The prevalence of hazardous drinking in older New Zealanders

Executive summary

Hazardous drinking prevalence in older New Zealanders

Estimates of hazardous drinking in older New Zealanders range from 15% (1) to between 40 and 50% (2-4). Hazardous drinking is a significant factor contributing to the burden of disease and injury, especially in old age. Facilitating early and accurate identification of hazardous drinking in older adults is therefore an important goal in primary health care settings.

The Alcohol Use Disorders Identification Test (AUDIT) (5) and its short versions, such as the 3-item AUDIT-C (6), are standardised alcohol screens assessing hazardous drinking at the primary healthcare level and in research in New Zealand. However, these screens focus only on levels of alcohol consumption, and are insensitive to the factors that might place older adults at significantly increased risk of harm even when drinking small amounts of alcohol (e.g., reduced metabolism, health conditions, and alcohol-interactive medication use). In this respect, there is concern that using a screen not measuring older adult-specific risk factors may result in inaccurate assessments of hazardous drinking rates in this population.

In a national survey of older adults, we compared the classification of hazardous versus non-hazardous drinkers based on the AUDIT-C and the Comorbidity Alcohol Risk Evaluation Tool (CARET) (7, 8). The CARET is an older adult-specific alcohol screen that assesses alcohol-related risks both based on consumption levels and the presence of factors increasing potential harm, including health conditions associated with alcohol use (such as diabetes), the use of alcohol-interacting medication (such as pain medications), symptoms of health issues or frailty (such as low mood, memory problems, and falls), and alcohol risk behaviours (such as drink-driving).

The aim of this study

This study aimed to:

1. compare the prevalence of hazardous drinking in New Zealand older adults using the AUDIT-C and the CARET

2. investigate whether the adoption of an older-adult specific assessment tool, such as the CARET, can improve screening of hazardous drinking in older adults

3. identify the key characteristics of older drinkers whose drinking may mark them as non-hazardous on the AUDIT-C, but whose comorbidities, medication use and health issues increase their likelihood of being deemed hazardous on the CARET.

The dataset

Data were drawn from the 2016 data collection wave of the New Zealand Health, Work and Retirement Longitudinal Study (NZHWR) and included 4,026 respondents aged 50-89. In total, 3,673 participants (91% of the sample) completed both alcohol measures. Participants also responded to a range of demographic questions (e.g., age, gender, marital status, work status, education level, economic living standard), measures of health (e.g., physical health, mental health), and past year healthcare utilisation (e.g., times visited their general practitioner).

The results

Analysis indicated that:

 83% of the sample were current drinkers and 17% were lifetime or current abstainers

 the prevalence of hazardous drinking ranged between 35% (CARET) and 40% (AUDIT-C)

 there was a 90% agreement between the AUDIT-C and the CARET in classifying non-hazardous drinkers and 77% in classifying hazardous drinkers

 10% of older drinkers were classified as non-hazardous by the AUDIT-C but as hazardous by the CARET because of health-related risk factors

 almost 50% of older New Zealand men were hazardous drinkers according to both the AUDIT-C and CARET screens.

The combination of AUDIT-C and CARET classification resulted in the identification of four drinking-related groups:

1. ‘Non-hazardous drinkers’ on both screens: Mainly healthy women; likely to visit GP at least three times a year; drink small amounts of alcohol infrequently with little-to-no binge drinking.

2. ‘Hazardous drinkers’ on both screens: Mainly healthy men; likely to visit GP at least three times a year; drink high amounts of alcohol very frequently with monthly binge drinking.

3. ‘Hazardous drinkers’ AUDIT-C only: Healthy men and women; less likely to visit GP at least three times a year; drink small amounts of alcohol very frequently with some binge drinking.

4. ‘Hazardous drinkers’ CARET only: Unhealthy men and women; more likely to visit GP at least three times a year; drink small amounts of alcohol frequently with little-to-no binge drinking; are likely to drive after drinking and likely to report symptoms related to health issues including mobility and memory problems.

Those categorised hazardous drinkers on the CARET but not the AUDIT-C are at considerable risk of alcohol-related harm. This is because, while they might fall below the consumption levels traditionally considered hazardous, they are drinking in conjunction with poor health and other health issues (memory problems, sleep problems, falls, depressed mood), and are more likely to drive under the influence of alcohol. However, they are frequent users of primary healthcare services so can be targeted for screening, drinking-related advice and intervention.

Screening for hazardous drinking in older New Zealanders

An AUDIT-C threshold of four or more will capture most hazardous older drinkers in New Zealand. However, a subset of those classified as non-hazardous drinkers based on the AUDIT-C screen will still be at significant risk of harm due to drink-driving. Health professionals can identify these at-risk older drinkers as those who are non-hazardous drinkers based on the AUDIT-C screen but:

A. have alcohol-related chronic conditions, or

B. report additional health symptoms (such as memory complaints or depressed mood), or

C. are likely to drive after drinking, or

D. see health professionals at least three times a year.

Supplementing the 3-item AUDIT-C screen with a further question concerning likelihood of driving after drinking reduces the discrepancy between the AUDIT-C and the older adult-specific CARET from 10% to 2%.

Figure 1 offers a quick indication of the key similarities and differences of the older adults in the drinking-related groups identified in this study. Health professionals screening older adults for hazardous drinking might use the characteristics provided to aid in their identification of older drinkers who are likely hazardous drinkers, but do not appear so in the AUDIT-C.