Sample size calculation in multi-centre clinical trials

Efficacy of acupuncture (Jin's three-needle) on motor symptoms and anxiety in patients with Parkinson's disease: protocol for a multicentre, randomised, assessor-blinded clinical trial

INTRODUCTION

Parkinson's disease (PD) has a significant impact on a substantial number of individuals in China. Notably, 31% of patients with PD also grapple with the additional burden of anxiety. This dual challenge of managing both PD and anxiety underscores the complexity of the condition and the diverse range of symptoms patients may experience. Considering the circumstances, the cost and potential drawbacks associated with traditional antiparkinsonian drugs become increasingly relevant. Acupuncture emerges as a significant non-pharmacological adjunct therapy. Offering a potentially safer and more cost-effective option, acupuncture addresses the pressing need for holistic and complementary treatments that may alleviate both the motor symptoms of PD and the accompanying anxiety.

METHODS AND ANALYSIS

This is a multicentre, randomised controlled and assessor-blind trial. A total of 210 eligible patients with PD will be randomly assigned (1:1) to Jin's three-needle (JTN) acupuncture group or waitlist (WL) group. Patients in the JTN group will receive acupuncture therapy three times per week for 4 weeks. Patients in the WL group will maintain their original dosage of antiparkinsonian drugs and receive acupuncture therapy after the observation period. The primary outcome measure will be the Unified Parkinson's Disease Rating Scale score. The secondary outcome measures will be the scores of the Hoehn-Yahr Rating Scale, Unified Dyskinesia Rating Scale, Non-Motor Symptoms Scale, 39-item Parkinson's Disease Questionnaire, Parkinson Anxiety Scale, Hamilton Anxiety Scale, Hamilton Depression Scale, Zarit burden interview and the level of cortisol and adrenocorticotropic hormone. The evaluation will be executed at baseline, the end of the treatment and a follow-up period.

ETHICS AND DISSEMINATION

The study was approved by the Ethics Committee of the First Affiliated Hospital of Guangzhou University of Chinese Medicine (K[2023]014). All patients have to provide written, informed consent. The study will be disseminated through presentations in peer-reviewed international journals and at national and international conferences.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry; ChiCTR2300074675.

Multi-centric clinic trials in evidence-based research - A narrative review on the Indian scenario

Evidence-based health care is gaining prominence since the past many decades. The ultimate goal of evidence-based medicine is providing the best available treatment to patients. The boom in pharmacy sector has seen a rapid rise in randomised controlled clinical trials. Novel medicines or diagnostic tests must be tested before introducing to the target population. Randomised controlled trials are at the top hierarchy of evidence-based health care, especially for testing newly invented drugs. The results obtained from randomised controlled trials cannot be generalised to the entire population. This has led to the evolvement of multi-centre trials in evidence-based research. Multi-centre trials can overcome the barriers associated with single-centre clinical trials. The conduct of multi-centre trials is still in a budding stage in India. Although there are many ongoing multi-centre trials in India, very few trials are conducted among the dental fraternity. The conduct of such trials has its own set of challenges involving funding, ethical committee approval, and logistic requirements. This paper will discuss the growth of multi-centre research, steps involved in conduct of multi-centre trials, and the challenges faced in conducting these trials by the dental specialists in India.

Coenzyme Q10 improves sperm motility and antioxidant status in infertile men with idiopathic oligoasthenospermia

OBJECTIVE

Oxidative stress is a key player in the development of idiopathic male infertility (IMI), and various antioxidants have been used for the treatment of IMI with inconsistent results. Coenzyme Q10 (CoQ10) is a cofactor and an antioxidant that may improve semen parameters and reduce oxidative stress in patients with idiopathic oligoasthenospermia (OA). Therefore, this study aimed to explore the effect of CoQ10 on semen parameters and antioxidant markers in patients with idiopathic OA.

METHODS

Fifty patients with idiopathic OA and 35 fertile controls were enrolled in this prospective controlled study. All participants underwent a comprehensive fertility assessment. All patients received CoQ10 (300 mg/day) orally once daily for 3 months. Semen parameters, seminal CoQ10 levels, reactive oxygen species (ROS) levels, total antioxidant capacity (TAC), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were measured in patients and controls at the start of the study and after 3 months.

RESULTS

Treatment with CoQ10 resulted in increased sperm progressive motility (p<0.05), total motility (p<0.01), seminal TAC (p<0.01), SOD (p<0.05), GPx (p<0.001), and seminal CoQ10 (p<0.001) levels and reduced ROS (p<0.01) in patients as compared to baseline. Sperm concentration and motility were also significantly correlated with antioxidant measures and seminal CoQ10 levels (r=0.38-0.57).

CONCLUSION

CoQ10 therapy (300 mg/day for 3 months) improved sperm motility and seminal antioxidant markers in patients with idiopathic OA. Therefore, CoQ10 could be a promising treatment for patients with idiopathic infertility and may improve their fertility potential.

Testing a new method of osteosynthesis of forearm fractures in children; a prospective randomized controlled longitudinal study

PURPOSE

Displaced children's forearms fractures are commonly treated surgically with Kirschner Wires or Elastic Stable Intramedullary Nails. The osteosynthesis system "Minimally Invasive Reduction and Osteosynthesis System" might be beneficial in the treatment of these fractures due to being minimally invasive while achieving fracture stability. In this exploratory prospective randomized controlled longitudinal study, we compared Minimally Invasive Reduction and Osteosynthesis System to Kirschner Wires and Elastic Stable Intramedullary Nails osteosynthesis.

METHODS

Twenty children were included consecutively to treatment with either conventional surgery (5 Kirschner Wires/5 Elastic Stable Intramedullary Nails) or Minimally Invasive Reduction and Osteosynthesis System (10). Evaluation of radiographic alignment and clinically of range of motion, pain status, grip strength, level of physical activity and scar size were compared after 3 months and after 5 years.

RESULTS

Surgical parameters of the duration of insertion- and removal-surgery, the need for postoperative casting and scar size were significantly better for Minimally Invasive Reduction and Osteosynthesis System. All osteosynthesis systems maintained radiographically fracture alignment at three months and 5 years follow-up. Clinical status regarding pain, grip strength difference, and return to recreational activities were not significantly different. The complication rates were nonsignificant, but MIROS had moderate severe complications of refractures, while mild complications occurred when operated on with Kirschner Wires/Elastic Stable Intramedullary Nails. Our study was sufficiently powered at 3 months, but the comparisons are suggestive at 5 years.

CONCLUSION

In conclusion, Minimally Invasive Reduction and Osteosynthesis System is not significantly different to other surgical methods in radiological outcomes for forearm fractures in children. Minimally Invasive Reduction and Osteosynthesis System has the clinical benefit of omitting casting after surgery, obtaining reduced scar size, and shorter insertion and removal time without general anesthesia. However, moderately severe complications occurred.

LEVEL OF EVIDENCE

Level II-a prospective comparative study.

Year-to-year variation in attack rates could result in underpowered RSV vaccine efficacy trials

OBJECTIVE

Year-to-year variation of respiratory viruses may result in lower attack rates than expected. We aimed to illustrate the impact of year-to-year variation in attack rates on the likelihood of demonstrating vaccine efficacy (VE) .

STUDY DESIGN AND SETTING

We considered an individually randomized maternal vaccine trial against respiratory syncytial virus-associated hospitalisations (RSVH). For 10 RSVH per 1,000 infants, sample size to have 80% power for true VE of 50% and 70% was 9,846 and 4,424 participants. We reported power to show VE for varying attack rates, selected to reflect realistic year-to-year variation using observational studies. Eight scenarios including varying number of countries and seasons were developed to assess the influence of these trial parameters.

RESULTS

Including up to three seasons decreased the width of the interquartile range for power. Including more seasons concentrated statistical power closer to 80%. Least powered trials had higher statistical power with more seasons. In all scenarios, at least half of the trials had <80% power. For three-season trials, increasing the sample size by 10% reduced the percentage of underpowered trials to less than one-quarter of trials.

CONCLUSION

Year-to-year variation in RSV attack rates should be accounted for during trial design. Mitigation strategies include recruiting over more seasons, or adaptive trial designs.

Decision making dyads and judgement overconfidence: Implications for high-risk industries

In the workplace, overconfidence is generally considered undesirable as it may increase people's propensity to take risks. In many areas (e.g., aviation, shipping, nuclear control, and driving), risk-taking is detrimental to safety. We hypothesised that decision-makers would be overconfident and, due to group polarisation, decision-making pairs would be more overconfident than single decision-makers. As was predicted, when answering a 24-item general knowledge questionnaire (d = 0.94) and a task exploring how they might reorient themselves if lost (d = 1.93), participants (N = 63) were overconfident about their performance; importantly, participants in pairs (n = 32) were more overconfident on general knowledge (Hedges' g = 0.51) and lost procedures (Hedges' g = 0.52), than were participants who completed the tasks alone (n = 31). The findings imply that in some situations, single decision-makers may exhibit less overconfidence. The safety implications for a number of areas are discussed.

Power(ful) myths: misconceptions regarding sample size in quality of life research

PURPOSE

Carefully selecting the sample size for a research study is one of the most fundamental ways to utilize resources in an ethical manner, maximize impact and replicability, and minimize research waste when investigating questions relevant to health-related quality of life (HRQOL). Despite an increased focus on sample size in the methodological literature, the topic has received limited attention in the HRQOL field, and there are still misconceptions that can weaken even well-intentioned sample size planning. This article aims to highlight common misconceptions, provide accessible and non-technical corrections to these misconceptions, and show how HRQOL researchers can benefit from a more nuanced understanding of sample size planning.

METHOD

Misconceptions were identified broadly through examples within the health, psychology, and HRQOL literatures. In examining these misconceptions, study-level (e.g., missing data, multilevel designs, multiple reported outcomes) and field-level (e.g., publication bias, replicability) issues relevant to HRQOL research were considered.

RESULTS

Misconceptions include: (a) researchers should use rules of thumb or the largest sample size possible, (b) sample size planning should always focus on power, (c) planned power = actual power, (d) there is only one level of power per study, and (e) power is only relevant for the individual researcher. Throughout the article, major themes linked to these misconceptions are mapped onto recent HRQOL studies to make the connections more tangible.

CONCLUSION

By clarifying several challenges and misconceptions regarding sample size planning and statistical power, HRQOL researchers will have the tools needed to augment the research literature in effective and meaningful ways.

Simulation-Based Virtual-Reality Patient-Specific Rehearsal Prior to Endovascular Procedures: A Systematic Review

Patient-specific rehearsal (PsR) is a new concept whereby a procedure can be rehearsed virtually using the exact patient’s anatomical data prior to performing the real procedure. The aim of this study was to ascertain if endovascular virtual-reality PsR simulation enhanced performance in real life. This was done by performing a systematic review following the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. A literature search was conducted in PubMed, Embase, The Cochrane Library and Web of Science concerning PsR in endovascular procedures. All publications were handled using Covidence. Reference lists were also screened. Data extracted from the studies were realism rating, procedure time, fluoroscopy time, contrast volume, number of angiograms and reduction of errors. Kirkpatrick’s four-level model for measuring the efficiency of training was used for guidance of the relevance of studies. The search yielded 1155 results after the exclusion of duplicates, and 11 studies were included. Four studies had a control group, including one randomized trial; the remaining seven were feasibility studies. The realism was rated high, and overall, the studies showed improvements in procedure time, fluoroscopy time and contrast volume after PsR. One study assessed and confirmed the reduction in errors after PsR. Only two studies included more than 15 patients in their cohort. Kirkpatrick’s model was applied to all studies, with one study reaching level 4. All studies found the concept of PsR to be feasible and realistic. The studies with a control group showed a reduction of overall procedure time, radiation exposure and potential errors in endovascular procedures following PsR.

Considerations for multi-centre conditioned pain modulation (CPM) research; an investigation of the inter-rater reliability, level of agreement and confounders for the Achilles tendon and Triceps Surae

Objective

This study aimed to investigate the inter-rater reliability of the conditioned pain modulation (CPM) effect.

Methods

The reliability between two examiners assessing the CPM effect via pressure pain thresholds and induced using the cold pressor test of 28 healthy volunteers at the mid-portion Achilles tendon (AT) and Triceps Surae musculotendinous junction was performed. Reliability was calculated using intraclass correlation coefficient (ICC). Confounders were assessed using multivariable generalised estimating equations (GEEs). Bias in the level of agreement was assumed if the confidence intervals (CIs) of the mean difference in Bland-Altman plots did not cross the line of equality.

Results

The inter-rater reliability of the CPM effect was poor to moderate in the AT (ICC 95% CI = 0.00-0.66) and Triceps Surae (ICC 95% CI = 0.00-0.69). However, when accounting for confounders within the GEE, there were no differences between testers and Bland-Altman plots reported good agreement between testers. Habitual completion of running-related physical activity was a confounder for both the AT parallel-paradigm (p = 0.017) and sequential-paradigm (p = 0.029). Testing order was a confounder for the AT (p = 0.023) and Triceps Surae (p = 0.014) parallel-paradigm.

Conclusion

This study suggests the CPM effect may be site specific (i.e. differences between the AT and Triceps Surae exist). In addition, differences in the reliability between examiners are likely due to the influence of confounders and not examiner technique and therefore appropriate analysis should be used in research investigating the CPM effect.

Sample size recalculation in multicenter randomized controlled clinical trials based on noncomparative data

Many late-phase clinical trials recruit subjects at multiple study sites. This introduces a hierarchical structure into the data that can result in a power-loss compared to a more homogeneous single-center trial. Building on a recently proposed approach to sample size determination, we suggest a sample size recalculation procedure for multicenter trials with continuous endpoints. The procedure estimates nuisance parameters at interim from noncomparative data and recalculates the sample size required based on these estimates. In contrast to other sample size calculation methods for multicenter trials, our approach assumes a mixed effects model and does not rely on balanced data within centers. It is therefore advantageous, especially for sample size recalculation at interim. We illustrate the proposed methodology by a study evaluating a diabetes management system. Monte Carlo simulations are carried out to evaluate operation characteristics of the sample size recalculation procedure using comparative as well as noncomparative data, assessing their dependence on parameters such as between-center heterogeneity, residual variance of observations, treatment effect size and number of centers. We compare two different estimators for between-center heterogeneity, an unadjusted and a bias-adjusted estimator, both based on quadratic forms. The type 1 error probability as well as statistical power are close to their nominal levels for all parameter combinations considered in our simulation study for the proposed unadjusted estimator, whereas the adjusted estimator exhibits some type 1 error rate inflation. Overall, the sample size recalculation procedure can be recommended to mitigate risks arising from misspecified nuisance parameters at the planning stage.

Effectiveness of a group-based psychosocial program to prevent depression and anxiety in older people attending primary health care centres: a randomised controlled trial

BACKGROUND

Evidence about the effectiveness of psychosocial interventions to reduce the incidence of depression and anxiety and promote subjective well-being in older people is limited, particularly in Latin-American countries. This study thus aims to assess a program specifically designed to address this issue in persons aged 65 to 80 and attending primary health care centres.

METHOD

Older people who use primary care centres are to be randomly assigned to the program or to a control group. Only independent users will be included; those having had a major depressive disorder or an anxiety disorder in the last 6 months will be excluded. The program is group based; it includes cognitive stimulation, expansion of social support networks and cognitive behaviour strategies. Depressive and anxiety symptoms and disorders, as well as psychological well-being, will be assessed using standardised instruments, once before implementing the program and later, after 18 and 36 weeks.

DISCUSSION

Primary care is a setting where interventions to improve mental health can be beneficial. Providing evidence-based programs that work with older people is a priority for public mental health.

TRIAL REGISTRATION

A protocol for this study has been registered prospectively at ISRCTN registry on 25 July 2018. Identifier: ISRCTN32235611 .