Jump to top menu Jump to main menu Jump to content
Research project

DUO trial

Status: Ongoing (January 2015 - 2021)

Duloxetine for chronic osteoarthritis pain; an important alternative?

What we do

About our project

Osteoarthritis (OA) is a highly prevalent painful condition of the musculoskeletal system. The effectiveness of current analgesic options (paracetamol, NSAIDS and opioids) has proven to be limited. Several randomized placebo-controlled trials have now demonstrated the efficacy of low dose duloxetine, an antidepressant with a centrally acting effect, in the treatment of pain in OA.

We hypothesize that low dose duloxetine is (cost-)effective as third choice pain medication for treating chronic pain with OA compared to usual care. Furthermore, we hypothesize that the presence of central sensitization in OA patients with chronic pain favorably modifies the response to treatment.

A pragmatic open-labeled cluster randomized controlled trial will be conducted with a follow-up period of a year. Patients (n=131) consulting their general practitioner because of chronic pain due to hip or knee OA in whom NSAIDs have failed will be included and will be treated according to their GP's treatment group. GPs are randomized to either: 1) prescribe duloxetine and provide usual care, 2) provide usual care only.

Our research focus

Primary outcome
The primary outcome is pain at 3 months measured with the pain subscale of the WOMAC (Western Ontario and MCMaster Universities Osteoarthritis Index).

Secondary outcome
The secondary outcome will be pain at 1 year, function (WOMAC), adverse reactions, and cost-effectiveness using direct costs (iMCQ) and productivity costs (iPCQ).

Funds & Grants

ZonMw GGG (Goed Gebruik Geneesmiddelen (836031009))


Dept. of Health Policy and Management, Erasmus University Rotterdam
Dept. of Public Health and Primary Care, LUMC, Leiden University Medical Center


van den Driest JJ, Schiphof D, Luijsterburg PAJ, Koffeman AR, Koopmanschap MA, Bindels PJE, Bierma-Zeinstra SMA. Effectiveness and cost-effectiveness of duloxetine added to usual care for patients with chronic pain due to hip or knee osteoarthritis: protocol of a pragmatic open-label cluster randomised trial (the DUO trial). BMJ Open. 2017 Sep 11;7(9):e018661. doi: 10.1136/bmjopen-2017-018661.

Our team

Dr. D. Schiphof (co-promotor), d.schiphof@erasmusmc.nl
Dr. A.E. Koffeman
Dr. M.A. Koopmanschap
Prof.dr. P.J.E. Bindels, p.bindels@erasmusmc.nl
Prof. Dr. S.M.A. Bierma-Zeinstra (promotor), s.bierma-zeinstra@erasmusmc.nl

Contact address for the project: j.vandendriest@erasmusmc.nl.