentially bias prevalence of outcomes, as well as exposure-outcome associations. This study examines the impact of attrition on the prevalence of child injury outcomes and the association between sociodemographic factors and child injury.

Participants were recruited as part of the Environments for Healthy Living (EFHL) birth cohort study. Baseline data were drawn from maternal surveys. Child injury outcome data were extracted from hospital records, 2006-2013. Participant attrition status was assessed up to 2014. Rates of injury-related episodes of care were calculated, taking into account exposure time and Poisson regression was performed to estimate exposure-outcome associations.

Of the 2222 participating families, 799 families (36.0%) had complete follow-up data. Those with incomplete data included 137 (6.2%) who withdrew, 308 (13.8%) were lost to follow-up and 978 families (44.0%) who were partial/non-responders. Families of lower socioeconomic status were less likely to have complete follow-up data (p<0.05). Systematic differences in attrition did not result in differential child injury outcomes or significant differences between the attrition and non-attrition groups in risk factor effect estimates. Participants who withdrew were the only group to demonstrate differences in child injury outcomes.

This research suggests that even with considerable attrition, if the proportion of participants who withdraw is minimal, overall attrition is unlikely to affect the population prevalence estimate of child injury or measures of association between sociodemographic factors and child injury.
Formatted abstract
Background Longitudinal research is subject to participant attrition. Systemic differences between retained participants and those lost to attrition potentially bias prevalence of outcomes, as well as exposure-outcome associations. This study examines the impact of attrition on the prevalence of child injury outcomes and the association between sociodemographic factors and child injury.

Methods Participants were recruited as part of the Environments for Healthy Living (EFHL) birth cohort study. Baseline data were drawn from maternal surveys. Child injury outcome data were extracted from hospital records, 2006–2013. Participant attrition status was assessed up to 2014. Rates of injury-related episodes of care were calculated, taking into account exposure time and Poisson regression was performed to estimate exposure-outcome associations.

Results Of the 2222 participating families, 799 families (36.0%) had complete follow-up data. Those with incomplete data included 137 (6.2%) who withdrew, 308 (13.8%) were lost to follow-up and 978 families (44.0%) who were partial/non-responders. Families of lower socioeconomic status were less likely to have complete follow-up data (p<0.05). Systematic differences in attrition did not result in differential child injury outcomes or significant differences between the attrition and non-attrition groups in risk factor effect estimates. Participants who withdrew were the only group to demonstrate differences in child injury outcomes.

Conclusion This research suggests that even with considerable attrition, if the proportion of participants who withdraw is minimal, overall attrition is unlikely to affect the population prevalence estimate of child injury or measures of association between sociodemographic factors and child injury.
Keyword Attrition
Child injury
Data linkage
Epidemiology
Longitudinal research
Methods
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: HERDC Pre-Audit
School of Public Health Publications
School of Earth and Environmental Sciences
Admin Only - School of Public Health
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 0 times in Thomson Reuters Web of Science Article
Scopus Citation Count Cited 0 times in Scopus Article
Google Scholar Search Google Scholar
Created: Tue, 01 Aug 2017, 00:11:40 EST by System User on behalf of School of Public Health