False claims undermine good causes

False claims undermine good causes

Today is White Ribbon Day. It is an important symbolic event reminding us all to be aware of violence against women.

Domestic violence and family abuse are a scourge on all human societies. Events such as White Ribbon Day play an significant role in breaking down the shame and stigma which makes it so hard for individuals to seek help. I wholeheartedly support this aim. What I do not support, however, are dodgy statistics and false claims which belittle this good cause. On Monday, 25th November, 2014, SkyNews Australia published the following tweet:

This is a sensational claim that is easily fact-checked. Research institutions such as the Australian Institute of Health and Wellbeing (AIHW), the Australian Bureau of Statistics (ABS) and the Australian Institute of Criminology (AIC) keep records of causes of death, and rates of victimisation for people in this age group every year.

To fact-check SkyNews Australia’s claim, let’s break down the most recent data we have for causes of death for men and women under the age of 45 (see Table 2 in the AIHW summary). Keep in mind these statistics are for both men and women:

1. Suicide                                 2,769 deaths

2. Accidental poisoning        1,534 deaths

3. Transport collisions          1,388 deaths

4. Heart disease                        915 deaths

5. Breast cancer                         509 deaths

Death by homicide does not make the top 5, for men or for women.

ABS data tells us that on average, one woman takes her life via suicide each day. AIC data tells us that in 2012, 33 women died from homicide, nationally, while 67 men did. In contrast, 336 women aged 15 – 45 died from suicide. Our rates of suicide should be our national shame. Combined, suicide and drug overdose claim eighty people per week under the age of 45, a significant proportion of whom are women. But violence is the sensational social issue du jour, so we do not hear about it. In May, 2014, ABCNews ran a story which stated:

Domestic violence is the leading cause of death and injury in women under 45, with more than one woman murdered by her   current or former partner every week.

Yet almost one woman dies every day from suicide, and almost two from breast cancer. So how is domestic violence “the leading cause of death” for women in this age group? Where does this claim even come from?

Source of the Claim

The claim comes from a ten year old report by the Australian government body VicHealth  tabled for the World Health Organisation. In 2004, VicHealth teamed up with a group of women’s advocates for the purposes of quantifying the overall health burden inflicted upon women and more broadly, society, from domestic violence.

In quantifying the burden of disease, the researchers involved chalked up health problems of victims as direct outcomes of exposure to violenceSee the figure below.

Untitled

Health outcomes contributing to the disease burden of intimate partner violence include mental health issues (73% of the total disease burden), tobacco use at 14% and cervical cancer at 1%.

In calculating the total “health burden” of violence, the study’s authors came to the conclusion that intimate partner violence was the leading cause of preventable illness, disease and disability for women aged 15-44. How they came to this conclusion is difficult to gather due to the report’s opacity. Yet astonishingly, at some point in our national discourse, the claim that intimate partner violence is “a leading cause of disease burden” has been replaced by this:

It behooves us then to take a closer look at the source of this claim, in order to see if it stands up to scrutiny.

Methodological Concerns

The VicHealth report is based on what is known as a cross-sectional design. Data was taken from pre-existing reports and in their analysis, health variables and exposure to violence were measured at the same time. The most fundamental limitation to such a design is confusing correlation with causation

Such a design cannot tell us whether or not violence came before the onset of mental health problems, tobacco use or cervical cancer nor any other health outcome.

While it is highly likely that victims of violence do go onto develop mental health problems such as depression, anxiety and PTSD. It is also highly likely that individuals with pre-existing mental health conditions find themselves in circumstances where such victimisation occurs. Last year’s report from the Australian Longitudinal Study on Women’s Health said the following:

Women in their 20s and 30s who report intimate partner violence experience poorer mental health prior to intimate partner violence, suggesting an inter-connected relationship; that is, intimate partner violence affects mental health status and likewise mental health affects intimate partner violence. [6 pp 83]

The only way to prove causality is to prove that violence occurred at a point in time prior to the onset of mental health problems. The authors of the report have not done this. They also have not proven any causal link between violence and cancer, or tobacco use either. When referring to this limitation in their ‘technical report’, they stated simply that they “decided” violence preceded such health variables as cancer. Take a look at their reasoning in their own words —

A cross-sectional analysis is a weak design to examine the relationship between a risk factor and disease outcomes because it cannot indicate whether exposure to the risk factor preceded the health outcome, a necessary condition to prove causality. A longitudinal study design would be better suited to study this issue. Despite the large overall study size of ALSWH the number of women who newly reported intimate partner violence between the first and second survey was too small and the health status information too limited to examine temporality. However, we decided that a causal relationship between intimate partner violence and health outcomes was much more plausible than a health outcome being the cause of intimate partner violence. [5 pp 742-743]

“We decided”

Let’s take a look at who “we” is. For the VicHealth report, “prevalence data review and expertise” was overseen by Melanie Heenan, from the Australian Centre for the Study of Sexual Assault. The “Health impact data review and expertise ” was overseen by Jill Astbury, of the Key Centre for Women’s Health in Society. These researchers have dual roles as political advocates.

The authors of the report “decided” that intimate partner violence caused negative health outcomes. But they did not prove it. They did not rule out alternative explanations for the relationship between violence and negative health outcomes. And they did not attempt to temper their study’s conclusions in light of these serious methodological flaws. They also looked at female victims only, despite the fact that intimate partner violence is known to affect men at significant levels as well.

Political biases do not always undermine the quality of research, but they can and sometimes do. This study (which has not been replicated) contains major limitations. Published in a WHO newsletter, as opposed to a scientific journal, the report has never passed what is generally considered an acceptable standard of peer review. It is a government report, overseen by bureaucrats, funded by taxpayers. In short, it is an example of bad research performed for a political agenda. And now it is the basis for sensationalist false claims promoted in Australia by Sky and ABC News.

On White Ribbon Day, or any other day, we do not need false claims about the impact of intimate partner violence to know that it is a shocking thing, and a scourge on our society. We do not need to be told that domestic violence is the leading cause of death for women aged 15 – 45 in order to take it seriously.

The more false claims are publicised about violence against women, the more community cynicism will grow.

We do not do women any favours by producing bad research, and making exaggerated claims in their name.

***

Update

Reader Stu makes the following comment.

More data from the ABS here:

http://www.abs.gov.au/AUSSTATS/abs@.nsf/DetailsPage/3303.02012?OpenDocument

From this we actually can break down the actual data to females between the ages of 15 and 44.

In all age subgroups (15-24,25-34,35-44), the top cause of death is suicide, although if you combine cancers into one group, cancer tops the 35-44 list. 

Overall the breakdown is similar to the gender-neutral one above – it is still suicide, followed by poisoning, then traffic accidents, then various subgroups of cancer and heart disease.

It’s hard to tell whether the false claims are deliberately dishonest or just carelessness, but they’re only harming the credibility of those who make them.

***

Further Links

ABC News – Domestic violence of epidemic proportions a ‘national emergency’: campaign groups

NSW Bureau of Crime Statistics and Research – New South Wales Recorded Crime Statistics 2013

NSW Bureau of Crime Statistics and Research – Trends and patterns in domestic violence assaults: 2001 to 2010

Carlson, M. D., & Morrison, R. S. (2009). Study design, precision, and validity in observational studiesJournal of palliative medicine12(1), 77-82.

The health costs of violence: Measuring the burden of disease caused by intimate partner violence: A summary of findings“, VicHealth, Carlton South, Australia, 2004

Holden L, Dobson A, Byles J, Loxton D, Dolja-Gore X, Hockey R, Lee C, Chojenta C, Reilly N, Mishra G, McLaughlin D, Pachana N, Tooth L & Harris M. “Mental Health: Findings from the Australian Longitudinal Study on Women’s Health.“, Report prepared for the Australian Government Department of Health & Ageing, June 2013.

Vos, T., Astbury, J., Piers, L. S., Magnus, A., Heenan, M., Stanley, L., … & Webster, K. (2006). Measuring the impact of intimate partner violence on the health of women in Victoria, Australia. Bulletin of the World Health Organization, 84(9), 739-744.