If you want to encourage your patients to exercise more, try writing a prescription. The tactic has been successful in New Zealand, a recent study reports.

As part of a “green prescription” program, clinicians counsel patients for 7-13 minutes, then write their exercise advice on a green script. The prescription is given to the patient and faxed to a local “exercise facilitator” who follows up with three monthly phone calls.

For this study, 1,089 women aged 40-74 years were equally divided into two groups. In one group, follow-up was extended to nine months, including an average of five 15-minute calls and a 30-minute in-office consultation after six months with the prescribing NP. The other (control) group received the standard protocol.

At baseline, 10% of the women in the intervention arm and 11% of the controls engaged in at least 150 minutes of moderate physical activity weekly. After 12 months, 43% of the intervention group and 30% of the controls had attained that level of moderate exercise. After 24 months, the rates were 39.3% and 32.8%, respectively.

“We expected deterioration over time,” the researchers write (BMJ. 2008;337:a2509). “While exercise levels had declined by 24 months, they were still substantially higher than at baseline and significantly higher in the intervention group than in the control group.”