About two decades ago I went head-to-head in an argument with the great Michael Marmot at the Medical Research Council. The topic of conversation was information that should be routinely collected in randomised trials. Marmot was arguing that social class and economic information should be collected. He made a valid point that these things are correlated with outcomes. I pointed out that although they may be correlated with outcomes, they were not necessarily correlated with treatment effects. Then came Marmot’s killer argument. Marmot asked whether I thought that sex and ethnic group should be collected. When I admitted that they should be, he rounded on me, saying that this proves his point. We met only recently and he remembered the argument and stood by his point. However, it turns out that it is not really important to collect information on the sex after all. Wallach and colleagues, writing in the BMJ, cite evidence from meta-analyses of RCTs to show that sex makes no difference to treatment effects when averaged across all studies. So there we have it, a parsimonious data set is optimal for trial purposes, since it increases the likelihood of collecting essential information to measure the parameter of interest.
— Richard Lilford, CLAHRC WM Director
- Wallach JD, Sullivan PG, Trepanowski JF, Steyerberg EW, Ioannidis JPA. Sex based subgroup differences in randomized controlled trials: empirical evidence from Cochrane meta-analyses. BMJ. 2016; 355: i5826.
There seems to be two models of feminism:
- Women and men are constitutionally identical (in everything but size and appearance), and any observed differences are entirely patterned by social influences.
- Differences between men and women are more than just anatomy and physiology, and women bring useful and unique attributes to society.
I am inclined to the second opinion. It is already known that female doctors are more likely to adhere to clinical guidelines, provide more preventative advice, and are better listeners than male doctors. Well they also seem to save more lives, according to a brilliant study from Yasuke Tsugawa and colleagues. They compared outcomes from Medicare beneficiaries treated by general internists in hospital. These were really sick patients with a death rate of over 11%. The patients treated by female doctors had a risk-adjusted difference in mortality of nearly 0.5% and also lower risk of readmission. Findings were similar if the analysis was restricted to patients treated by ‘hospitalists’ – a general physician on call for emergencies. Patients hospitalised for an emergency medical condition are less likely to select their physician than patients who are admitted electively, and severity and condition profiles were well balanced between male and female physicians. The authors claim that this means their study was ‘quasi-randomised’. The results are congruent with other studies; across many industries it has been shown that men, compared to women, are “less deliberate in their approach to solving complex problems.”
In ‘My Fair Lady’ Henry Higgins sings “Why can’t a women by more like a man?” In the context of clinical care it seems that the song should go “Why can’t a man be more like a woman?”
— Richard Lilford, CLAHRC WM Director
- Tsugawa Y, Jena AB, Figueroa JF, et al. Comparison of Hospital Mortality and Readmission Rates for Medicare Patients Treated by Male vs Female Physicians. JAMA Intern Med. 2016.
A large amount of international research is done sitting at the desk and analysing large datasets. Arguably the largest and most widely used dataset concerning low- and middle-income countries is the Demographic and Health Services (DHS) dataset. This dataset is based on repeated cross-sectional questionnaires in many low- and medium-income countries. The emphasis is on reproductive and infant health. Large databases often disappoint, but DHS is producing some gems.
The authors of a recent World Bank report were interested in a possible preference for sons in sub-Saharan Africa. However, the difference in birth ratio of boys and girls seen in China and India was not found in Africa. So they examined reproductive choices in families where the existing children were all girls or boys. They found that people continue to have children to a greater extent when their existing children are girls rather than boys. There still appears to be a strong cultural preference for boys over much of the world, although manifested in a more subtle way in Africa than in Asia; perhaps because people do not have access to ultrasound to determine the sex of the early foetus, or perhaps because they are less reluctant to have large families. The findings show that many people can control their fertility, suggesting, perhaps, that behavioural factors rather than poor access to contraception is the main cause of the slower decline in family size seen in Africa compared to Asia and South America.
— Richard Lilford, Director CLAHRC WM
- Milazzo A. Son Preference, Fertility and Family Structure. Evidence from Reproductive Behavior among Nigerian Women. Policy Research Working Paper 6869. Washington, D.C.: World Bank Development Research Group. 2014.