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Using ecological momentary assessment in testing the effectiveness of an alcohol intervention: a two-arm parallel group randomized controlled trial.

Voogt CV, Kuntsche E, Kleinjan M, Poelen EA, Lemmers LA, Engels RC - PLoS ONE (2013)

Bottom Line: By using 25 follow-up time-points, this study tested whether intervention effects are robust or might vary over time.According to the intention-to-treat principle, regression analyses revealed that intervention effects on alcohol consumption varied when exploring multiple follow-up time-points.This research showed that the commonly used one and six month follow-up time-points are relatively arbitrary and not using EMA might bring forth erroneous conclusions on the effectiveness of interventions.

View Article: PubMed Central - PubMed

Affiliation: Behavioural Science Institute, Radboud University, Nijmegen, The Netherlands.

ABSTRACT

Background: Alcohol consumption of college students has a fluctuating nature, which might impact the measurement of intervention effects. By using 25 follow-up time-points, this study tested whether intervention effects are robust or might vary over time.

Methods: Data were used from a two-arm parallel group randomized controlled trial applying ecological momentary assessment (EMA) with 30 data time-points in total. Students between 18 and 24 years old who reported heavy drinking in the past six months and who were ready to change their alcohol consumption were randomly assigned to the experimental (n = 456: web-based brief alcohol intervention) and control condition (n = 451: no intervention). Outcome measures were weekly alcohol consumption, frequency of binge drinking, and heavy drinking status.

Results: According to the intention-to-treat principle, regression analyses revealed that intervention effects on alcohol consumption varied when exploring multiple follow-up time-points. Intervention effects were found for a) weekly alcohol consumption at 1, 2, 3, 4, and 7 weeks follow-up, b) frequency of binge drinking at 1, 2, 7, and 12 weeks follow-up, and c) heavy drinking status at 1, 2, 7, and 16 weeks follow-up.

Conclusions: This research showed that the commonly used one and six month follow-up time-points are relatively arbitrary and not using EMA might bring forth erroneous conclusions on the effectiveness of interventions. Therefore, future trials in alcohol prevention research and beyond are encouraged to apply EMA when assessing outcome measures and intervention effectiveness.

Trial registration: Netherlands Trial Register NTR2665.

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Related in: MedlinePlus

Flow diagram following Consolidated Standards of Reporting Trials (CONSORT) guidelines.
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pone-0078436-g001: Flow diagram following Consolidated Standards of Reporting Trials (CONSORT) guidelines.

Mentions: The current study used data from a two-arm parallel group RCT applying an EMA approach with 30 data time-points. From September until December 2010, participants were recruited at Higher Professional Education (HBO) institutions and universities in the Netherlands via distributing flyers. Students between 18 and 24 years old who reported heavy drinking in the past six months, were ready to change their alcohol consumption, had daily access to the Internet, and signed an informed consent form were included in the study. Students reporting a score of 20 or higher on the Alcohol Use Disorders Identification Test (AUDIT: [23]) and/or receiving treatment for alcohol-related problems were excluded from the study and advised to seek treatment since the intervention was developed for the reduction of heavy drinking and not the reduction of problem drinking. A sample size of 908 participants was required given an anticipated dropout rate of 30% after randomization to detect an increase in the percentage of participants adhering to low-risk drinking guidelines after one month of 42% in the experimental condition versus 31% in the control condition [24] with a two-sided 5% significance level and a power of 80%. Students who met the inclusion criteria were randomly assigned to the experimental condition and control condition by an independent researcher of the Behavioural Science Institute (see Figure 1). Randomization occurred centrally using a blocked randomization scheme (block size 4) and was stratified by sex before the baseline assessment in January 2011 [19].


Using ecological momentary assessment in testing the effectiveness of an alcohol intervention: a two-arm parallel group randomized controlled trial.

Voogt CV, Kuntsche E, Kleinjan M, Poelen EA, Lemmers LA, Engels RC - PLoS ONE (2013)

Flow diagram following Consolidated Standards of Reporting Trials (CONSORT) guidelines.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3818333&req=5

pone-0078436-g001: Flow diagram following Consolidated Standards of Reporting Trials (CONSORT) guidelines.
Mentions: The current study used data from a two-arm parallel group RCT applying an EMA approach with 30 data time-points. From September until December 2010, participants were recruited at Higher Professional Education (HBO) institutions and universities in the Netherlands via distributing flyers. Students between 18 and 24 years old who reported heavy drinking in the past six months, were ready to change their alcohol consumption, had daily access to the Internet, and signed an informed consent form were included in the study. Students reporting a score of 20 or higher on the Alcohol Use Disorders Identification Test (AUDIT: [23]) and/or receiving treatment for alcohol-related problems were excluded from the study and advised to seek treatment since the intervention was developed for the reduction of heavy drinking and not the reduction of problem drinking. A sample size of 908 participants was required given an anticipated dropout rate of 30% after randomization to detect an increase in the percentage of participants adhering to low-risk drinking guidelines after one month of 42% in the experimental condition versus 31% in the control condition [24] with a two-sided 5% significance level and a power of 80%. Students who met the inclusion criteria were randomly assigned to the experimental condition and control condition by an independent researcher of the Behavioural Science Institute (see Figure 1). Randomization occurred centrally using a blocked randomization scheme (block size 4) and was stratified by sex before the baseline assessment in January 2011 [19].

Bottom Line: By using 25 follow-up time-points, this study tested whether intervention effects are robust or might vary over time.According to the intention-to-treat principle, regression analyses revealed that intervention effects on alcohol consumption varied when exploring multiple follow-up time-points.This research showed that the commonly used one and six month follow-up time-points are relatively arbitrary and not using EMA might bring forth erroneous conclusions on the effectiveness of interventions.

View Article: PubMed Central - PubMed

Affiliation: Behavioural Science Institute, Radboud University, Nijmegen, The Netherlands.

ABSTRACT

Background: Alcohol consumption of college students has a fluctuating nature, which might impact the measurement of intervention effects. By using 25 follow-up time-points, this study tested whether intervention effects are robust or might vary over time.

Methods: Data were used from a two-arm parallel group randomized controlled trial applying ecological momentary assessment (EMA) with 30 data time-points in total. Students between 18 and 24 years old who reported heavy drinking in the past six months and who were ready to change their alcohol consumption were randomly assigned to the experimental (n = 456: web-based brief alcohol intervention) and control condition (n = 451: no intervention). Outcome measures were weekly alcohol consumption, frequency of binge drinking, and heavy drinking status.

Results: According to the intention-to-treat principle, regression analyses revealed that intervention effects on alcohol consumption varied when exploring multiple follow-up time-points. Intervention effects were found for a) weekly alcohol consumption at 1, 2, 3, 4, and 7 weeks follow-up, b) frequency of binge drinking at 1, 2, 7, and 12 weeks follow-up, and c) heavy drinking status at 1, 2, 7, and 16 weeks follow-up.

Conclusions: This research showed that the commonly used one and six month follow-up time-points are relatively arbitrary and not using EMA might bring forth erroneous conclusions on the effectiveness of interventions. Therefore, future trials in alcohol prevention research and beyond are encouraged to apply EMA when assessing outcome measures and intervention effectiveness.

Trial registration: Netherlands Trial Register NTR2665.

Show MeSH
Related in: MedlinePlus