Injured workers in the mining and construction industry and those who live in rural areas are more likely to receive opioid prescriptions, according to a study released Thursday by the Workers Compensation Research Institute that linked worker characteristics with the likelihood of opioid dispensing.

In examining 1.4 million pain-medication prescriptions in 2014 and 2015 across 27 states, the Cambridge, Massachusetts-based institute zeroed in on correlations between age, gender, industry and location — among other characteristics — and opioid prescriptions.

The study found that 33% of injured workers employed in mining and 29% of those in construction received opioids for certain injuries. The study also found that workers in those industries were more likely to receive opioids on a longer-term basis and at higher doses.

Injured workers residing in counties with higher amounts of opioids dispensed per person and those residing in rural and very rural counties were more likely to receive opioid prescriptions, according to data that found 68% of injured workers living in very rural areas tend to be prescribed opioids compared to 54% in urban areas.

The study hypothesizes that injured workers in more populated areas might have greater access to other therapies, adding that “higher availability of physical therapists and other practitioners with restricted prescribing authority in the region may result in fewer opioids.”

“Some regions may also have a higher concentration of pain clinics and doctors who specialize in pain treatment than others,” the study states. “In areas where patients have easier access to clinics specializing in the treatment of pain, the prescribing patterns may differ from areas where there are few pain clinics.”

The study also found that older workers were more likely to receive opioid prescriptions compared with younger workers, with 49% of injured workers age 49 or older receiving opioids compared to 42% of workers between the ages of 25 and 39.

Meanwhile, a higher percentage — 66% to 79% — of workers who sustained fractures, carpal tunnel and neurologic spine pain received at least one opioid prescription for pain relief.

The study states were Arkansas, California, Connecticut, Delaware, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Nevada, New Jersey, New York, North Carolina, Pennsylvania, South Carolina, Tennessee, Texas, Virginia and Wisconsin.