Minimum important difference is minimally important in sample size calculations

An investigation of the association between parenting style and child's dental caries: a cross-sectional study

To investigate the association between parenting style and child's dental caries. Parents presenting with their children to the Department of Pediatric Dentistry at Tufts University School of Dental Medicine for an initial exam or re-care appointment completed a demographic survey and the parenting styles and dimensions questionnaire. Recruitment of subjects started in May 2019 and ended in February of 2020. Child's decayed, missing, and filled teeth (dmft) index, diet score, sex, and age were recorded, as were parent's race, education level, and form of payment. Adjustment for confounders was done using multivariable negative binomial regression. The sample size was 210 parent/child dyads. In the multivariable analysis, parenting style and child's dmft were not significantly associated (p > 0.05). Parents with an education level less than high school (p = 0.02) and at the high school graduate level (p = 0.008) were significantly associated with children who had higher dmft, compared to parents with a college degree or higher. Children with excellent diet scores had significantly lower dmft than children with a diet score in the "needs improvement" category (p = 0.003). There was no significant evidence that parenting style is associated with child's dental caries. Parent's education level and child's diet score were significantly associated with child's dmft, less than high school (p = 0.02) and at the level of high school graduate (p = 0.008). Pediatric dental professionals should be aware of these risk indicators.

Low-dose naltrexone for post-COVID fatigue syndrome: a study protocol for a double-blind, randomised trial in British Columbia

INTRODUCTION

A significant proportion of individuals suffering from post COVID-19 condition (PCC, also known as long COVID) can present with persistent, disabling fatigue similar to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and post-viral fatigue syndromes. There remains no clear pharmacological therapy for patients with this subtype of PCC, which can be referred to as post-COVID fatigue syndrome (PCFS). A low dose of the opioid antagonist naltrexone (ie, low-dose naltrexone (LDN)) has emerged as an off-label treatment for treating fatigue and other symptoms in PCC. However, only small, non-controlled studies have assessed LDN in PCC, so randomised trials are urgently required.

METHODS AND ANALYSIS

A prospective, randomised, double-blind, parallel arm, placebo-controlled phase II trial will be performed to assess the efficacy of LDN for improving fatigue in PCFS. The trial will be decentralised and open to eligible individuals throughout the Canadian province of British Columbia (BC). Participants will be recruited through the province-wide Post-COVID-19 Interdisciplinary Clinical Care Network (PC-ICCN) and research volunteer platform (REACH BC). Eligible participants will be 19-69 years old, have had a confirmed or physician-suspected SARS-CoV-2 infection at least 3 months prior and meet clinical criteria for PCFS adapted from the Institute of Medicine ME/CFS criteria. Individuals who are taking opioid medications, have a history of ME/CFS prior to COVID-19 or history of significant liver disease will be excluded. Participants will be randomised to an LDN intervention arm (n=80) or placebo arm (n=80). Participants in each arm will be prescribed identical capsules starting at 1 mg daily and follow a prespecified schedule for up-titration to 4.5 mg daily or the maximum tolerated dose. The trial will be conducted over 16 weeks, with assessments at baseline, 6, 12 and 16 weeks. The primary outcome will be fatigue severity at 16 weeks evaluated by the Fatigue Severity Scale. Secondary outcomes will include pain Visual Analogue Scale score, overall symptom severity as measured by the Patient Phenotyping Questionnaire Short Form, 7-day step count and health-related quality of life measured by the EuroQol 5-Dimension questionnaire.

ETHICS AND DISSEMINATION

The trial has been authorised by Health Canada and approved by The University of British Columbia/Children's and Women's Health Centre of British Columbia Research Ethics Board. On completion, findings will be disseminated to patients, caregivers and clinicians through engagement activities within existing PCC and ME/CFS networks. Results will be published in academic journals and presented at conferences.

TRIAL REGISTRATION NUMBER

NCT05430152.

Editorial Commentary: The Minimal Clinically Important Difference Is Less Important Than It Sounds: Patients Seek to Achieve Substantial Clinical Benefits and Not Minimally Perceptible Improvements When They Undergo Arthroscopic Surgery

The minimal clinically important difference (MCID) is a frequently reported metric for describing within-patient improvement in patient-reported outcome measures (PROMs). It was originally defined by Jaeschke et al. as "the smallest difference in score in the domain of interest which patients perceive as beneficial and which would mandate, in the absence of troublesome side effects and excessive cost, a change in the patient's management." The latter part of this statement is often omitted, and this results in a loss of the originally intended value through lack of sufficient clinical importance to change management. Other pitfalls in the use of the MCID include that they are population- and condition-specific. As such, MCIDs lack external validity and cannot easily be extrapolated from one study to another. Furthermore, broadly different values can be obtained depending on the calculation method used. This makes the MCID an unhelpful metric when seeking to understand the true efficacy of a given intervention. The Food and Drug Administration recommends anchor-based methodologies (which take into account patient perception), over distribution-based methods (which are purely statistical and do not account for clinical meaningfulness to patients). Regardless, it should be noted that even anchor-based methodologies are susceptible to statistical bias, and measures are apt to be influenced by the regression to mean phenomena, where the value of the preintervention scores and their relationship to postintervention scores can bias estimates of the MCID. Finally, when using MCIDs, one must consider that they are a low bar. This means that patients do not undergo treatment to achieve minimally perceptible clinical improvements; instead, they undergo treatment with the hope of achieving substantial clinical benefit or a patient acceptable symptom state, and so these are more appropriate individual-level metrics to consider when evaluating clinically meaningful outcomes of treatment.

How to use the Harmonising Outcome Measures for Eczema Core Outcome Set for atopic dermatitis trials: a users' guide

BACKGROUND

The Harmonising Outcome Measures for Eczema (HOME) initiative has agreed upon the Core Outcome Set (COS) for use in atopic dermatitis (AD) clinical trials, but additional guidance is needed to maximize its uptake.

OBJECTIVES

To provide answers to some of the commonly asked questions about using the HOME COS; to provide data to help with the interpretation of trial results; and to support sample size calculations for future trials.

METHODS AND RESULTS

We provide practical guidance on the use of the HOME COS for investigators planning clinical trials in patients with AD. It answers some of the common questions about using the HOME COS, how to access the outcome measurement instruments, what training/resources are needed to use them appropriately and clarifies when the COS is applicable. We also provide exemplar data to inform sample size calculations for eczema trials and encourage standardized data collection and reporting of the COS.

CONCLUSIONS

By encouraging adoption of the COS and facilitating consistent reporting of outcome data, it is hoped that the results of eczema trials will be more comprehensive and readily combined in meta-analyses and that patient care will subsequently be improved.

A Comprehensive Study on Tear Meniscus Height Inter-Eye Differences in Aqueous Deficient Dry Eye Diagnosis

(1) Background: Dry eye disease (DED) is a chronic ocular surface condition that requires precise diagnostic tools. The present study aimed to investigate the diagnostic potential of the absolute inter-eye difference (|OD-OS|) in tear meniscus height (TMH) for the detection of the presence of aqueous deficient dry eye (ADDE). (2) Methods: A sample of 260 participants with dry eye complaints underwent ocular surface examinations thorough diagnostic assessments based on the Tear Film and Ocular Surface Society guidelines (TFOS DEWS II). Participants were subsequently categorized as No ADDE and ADDE based on TMH. Statistical analyses to determine the optimal TMH|OD-OS| cut-off value in a randomly selected study group (200 participants) were performed, while a separate validation analysis of the cut-off value obtained in a random cross-validation group (60 participants) was also performed. (3) Results: The significant diagnostic capability of TMH|OD-OS| (area under the curve = 0.719 ± 0.036, p < 0.001) was found. The identified cut-off value of 0.033 mm demonstrated reliable specificity (77.6%) and moderate sensitivity (59.1%). Cross-validation confirmed the cut-off value's association with the TFOS DEWS II diagnostic criterion (Cramer's V = 0.354, p = 0.006). (4) Conclusions: The present study provides evidence for the diagnostic potential of TMH|OD-OS| in identifying ADDE. The identified cut-off value enhances the specificity and offers moderate sensitivity, providing an objective tool for clinical decision making.

COVID-19 infodemic and health-related quality of life in patients with chronic respiratory diseases: A multicentre, observational study

Background

The explosion of information, misinformation and disinformation (the "infodemic") related to the coronavirus disease 2019 (COVID-19) pandemic on digital and social media is reported to affect mental health and quality of life. However, reports assessing the COVID-19 infodemic on health-related quality of life (HRQL) in patients with chronic diseases are scarce. In this study, we investigated the associations between the infodemic and HRQL in uninfected individuals with pre-existing chronic respiratory diseases (CRDs) such as asthma, chronic obstructive pulmonary disease (COPD) and other CRDs.

Methods

We conducted a multi-national, cross-sectional, observational study in Canada, India, New Zealand and the United Kingdom where we distributed a set of digitised questionnaires among 1018 participants with chronic respiratory diseases who were not infected with the SARS-CoV-2 virus at least three months prior to the study. We collected information about the infodemic such as news watching or social media use more than usual during the pandemic. HRQL was assessed using the short form of the chronic respiratory questionnaire (SF-CRQ). Demographic information, comorbidities, compliance, mental health, behavioural function, and social support were also recorded. We analysed the direct and indirect relationships between infodemic and HRQL using structural equation models (SEM).

Results

Of all participants, 54% were females and had a mean (standard deviation (SD)) age of 53 (17) years. We found that higher infodemic was associated with worse emotional function (regression coefficient β = -0.08; 95% confidence interval (CI) = -0.14 to -0.01), which means a one SD change of the higher infodemic latent variable was associated with a 0.08 SD change of emotional function level. The association between higher infodemic and worse emotional function was mediated by worse mental health and behavioural functions but is marginally ameliorated by improved social support. In stratification analysis, we found significant disease and country-wise variations in the associations between infodemic and SF-CRQ domain scores.

Conclusions

These results provide new evidence that the COVID-19 infodemic significantly influences the HRQL in patients with CRDs through a complex interplay between mental health, behavioural function, and social support. This new dimension of research also opens avenues for further research on infodemic-related health effects in other chronic diseases.

Clinically important effect sizes for clinical trials using infarct growth reduction as the primary outcome: a systematic review

BACKGROUND

Infarct growth on multimodal imaging is a common lead outcome in phase 2 proof-of-concept and dose-optimization neuroprotective agent stroke trials. However, the effect size in infarct growth reduction that correlates with clinically meaningful differences in clinical global disability outcomes has not been well delineated.

METHODS

A systematic literature search identified all endovascular thrombectomy randomized trials reporting magnitude of treatment effect on both infarct growth reduction and increase in functional independence (modified Rankin Scale (mRS) 0-2). Data aggregation determined the size of infarct growth reductions salient to four types of clinically meaningful effect sizes of increase in functional independence: (1) the minimal clinically important difference (MCID)-outcome specific; (2) the MCID-practice changing; (3) the realistic target difference; and (4) the reasonable comparability effect size.

RESULTS

A systematic search identified four trials enrolling 612 imaged participants. Across the trials, the amount of functional independence (mRS 0-2) increase associated with each 1 mL reduction in infarct growth was mean 2.3±0.6%. An infarct growth reduction of 0.57 mL correlated with the mRS 0-2 increase MCID of 1.3%. Infarct growth reductions of 2.27 mL, 4.35 mL, and 6.53 mL correlated with realistic effect and reasonable comparability effects sizes of mRS 0-2 increases of 5%, 10%, and 15%, respectively.

CONCLUSION

In formal meta-analysis of randomized treatment trials, every 1 mL reduction in infarct growth was associated with a 2.3% increase in functional independence (mRS 0-2) at 3 months. This conversion factor can inform selection of infarct growth effect size targets for phase 2 trials of neuroprotective agents.

The importance of clinical importance when determining the target difference in sample size calculations

Recently, it was argued that clinically important differences should play no role in sample size calculations. Instead, it was proposed that sample size calculations should focus on setting realistic estimates of treatment benefit. We disagree, and argue in this article that considering the importance of a target difference is necessary in the context of randomised controlled trials of effectiveness, particularly definitive phase III trials. Ignoring clinical importance could have serious ethical and practical consequences.