The Effects of Patient and Visit Characteristics on Health Outcomes in Knee Osteoarthritis
- Conditions
- Knee Osteoarthritis
- Interventions
- Drug: Topical Diclofenac gel 1%
- Registration Number
- NCT06574191
- Lead Sponsor
- University of California, Davis
- Brief Summary
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:
* 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
- Detailed Description
220 older adults with symptomatic knee OA will attend a single research clinic visit (one of four different types of study visits) with a study clinician. The investigators will video record the visits and measure participant heart rate and skin conductance during the visit. Participants will complete baseline questionnaires immediately prior to the study visit. All participants will receive diclofenac gel (a topical over-the-counter non-steroidal anti-inflammatory drug \[NSAID\]), a guideline recommended treatment for knee OA-related pain at the end of the first study visit. Participants will identify an "index" knee (worst pain, right or left) that they will treat and follow during the study. Between study visit 1 and the 8-week follow-up visit, participants will receive an every other week text message asking them to report on pain and diclofenac use to better understand changes in pain over time. Final questionnaires will be completed at the second study visit at week 8.
Recruitment & Eligibility
- Status
- RECRUITING
- Sex
- All
- Target Recruitment
- 220
- 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.
- 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)
- 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)
- 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.
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- SINGLE_GROUP
- Arm && Interventions
Group Intervention Description Diclofenac Topical Diclofenac gel 1% 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.
- Primary Outcome Measures
Name Time Method Knee Pain 8 weeks Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain score from the index knee at 8 weeks. Score range 0-20. Higher scores signify worse pain.
Knee Function 8 weeks Western Ontario and McMaster Universities Arthritis Index (WOMAC) physical function score from the index knee at 8 weeks. Score range 0-68. Higher scores signify worse function.
- Secondary Outcome Measures
Name Time Method Global Impressions 30 minutes Baseline-adjusted end of visit global impression ratings from study visit video recordings. Each global impression is measured on a 1-9 scale. Global impressions include engagement (clinician and patient), friendliness (clinician and patient), relaxed (clinician and patient), empathic (clinician), reciprocity (dyad), business-like (clinician), dominant (clinician), rushed/hurried (clinician), bored/uninterested (clinician), confident (patient), and pleased (patient). We will construct a Global Impression Summative Scale Score if a preliminary round of psychometric evaluation determines that a combination of the individual construct scores can be constructed that has adequate internal consistency and unidimensionality.
Non-verbal Behaviors 30 minutes Baseline-adjusted end of visit non-verbal behaviors from study visit video recordings. Each non-verbal behavior is measured as counts (number of times) or total length of time within a discrete period of time (i.e., 2 minutes) from the video. Nonverbal behaviors that will be counted or timed for both parties include: gaze duration and number, smile duration and number, number of nods, self-touch, and gestures. We will also assess the number of clinician backchannel responses while patients spoke, the number of instances of shared laughter between the dyads, and the length of time that both the patient and clinician spoke. We will construct a Non-verbal Behavior Summative Score if a preliminary round of psychometric evaluation determines that a combination of the individual construct scores can be constructed that has adequate internal consistency and unidimensionality.
Skin conductance index measure 30 minutes Concordance in skin conductance response (measured in micro Siemens) from electrodes attached to the patient's and clinician's fingers over the course of the study visit will be calculated using an established approach (Marci CD, 2007; PMID 17299296) to create a single index value for the visit. The natural logarithm of this value will be taken to reduce skew. A value greater than 0 means more than 50% concordance in the data, a value less than zero means less than 50% concordance in the data.
Change in patient skin conductance response 30 minutes Change in patient skin conductance response from beginning to end of the initial study visit in micro-Siemens as measured by skin electrodes. Change score will be calculated as mean skin conductance response for the first 2 minutes of the study visit minus the mean value for the last 2 minutes of the study visit.
Heart rate variability index measure 30 minutes Concordance in heart rate variability, measured from electrodes attached to the patient and clinician, over the course of the study visit, will be calculated using established approaches (see references below). Concordance is quantified by the degree to which heart rate variability of the patient and clinician are "in-phase" or "anti-phase" linked (i.e., coordinated changes in the same or opposite direction) along the study visits.
https://pubmed.ncbi.nlm.nih.gov/29683720/ https://pubmed.ncbi.nlm.nih.gov/21910541/ https://pubmed.ncbi.nlm.nih.gov/24708502/ https://pubmed.ncbi.nlm.nih.gov/35315937/Change in patient RMSSD (root mean square of successive differences) 30 minutes The RMSSD component (proxy for high frequency heart rate variability) will be measured in the patient over the course of the study visit. Change score will be calculated as mean RMSSD value for the first 5 minutes of the study visit minus the mean value for the last 5 minutes of the study visit.
Trial Locations
- Locations (1)
University of California Davis Health
🇺🇸Sacramento, California, United States