London, Jun 3 (IANS): A smartphone app called "PainCoach" helps improve pain control and reduce opiate pain-killer use in patients who have undergone total knee replacement surgeries, says a study.

Patients feed their pain level (no pain, bearable pain, unbearable pain, or untenable pain) in the app and based on that and the days post-surgery, it offers advice on drug pain relief use and exercises or rest.

Study participants who used the app experienced lower pain scores and felt lesser dependency on opioids, the findings showed.

"These are important findings given the current demand on the healthcare system and the growing misuse of prescription painkillers worldwide", said Amar Sheombar, a researcher of Indian origin, from Kliniek ViaSana in the Netherlands.

"Few clinically-tested mobile apps exist with clear measurable goals to guide patients in pain control and opiate use at home after surgery," Sheombar said.

To study the effect of PainCoach app on pain and opiate use, the researchers randomly assigned 71 patients aged 56-70 years undergoing total knee replacement.

While 38 of the assigned patients relied on both -- the app as well as the usual post-surgery care, 33 patients depended only on pain killers during the first two weeks at home post-surgery.

Compared with the control group, users of the PainCoach app used 23 per cent less opiates and 15 per cent more paracetamol in the first two weeks following surgery.

Regular app users reported four times faster reduction in pain during activity, six times faster reduction in pain at night, and 44 per cent less opiate and 76 per cent less gabapentin use, said the study.

"That 80 per cent of interactive advice is remembered may explain why regular use of the PainCoach app contributes to lower pain scores and reduced opiate use", said Sheombar.

The study was presented at the annual meeting of the European Society of Anaesthesiology in Austria.