"around 1.5 million children are growing up with a parent addicted to drugs or alcohol"
The Daily Telegraph, 25 October 2012
It's a shocking statistic and one that could be held up as evidence by those who'd argue that we're living in 'Broken Britain'.
The subject of the Daily Telegraph's article is a speech by the Secretary of State for Work and Pensions, Iain Duncan Smith. However, the 1.5 million figure isn't to be found in what Mr Duncan Smith said.
We can trace the true origin of the figure to the Centre for Social Justice (CSJ), the think-tank established by Mr Duncan Smith in 2006. A feature on their website cites:
"Approximately 1.5 million children in the UK are affected by parental alcohol problems, and 250-350 000 are living with parents who are mis-using drugs".
Yet the CSJ's figure does not match the number quoted in the Daily Telegraph. Apparently, by the CSJ's estimate, there are some 1.9 million children living with parents addicted to drugs or alcohol.
How many children are growing up with a parent who's a drug addict?
The CSJ figure for problem drug use is one that we find noted in various government reports. A 2003 Home Office study concluded that in the UK there were 250-350,000 children "dependent" on a parent abusing drugs. The authors of the research obtained information on around 313,000 drug users receiving treatment in England and Wales between 1996 and 2000. Parenthood data was available for 221,000 of these drug users; of them, 95,000 (43%) reported having children. Data for Scotland was collected separately.
On average, there were approximately two children for every drug-using mother and two for every drug-using father. Because an unknown number of children would have had both their mother and father in drug treatment, the Home Office estimated the minimum and maximum number affected to produce a total of between 200,000 and 300,000 children. Adding in estimates for Scotland raised the total to between 250,000 and 350,000.
The researchers then arrived at a very similar figure by analysing census data for 2000/01 on the number of people in England and Wales receiving drug treatment, effectively "double-checking" their estimate using a different method.
It's important to note that there are a couple of problems with this data. The final figure only includes those people who were receiving treatment for their drug addiction - it's not a reflection of the total number of parents who might have been in need of help. The study's researchers therefore conclude that there are likely to be more than 250-350,000 children growing up with a parent addicted to drugs.
What's more, this figure of 250-350,000 children is now likely to be out-of-date. From data collated by the National Drug Treatment Monitoring System (NDTMS) since 2005, we can see that the number of individuals in drug treatment has increased since 2000 (the end-date of the original Home Office study). And whilst the NDTMS isn't able to tell us how many of these people are parents, we can expect - to an extent - a proportionate rise in their numbers.
How many children are living with an alcoholic parent?
The Children's Commissioner recently claimed that it's "largely unknown" how many children in the UK are affected by a parent's alcohol abuse. However, there have been attempts to estimate the number.
A group of researchers, writing in the Journal of Public Health, calculated that there are 705,000 children living with parents addicted to alcohol. They used sample statistics from the Health Survey for England and General Household Survey to extrapolate numbers for the population at large.
Meanwhile, the National Association for Children of Alcoholics (NACOA) puts the number higher - at 920,000 children. However, NACOA's estimate is based on a questionnaire that it sent out to 9,789 adults. It asked these individuals, selected to be representative of the population at large, to answer questions about their childhood, including "Did you grow up in a home in which either or both of your parents drank too much?".
Crucially, this survey is retrospective - we're not talking about children who are currently living with a parent who's addicted to alcohol, but adults who reportedly experienced this during their childhood. There's as yet little data to prove whether people had a greater (or lesser) chance of growing up with an alcoholic parent 20, 30 or 40 years ago.
Furthermore, not only are some people more likely than others to return answers to a questionnaire, but the question is also phrased to invite subjective responses. One person's drinking to excess might be another's relative sobriety.
Both the Journal of Public Health and NACOA offer lower estimates than the CSJ's calculation of 1.5 million children affected. The 2004 Alcohol Harm Reduction Strategy for England suggests that any estimate will be broad: it states that there are between 780,000 and 1.3 million children living with an adult abusing alcohol (but there is no accompanying explanation of how this number has been calculated).
Is the Daily Telegraph reporting an accurate statistic?
The Daily Telegraph reports that around 1.5 million children in Britain are growing up with a parent addicted to drugs or alcohol. Based on the available data, this is certainly a plausible figure were we to simply add up the range of estimates for both alcohol and problem drug use.
The CSJ's estimate is similar but not quite the same - they seem to indicate that 1.5 million children are dealing with parents addicted to alcohol and that the problem drug-users are a separate cohort. We'll be contacting the CSJ to confirm how they've added up their numbers.
The problem is that we can't simply add up the totals from different studies. As all the studies are separate there's no way of accounting for overlaps. For instance, we might expect some of the 250-350,000 children with a parent addicted to drugs to also be one of those children who have a parent abusing alcohol (705,000 or 1.3 million, depending on the study). In other words, many problem drug-users might also be identified separately as alcoholics.
What's more, not every study applies to the same time period or the same country (some cover England, others the UK as a whole). This means that it's tricky to draw comparisons or to plot changes over time.
So, depending on what combination of totals we choose, we could end up with a total figure that's anywhere between 950,000 to 1.9 million children. This is a hardly a small confidence interval. As a a result, we ought to handle these statistics with care.