Two-thirds of patients who use complementary medicines are keeping mum about it when they seek medical help, but GPs can help boost disclosure rates by raising the topic, say Australian researchers.

Lack of disclosure remains a major challenge for doctors, with just 33% of patients raising their complementary medicine use during a consultation, according to a landmark systematic review of 86 international studies published in Scientific Reports.

This shows little discernible improvement in disclosure rates over the past 13 years, despite a majority (67%) of participants believing it was important, say the University of Technology Sydney-led researchers.

They found fear of doctor disapproval was the most common reason for not raising complementary medicine use, despite fewer than 20% of study participants reporting a previous negative or discouraging response.