Nursing interventions
Calculating alcohol consumption
Assessing levels of consumption is often left
to the individual. However, these calculations
are not without their problems and can lead to
underestimations. Comparison between what
people claim to consume and annual alcohol sales
figures, reveals that sales are up to 40% higher
than claimed consumption levels (Boniface and
Shelton 2013). It is acknowledged that self-reporting
methods may be partly responsible for this gap, and
that individuals may not provide accurate figures,
either intentionally or unintentionally.
If survey figures are adjusted to take into
account underestimates, Boniface and Shelton
(2013) calculated that weekly guidelines on
alcohol are likely to be exceeded by over one
third of adults, and daily limits are exceeded by
over three quarters of adults. This suggests that
a significant number of people may be at risk of
harmful alcohol consumption.
One explanation for the underestimation of
the amount of alcohol consumed is the difficulty
in accurately estimating the alcohol volume of
drinks. For example, Gill and O’May (2007)
found misunderstandings regarding unit values
were influenced by the different size and shape
of glasses. In their study, a sample of 297 people
were presented with a range of different sizes of
glass sold as ‘small’ and asked to select what they
estimated would provide a one unit measure of
alcohol. The sample chose glasses with capacities
varying between 250mL and 360mL, which is
more than double the recommended small glass
size of 125mL (DH 2007). Consumption of
alcohol based on such decisions would result in
individuals consuming double the recommended
units of alcohol.
Gill and O’May (2007) asked participants to
pour the equivalent of their usual drink and tested
their knowledge of unit allowances. The results
showed that 49% of participants did not know
the recommended daily allowance. In addition,
the glass size appeared to have an effect on the
amount of alcohol dispensed, with more alcohol
being poured into large volume glasses compared
to smaller glasses. Men poured larger amounts of
red wine than women, resulting in high unit levels
of alcohol consumed per drinking session. The
study concluded that people visually calculate one
unit of alcohol based on the size of the glass in
which it is served; this is often an underestimate
and does not consider the percentage of alcohol
present in the drink. This evidence suggests that
individuals calculating how much alcohol they
consume may underestimate the degree of risk
they are exposed to.
An alternative system is for the nurse to work
with individuals to calculate alcohol consumption
using online tools such as the Drinkaware Unit
Calculator (tinyurl.com/drinkaware-unitcalculat).
The nurse or patient can select the type,
brand, alcohol by volume (ABV) and quantity
of alcoholic drinks consumed in one day or one
week. The calculator then displays the number
of units and calories consumed, and minutes of
exercise (running) required to use up the calories.
The calculator also displays the risk level of alcohol
affecting your health. Use of the calculator can take
place during any nurse-patient encounter where
access to a computer or online facilities, such as
smart telephone or tablet, is available.