Cholinesterase inhibitor to prevent falls in Parkinson's disease (CHIEF-PD) trial: a phase 3 randomised, double-blind placebo-controlled trial of rivastigmine to prevent falls in Parkinson's disease

BACKGROUND

Falls are a common complication of Parkinson's disease. There is a need for new therapeutic options to target this debilitating aspect of the disease. Cholinergic deficit has been shown to contribute to both gait and cognitive dysfunction seen in the condition. Potential benefits of using cholinesterase inhibitors were shown during a single centre phase 2 trial. The aim of this trial is to evaluate the effectiveness of a cholinesterase inhibitor on fall rate in people with idiopathic Parkinson's disease.

METHODS

This is a multi-centre, double-blind, randomised placebo-controlled trial in 600 people with idiopathic Parkinson's disease (Hoehn and Yahr stages 1 to 4) with a history of a fall in the past year. Participants will be randomised to two groups, receiving either transdermal rivastigmine or identical placebo for 12 months. The primary outcome is the fall rate over 12 months follow-up. Secondary outcome measures, collected at baseline and 12 months either face-to-face or via remote video/telephone assessments, include gait and balance measures, neuropsychiatric indices, Parkinson's motor and non-motor symptoms, quality of life and cost-effectiveness.

DISCUSSION

This trial will establish whether cholinesterase inhibitor therapy is effective in preventing falls in Parkinson's disease. If cost-effective, it will alter current management guidelines by offering a new therapeutic option in this high-risk population.

TRIAL REGISTRATION

REC reference: 19/SW/0043. EudraCT: 2018-003219-23.

ISCRTN

41639809 (registered 16/04/2019). ClinicalTrials.gov Identifier: NCT04226248 PROTOCOL AT TIME OF PUBLICATION: Version 7.0, 20th January 2021.

Do patient characteristics matter when calculating sample size for eczema clinical trials?

Background

The Patient‐Oriented Eczema Measure (POEM) is the core outcome instrument recommended for measuring patient‐reported atopic eczema symptoms in clinical trials. To ensure that the statistical significance of clinical trial results is meaningful, trials are often designed by specifying the target difference in the primary outcome as part of the sample size calculation. One method used to specify the target difference is a score that corresponds to a standardized effect size.

Objectives

to assess how the standardized effect size of POEM scores vary across age, gender, ethnicity and disease severity.

Methods

This study combined data from five UK‐based randomized clinical trials of eczema treatments in order to assess differences in self‐reported eczema symptoms (POEM) corresponding to a standardized effect size (0.5 SD of baseline POEM scores) across age, gender, ethnicity and disease severity.

Results

POEM scores corresponding to 0.5 SD_(baseline) were remarkably consistent across participants of varying ages, gender, ethnicity and disease severity from datasets of five UK trials in children (range 2.99–3.45).

Conclusions

This study provides information that can support those designing clinical trials to determine their sample size and can aid individuals interpreting trial results. Further exploration of differences in populations beyond the United Kingdom is needed.

Comparison of patient (POEM), observer (EASI, SASSAD, TIS) and corneometry measures of emollient effectiveness in children with eczema: findings from the COMET feasibility trial

BACKGROUND

Eczema affects around 20% of children, but multiple different outcome measures have hampered research into the effectiveness of different treatments.

OBJECTIVES

To compare the change in scores and correlations within and between five measures of eczema severity: Patient-Orientated Eczema Measure (POEM), Eczema Area and Severity Index (EASI), Six Area, Six Sign Atopic Dermatitis (SASSAD), Three Item Severity (TIS) and skin hydration (corneometry).

METHODS

Data from a feasibility trial that randomized young children with eczema to one of four emollients were used. Participants were followed for 3 months (84 days). Descriptive statistics (by emollient over time) and Spearman's correlation coefficients comparing scores at each time point and absolute change (between adjacent time points) for each outcome measure were calculated.

RESULTS

In total, 197 children, mean ± SD age 21·7 ± 12·8 months, were randomized. POEM and TIS appeared to capture a range of eczema severity at baseline, but only POEM had close approximation to normal distribution. Mean POEM, EASI, SASSAD and TIS scores improved month by month, with POEM showing the greatest sensitivity (effect size 0·42). Correlations within POEM, EASI, SASSAD and TIS were moderate to good, decreasing over time. Correlations between measures were strongest for EASI, SASSAD and TIS. By contrast, corneometry scores were more variable, correlated less well over time and were poorly correlated with the other measures.

CONCLUSIONS

Except for corneometry, all measures appear to change in relation to emollient use over time and correlate well with themselves. POEM demonstrated the greatest range of scores at baseline and change in eczema severity over the first 28 days.

The Patient-Oriented Eczema Measure in young children: responsiveness and minimal clinically important difference

Background

The Patient‐Oriented Eczema Measure (POEM) has been recommended as the core patient‐reported outcome measure for trials of eczema treatments. Using data from the Choice of Moisturiser for Eczema Treatment randomized feasibility study, we assess the responsiveness to change and determine the minimal clinically important difference (MCID) of the POEM in young children with eczema.

Methods

Responsiveness to change by repeated administrations of the POEM was investigated in relation to change recalled using the Parent Global Assessment (PGA) measure. Five methods of determining the MCID of the POEM were employed; three anchor‐based methods using PGA as the anchor: the within‐patient score change, between‐patient score change and sensitivity and specificity method, and two distribution‐based methods: effect size estimate and the one half standard deviation of the baseline distribution of POEM scores.

Results

Successive POEM scores were found to be responsive to change in eczema severity. The MCID of the POEM change score, in relation to a slight improvement in eczema severity as recalled by parents on the PGA, estimated by the within‐patient score change (4.27), the between‐patient score change (2.89) and the sensitivity and specificity method (3.00) was similar to the one half standard deviation of the POEM baseline scores (2.94) and the effect size estimate (2.50).

Conclusions

The Patient‐Oriented Eczema Measure as applied to young children is responsive to change, and the MCID is around 3. This study will encourage the use of POEM and aid in determining sample size for future randomized controlled trials of treatments for eczema in young children.