ALCOHOLISM: CLINICAL AND EXPERIMENTAL RESEARCH
Vol. 39, No. 8 August 2015
First Steps in Estimating Population Prevalence of Combined Alcohol and Energy Drink Use Tim Slade and Sharlene Kaye
A
LCOHOL CONSUMPTION BOTH at an individual and at a population level is an evolving phenomenon. New trends in alcohol consumption practices are continually emerging, and an accurate picture of this evolution is critical if we are to appropriately respond to the burden associated with alcohol use. Changing trends in the types of alcohol consumed (e.g., Kraus et al., 2015), the patterns of alcohol consumption (e.g., Kerr et al., 2009), or indeed the norms and values associated with alcohol use (e.g., Keyes et al., 2012), each point to important individuals or behaviors that may, in the near future, require targeted investigation and/or intervention. One recent trend that is receiving both media and academic interest is the issue of energy drink use and its coincidence with alcohol consumption. The unique harms brought about by combined alcohol and energy drink use make this consumption pattern one of potentially high public health importance. A recent review of the effects of mixing energy drinks with alcohol concludes that combined use may facilitate drinking and alcohol-related harms through increased stimulation and alertness (McKetin et al., 2015). In this issue of Alcoholism: Clinical and Experimental Research, Pennay and colleagues (2015) report the results of a population-based survey on energy drink use, both outside of and within the context of alcohol use. One in 6 people reported energy drink use in the 3 months prior to the survey, and around 1 in 20 reported combined energy drink and alcohol use. Combined alcohol and energy drink use was concentrated in the younger age groups and was found to be associated with problem gambling and psychological distress. As with all research findings based on survey methodology, the curse of nonresponse bias is ever present. The veracity of prevalence estimates derived from survey data is intrinsically linked to the representativeness of the survey sample, and with a response rate of 19.5%, cautious interpretation is warranted. It would be interesting to know
From the National Drug and Alcohol Research Centre (TS, SK), University of New South Wales, Randwick, NSW, Australia. Received for publication May 28, 2015; accepted June 1, 2015. Reprint requests: Tim Slade, National Drug and Alcohol Research Centre, University of New South Wales, 22-32 King Street, Randwick, NSW 2032, Australia; Tel.: +612-93850267; Fax: +612-9385-0222; E-mail: [email protected] Copyright © 2015 by the Research Society on Alcoholism.
whether nonresponse was universal or concentrated among some demographic subgroups. The age distribution of the achieved sample provides some clues to this. Given prior research showing a particular concentration of alcohol and energy drink use among late teenage/early adult age groups, it is potentially problematic that 49% of the sample are aged 50 or older. Poststratification to population benchmarks is critical, and the methods employed by Pennay and colleagues (2015) are up to industry standards. At the same time, however, it is important to reflect on whether certain demographic subgroups were prone to nonresponse more so than others. For example, were the 18- to 24-year-olds who ended up participating in this survey different, in unmeasured ways, to all 18- to 24-year-olds? Answering this question requires speculation, but this may go part way to explaining the relatively low prevalence of energy drink use and combined energy drink and alcohol use. Putting prevalence estimation aside, the observed associations between combined alcohol and energy drink consumption and other measured characteristics point to some interesting avenues for further investigation. For example, the relationship between combined alcohol and energy drink consumption and binge drinking is still unclear. While the evidence to date, including the findings of Pennay and colleagues (2015), suggests that those who combine alcohol and energy drinks are heavier and more frequent consumers of alcohol, a causal role of the combination of alcohol and energy drinks in increasing alcohol consumption has yet to be established. Studies conducting within-subject comparisons of alcohol consumption during episodes of alcohol and energy drink use with consumption during episodes where only alcohol is used have yielded mixed results (McKetin et al., 2015). Given binge drinking is associated with a range of adverse health effects, further efforts to elucidate the role of combined alcohol and energy drink use are warranted. The finding that combined alcohol and energy drink use was associated with increased levels of problem gambling is also of interest. Although some studies have found combined alcohol and energy drink use to be associated with other forms of risk-taking, for example, drink-driving, sexual risk behaviors, and alcohol-related injury (Brache and Stockwell, 2011; O’Brien et al., 2013; Snipes and Benotsch, 2013), there has been virtually no investigation of problem gambling in relation to such use. Moreover, in their study
DOI: 10.1111/acer.12798 1328
Alcohol Clin Exp Res, Vol 39, No 8, 2015: pp 1328–1329
COMMENTARY
1329
measuring a range of risk behaviors, Peacock and colleagues (2012) found that the odds of gambling during an episode of combined alcohol and energy drink use were lower than during an episode of alcohol use only. Whether problem gambling, or risk-taking more generally, is a direct result of combined alcohol and energy drink use per se or due to increased alcohol consumption among those who combine alcohol with energy drinks is a question yet to be answered. Surveys such as the one carried out by Pennay and colleagues (2015) will remain critical to increasing our understanding of the extent, distribution, and associated harms of combined alcohol and energy drink use at a population level. The challenges brought about by survey nonresponse are not unique to this study, they are a global problem and one that is becoming more pronounced with declining survey response rates across many areas of survey research (Galea and Tracy, 2007). The survey carried out by Pennay and colleagues (2015) represents a fundamental first step in our understanding of this emerging public health issue. REFERENCES Brache K, Stockwell T (2011) Drinking patterns and risk behaviors associated with combined alcohol and energy drink consumption in college drinkers. Addict Behav 36:1133–1140.
Galea S, Tracy M (2007) Participation rates in epidemiologic studies. Ann Epidemiol 17:643–653. Kerr WC, Greenfield TK, Bond J, Ye Y, Rehm J (2009) Age-period-cohort modelling of alcohol volume and heavy drinking days in the US National Alcohol Surveys: divergence in younger and older adult trends. Addiction 104:27–37. Keyes KM, Schulenberg JE, O’Malley PM, Johnston LD, Bachman JG, Li G, Hasin D (2012) Birth cohort effects on adolescent alcohol use: the influence of social norms from 1976–2007. Arch Gen Psychiatry 69:1304–1313. Kraus L, Tingh€ og ME, Lindell A, Pabst A, Piontek D, Room R (2015) Age, period and cohort effects on time trends in alcohol consumption in the Swedish adult population 1979–2011. Alcohol Alcohol 50:319–327. McKetin R, Coen A, Kaye S (2015) A comprehensive review of the effects of mixing caffeinated energy drinks with alcohol. Drug Alcohol Depend 151:15–30. O’Brien MC, McCoy TP, Egan KL, Goldin S, Rhodes SD, Wolfson M (2013) Caffeinated alcohol, sensation seeking, and injury risk. J Caffeine Res 3:59–66. Peacock A, Bruno R, Martin FH (2012) The subjective physiological, psychological, and behavioural risk-taking consequences of alcohol and energy drink co-ingestion. Alcohol Clin Exp Res 36:2008–2015. Pennay A, Cheetham A, Droste N, Miller P, Lloyd B, Pennay D, Dowling N, Jackson A, Lubman DI (2015) An examination of the prevalence, consumer profiles, and patterns of energy drink use, with and without alcohol, in Australia. Alcohol Clin Exp Res doi: 10.1111/acer.12764 [Epub ahead of print]. Snipes DJ, Benotsch EG (2013) High-risk cocktails and high-risk sex: examining the relation between alcohol mixed with energy drink consumption, sexual behavior, and drug use in college students. Addict Behav 38:1418– 1423.
Vol. 39, No. 8 August 2015
First Steps in Estimating Population Prevalence of Combined Alcohol and Energy Drink Use Tim Slade and Sharlene Kaye
A
LCOHOL CONSUMPTION BOTH at an individual and at a population level is an evolving phenomenon. New trends in alcohol consumption practices are continually emerging, and an accurate picture of this evolution is critical if we are to appropriately respond to the burden associated with alcohol use. Changing trends in the types of alcohol consumed (e.g., Kraus et al., 2015), the patterns of alcohol consumption (e.g., Kerr et al., 2009), or indeed the norms and values associated with alcohol use (e.g., Keyes et al., 2012), each point to important individuals or behaviors that may, in the near future, require targeted investigation and/or intervention. One recent trend that is receiving both media and academic interest is the issue of energy drink use and its coincidence with alcohol consumption. The unique harms brought about by combined alcohol and energy drink use make this consumption pattern one of potentially high public health importance. A recent review of the effects of mixing energy drinks with alcohol concludes that combined use may facilitate drinking and alcohol-related harms through increased stimulation and alertness (McKetin et al., 2015). In this issue of Alcoholism: Clinical and Experimental Research, Pennay and colleagues (2015) report the results of a population-based survey on energy drink use, both outside of and within the context of alcohol use. One in 6 people reported energy drink use in the 3 months prior to the survey, and around 1 in 20 reported combined energy drink and alcohol use. Combined alcohol and energy drink use was concentrated in the younger age groups and was found to be associated with problem gambling and psychological distress. As with all research findings based on survey methodology, the curse of nonresponse bias is ever present. The veracity of prevalence estimates derived from survey data is intrinsically linked to the representativeness of the survey sample, and with a response rate of 19.5%, cautious interpretation is warranted. It would be interesting to know
From the National Drug and Alcohol Research Centre (TS, SK), University of New South Wales, Randwick, NSW, Australia. Received for publication May 28, 2015; accepted June 1, 2015. Reprint requests: Tim Slade, National Drug and Alcohol Research Centre, University of New South Wales, 22-32 King Street, Randwick, NSW 2032, Australia; Tel.: +612-93850267; Fax: +612-9385-0222; E-mail: [email protected] Copyright © 2015 by the Research Society on Alcoholism.
whether nonresponse was universal or concentrated among some demographic subgroups. The age distribution of the achieved sample provides some clues to this. Given prior research showing a particular concentration of alcohol and energy drink use among late teenage/early adult age groups, it is potentially problematic that 49% of the sample are aged 50 or older. Poststratification to population benchmarks is critical, and the methods employed by Pennay and colleagues (2015) are up to industry standards. At the same time, however, it is important to reflect on whether certain demographic subgroups were prone to nonresponse more so than others. For example, were the 18- to 24-year-olds who ended up participating in this survey different, in unmeasured ways, to all 18- to 24-year-olds? Answering this question requires speculation, but this may go part way to explaining the relatively low prevalence of energy drink use and combined energy drink and alcohol use. Putting prevalence estimation aside, the observed associations between combined alcohol and energy drink consumption and other measured characteristics point to some interesting avenues for further investigation. For example, the relationship between combined alcohol and energy drink consumption and binge drinking is still unclear. While the evidence to date, including the findings of Pennay and colleagues (2015), suggests that those who combine alcohol and energy drinks are heavier and more frequent consumers of alcohol, a causal role of the combination of alcohol and energy drinks in increasing alcohol consumption has yet to be established. Studies conducting within-subject comparisons of alcohol consumption during episodes of alcohol and energy drink use with consumption during episodes where only alcohol is used have yielded mixed results (McKetin et al., 2015). Given binge drinking is associated with a range of adverse health effects, further efforts to elucidate the role of combined alcohol and energy drink use are warranted. The finding that combined alcohol and energy drink use was associated with increased levels of problem gambling is also of interest. Although some studies have found combined alcohol and energy drink use to be associated with other forms of risk-taking, for example, drink-driving, sexual risk behaviors, and alcohol-related injury (Brache and Stockwell, 2011; O’Brien et al., 2013; Snipes and Benotsch, 2013), there has been virtually no investigation of problem gambling in relation to such use. Moreover, in their study
DOI: 10.1111/acer.12798 1328
Alcohol Clin Exp Res, Vol 39, No 8, 2015: pp 1328–1329
COMMENTARY
1329
measuring a range of risk behaviors, Peacock and colleagues (2012) found that the odds of gambling during an episode of combined alcohol and energy drink use were lower than during an episode of alcohol use only. Whether problem gambling, or risk-taking more generally, is a direct result of combined alcohol and energy drink use per se or due to increased alcohol consumption among those who combine alcohol with energy drinks is a question yet to be answered. Surveys such as the one carried out by Pennay and colleagues (2015) will remain critical to increasing our understanding of the extent, distribution, and associated harms of combined alcohol and energy drink use at a population level. The challenges brought about by survey nonresponse are not unique to this study, they are a global problem and one that is becoming more pronounced with declining survey response rates across many areas of survey research (Galea and Tracy, 2007). The survey carried out by Pennay and colleagues (2015) represents a fundamental first step in our understanding of this emerging public health issue. REFERENCES Brache K, Stockwell T (2011) Drinking patterns and risk behaviors associated with combined alcohol and energy drink consumption in college drinkers. Addict Behav 36:1133–1140.
Galea S, Tracy M (2007) Participation rates in epidemiologic studies. Ann Epidemiol 17:643–653. Kerr WC, Greenfield TK, Bond J, Ye Y, Rehm J (2009) Age-period-cohort modelling of alcohol volume and heavy drinking days in the US National Alcohol Surveys: divergence in younger and older adult trends. Addiction 104:27–37. Keyes KM, Schulenberg JE, O’Malley PM, Johnston LD, Bachman JG, Li G, Hasin D (2012) Birth cohort effects on adolescent alcohol use: the influence of social norms from 1976–2007. Arch Gen Psychiatry 69:1304–1313. Kraus L, Tingh€ og ME, Lindell A, Pabst A, Piontek D, Room R (2015) Age, period and cohort effects on time trends in alcohol consumption in the Swedish adult population 1979–2011. Alcohol Alcohol 50:319–327. McKetin R, Coen A, Kaye S (2015) A comprehensive review of the effects of mixing caffeinated energy drinks with alcohol. Drug Alcohol Depend 151:15–30. O’Brien MC, McCoy TP, Egan KL, Goldin S, Rhodes SD, Wolfson M (2013) Caffeinated alcohol, sensation seeking, and injury risk. J Caffeine Res 3:59–66. Peacock A, Bruno R, Martin FH (2012) The subjective physiological, psychological, and behavioural risk-taking consequences of alcohol and energy drink co-ingestion. Alcohol Clin Exp Res 36:2008–2015. Pennay A, Cheetham A, Droste N, Miller P, Lloyd B, Pennay D, Dowling N, Jackson A, Lubman DI (2015) An examination of the prevalence, consumer profiles, and patterns of energy drink use, with and without alcohol, in Australia. Alcohol Clin Exp Res doi: 10.1111/acer.12764 [Epub ahead of print]. Snipes DJ, Benotsch EG (2013) High-risk cocktails and high-risk sex: examining the relation between alcohol mixed with energy drink consumption, sexual behavior, and drug use in college students. Addict Behav 38:1418– 1423.
