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What predicts response to diclofenac gel in knee osteoarthritis pain

Studies which patient and visit traits relate to results of diclofenac gel for knee osteoarthritis.

Key facts

Who runs it
University of California, Davis
Where
Sacramento, United StatesSee the site
Trial code
Registry title
The Effects of Patient and Visit Characteristics on Health Outcomes in Knee Osteoarthritis
Status
Recruiting
People taking part
220 people, planned
Started
29 Jan 2025
Expected to end
27 Jan 2028
Type of study
Interventional
Treatments tested
  • Topical Diclofenac gel 1%
Record updated
30 March 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for English-speaking adults aged 50 or older with knee osteoarthritis pain. Participants will put topical diclofenac gel on the knee for 8 weeks.

Age
50 years or older
Sex
All sexes
Disease stage
Knee osteoarthritis confirmed by X-ray within the past 2 years, K/L grade 2 or higher. Knee pain at least 15 days/month. Average worst daily pain 3/10 or higher over two weeks.
Earlier treatment
No knee injection in the study knee in the last 12 weeks. No partial or total knee replacement of the study knee. No use of topical or oral NSAIDs more than 3 days per week.

Main reasons for not taking part

  • Medical reasons not to take NSAIDs, such as recent heart attack or stroke (past 6 months), chronic kidney disease stage ≥4, cirrhosis, or NSAID or aspirin allergy
  • Current pregnancy or taking blood thinners (aspirin 81 mg daily is okay)
  • Inflammatory arthritis
  • Knee or lower limb surgery planned during the two-month study
  • Active cancer treatment not in remission, life expectancy less than 6 months, or unable to give consent

The registry criteria, word for word

Show all 15 criteriaShow less

Who can take part

  • English-speaking
  • 50 years of age or older
  • Radiographically confirmed knee OA of K/L grade 2 or higher within the past 2 years
  • Knee pain at least 15 days/month
  • Average worst daily pain 3/10 or higher over a two-week period

Who cannot take part

  • Planned knee/lower limb surgery during the two-month study period
  • Active cancer treatment not in remission or life expectancy less than 6 months
  • Inability to provide informed consent (e.g. dementia)
  • Medical contraindication to taking NSAIDs such as: history of coronary artery bypass graft, myocardial infarction, coronary artery stent placement, or stroke within the past 6 months; systolic heart failure with ejection fraction <45%; chronic kidney disease stage ≥4; severe gastrointestinal bleed or stomach ulcer within the past 6 months; current pregnancy; cirrhosis; currently taking blood thinners (aspirin 81 mg daily is okay); allergy to NSAIDs or aspirin; or any other medical contraindication to using topical NSAIDs
  • Inflammatory arthritis
  • Partial or total knee replacement of the index knee
  • Recent therapeutic injection of the index knee (less than 12 weeks)
  • Current use of topical or oral NSAIDs more than 3 days per week
  • Inability to receive text messages or emails to complete questionnaires between study visits
  • Unable to follow the study protocol

Where in United States

  • University of California Davis HealthSacramento, United StatesContact: Michelle Dossett, MD, PhD, MPHTaking people

About the trial

What the trial wants to find out

The goal of this clinical trial is to understand the patient and clinic visit characteristics that affect health outcomes for individuals with knee osteoarthritis (OA) pain using topical diclofenac gel. The main questions it aims to answer are:

Read full original descriptionShow less

* What baseline patient characteristics predict response to topical diclofenac? * Does patient physiology during the study visit predict response to topical diclofenac? * Do study visit characteristics predict response to topical diclofenac?

Participants will:

* attend 2 study visits to complete study questionnaires and have blood drawn * apply topical diclofenac to their knee for 8 weeks * complete biweekly questions about knee pain and diclofenac use between study visits

The group in the trial

  • DiclofenacTreatment being tested

    All study participants receiving topical diclofenac gel 1%. Participants will be instructed to apply 4 grams of the gel to the index knee at least once per day, and up to 4 times per day, for 8 weeks.

    Treatment: Topical Diclofenac gel 1%

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record → Contacts and Locations

Print a page for my doctor

Data and sources

Registry record
Listed on ClinicalTrials.gov.
Official title
The Effects of Patient and Visit Characteristics on Health Outcomes in Knee Osteoarthritis
Plain-language title
What predicts response to diclofenac gel in knee osteoarthritis painGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 14 November 2026.
Record updated
30 March 2026