New York: People living with chronic low back pain are more likely to use illicit drugs -- including marijuana, cocaine, heroin, and methamphetamine -- compared to those without back pain, says a study. In addition, chronic low back pain patients with a history of illicit drug use are more likely to have a current prescription for pain-relieving drugs, said one of the researchers Anna Shmagel from University of Minnesota, Minneapolis, US. The researchers analysed survey responses from more than 5,000 US adults (aged 20 to 69) from a nationally representative health study. About 13 per cent of respondents met the study definition of chronic low back pain -- back pain present for three months or longer. The confidential survey also asked participants about their use of illicit drugs -- marijuana, cocaine, heroin, and methamphetamine. The results, published in the journal Spine, suggested that back pain was linked to higher rates of illicit drug use. About 49 per cent of adults with chronic low back pain said they had ever used illicit drugs, compared to 43 per cent of those without the condition. Rates of current illicit drug use (within the past 30 days) were also higher in the chronic low back pain group -- 14 per cent versus nine percent. Participants with chronic low back pain were more than twice as likely to report methamphetamine and heroin use, the findings showed. The results also suggested a link between illicit drugs and prescription opioids among patients with chronic low back pain. Those who had ever used illicit drugs were more likely to have an active prescription for opioid analgesics -- 22.5 per cent versus 15 per cent. Prescription opioids are widely used by patients with chronic low back pain, raising concerns about addiction, misuse, and accidental overdose.