Narcotics and diagnostic tests are overused for chronic neck pain, a U.S. study suggests.

Neck pain affects 30 to 50 per cent of adults and most of them find their symptoms don't completely resolve, according to previous studies.

Like lower back pain, chronic back pain often does not respond to treatment and can result in lost work time and higher health costs.

In the November issue of the journal Arthritis Care & Research, researchers at Duke University and the University of North Carolina analyzed responses from 135 adults over 21 who had chronic neck pain — defined as pain and activity limitations nearly every day for the previous three months, or more than 24 episodes of pain in the previous year that limited activity for one or more days.

More than 56 per cent of those in the study used non-steroidal anti-inflammatory drugs, 29 per cent reported taking strong narcotics like oxycodone and 23 per cent used weak narcotics such as codeine for their neck pain, Adam Goode, a professor of physical therapy at UNC, and his colleagues found.

But the medical evidence on the effectiveness of medications for treating chronic neck pain is quite limited, the researchers noted.

"Based on current evidence for best practice, our findings indicate over-utilization of diagnostic testing, narcotics and modalities, and the under-utilization of effective treatments such as therapeutic exercise," the study's authors concluded.

Study participants received diagnostic tests such as spinal X-rays (45 per cent), MRIs (30 per cent) and CT scans (24 per cent).

Treatments also included electrotherapy therapy stimulation (30 per cent), braces (21 per cent), massage (28 per cent), ultrasound (27 per cent), heat (57 per cent) and cold (47 per cent).