Sample Size Calculation Research Articles

Cloud Computing and Mobile Technologies as a Marketing Strategy towards Innovation and Business Growth among Small Tourism Enterprises

This study examined the impact of Cloud Computing and Mobile Technologies as marketing strategy towards innovation, business growth among small tourism enterprises (STEs). Mobile commerce is viewed as next generation, e-commerce refers to any transactions, either direct or indirect, via mobile devices, such as phones or personal digital assistants (PDAs). Most significant features of mobile technology are mobility and portability. Ability to access services ubiquitously, on the move, through wireless networks, various devices. The study highlights business risk of being left behind and gives a contemporary research gap, how frequent businesses are engaging with mobile technologies and innovation marketing strategies. Positivist Paradigm- Targeted population were Southern African border countries players in STEs. Data analysis utilised SMARTPLS, Tested CFA, Model Fit, Reliability and Validity, Path Modelling and hypothesis. Raosoft calculator was used to calculate sample size. Calculation considered population of approximately 350 STEs officially registered with Southern Africa Tourism Services Association (SATSA), a 5% margin of error, 90% confidence interval & recommended 50% distribution, and returned a minimum sample size of 184 respondents. Findings revealed transactions can be business to business applications (targeted to other firms, business to consumer applications (targeted to final customers, e.g. advertisements based on SMS/ MMS) e- catalogues on what the small tourism enterprise offers and networking regionally and at global level. Keywords: cloud computing, innovation, mobile technology, tourism enterprise, marketing strategy, business growth

Patent Foramen Ovale Closure in Older Patients With Stroke: Patient Selection for Trial Feasibility.

Whether patent foramen ovale (PFO) closure benefits older patients with PFO and cryptogenic stroke is unknown because randomized controlled trials (RCTs) have predominantly enrolled patients younger than 60 years of age. Our objective was to estimate anticipated effects of PFO closure in older patients to predict the numbers needed to plan an RCT. Effectiveness estimates are derived from major observational studies (Risk of Paradoxical Embolism [RoPE] Study and Oxford Vascular Study, together referred to as the "RoPE-Ox" database) and all 6 major RCTs (Systematic, Collaborative, PFO Closure Evaluation [SCOPE] Consortium). To estimate stroke recurrence risk, observed outcomes were calculated for patients older than 60 years in the age-inclusive observational databases (n = 549). To estimate the reduction in the rate of recurrent stroke associated with PFO closure vs medical therapy based on the RoPE score and the presence of high-risk PFO features, a Cox proportional hazards regression model was developed on the RCT data in the SCOPE database (n = 3,740). These estimates were used to calculate sample sizes required for a future RCT. Five-year risk of stroke recurrence using Kaplan-Meier estimates was 13.7 (95% CI 10.5-17.9) overall, 14.9% (95% CI 10.2-21.6) in those with high-risk PFO features. Predicted relative reduction in the event rate with PFO closure was 12.9% overall, 48.8% in those with a high-risk PFO feature. Using these estimates, enrolling all older patients with cryptogenic stroke and PFO would require much larger samples than those used for prior PFO closure trials, but selectively enrolling patients with high-risk PFO features would require totals of 630 patients for 90% power and 471 patients for 80% power, with an average of 5 years of follow-up. Based on our projections, anticipated effect sizes in older patients with high-risk features make a trial in these subjects feasible. With lengthening life expectancy in almost all regions of the world, the utility of PFO closure in older adults is increasingly important to explore.

Quality assessment of paediatric randomized controlled trials published in China from 1999 to 2022: a cross-sectional study

BackgroundRandomized controlled trials (RCTs) are usually the basis of evidence-based medicine, but whether the results of RCTs can be correctly translated into clinical practice depends on the quality of the literature reported. In this study, we evaluated the general characteristics and quality of paediatric RCTs published in China to provide evidence for the reporting of paediatric RCTs and their application in clinical practice.MethodsWe conducted a cross-sectional observational study of paediatric RCTs published in paediatric journals in China between January 1, 1999, and December 30, 2022. All RCTs that included children (younger than 18 years old) were retrieved, and the general characteristics of the RCTs were extracted and analysed. The quality of the RCTs was assessed by the Cochrane quality assessment protocol.ResultsAfter screening 20 available paediatric journals, 3545 RCTs were included for analysis. The average annual growth rate of the number of published paediatric RCTs from 1999 to 2022 was 7.8% (P = 0.005, R2 = 0.311). Most of the studies were carried out in East China [1148 (32.4%]; the centres of the RCTs were mainly single-centre [3453 (97.4%], and the interventions were mainly medication [2442 (68.9%)]. Comparing RCTs published in 2017–2022 with RCTs published in 1999–2004, the quality of RCTs significantly improved in terms of random sequence generation, allocation concealment, blinding participants and personnel, incomplete outcome data and selective outcome reporting. RCTs published in multiple centres from the Chinese Science Citation Database were identified, and the approval of the ethics committee was of better quality for all the analysed risk of bias items.ConclusionThe number and quality of paediatric RCTs reported in China have improved in recent years, but the overall quality was relatively low. Special attention should be given to allocation concealment and blinding outcome assessment, and dropouts, adverse effects and sample size calculations should be reported. Promoting government policies, strengthening the standardization of journal publishing and advancing the registration of clinical trials are feasible measures.

Group sequential design for time-to-event outcome with non-proportional hazards using the concept of relative time utilizing two different Weibull distributions

A group sequential design allows investigators to sequentially monitor efficacy and safety as part of interim testing in phase III trials. Literature is well developed in the case of continuous and binary outcomes, however, in case of trials with a time-to-event outcome, popular methods of sample size calculation often assume proportional hazards. In situations where the proportional hazards assumption is inappropriate as indicated by historical data, these popular methods are very restrictive. In this paper, a novel simulation-based group sequential design is proposed for a two-arm randomized phase III clinical trial with a survival endpoint for the non-proportional hazards scenario. By assuming that the survival times for each treatment arm follow two different Weibull distributions, the proposed method utilizes the concept of Relative Time to calculate the efficacy and safety boundaries at selected interim testing points. The test statistic used to generate these boundaries is asymptotically normal, allowing p-value calculation at each boundary. Many design features specific to time-to-event data can be incorporated with ease. Additionally, the proposed method allows the flexibility of having the accelerated failure time model and the proportional hazards model as constrained special cases. Real life applications are discussed demonstrating the practicality of the proposed method.

A Unified Theory of Acceptance and Use of Technology Assessment in Learning Resources Management and Development System

The platform for Learning Resource Management and Development System (LRMDS) has the potential to be helpful for learning. Teachers find support and resources from the learning portal of the Department of Education. This study focused on determining the acceptance of the Learning Resources Management Development System (LRMDS) as a learning resource portal using the Unified Theory of Acceptance and Use of Technology (UTAUT) model among EPP/TLE/TVL teachers in the Division of Iligan City. For the sample selection based on structures and items, Soper's (2024) a-priori sample size calculator for structural modeling was utilized. This calculator calculates the minimum need to identify desired effects for a structural equation model inquiry by considering variables, effect size, and power levels. The study was based on quantitative and qualitative research designs via demographic questionnaire based on the UTAUT theory model and the perception questions. Findings indicate that the effort expectancy and social influence have positive effects on behavior intentions and facilitating conditions; behavioral intentions also have positive effects on use behavior. However, Performance expectancy is not significant. Additionally, qualitative findings suggest that teachers believe the LRMDS can greatly improve teaching effectiveness when viewed as valuable and dependable, resulting in its effective use. Teachers generally consider the content provided by LRMDS to be relevant and sufficient. However, a significant issue is that some resources, particularly in TLE (Technology and Livelihood Education), are outdated, likely due to limited access to ready-made resources and sufficient learning materials. The findings of this study also suggest that enhancing LRMDS integration, communication and outreach efforts are recommended, including a training guide matrix to raise awareness of LRMDS benefits and address misconceptions through targeted campaigns, workshops, and peer sharing. Recommendations include improving knowledge management, simplifying user interfaces, informing teachers about support conditions, and implementing the training guide matrix in public schools to highlight the advantages of the LRMDS portal.

Understanding tightened muscle in knee osteoarthritis and the impacts of Fu's subcutaneous needling: A pilot trial with shear-wave elastography and near-infrared spectroscopy.

Given the scarce reports on the interplay between Fu's subcutaneous needling (FSN), tightened muscle, and therapeutic effects, we developed a clinical research protocol to synchronously collect data on clinical efficacy and muscle characteristics in patients with knee osteoarthritis, exploring the mechanism of FSN action. The primary aim was to assess the feasibility and safety of this protocol, guiding future trials and their sample size calculations. In this prospective, single-blind, self-controlled study, 19 patients with early to mid-stage unilateral knee osteoarthritis underwent FSN therapy on both knees over 1 week (4 sessions, every other day). We measured local elastic modulus, muscle thickness, blood flow volume, and oxygen consumption rate of bilateral vastus lateralis muscles using shear-wave elastography and near-infrared spectroscopy (NIRS) before and after the first and fourth treatments. Additionally, real-time NIRS indicators (oxygenated hemoglobin [O2Hb], deoxyhemoglobin [HHb], total hemoglobin [THb], and tissue saturation index [TSI]) were recorded during these treatments. Pain intensity (visual analogue scale [VAS]), functional status (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]), and active range of motion were evaluated before these treatments. All 19 participants completed the trial without serious adverse events. After 3 FSN treatments, significant changes were observed in VAS and WOMAC scores (VAS: P < .001; WOMAC: P < .001), and knee flexion (P < .001) and external rotation (P = .02), except for internal rotation. No meaningful significant differences were observed in muscle characteristics at baseline or between pre- and post-treatment periods. NIRS results during treatments indicated significant increases in local O2Hb and THb post-FSN therapy (First treatment: O2Hb: P = .005; THb: P = .006. Fourth treatment: O2Hb: P = .002; THb: P = .004); however, no significant increases were observed for HHb (First treatment: P = .06; Fourth treatment: P = .28). No linear correlation was found between therapeutic effects and changes in tightened muscle indices. FSN reduces pain and improves joint function in knee osteoarthritis, while also enhancing blood flow and oxygenation in the vastus lateralis muscle of the affected side. Further revisions of this protocol are warranted based on our insights.

The Prevalence of BRCA1 and BRCA2 Mutations in Breast Cancer Patients

Aim: Genetic mutations in BRCA1 and BRCA2 are crucial for breast cancer risk assessment and treatment planning. Methods: This prospective observational study at Jinnah Postgraduate Medical Centre, Pakistan, involved female breast cancer patients aged 18 or older. The sample size calculation was based on a 3.4% prevalence rate of BRCA mutations, aiming for a 95% confidence level. Data on demographic, clinical characteristics, and genetic testing for BRCA mutations were collected and analyzed using SPSS version 23. Results: Among the study participants, 10% exhibited BRCA1 or BRCA2 mutations. The majority were diagnosed at stage 3 tumor development, with invasive ductal carcinoma being the predominant histological type. No significant familial predisposition to breast cancer was noted among the majority. Educational status and ethnicity showed varying associations with BRCA mutation presence. Conclusion: The study highlights a modest incidence of BRCA mutations among Pakistani breast cancer patients, underscoring the importance of genetic testing for risk assessment and targeted treatment. The findings support the need for comprehensive genetic screening programs in Pakistan, considering the diverse demographic and clinical characteristics of the population. Keywords: BRCA mutations, breast cancer, genetic testing, Pakistan, risk assessment, targeted treatment.

Drains in Breast Reduction: How Good Is the Recommendation Not to Use Them?

A clinical practice guideline (CPG) from the American Society of Plastic Surgeons recommended not to use drains in breast reduction. This CPG was based on 3 randomized controlled trials (RCTs). The objective of this review was to double-check the methodological quality of the 3 RCTs. These RCTs were critically appraised using: (1) the "User's Guide to the Surgical Literature" checklist to critically appraise the methodological quality, (2) the CONSORT guidelines for reporting quality, and (3) the Cochrane risk-of-bias tool 2 (RoB 2) for risk of bias. Weaknesses were identified in all assessments for the 3 RCTs. Items with the poorest adherence in the "User's Guide" included: "Were patients stratified?," "Was follow-up complete?," and "Were all clinically important outcomes considered?" The overall adherence to the CONSORT reporting checklist across all 3 studies was moderate with 40.0%, 62.1%, and 48.3% adherence. All 3 RCTs had a similar low to moderate risk of bias, with no areas with a high risk of bias. None of the studies took into consideration a single critical outcome (such as major hematoma) and the outcome's minimally important difference as the basis for the sample size and power calculation of the study. All 3 RCTs additionally lacked clear reporting of treatment effect sizes or precision of estimates. Our re-examination of the evidence questions the recommendation of the CPG. We believe that the recommendation should have been: "We remain uncertain whether drains in breast reduction have a salutary effect." As such, we recommend that a methodologically robust RCT be conducted to resolve the question of whether drains should be used in breast reduction.

Working To-Get-There: Student and teacher relationship towards a meaningful teaching and learning Experience

The enhancement of a meaningful learning experience becomes more pronounced when positive relationships exist between teachers and students. Student-teacher relationships (STR) are intricately tied to the everyday scenarios prevalent in the current generation. They exert significant effects on student engagement, encompass common challenges that may impede the establishment of positive rapport, and are perceived to influence the actualization of a meaningful teaching and learning experience. Employing a convergent mixed-method approach, the study utilized an expert-validated interview protocol and survey questionnaire. Audio-taped semi-structured interviews and surveys among purposively selected (n=16) and randomly picked (n=250) Grade 10 students and teacher-participants computed through the Raosoft sample size calculator in Southville 5A Integrated National High School were performed. Based on the descriptive statistical tools and thematic analysis with themes validation through focus group discussion, the most common STR situations relate to collaborative, encouraging, and respectful affairs among students and teachers. The most common effects of STR on students’ engagement are linked to active participation, increased interest to learn, and improved self-confidence. Meanwhile, factors that hinder positive STR correlate with ineffective communication, poor classroom environment, and high teacher expectations. Further, positive STR impacts authentic learning, the realization of equity and equality, and the idea of learning from setbacks. To-Get-There and successfully achieve meaningful teaching-and-learning experiences, the study recommends ways to foster positive STR, addressing challenges, establishing effective communication including expectations, consistent provision of equal and equity opportunities, and the nurture of values among students and teachers such as empathy, respect, self-growth, and reflective thinking. Keywords: Convergent-parallel mixed research approach, Meaningful teaching-and-learning experiences, Student-teacher relationships, Binan City, Laguna, Philippine

Studying the Impact Of D.P.SL Model on Online Identity Management

This paper investigates online identities through social media language use, with a focus on classifying online identity within textual conversations. It sheds light on how Demographic (D) groups and Personality (P) impact the use of Social-Media Language (SL) for identity representation online. This study was conducted in 2023 when there were 4.76 billion social media users worldwide, making it essential to study how social media language is used in textual conversations to convey online identity. The study defines social media language as consisting of emoticons/emojis, abbreviations, and mixed language within textual conversations, which have become essential for expressing feelings and emotions during conversations. The D.P.SL based survey conducted for this work aimed to understand how demographic groups and personality are related to social media language. Based on the total number of social media user worldwide, 400 responses (required based on Cochran and Yamane’s formulae sample-size calculation) and the survey was distributed across various verified online survey exchange platforms. However, 406 responses were recorded with young people in age groups of 18-24 and 25-34 using social media language more as it has become a part of their social media habits. The study also found that emoticons/emojis and slang abbreviations with letter reduplication were quite common, making conversations lively and funny. Additionally, individuals whose primary language is not English use their native language but type in English for quick communication. Subsequent study is to be conducted using online mock group conversations between participating respondents to further understand correlations, causation, and concurrency on how ‘online identity’ is managed during online communications via social media language, its context of use, and polarity sentiment.

Hyperpure chlorine dioxide versus chlorhexidine in intra-oral halitosis (ODOR trial) – protocol of a double-blinded, double-arm, parallel non-inferiority pilot randomized controlled trial

IntroductionIntra-oral halitosis (IOH) is the most common type of bad breath; its consequences impair quality of life. However, evidence-based treatment protocols and guidelines are lacking. Our aim is to investigate the effectiveness of chlorine dioxide as an applicable complementary treatment modality in IOH after tongue cleaning.Methods and analysisThe ODOR trial will be a single-center, double-blinded, parallel-group, double-armed pilot randomized controlled trial with a non-inferiority design. The efficacy of hyperpure chlorine dioxide will be compared to chlorhexidine mouthwash. We plan to investigate the short-term effects of the intervention over a 3-h period. The primary endpoint will be changes in organoleptic test scores. At the end of the pilot investigation of the first 30 patients each, sample size calculation will be performed. If feasible, the investigators will continue the study by enrolling more patients.Trial registrationThe trial has been registered at ClinicalTrials.gov (NCT06219226).

Effects of Hydrotherapy on the Management of Childbirth and Its Outcomes-A Retrospective Cohort Study.

The main objective of this study was to generate further evidence on maternal and birth outcomes associated with the use of hydrotherapy during labor, specifically aiming to describe the effects of water immersion during all stages of labor (first, second, and third) on women. A retrospective cohort study was carried out on a random sample of women who gave birth at the Costa del Sol Hospital between January 2010 and December 2020. The calculated sample size was 377 women and the data were extracted from their partograms. After data extraction, two groups were formed: one group used hydrotherapy during childbirth (n = 124), while the other group included women who did not use hydrotherapy during the childbirth process (n = 253). The results highlight significant differences in pain perception, analgesia use, types of labor, and delivery times between the two groups. Women who did not use hydrotherapy reported higher pain perception, with a median (IQR) of 8 (7-9) on a numerical scale, compared to a median (IQR) of 6 (5-7) for the hydrotherapy group. Furthermore, the group without hydrotherapy required epidural analgesia in 40% of cases, while in the hydrotherapy group, it was only necessary in 20%. In terms of the type of delivery, the hydrotherapy group had more spontaneous vaginal deliveries compared to the non-hydrotherapy group, which had more operative vaginal deliveries. The overall duration of labor was longer in the hydrotherapy group, especially in women who arrived at the hospital late in labor. Hydrotherapy is associated with a longer time to delivery. Women with a higher pain tolerance tend to opt for hydrotherapy instead of epidural analgesia.

A Cross-Sectional Descriptive Study: Proportion of Authenticity and Complete Product Information of FarmaTag Hologram on Registered Pharmaceutical Products among Selected Mainstream Medicines’ Sellers in the State of Sabah (ProvoS)

FarmaTag Hologram is a two-dimensional QR code sticker that is required on all registered pharmaceutical products (RPP) in Malaysia. By scanning the QR code, the authenticity and product information of the hologram are displayed. However, FarmaTag holograms with incomplete product information may be susceptible to being misused by manufacturers/distributors/suppliers (MDS) for different pharmaceutical products, unregistered pharmaceutical products, or counterfeit products. In addition to misusing, these callous acts may lead to consumer distrust, doubt, and a lack of confidence in the authenticity of RPP. A cross-sectional descriptive study was conducted among Selected Mainstream Medicines’ Sellers in the State of Sabah between January 2022 and September 2022 to evaluate the proportion of authenticity and complete product information of FarmaTag Hologram on registered pharmaceutical products (RPP) available among selected Mainstream Medicines’ Sellers (MMS) in the state of Sabah. The total sample size was 5048 registered pharmaceutical products. There was no formal sample size calculation performed because this was the first study to explore this topic. All samples being selected from MMS were authentic (100%), which included 31.7% (n = 1600) from private medical clinics, 18.8% (n = 948), from retail pharmacies, and 49.5% (n = 2500) from Non-Pharmacy Drug Stores (NPDS). However, only 268 (5.3%) samples were found to have complete product information. The findings of this study provide preliminary information to relevant authorities on the authenticity and complete product information of FarmaTag Hologram on registered pharmaceutical products among selected MMS in the state of Sabah.

KNOWLEDGE OF NUTRITIONAL SUPPLEMENTS AMONG UNIVERSITY STUDENTS OF PESHAWAR, KHYBER PAKHTUNKHWA, PAKISTAN

OBJECTIVE: To find out the knowledge of students, and the frequency and reasons behind nutritional supplement use among university students of Peshawar MATERIALS AND METHODS A descriptive cross-sectional study was conducted using a convenient sampling method. Data was collected from September 2022 to February 2023. The sample size was approximately 383, determined using the WHO sample size calculator, and a prevalence of 50%. Students aged 18-25 years were included in the study. RESULTS Results showed that among university students, 58.5% use dietary supplements. 41.17% of males and 70% of females were found using dietary supplements, with a higher prevalence among females. The reasons for using dietary supplements varied, with 34.46% using them to improve diet, 19.84% to treat medical conditions, 20.89% to enhance the immune system, and 7.89% for weight management. Additionally, some students believed that dietary supplements were essential for their health (71.28%), while others did not consider them essential (18.02%). The majority of participants agreed that these supplements have beneficial effects, such as improving cognitive ability, preventing illnesses, aiding in recovery, enhancing athletic performance, promoting skin and hair health, building muscle mass, and improving appetite CONCLUSION It was found that the use of nutritional supplements was high among students, especially females. The primary reasons for using these supplements included improving diet and enhancing the immune system. Keywords: Nutritional supplements, University students, diet, immune system

TEACHERS’ CONFLICT-INDUCING ATTITUDES AND THEIR REPERCUSSIONS ON STUDENTS’ PSYCHOLOGICAL HEALTH

This purpose of the study was to determine the influence of teachers conflict-inducing attitudes on the students psychological health. A total of 110 public elementary school teachers teaching in Tarragona District, Davao Oriental Division were identified through Tabachnick and Fidell (2007) calculation of sample size. The study utilized a descriptive-correlation design. Mean, Pearson r, and regression analysis were used as statistical tools of the study. Results revealed on the extent of teachers conflict inducing attitudes in terms of Teacher Incivility were sometimes evident, in terms of Teacher Discrimination was sometimes evident, in terms of University Resources was oftentimes evident. On the Students Psychological Health was always evident. Clearly, the findings inferred a strong significant relationship between teachers conflict-inducing attitudes and students psychological health. Based on the result of the analysis, the teachers conflict inducing attitudes domains namely: teacher incivility, teacher discrimination, and university resources significantly influences students psychological health by registering a p-value of less than.000 in the level of significance. Further, the result indicates that for every unit increase in the three domains of teachers conflict inducing attitudes predictors, the students psychological health will increase by 3.894 holding other factors constant. Conflict inducing attitudes significantly influenced students psychological health. Hence, this study recommends teachers should be encouraged professional development programs that target specific conflict-inducing attitudes, leading to personal growth and improved professional practice. Teachers should engage in training and workshops that help them develop stronger interpersonal skills and conflict resolution strategies. KEYWORDS: Teachers conflict inducing attitudes, psychological health, teacher incivility, teacher discrimination, university resources

Comparison of plasma and neuroimaging biomarkers to predict cognitive decline in non-demented memory clinic patients.

Plasma biomarkers of Alzheimer's disease (AD) pathology, neurodegeneration, and neuroinflammation are ideally suited for secondary prevention programs in self-sufficient persons at-risk of dementia. Plasma biomarkers have been shown to be highly correlated with traditional imaging biomarkers. However, their comparative predictive value versus traditional AD biomarkers is still unclear in cognitively unimpaired (CU) subjects and with mild cognitive impairment (MCI). Plasma (Aβ42/40, p-tau181, p-tau231, NfL, and GFAP) and neuroimaging (hippocampal volume, centiloid of amyloid-PET, and tau-SUVR of tau-PET) biomarkers were assessed at baseline in 218 non-demented subjects (CU = 140; MCI = 78) from the Geneva Memory Center. Global cognition (MMSE) was evaluated at baseline and at follow-ups up to 5.7 years. We used linear mixed-effects models and Cox proportional-hazards regression to assess the association between biomarkers and cognitive decline. Lastly, sample size calculations using the linear mixed-effects models were performed on subjects positive for amyloid-PET combined with tau-PET and plasma biomarker positivity. Cognitive decline was significantly predicted in MCI by baseline plasma NfL (β=-0.55), GFAP (β=-0.36), hippocampal volume (β = 0.44), centiloid (β=-0.38), and tau-SUVR (β=-0.66) (all p < 0.05). Subgroup analysis with amyloid-positive MCI participants also showed that only NfL and GFAP were the only significant predictors of cognitive decline among plasma biomarkers. Overall, NfL and tau-SUVR showed the highest prognostic values (hazard ratios of 7.3 and 5.9). Lastly, we demonstrated that adding NfL to the inclusion criteria could reduce the sample sizes of future AD clinical trials by up to one-fourth in subjects with amyloid-PET positivity or by half in subjects with amyloid-PET and tau-PET positivity. Plasma NfL and GFAP predict cognitive decline in a similar manner to traditional imaging techniques in amyloid-positive MCI patients. Hence, even though they are non-specific biomarkers of AD, both can be implemented in memory clinic workups as important prognostic biomarkers. Likewise, future clinical trials might employ plasma biomarkers as additional inclusion criteria to stratify patients at higher risk of cognitive decline to reduce sample sizes and enhance effectiveness.

The PAncreatic Surgery Composite Endpoint PACE – Development and Validation of a Clinically Relevant Endpoint Requiring Lower Sample Sizes

Abstract Background Single endpoints in prospective and randomized studies have become impractical due to their low frequency and the marginal benefit of new interventions. Aims To provide a composite endpoint in pancreatic surgery. Methods Data from prospective studies were used to develop (n=1273) and validate (n=544) a composite endpoint based on postoperative pancreatic fistula, post-pancreatectomy hemorrhage as well as reoperation and reinterventions. All patients had pancreatectomies of different extents. The association of the developed PAncreatic surgery Composite Endpoint (PACE) with prolonged length of hospital stay (LOS) &amp;gt;75th percentile and mortality were assessed. A single-institution database was used for external validation (n = 2666). Sample size calculations were made for single outcomes and the composite endpoint. Results In the internal validation cohort, the PACE demonstrated an AUC of 78.0%, a sensitivity of 90.4% and a specificity of 67.6% in predicting a prolonged LOS. In the external cohort, the AUC was 76.9%, the sensitivity 73.8% and the specificity 80.1%. The 90-day mortality rate was significantly different for patients with a positive versus a negative PACE both in the development and internal validation cohort (5.1% vs 0.9%; P&amp;lt; 0.001), as well as in the external validation cohort (8.5% vs 1.2%, P&amp;lt; 0.001). The PACE enabled sample size reductions of up to 80.5% compared to single outcomes. Conclusion The PACE performed well in predicting prolonged hospital stays and can be used as a standardized and clinically relevant endpoint for future prospective trials enabling lower sample sizes and therefore improved feasibility compared to single outcome parameters.

Has Coca-Cola treatment become the first-line therapy for gastric bezoars, both in general and specifically for western countries?

Phytobezoars is a rare disease and less common in Western countries. The stomach is the primary site for these formations, and endoscopic treatment involving fragmentation and extraction has traditionally been the most effective approach. However, medical treatments using enzymatic and chemical agents, such as cellulase and Coca-Cola, aimed at dissolving the bezoars, have also been utilized, showing varying degrees of resolution success. Notably, the oral dissolution treatment with Coca-Cola has emerged as a promising, simpler, and more cost-effective method. The study by Liu et al represents an important step in clinical research on this topic, despite some limitations that need addressing for a more comprehensive understanding of its findings. Key considerations for future research include sample size calculation, endoscopic procedure details, outpatient vs. inpatient treatment, and detailed cost calculations. The study's exclusions, such as patients with upper gastric surgery, phytobezoars older than 14 d, and cases of gastroparesis, limit its applicability to broader populations, especially in Western countries. Given the promising outcomes of the Coca-Cola treatment, it's advocated as a first-line therapy for phytobezoars. Nonetheless, further research is essential to overcome these limitations. However special situations such as perforation or small bowel obstruction will require surgical treatment.

Multilevel Intervention Stepped Wedge Designs (MLI-SWDs)

Multilevel interventions (MLIs) hold promise for reducing health inequities by intervening at multiple types of social determinants of health consistent with the socioecological model of health. In spite of their potential, methodological challenges related to study design compounded by a lack of tools for sample size calculation inhibit their development. We help address this gap by proposing the Multilevel Intervention Stepped Wedge Design (MLI-SWD), a hybrid experimental design which combines cluster-level (CL) randomization using a Stepped Wedge design (SWD) with independent individual-level (IL) randomization. The MLI-SWD is suitable for MLIs where the IL intervention has a low risk of interference between individuals in the same cluster, and it enables estimation of the component IL and CL treatment effects, their interaction, and the combined intervention effect. The MLI-SWD accommodates cross-sectional and cohort designs as well as both incomplete (clusters are not observed in every study period) and complete observation patterns. We adapt recent work using generalized estimating equations for SWD sample size calculation to the multilevel setting and provide an R package for power and sample size calculation. Furthermore, motivated by our experiences with the ongoing NC Works 4 Health study, we consider how to apply the MLI-SWD when individuals join clusters over the course of the study. This situation arises when unemployment MLIs include IL interventions that are delivered while the individual is unemployed. This extension requires carefully considering whether the study interventions will satisfy additional causal assumptions but could permit randomization in new settings.

Sample size calculation for comparing two screening tests when the gold standard is missing at random.

Sample size formulas have been proposed for comparing two sensitivities (specificities) in the presence of verification bias under a paired design. However, the existing sample size formulas involve lengthy calculations of derivatives and are too complicated to implement. In this paper, we propose alternative sample size formulas for each of three existing tests, two Wald tests and one weighted McNemar's test. The proposed sample size formulas are more intuitive and simpler to implement than their existing counterparts. Furthermore, by comparing the sample sizes calculated based on the three tests, we can show that the three tests have similar sample sizes even though the weighted McNemar's test only use the data from discordant pairs whereas the two Wald tests also use the additional data from accordant pairs.