Diaries may have unintended consequences for people suffering from chronic pain, according to a recent study.

For some people suffering from chronic pain, part of their daily routine is recording the extent of it in a pain diary. Often done at the request of their physician or therapist, patients may be asked to record how severe the pain is, how it affects daily activities and which treatments ease it or make it worse.

For the study, researchers at the University of Alberta Faculty of Medicine & Dentistry examined the effect of a daily pain diary on recovery from acute lower back sprain. Fifty-eight patients with lower back or lumbar sprains were recruited, all in their early 30s. Half the subjects were asked to keep a pain diary for four weeks and given instructions to rate their daily pain on a scale of one to ten. The other half acted as a control group and did not keep diaries.

The level of disability was the same in both groups at the start of the study. After three months, subjects underwent a follow-up assessment and were asked if they had recovered from their injuries. A stark difference was noted among the patients.

They found that the group who kept the pain diary -- even though we didn't ask them to keep an extensive diary, and even though many of them didn't keep a complete diary -- had a much worse outcome. The self-reported recovery rates were 52 percent in the group that kept a pain diary and 79 percent recovery at three months in the group that did not keep a pain diary.

"That's a fairly profound effect. There aren't many things we do to patients in terms of treatment that affect the recovery for a group by 25 percent," researcher Robert Ferrari, a clinical professor in the Faculty of Medicine & Dentistry's Department of Medicine and a practicing physician in several Edmonton medical clinics, said in a statement. "

Ferrari believes the findings are a clear indication that asking patients to focus too much on symptoms may cause them to amplify them, creating a perception of illness and in turn preventing recovery. In light of the findings he recommends physicians and therapists not ask their patients to keep pain diaries.

The findings are detailed in the journal Rheumatology International.