Invisible Women: Data Bias in a World Designed for Men

Assuming a woman gets lucky and has her heart disease diagnosed, she must then navigate the obstacle course of male-biased treatment: sex differences have not generally been integrated either into ‘received medical wisdom’ or even clinical guidelines.25 For example, say a man and a woman are both diagnosed with a swollen aorta (the aorta is the main blood vessel that runs from the heart down through the chest and stomach). They are both suffering from an equal level of swelling – but their risk is not the same: the woman has a higher risk of rupture, which carries with it a 65% chance of death.26 And yet, in Dutch clinical guidelines, the thresholds for surgery don’t differ for each sex.27

Diagnostic tests developed around male bodies are also a problem in other medical disciplines, even those where women are more at risk. Women have a higher risk than men of developing right-sided colon cancer, which often develops more aggressively,28 but the faecal blood test commonly used to detect colon cancer is less sensitive in women than in men.29 Meanwhile, because women have on average a longer and narrower colon than men, colonoscopies in women may be incomplete.30 Then there’s what the WHO calls the ‘frequent mistake’ of underestimating the importance of symptoms that can only occur in one sex, such as vaginal bleeding in dengue fever.31 When symptoms are listed in order of frequency for all patients rather than separated by sex, female-specific symptoms can be presented as less significant than they are in reality.

The impact of such data gaps can snowball. When it comes to tuberculosis (TB), for example, a failure to account for how female social roles could make the disease more dangerous for women combines with a failure to collect sex-disaggregated data, leading to potentially deadly consequences.32 Men are more likely to have latent TB, but women are more likely to develop the active disease.33 Studies also suggest that women in developing countries who cook in poorly ventilated rooms with biomass fuels (as we’ve seen, this means millions of women) have impaired immune systems which leave them less able to fight off the bacteria.34 The result is that TB kills more women globally than any other single infectious disease. More women die annually of TB than of all causes of maternal mortality combined.35 But TB is nevertheless often considered to be a ‘male disease’, and as a result women are less likely to be screened for it.

Even when women are screened, they are less likely to be diagnosed.36 Women may have a different immune response to TB resulting in different symptoms,37 and one study on why women are misdiagnosed found that TB lung lesions might not appear as severe in women.38 There is also evidence of sex differences in the sensitivity of commonly used screening tests.39 The standard way to test for TB in resource-limited settings is to get patients to cough up sputum and examine it under the microscope.40 But women with TB are less likely to have a sputum-producing cough, and even if they do have one their sputum is less likely to test positive for the disease.41 The sputum test is also problematic for social reasons: a study in Pakistan reported that women felt uncomfortable coughing up the mucus needed for the examination, and health workers weren’t explaining why they needed to. So they didn’t.42

Medical practice that doesn’t account for female socialisation is a widespread issue in preventative efforts as well. The traditional advice of using condoms to avoid HIV infection is simply not practicable for many women who lack the social power to insist on their use. This also goes for Ebola, which can remain present in semen for up to six months. And although a gel has been developed to address this problem,43 it fails to account for the practice of ‘dry sex’ in certain parts of sub-Saharan Africa.44 A gel which also acts as a lubricant will not be acceptable in areas where women de-lubricate their vaginas with herbs in order to indicate that they are chaste.

Failing to account for female socialisation can also lead to women living for decades with undiagnosed behavioural disorders. For years we have thought that autism is four times more common in boys than in girls, and that when girls have it, they are more seriously affected.45 But new research suggests that in fact female socialisation may help girls mask their symptoms better than boys and that there are far more girls living with autism than we previously realised.46 This historical failure is partly a result of the criteria for diagnosing autism having been based on data ‘derived almost entirely’ from studies of boys,47 with a 2016 Maltese study concluding that a significant cause of misdiagnosis in girls was ‘a general male-bias in diagnostic methods and clinical expectations’.48 There is also emerging evidence that some girls with anorexia may in fact be suffering from autism, but because it’s not a typical male symptom it’s been missed.49 Sarah Wild, head of Limpsfield Grange, the UK’s only state-funded residential school for girls with special needs, told the Guardian that ‘the diagnostic checklists and tests have been developed for boys and men, while girls and women present completely differently’.50 Meanwhile, a recently published draft of new NHS guidance on autism made no mention of women’s differing needs.51

There are similar diagnostic problems when it comes to attention deficit hyperactivity disorder and Asperger’s. A 2012 survey by the UK’s National Autistic Society found that just 8% of girls with Asperger’s syndrome were diagnosed before the age of six, compared with 25% of boys; by the age of eleven the figures were 21% and 52%, respectively.52 Up to three-quarters of girls with ADHD are estimated to be undiagnosed – a gap which Dr Ellen Littman, the author of Understanding Girls with ADHD, puts down to the early clinical studies of ADHD having been done on ‘really hyperactive young white boys’. Girls tend to present less as hyperactive and more as disorganised, scattered and introverted.53

More broadly, researchers suggest that because women are socialised to ‘take turns in conversation, to downplay their own status, and to demonstrate behaviors that communicate more accessibility and friendliness’, the traditional medical interview model may be unsuccessful in getting the information from women that is needed to diagnose them effectively.54 But sometimes – often – women are providing the information. It’s just that they aren’t being believed.

American news website ThinkProgress reported the story of Kathy, whose heavy periods left her feeling so faint she couldn’t stand.55 But when it came to getting a diagnosis, Kathy faced the same problem encountered by Michelle in the previous chapter. Four different medical professionals thought it was in her head, that ‘she was simply struggling with anxiety and perhaps even had a serious mental health disorder’. Her primary-care doctor went so far as to tell her more than once, ‘All your symptoms are in your imagination.’

But they weren’t in her imagination. In fact, Kathy turned out to have ‘potentially life-threatening uterine fibroids that required surgical intervention’, something that was only discovered after she demanded an ultrasound. She wasn’t anxious (although after nine months of being told she was crazy who could blame her if she was), she was anaemic.

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