scholarly journals Replication and contradiction of highly cited research papers in psychiatry: 10-year follow-up

2015 ◽  
Vol 207 (4) ◽  
pp. 357-362 ◽  
Author(s):  
Aran Tajika ◽  
Yusuke Ogawa ◽  
Nozomi Takeshima ◽  
Yu Hayasaka ◽  
Toshi A. Furukawa
Keyword(s):  
Sample Size ◽  
Small Sample Size ◽  
Total Sample ◽  
Small Sample ◽  
Research Papers ◽  
Effective Interventions ◽  
Mean Differences ◽  
Larger Sample ◽  
Highly Cited

BackgroundContradictions and initial overestimates are not unusual among highly cited studies. However, this issue has not been researched in psychiatry.AimsTo assess how highly cited studies in psychiatry are replicated by subsequent studies.MethodWe selected highly cited studies claiming effective psychiatric treatments in the years 2000 through 2002. For each of these studies we searched for subsequent studies with a better-controlled design, or with a similar design but a larger sample.ResultsAmong 83 articles recommending effective interventions, 40 had not been subject to any attempt at replication, 16 were contradicted, 11 were found to have substantially smaller effects and only 16 were replicated. The standardised mean differences of the initial studies were overestimated by 132%. Studies with a total sample size of 100 or more tended to produce replicable results.ConclusionsCaution is needed when a study with a small sample size reports a large effect.

scholarly journals Chloroquine and Hydroxychloroquine could be an Available Weapons to Treat COVID-19 Associated Pneumonia

2020 ◽  
pp. 52-60
Author(s):  
Nehad J. Ahmed
Keyword(s):  
Clinical Trials ◽  
Angiotensin Converting Enzyme ◽  
Sample Size ◽  
Small Sample Size ◽  
Small Sample ◽  
Google Scholar ◽  
Converting Enzyme ◽  
Larger Sample

Aims: This study aims to review the efficacy of chloroquine and hydroxychloroquine to treat coronavirus disease 2019 (COVID-19) associated pneumonia. Methodology: This review includes searching Google scholar for publications about the use of hydroxychloroquinein the treatment of COVID-19 using the words of (Covid-19) AND hydroxychloroquine. Results: Chloroquine and hydroxychloroquine have proven effective in treating coronavirus in China in vitro, but till now only few clinical trials are available and these trials were conducted on a small sample size of the patients. The efficacy of chloroquine and hydroxychloroquine is mainly due to its effect on angiotensin-converting enzyme II (ACE2). Conclusion: The use of chloroquine and hydroxychloroquine could be very promising but more trials are needed that include larger sample size and more data are required about the comparison between chloroquine and hydroxychloroquine with other antivirals.

Abstract W P20: A Model to Calculate the Expected Treatment Effect in Acute Endovascular Stroke Trials

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Maarten G Lansberg ◽  
Robin Lemmens ◽  
Soren Christensen ◽  
Nishant K Mishra ◽  
Gregory W Albers
Keyword(s):  
Literature Review ◽  
Sample Size ◽  
Endovascular Therapy ◽  
Treatment Effect ◽  
Small Sample Size ◽  
Small Sample ◽  
Absolute Difference ◽  
Sample Size Calculations ◽  
And Control ◽  
Larger Sample

Background: Recent trials have shown no benefit of endovascular therapy. This may, in part, be explained by inaccurate estimates of the treatment effect used in the sample size calculations of these trials. A predictive model which includes variables that modify the expected treatment effect might yield more accurate estimates, and could be valuable in the design of future acute stroke trials. Methods: We conducted a literature review to obtain estimates of parameters that are associated with good functional outcome (GFO) following recanalization. We developed a model to estimate the treatment effect in endovascular stroke trials and applied this model to two recently published endovascular stroke trials. Results: We estimated a 40% absolute difference in the proportion of GFO (mRS 0-2 at 90 days) associated with reperfusion in patients with ICA or M1 occlusions who have a substantial ischemic penumbra at baseline. To estimate the effect size in trials, this value was multiplied by: 1) the proportion of patients undergoing endovascular therapy in the active treatment arm; 2) the proportion of patients with occlusions of the ICA or MCA-M1; 3) the proportion of patients with a substantial penumbra and a DWI lesion <50mL; and 4) the absolute difference in the proportion of patients with reperfusion, defined as TICI 2B-3, between the endovascular treatment and control arms. Based on literature review we assumed a reperfusion rate of 20% in the control arms of IMS III and MR Rescue, a 50% prevalence of patients with substantial penumbra and DWI lesions<50 mL in IMS III, and a 75% prevalence in the penumbral arms of MR Rescue. Based on these model inputs, a 2.2% increase in GFO with endovascular therapy was expected in IMS III, which closely matches the observed 2.1% increase. For MR Rescue, the model predicted a 1.5% increase in GFO with endovascular therapy. Considering the small sample size, this equates to 0.5 additional patients with GFO which closely matches the observed result of 3 fewer patients with GFO. Conclusion: A simple model shows promise for estimating the treatment effect of endovascular stroke trials. It may be useful for the design of future trials and could lead to different inclusion criteria or larger sample sizes compared to the recently conducted studies.

eHealth Interventions for Fruit and Vegetable Intake: A Meta-Analysis of Effectiveness

2019 ◽  
Vol 46 (6) ◽  
pp. 947-959 ◽  
Author(s):  
Norma Patricia Rodriguez Rocha ◽  
Hyekyeong Kim
Keyword(s):  
Fruits And Vegetables ◽  
Vegetable Intake ◽  
Small Sample Size ◽  
Meta Analysis ◽  
Small Sample ◽  
Risk Of Bias ◽  
Healthy Population ◽  
Effective Interventions ◽  
Minimum Number ◽  
Mean Differences

Background. An adequate intake of fruits and vegetables (FVI) has shown benefits for reduced risk of manifesting chronic diseases. Thus, development of effective interventions to promote FVI is paramount. Aim. To assess the effectiveness of eHealth interventions for FVI targeted to healthy population, in comparison with control groups, and identify the moderators contributing to their effectiveness. Method. A database search was conducted in April 2016 and July 2018 using MEDLINE, PsycINFO, ERIC, Google Scholar, SciELO, and RISS, yielding 19 eligible studies. Risk of bias was assessed using Cochrane’s Risk of Bias Tool. Random-effects model was used to calculate effect sizes (ES) by weighted standardized mean differences. Results. This meta-analysis includes 19 studies and 6,894 participants. The most common eHealth tool used was Internet-based interventions ( n = 10). Most of studies were conducted in adults ( n = 11), followed by children ( n = 4), and adolescents ( n = 4). The minimum number of behavior change techniques (BCTs) used was one, and the maximum seven. The overall ES was small (0.26, p < .001), favoring eHealth interventions. The between-studies heterogeneity was large ( I2 = 62.77%, p < .001). Subgroup analyses showed that the components with larger ES were tailored interventions (0.27, p < .001), computer-based interventions (0.44, p < .001), and use of ≥7 BCTs (0.42, p < .001). Discussion. All studies showed a positive ES favoring interventions. Large heterogeneity could be explained in part by the number of BCTs and type of eHealth tool used. Nonetheless, more concrete evidence regarding other intervention components effectiveness was limited by small sample size. Conclusion. The use of eHealth tools for the improvement of FVI showed to be more effective compared with nonintervention and interventions not using these technologies. Nonetheless, more research is needed to determine the specific combination of intervention components that could translate into larger effectiveness.

scholarly journals Surgically accelerated orthodontic techniques and periodontal response: a systematic review

2020 ◽  
Vol 42 (6) ◽  
pp. 635-642 ◽  
Author(s):  
Umar Rekhi ◽  
Raisa Queiroz Catunda ◽  
Monica Prasad Gibson
Keyword(s):  
Systematic Review ◽  
High Risk ◽  
Sample Size ◽  
Orthodontic Treatment ◽  
Small Sample Size ◽  
Small Sample ◽  
Risk Of Bias ◽  
Long Term Follow Up

Summary Background Reduction in orthodontic treatment time is gaining popularity due to patient demands. Several new techniques of acceleratory orthodontic treatment have been introduced to effectively treat the malocclusion in a shorter time period with minimal adverse effects. Objective The objective of this systematic review is to critically evaluate the potential effect of accelerated surgically assisted orthodontic techniques on periodontal tissues. Materials and methods Electronic databases used to perform the search were Medline (Ovid), EMBASE, PubMed, Scopus, Cochrane, Google Scholar, and hand searching of the literature was also performed. Selection criteria Only randomized control trials (RCTs) that assessed the relationship between accelerated surgically assisted orthodontic techniques and its effects on periodontium were included. Data collection and analysis The Joanna Briggs Institute (JBI) critical appraisal checklist tool (2016) was used to assess the finally selected studies. Among these studies, five evaluated corticotomy-facilitated orthodontics, two tested accelerated tooth movement with piezocision, one compared corticotomy-facilitated orthodontics with piezocision, and one studied the effects of periodontally accelerated osteogenic orthodontics. The duration of these studies was relatively short and had moderate to high risk of bias. Results Literature search identified 225 records from 5 databases and 50 articles from the partial grey literature (Google scholar) search. Finally, nine eligible RCTs were included in the review. Limitations Most of the included studies were of a high risk of bias due to high experimental heterogeneity and small sample size. Long-term follow-up of the periodontal response to these interventions was also lacking. Conclusions There is an absence of evidence considering the lack of long-term follow-up and small sample size therefore, the results of this review should be carefully interpreted. Implications Due to the need for more studies with less risk of bias, these techniques should be implemented in dental practice with caution. With stronger evidence, the study may be confirmed to provide quicker desired results for orthodontic patients. Registration This study protocol was not registered. Funding No funding was obtained for this systematic review.

The Impact of Three Gross Irn Bru on an Out-Patient Clinic for Depressed Men

1992 ◽  
Vol 20 (1) ◽  
pp. 73-78
Author(s):  
Jacqueline M. Atkinson ◽  
Denise A. Coia
Keyword(s):  
Sample Size ◽  
Multidisciplinary Team ◽  
Small Sample Size ◽  
Small Sample ◽  
Patient Relationship ◽  
Methodological Issues ◽  
Clinical Behaviour ◽  
Methodological Problems ◽  
The Impact

Using an ABA design, the impact of the unexpected delivery of Irn Bru to an out-patient clinic for depressed men was investigated using the Montgomery-Åsberg scale for depression. A significant improvement in both behaviour and affect was seen immediately, some benefit still showing at one month follow-up. The effect of the procedure on the multidisciplinary team is also discussed. Some methodological issues, including small sample size are explored. Despite the methodological problems the serious element of the study points to the important impact of unexpected, non-therapeutic elements on clinical behaviour, possibly as a result of the challenge to the therapist-patient relationship.

scholarly journals Lineage analysis of human papillomavirus type 39 in cervical samples of Iranian women

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Neda Hosseini ◽  
Zabihollah Shoja ◽  
Arash Arashkia ◽  
Amir-Hossein Khodadadi ◽  
Somayeh Jalilvand
Keyword(s):  
Sample Size ◽  
Small Sample Size ◽  
Small Sample ◽  
Long Control Region ◽  
E6 Gene ◽  
Sequence Variations ◽  
Geographical Regions ◽  
Hpv Types ◽  
Almost All ◽  
Larger Sample

Abstract Background The data with regards to the regional variants of distinct HPV types is of great value. Accordance with this, this study aimed to investigate the sequence variations of E6 gene and long control region of HPV 39 among normal, premalignant and malignant cervical samples in order to characterize the frequent HPV 39 variants circulating in Tehran, Iran. Methods In total, 70 cervical samples (45 normal, 16 premalignant, and 9 malignant samples) infected with HPV 39 were analyzed by nested-PCR and sequencing. Results Our results revealed that all samples belonged to A lineage. Almost all sequences (98.6%) were classified in A1 sublineage and only one sample (1.4%) was A2 sub lineage. Conclusions Our findings showed that lineages A, sublineage A1, is dominant in Tehran, Iran. However, the small sample size was the most important limitations of this study. Further studies with larger sample size from different geographical regions of Iran are necessary to estimate the pathogenicity risk of HPV 39 variants in this population.

scholarly journals Tools for Ergonomic Intervention: The Development and Analysis of a Cost Calculator

2020 ◽  
Vol 64 (1) ◽  
pp. 465-469
Author(s):  
Derek Stephens ◽  
Diana J. Schwerha
Keyword(s):  
Decision Making ◽  
Sample Size ◽  
Small Sample Size ◽  
Small Sample ◽  
Quality Data ◽  
Sample Sizes ◽  
System Usability ◽  
The Mean ◽  
Larger Sample ◽  
Ergonomic Intervention

The purpose of this study was to determine if safety professionals can use an ergonomic intervention costing calculator, which integrates performance and quality data into the costing matrix, to increase communication and better of decision making for the company. The sample size included 9 participants, which included four safety managers, four EHS managers, and one HR generalist. Results showed that all participants found the calculator very useful, well integrated, and it increased communication across the company. The mean System Usability Score (SUS) score was 82, which is rated as a perfectly acceptable software for use. Recommendations from this study include adding some additional features to the calculator, increasing awareness and availability of the calculator, and conducting further analysis using larger sample sizes. Limitations in this study include small sample size and limited interventions that were tested.

scholarly journals Standardized mean differences cause funnel plot distortion in publication bias assessments

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Peter-Paul Zwetsloot ◽  
Mira Van Der Naald ◽  
Emily S Sena ◽  
David W Howells ◽  
Joanna IntHout ◽  
...  
Keyword(s):  
Sample Size ◽  
Publication Bias ◽  
Small Sample Size ◽  
Small Sample ◽  
Mean Difference ◽  
Funnel Plot ◽  
Funnel Plots ◽  
Mean Differences ◽  
Meta Analyses ◽  
Positive Results

Meta-analyses are increasingly used for synthesis of evidence from biomedical research, and often include an assessment of publication bias based on visual or analytical detection of asymmetry in funnel plots. We studied the influence of different normalisation approaches, sample size and intervention effects on funnel plot asymmetry, using empirical datasets and illustrative simulations. We found that funnel plots of the Standardized Mean Difference (SMD) plotted against the standard error (SE) are susceptible to distortion, leading to overestimation of the existence and extent of publication bias. Distortion was more severe when the primary studies had a small sample size and when an intervention effect was present. We show that using the Normalised Mean Difference measure as effect size (when possible), or plotting the SMD against a sample size-based precision estimate, are more reliable alternatives. We conclude that funnel plots using the SMD in combination with the SE are unsuitable for publication bias assessments and can lead to false-positive results.

scholarly journals Mindfulness Based Specific Phobia Intervention: A Pilot Study of Dissociated Ego State Resolution

2020 ◽  
Vol 39 (1-2) ◽  
Author(s):  
Genine Smith ◽  
Glenn Hartelius
Keyword(s):  
Pilot Study ◽  
Small Sample Size ◽  
Research Question ◽  
Specific Phobia ◽  
Small Sample ◽  
Medical Assistance ◽  
Individual Session ◽  
Post Test ◽  
Larger Sample

This pilot study was designed to investigate the efficacy of a mindfulness based intervention for the treatment of needle phobia. The research question was whether one session of the dissociated ego state [DES] trauma release intervention would result in significant and durable release of needle phobia. It was hypothesized that the process tested in this study may reduce needle phobia by locating, identifying, and engaging with a dissociated aspect of the psyche developed from earlier trauma. Six participants who self reported fear of needles and resulting avoidance of medical assistance completed one 60-minute, individual session of a mindfulness based protocol for the release of specific phobia. After the DES intervention session, all participants but one reported reduced subjective units of distress while holding the needle against their skin: reduction of 61% post-test, 71% at 3-month follow-up, and 70% at 6-month follow up. Results at 6-month follow-up were statistically significant despite small sample size. Future investigations should involve larger sample sizes, populations drawn from various settings, more facilitators and a randomized, waitlist group.

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