A team led by St Andrews University has said that doctors often fail to distinguish between the two, which can make treatment for some patients ineffective or inappropriate.
In an article published in the British Medical Journal on Friday, the authors argue that the distinction is “critical” for good healthcare, and failing to account for it can lead to “errors” which can negatively affect all patients.
A distinction between sex and gender is made by the World Health Organisation, with sex relating to biology and gender to societal roles, but the researchers say that current medical practice often uses the two terms interchangeably.
“There are many instances of sex and gender being confused by the research community and society more broadly,” said Dr Margaret McCartney, of the School of Medicine at St Andrews University.
“Unless we identify and count categories correctly, we will end up with errors which serves all populations poorly, including minority populations.”
Professor Susan Bewley, Emeritus Professor (honorary) in Obstetrics and Women’s Health at King’s College London, said the differentiation is important for all patients’ healthcare.
“Medical care requires an understanding of the difference between sex and gender categories; untangling them is crucial for safe, dignified, and effective healthcare of all groups,” she said.
“Avoidable harm may result when they are conflated – for example, if sex specific laboratory reference ranges are used for people whose gender is recorded but not their biological sex or hormone prescription.”
The World Health Organisation provides a distinct meaning for each term, stating: “Gender is used to describe the characteristics of women and men that are socially constructed, while sex refers to those that are biologically determined.”
The article adds: “Sex and gender are not synonymous. Sex, unless otherwise specified, relates to biology: the gametes, chromosomes, hormones, and reproductive organs.
"Gender relates to societal roles, behaviours, and expectations that vary with time and place, historically and geographically.
"These categories describe different attributes that must be considered depending on the purpose they are intended for.