The Effect of Elective Sham Dose Escalation on the Placebo Response During an Antimuscarinic Trial for Overactive Bladder Symptoms

To respond or not to respond: exploring empathy-related psychological and structural brain differences between placebo analgesia responders and non-responders

Introduction

Placebo responsiveness is highly variable across individuals. In the domain of pain, it may range from pronounced hypoalgesia to no response at all. Which factors predict such variation awaits clarification, as the available literature is characterized by mixed and inconclusive results. Particularly interesting in this case are social factors such as empathy or prosocial behavior, as prior work has stressed the connection between feeling pain yourself and empathizing with pain observed in others.

Methods

In a mixed confirmatory and exploratory approach, this study investigated potential psychological and structural brain differences between placebo responders and non-responders in the domain of pain. We aggregated data of four behavioral and neuroimaging studies that had been designed to investigate the effects of placebo analgesia on empathy.

Results

Analyses comparing groups of placebo responders and non-responders showed significant group differences in trait characteristics, with responders reporting increased helping behavior and lower psychopathic traits compared to non-responders. Uncorrected results further showed higher pain-related empathic concern in responders vs. non-responders. These results were accompaniedby tentative group differences in brain structure: placebo analgesia non-responders exhibited increased gray matter volume in left inferior temporal and parietal supramarginal cortical areas, and an increased cortical surface area in bilateral middle temporal cortex.

Discussion

Together, our findings suggest that modifiability of one's pain perception by means of placebo effects is linked to personality traits characterizing social emotions and behavior. They also hint that these psychological as well as brain structural characteristics might be beneficial for the identification of placebo responders. At the same time, they stress the importance of considering contextual factors such as the study setting or paradigm when investigating the association between individual characteristics and placebo responding.

Study Designs for Evaluation of Combination Treatment: Focus on Individual Patient Benefit

Combination treatment, i.e., the use of two or more drugs for the same condition, is frequent in medicine if monotherapy yields an insufficient therapeutic response. We review and challenge clinical study designs and formats of reporting outcomes for the evaluation of the benefit/risk ratio of combination treatment over monotherapy. We demonstrate that benefits of combination treatment at the group level overestimate the probability of benefit at the single patient level based on outcome simulations under almost any imaginable setting. Based on these findings, we propose that studies testing combination treatment should always report on percentages of responders to monotherapy and combination treatment. We provide equations that allow the calculation of the percentage of patients truly benefitting from combination (responders to both monotherapies) and that of patients exposed to risk of harm from adverse effects without a reasonable expectation of individual benefit. These considerations are explained based on real clinical data, mostly from the field of functional urology (male lower urinary tract symptoms).

Factors Associated with Decisions for Initial Dosing, Up-Titration of Propiverine and Treatment Outcomes in Overactive Bladder Syndrome Patients in a Non-Interventional Setting

Two doses of propiverine ER (30 and 45 mg/d) are available for the treatment of overactive bladder (OAB) syndrome. We have explored factors associated with the initial dosing choice (allocation bias), the decision to adapt dosing (escalation bias) and how dosing relative to other factors affects treatment outcomes. Data from two non-interventional studies of 1335 and 745 OAB patients, respectively, receiving treatment with propiverine, were analyzed post-hoc. Multivariate analysis was applied to identify factors associated with dosing decisions and treatment outcomes. Several parameters were associated with dose choice, escalation to higher dose or treatment outcomes, but only few exhibited a consistent association across both studies. These were younger age for initial dose choice and basal number of urgency and change in incontinence episodes for up-titration. Treatment outcome (difference between values at 12 weeks vs. baseline) for each OAB system was strongly driven by the respective baseline value, whereas no other parameter exhibited a consistent association. Patients starting on the 30 mg dose and escalating to 45 mg after 4 weeks had outcomes comparable with those staying on a starting dose of 30 or 45 mg. We conclude that dose escalation after 4 weeks brings OAB patients with an initially limited improvement to a level seen in initially good responders. Analysis of underlying factors yielded surprisingly little consistent insight.

Factors associated with dose escalation of fesoterodine for treatment of overactive bladder in people >65 years of age: A post hoc analysis of data from the SOFIA study

AIM

To investigate factors which may influence dose escalation of antimuscarinics for overactive bladder (OAB) in older patients and how dose escalation affects treatment efficacy.

MATERIALS AND METHODS

A post hoc analysis of data from the 12-week randomized, placebo controlled phase of the SOFIA study investigating treatment with fesoterodine in older people with OAB. Predictors and outcomes in patients aged ≥65 years with OAB who did or did not choose to escalate from fesoterodine 4 to 8 mg before the first dose-escalation choice point (week 4) and at the end of the study (week 12) were assessed.

RESULTS

Variables which significantly increased likelihood of dose escalation were, at baseline, body mass index (OR: 1.06, 95% CI 1.01, 1.12; P = 0.0222), and male gender (OR: 2.06, 95% CI 1.28, 3.32; P = 0.0028) and at week 4, change from baseline in urgency episodes (OR: 1.12, 95% CI 1.05, 1.20; P = 0.0008), patient perception of bladder control (PPBC) (OR: 1.44, 95% CI 1.12, 1.84; P = 0.004). At week 12, dose escalation was associated with slightly reduced treatment outcomes compared to week 4 non-escalators.

CONCLUSIONS

No baseline disease related factor associated with dose escalation was identified. Magnitude of change in urgency episodes and reduction in PPBC at 4 weeks were associated with dose escalation. These data may be of use to healthcare providers as they allow judgement to be made in individual patients, allowing treatment decisions to be made. At end of treatment, improvements in efficacy and quality of life were achieved in both escalators and non-escalators.