The Drinking Patterns of Older New Zealanders: National and International Comparisons.

Abstract

Executive summary Very little is known about the role of alcohol in older people’s lives over the lifespan, patterns of alcohol use over older adulthood, and how the drinking patterns of older New Zealanders compare with patterns in older adults in other countries. Using data from the New Zealand Health, Work & Retirement Longitudinal Study (NZHWR), the current report explores the patterns of drinking in older New Zealanders at a national level and in an international context. Specifically, this report presents: • a review of drinking patterns in older adults • a comparison of drinking in older Māori and non-Māori New Zealanders • an international comparison of the alcohol use patterns in older New Zealanders and older adults in eight other countries. Patterns of drinking in New Zealand older adults In this report, the term ‘older adults’ refers to individuals aged 50 years and over. This was because the report includes comparisons with developing countries, and because many of the world’s leading longitudinal studies of ageing use samples aged 50 years and over (eg, the World Health Organization (WHO)’s Study on Global Ageing and Adult Health). Drinking frequency, drinking quantity & binge drinking: Māori & non-Māori patterns In New Zealand, Māori are a population that is at high risk of experiencing alcohol-related harm. Given that Māori are at high risk and constitute a significant proportion of the older New Zealand population, a comparison of potential differences in alcohol use patterns between older Māori and non-Māori was warranted. Using a short-form of the WHO’s Alcohol Use Disorders Identification Test (the AUDIT-C) included in the 2010 NZHWR dataset, we compared the frequency of alcohol use, the average quantity consumed, and instances of binge drinkingc in older Māori and non-Māori. This comparison revealed that: • older Māori (23%) were more likely to abstain than older non-Māori (14%) • older Māori drank alcohol slightly less frequently than older non-Māori • older Māori consumed a slightly higher quantity of alcohol per occasion than older non-Māori • older Māori and non-Māori shared a similar binge drinking frequency. Statistical analysis showed that the differences observed between older Māori and non-Māori were very small. However, there were significant gender differences in drinking frequency, average quantity consumed, and binge drinking. Specifically: • older men drank alcohol far more frequently than older women • older men consumed much more on typical occasions when drinking alcohol than older women • older men were far more likely to binge drink than older women. Patterns & predictors of hazardous drinking We then used the AUDIT-C screening score to assess the prevalence of ‘hazardous drinking’. Our comparison illustrates that older Māori and non-Māori shared similar hazardous drinking rates: • Overall, 37% of older Māori and 43% of older non-Māori were hazardous drinkers. • 26% of older Māori women and 30% of older non-Māori women were hazardous drinkers. • 52% of older Māori men and 55% of older non-Māori men were hazardous drinkers. Second, we undertook a statistical analysis to assess whether self-reported ethnicity was related to scores on the AUDIT-C scale over and above the influence of known demographic, physical health, psychosocial and economic determinants of drinking. The results of this analysis revealed that: • hazardous drinking scores in older New Zealanders were higher in men, those with good economic living standards, and those in good physical health • self-reported Māori ethnicity had no relationship with the hazardous drinking score. This analysis provided the researchers with strong rationale for combining older Māori and non-Māori alcohol use data for the comparison with international counterparts. An international comparison of older adult drinking patterns An international collaboration led by the New Zealand researchers identified datasets from four studies that were all collected in 2010: 1. The New Zealand Health, Work & Retirement Longitudinal Study (NZHWR). 2. The English Longitudinal Study of Ageing in England. 3. The United States Health and Retirement Study. 4. The World Health Organization’s Study on Global Ageing and Adult Health. All studies included alcohol use questions which reflect older adult alcohol use patterns in nine countries: New Zealand, England, the United States, South Africa, China, Mexico, Ghana, India, and the Russian Federation. The questions from each study were not directly comparable, but cross-study harmonisation of these questions resulted in the following set of comparable alcohol use variables from each country: • Proportion of past-year drinkers. • Frequency of weekly drinking. • Quantity consumed on typical drinking occasion. • Frequency of heavy drinking. Past year drinking across countries The initial analysis compared the proportion of current drinkers across countries overall, and split by gender. The results showed that: • New Zealand had the second highest proportion of older drinkers (83%) behind only England (87%), and considerably more than other OECD countries such as the United States (62%) and Mexico (56%) • approximately 88% of older men and 79% of older women in New Zealand were drinkers, a gender gap similar to that in older English adults. This gap was much smaller than seen in most other countries such as the Russian Federation (87% vs. 66%) and China (56% vs. 11%). Frequency of weekly drinking The harmonisation of drinking frequency questions across studies allowed us to compare the frequency of weekly drinking in older adults using the following thresholds: 0 days, 1 day, 2-3 days, and 4 or more days per week. The results of this cross-country comparison revealed that: • older New Zealanders showed a tendency towards ‘frequent’ drinking • 60% consume alcohol on two or more days per week on average which was similar to England (60%) and India (57%), but more frequent than other countries • 34% of older NZ drinkers consume four or more days per week which is lower than China (64%), similar to England (32%), but higher than the United States (23%), the Russian Federation (11%) and Mexico (8%) • older NZ men and women tend to drink at a frequency more similar to one another than seen in other countries where women tend to drink a lot less frequently than men (eg, the Russian Federation, Mexico, India). Quantity of drinks consumed on a typical drinking occasion The typical drinking quantity question from each study was harmonised to produce standardised responses reflecting the average quantity of alcohol consumed on typical drinking occasions, and grouped as follows: up to 2 drinks, 3-4, 5-6, 7-9, and 10 or more drinks. The results of this cross-country comparison showed that: • 64% of older New Zealand drinkers typically consumed up to two drinks which was a slightly greater proportion than in some countries (eg, England, the Russian Federation), but lower than in other countries (eg, the United States, Ghana) • there were far more older New Zealand women drinkers (82%) than men (46%) who typically consumed up to two drinks • 16% of older New Zealand drinkers consumed five or more drinks on a typical occasion. The proportion of older New Zealand male drinkers who typically consumed five or more drinks on each occasion (26%) was four times the proportion of New Zealand women (6%), and one of the highest for men across all countries. Frequency of heavy drinking Using a definition of heavy drinking frequency developed by WHO experts, we identified heavy drinkers (defined as five or more drinks for men and three or more drinks for women) in each country whose alcohol consumption was frequent (two-three days per week) or very frequent (four or more days per week). The results revealed that: • New Zealand (18%) had a higher proportion of frequent or very frequent heavy drinkers compared with all other countries except China (31%) and South Africa (23%) • this 18% of older NZ heavy drinkers consumed either frequently (6%) or very frequently (12%) • the proportion of older NZ men (22%) who were either frequent or very frequent heavy drinkers was much greater than the proportion of older NZ women (14%) • there were considerable gender differences across countries in the proportion of heavy drinking and the frequency of heavy drinking. In New Zealand, older men who were heavy drinkers were more likely to drink very frequently compared to older women, while in England, older women were more likely to drink very frequently. Factors potentially explaining cross-country differences in drinking patterns Using data provided by the 2015 Global AgeWatch Index, we explored the relationships between the proportion of older adults in each country who drank and four key indicators of social and economic wellbeing in older adults: 1. Gross National Income (GNI) per capita. 2. Healthy life expectancy at 60 (HALE60). 3. Proportion of older adults with education at secondary-level or above. 4. Proportion of older adults identifying as socially connected. The results of this cross-country comparison indicated that: • the proportion of older drinkers was highest in countries with higher relative wealth, higher levels of education in their older adult population, and where older adults felt greater social connectedness • there was little relationship between the proportion of older adults who drank in each country and that country’s healthy life expectancy at 60 years of age.