Methods for pragmatic randomized clinical trials of pain therapies: IMMPACT statement.

Pragmatic, randomized, controlled trials hold the potential to directly inform clinical decision making and health policy regarding the treatment of people experiencing pain. Pragmatic trials are designed to replicate or are embedded within routine clinical care and are increasingly valued to bridge the gap between trial research and clinical practice, especially in multidimensional conditions, such as pain and in nonpharmacological intervention research. To maximize the potential of pragmatic trials in pain research, the careful consideration of each methodological decision is required.

Continuous Levodopa Delivery with an Intraoral Micropump System: An Open-Label Pharmacokinetics and Clinical Study.

Background: Double-blind studies have demonstrated that motor complications in Parkinson's disease (PD) can be reduced with continuous delivery of levodopa. The DopaFuse system is a novel, intraoral micropump that attaches to a retainer and uses a propellant to deliver levodopa/carbidopa (LD/CD) continuously into the mouth.

Objectives: Evaluate the safety, pharmacokinetics, and efficacy of LD/CD delivered via the DopaFuse system compared to treatment with intermittent doses of standard oral LD/CD in PD patients with motor fluctuations.

Transdermal Nicotine Treatment and Progression of Early Parkinson's Disease.

BACKGROUND: Epidemiologic studies show that smokers have a lower incidence of Parkinson’s disease. Nicotine has been hypothesized to slow progression in early Parkinson’s disease. METHODS: In a double-blind, placebo-controlled multicenter trial, we randomly assigned patients with Parkinson’s disease, diagnosed within 18 months, who were in Hoehn and Yahr disease stage less than or equal to 2 (range from 0 to 5; higher scores indicate greater impairment), who were therapy naïve (except for stable monoamine-oxidase-B inhibition), and not requiring dopaminergic therapy, to transdermal nicotine or placebo.

Research objectives and general considerations for pragmatic clinical trials of pain treatments: IMMPACT statement.

Many questions regarding the clinical management of people experiencing pain and related health policy decision-making may best be answered by pragmatic controlled trials. To generate clinically relevant and widely applicable findings, such trials aim to reproduce elements of routine clinical care or are embedded within clinical workflows. In contrast with traditional efficacy trials, pragmatic trials are intended to address a broader set of external validity questions critical for stakeholders (clinicians, healthcare leaders, policymakers, insurers, and patients) in considering the adoption and use of evidence-based treatments in daily clinical care.

Interpretation of chronic pain clinical trial outcomes: IMMPACT recommended considerations.

Interpreting randomized clinical trials (RCTs) is crucial to making decisions regarding the use of analgesic treatments in clinical practice. In this article, we report on an Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) consensus meeting organized by the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks, the purpose of which was to recommend approaches that facilitate interpretation of analgesic RCTs. We review issues to consider when drawing conclusions from RCTs, as well as common methods for reporting RCT results and the limitations of each method.

Peripheral Biomarkers of Parkinson's Disease Progression and Pioglitazone Effects.

Pioglitazone, an oral hypoglycemic agent, recently failed to show promise as a disease-modifying agent in a 44-week phase 2 placebo-controlled study in 210 Parkinson's disease (PD) subjects. We analyzed peripheral biomarkers, including leukocyte PGC-1α and target gene expression, plasma interleukin 6 (IL-6) as a marker of inflammation, and urine 8-hydroxydeoxyguanosine (8OHdG) as a marker of oxidative DNA damage. Baseline or changes from baseline in biomarker levels were not associated with the rate of progression of PD.

Effect of creatine monohydrate on clinical progression in patients with Parkinson disease: a randomized clinical trial.

Importance: There are no treatments available to slow or prevent the progression of Parkinson disease, despite its global prevalence and significant health care burden. The National Institute of Neurological Disorders and Stroke Exploratory Trials in Parkinson Disease program was established to promote discovery of potential therapies.

Objective: To determine whether creatine monohydrate was more effective than placebo in slowing long-term clinical decline in participants with Parkinson disease.

Caffeine consumption and risk of dyskinesia in CALM-PD.

Background: Adenosine A2A receptor antagonists reduce or prevent the development of dyskinesia in animal models of levodopa-induced dyskinesia.

Methods: We examined the association between self-reported intake of the A2A receptor antagonist caffeine and time to dyskinesia in the Comparison of the Agonist Pramipexole with Levodopa on Motor Complications of Parkinson's Disease (CALM-PD) and CALM Cohort extension studies, using a Cox proportional hazards model adjusting for age, baseline Parkinson's severity, site, and initial treatment with pramipexole or levodopa.

Results: For subjects who consumed >12 ounces of coffee/day, the adjusted hazard ratio for the development of dyskinesia was 0.

Long term understanding of study information in research participants with Parkinson's disease.

Context: Little is known about research participants' understanding of consent information over the course of a clinical study and the relationship of this information with participant behavior.

Methods: We conducted a cross sectional patient completed questionnaire of comprehension and satisfaction administered at the end of a Parkinson's disease clinical trial.

Main Outcome: Scores on 9 comprehension items in a 30 item questionnaire covering the key elements of informed consent.

A randomized, placebo-controlled trial of oxycodone and of gabapentin for acute pain in herpes zoster.

Although acute pain in patients with herpes zoster can be severe and has a substantial impact on health-related quality of life, there have been no randomized clinical trials of oral medications specifically for its ongoing treatment. A randomized clinical trial was conducted in which 87 subjects >or=50 years of age with herpes zoster within 6 calendar days of rash onset and with worst pain in the past 24h >or=3 on a 0-10 rating scale initiated 7 days of treatment with famciclovir in combination with 28 days of treatment with either controlled-release (CR) oxycodone, gabapentin, or placebo. Subjects were evaluated for adverse effects of treatment, acute pain, and health-related quality of life.

Impact of pramipexole on the onset of levodopa-related dyskinesias.

Dyskinesias are a major complication of dopaminergic therapy in the long-term treatment of Parkinson's disease. In the CALM-PD trial, subjects were initially randomized to levodopa or pramipexole and could later add levodopa if needed. After adjusting for disease duration and daily levodopa dosage, the incidence of dyskinesias after initiating levodopa was not significantly different among subjects initially randomized to levodopa and those initially randomized to pramipexole.

Self-reported adherence versus pill count in Parkinson's disease: the NET-PD experience.

Purpose: To compare the Morisky medication adherence questionnaire to pill counts as measures of adherence in the NET-PD futility clinical trials.

Background: Like in other chronic diseases, non-adherence with medications occurs in Parkinson's disease (PD), although nonadherence has not been of significant concern in most PD clinical trials. The most common approach to assessment is to do a pill count at each visit.

A responsive outcome for Parkinson's disease neuroprotection futility studies.

Futility studies are designed to test new treatments over a short period in a small number of subjects to determine if those treatments are worthy of larger and longer term studies, or if they should be abandoned. An appropriate outcome measure for a neuroprotection futility study in Parkinson's disease (sensitive to tracking disease progression in the short-term) has not been determined. Data sets from three clinical trials were used to compare Parkinson's disease outcome measures.

Pramipexole vs levodopa as initial treatment for Parkinson disease: a 4-year randomized controlled trial.

Background: The best way to initiate dopaminergic therapy for early Parkinson disease remains unclear.

Objective: To compare initial treatment with pramipexole vs levodopa in early Parkinson disease, followed by levodopa supplementation, with respect to the development of dopaminergic motor complications, other adverse events, and functional and quality-of-life outcomes.

Design: Multicenter, parallel-group, double-blind, randomized controlled trial.