New Zealanders' alcohol consumption patterns across the lifespan

Executive summary

Alcohol consumption over the lifespan

Hazardous drinking increases the risk of alcohol-related harm for older drinkers because they are more sensitive to the effects of alcohol, and more likely to have chronic health conditions or use medications that alcohol can interfere with [1]. One way to effectively prevent alcohol-related harm in later life is to better understand the early- and mid-life factors and life events that trigger hazardous drinking.

An individual’s alcohol use at any point in the lifespan is influenced by a range of environmental and personal factors [2, 3]. Environmental influences include social norms around drinking [4, 5], availability and price of alcohol [6], or opportunities for alcohol consumption [7]. Personal influences include biological markers and genetic vulnerabilities [2, 3], individual differences in personality or temperament [8, 9], or socio-demographic characteristics (e.g., gender, marital status) [10]. Protective (i.e., skills, resources or attributes that eliminate or mitigate risk) and risk factors might be present at different stages of life and influence drinking behaviour. Over the course of the lifespan, people experience different events that might prompt them to increase or decrease their drinking.

Aims of this study

This study aimed to answer the following questions:

Question 1: Initiation of alcohol use

 What key demographic factors and early childhood life events were associated with early initiation of alcohol use in the current cohort of New Zealanders aged 60 years or older?

Question 2: Patterns of alcohol use over the lifespan

 What are the main patterns of alcohol use of older New Zealanders over the lifespan?

 What are the key demographic factors and early childhood life events associated with lifespan drinking trajectories of older New Zealanders?

Question 3: Transitioning from hazardous to non-hazardous drinking

 What are the key life events and life transitions that created a context for the development of hazardous alcohol use in older New Zealanders?

Methods

The data for this study were drawn from the Life Course History (LCH) Interview Study embedded in the New Zealand Health, Work and Retirement Longitudinal Study (NZHWR). A total of 801 NZHWR participants completed interviews.

The LCH interviews were 1-2 hour-long computer-assisted telephone interviews, and collected information from participants regarding key early- and mid-life events and circumstances likely to influence their health, wealth and social stability in older adulthood.

Results of the study

Question 1: Initiation of alcohol use

In an evaluation of the key factors and early childhood life events that were associated with initiation of alcohol use during adolescence and young adulthood in this cohort of older New Zealanders, we found that:

 68% had their first drink between the age of 14 and 18, and the majority (88%) before the age of 23

 only 4% of the sample were lifetime abstainers (i.e., never consumed alcohol)

 82% of men had started drinking by 18 years of age compared to only 56% of women

 increased likelihood of earlier drinking initiation was related to:

o higher childhood socioeconomic status

o having a parent that smoked

o being of Māori descent

 reduced likelihood of early initiation was related to having better self-reported educational achievement

 overall, when all predictor variables were considered together, only gender, socioeconomic status and parents’ smoking behaviour influenced early initiation. This suggests that any differences in education and ethnicity are likely attributable to underlying differences in socioeconomic status.

Question 2: Patterns of alcohol use over the lifespan

When we explored the alcohol use patterns (frequency of use and quantity typically consumed on each occasion) of this cohort of older New Zealanders, we found three distinct groups of men and two distinct groups of women who shared common drinking patterns across their lifespan.

The three groups of male drinkers were made up of:

1. those who drank alcohol infrequently in moderate-to-low quantities over their lifespan (36%)

2. those who drank alcohol frequently in moderate-to-low quantities over their lifespan (51%)

3. those who drank alcohol frequently and in high quantities over the lifespan (13%).

The two groups of female drinkers were made up of:

1. those who drank alcohol infrequently and consumed low quantities at each occasion (48%)

2. those who drank frequently in moderate-to-low quantities over the lifespan (52%).

An investigation of the factors associated with these lifespan drinking trajectories found that:

 men who were frequent drinkers consuming low-to-moderate quantities were more likely to have initiated alcohol use earlier and had better school performance at the age of 10 than infrequent male drinkers

 women who were high frequency drinkers and consumed low quantities per occasion initiated alcohol use at an earlier age and had more affluent childhood socioeconomic status than infrequent female drinkers

 men who were high frequency drinkers consuming high quantities per occasion initiated alcohol use earlier, had poorer socioeconomic status, and were much more likely to have a heavily drinking parent than infrequent male drinkers.

Question 3: Transitioning from hazardous to non-hazardous drinking

In terms of the nature of hazardous drinking levels across the lifespan of this cohort of older New Zealanders:

 drinking patterns were largely stable across lifespan, with long periods of hazardous or non-hazardous drinking being the norm

 one-third of participants (36%) became hazardous drinkers as adolescents or young adults, and remained hazardous drinkers throughout the lifespan

 only a small proportion (14%) were life-long (i.e., from adolescence onwards) non-hazardous drinkers

 transition into or out of hazardous drinking was not common (less than 10% in each decade); when it occurred, it was usually a singular event in the lifespan (i.e., no further transitions occurred).

Transitioning in and out of hazardous drinking was linked to three key life events:

 Unemployment prior to mid-life (i.e., before 40s) was associated with increased likelihood of developing hazardous drinking habits, which, in turn, was associated with further difficulties with finding employment.

 Relationship breakdown in mid-life was associated with an increased likelihood of hazardous drinking. However, hazardous drinking was not associated with an increased probability of future divorce or separation.

 Development of a chronic health condition in young adulthood and mid-life was associated with an increased likelihood of transitioning from hazardous to non-hazardous drinking.

Conclusion

In a sample of over 800 older New Zealanders, initiation of alcohol use during adolescence (from 14 to 18 years of age) was common, more likely in men, and a hallmark of frequent drinking in later life. In men, early initiation was more likely in households with parents that smoked, while in women it was more likely in higher socioeconomic households.

For men, better educational performance in childhood was associated with frequent but lower quantity drinking across adulthood, whereas a childhood of economic disadvantage and the presence of heavy-drinking parents was linked to high frequency and high quantity drinking patterns later in life. For women, a childhood of economic advantage predicted high frequency but low quantity drinking.

Thirteen percent of the sample were hazardous drinkers across the lifespan. Change from hazardous to non-hazardous drinking (or vice versa) was uncommon (i.e., less than 10% in each decade). If it did occur, further transitions were unlikely. The stability of drinking in this cohort suggests that, once established, a pattern of drinking (whether hazardous or non-hazardous) is unlikely to be modified and becomes a stable trait. This indicates that the likelihood of normalising hazardous drinking patterns is at the point of initiation in adolescence and early adulthood, and thus the critical point of intervention to reduce alcohol-related harm.

Only a small minority of participants showed movement between hazardous and non-hazardous drinking patterns across their lives, which appeared to be indicative of key early- to mid-life events. Unemployment between ages 20 and 40 and loss of a relationship between ages 30 and 50 increased the risk of changing from a non-hazardous to a hazardous drinker. Conversely, developing a chronic health condition before 50 years of age increased the likelihood of transitioning from hazardous to non-hazardous consumption.

These results indicate that middle adulthood (from 30 to 50) is the period when change in drinking behaviour may occur and for very specific reasons. This is the time when people experience the most financial challenges (e.g., raising children, paying off mortgage) and greatest responsibilities, both in their personal (looking after children and ageing parents) and professional lives (career development). Separation and unemployment present major financial strains, which have been found to predict hazardous drinking [11]. At the same time, when people acquire chronic diseases earlier in life, they might be more motivated to make positive lifestyle changes. Middle adulthood (from 30 to 50) is an age-group that is rarely considered to be at risk, and therefore, rarely targeted by interventions or policies.

Overall, drinking behaviour in old age mirrors drinking habits developed in young adulthood. While alcohol consumption is generally stable over the lifespan, difficult life events experienced mid-life are likely to prompt significant changes in alcohol use. This highlights the importance for policies to promote low-risk alcohol drinking and reduction of use across the lifespan and for health care providers to pay particular attention to individuals experiencing difficult life transitions so that targeted interventions can take place if needed.