Sample size requirements and the cost of a randomized clinical trial with repeated measurements

1986 ◽  
Vol 5 (6) ◽  
pp. 663-667 ◽  
Author(s):  
Daniel A. Bloch
Keyword(s):  
Clinical Trial ◽  
Sample Size ◽  
Randomized Clinical Trial ◽  
Repeated Measurements ◽  
The Cost

Citation Analysis of Articles about Hand Surgery Published in Orthopaedic and Hand Surgery Journals

2019 ◽  
Vol 24 (01) ◽  
pp. 36-44 ◽  
Author(s):  
Yuki Fujihara ◽  
Nasa Fujihara ◽  
Michiro Yamamoto ◽  
Hitoshi Hirata
Keyword(s):  
Clinical Trial ◽  
Sample Size ◽  
Randomized Clinical Trial ◽  
Study Design ◽  
Comparative Studies ◽  
Clinical Studies ◽  
Hand Surgery ◽  
The Impact ◽  
Larger Sample ◽  
Surgery Journals

Background: To date, little is known about the characteristics of highly cited studies in hand surgery compared with other orthopaedic subspecialties. We aimed to assess the position of hand surgery within the orthopedic surgery literature. Methods: We conducted a bibliographic analysis using the Web of Science database to review 1,568 articles published between January 2012 and December 2012 in 4 relevant general orthopedic and 2 hand surgery journals. We used the number of citations within 3 years of publication to measure the impact of each paper. To analyze prognostic factors using logistic regression analysis, we extracted data on orthopedic subspecialty, published journal, location of authorship, and type of study for all articles. For clinical studies, we also recorded details on study design and sample size. Results: Of eligible hand surgery articles (n = 307), the majority (62%) were case reports/series. Only 19% were comparative studies, comprising a significantly smaller proportion of comparative studies from other subspecialties in general orthopedic journals. Systematic reviews/meta-analyses generated a significantly higher number of average citations, whereas educational reviews were consistently cited less frequently than other study types (14.9 and 6.1 average citations, respectively). Being published in the Journal of Bone and Joint Surgery, American volume, having authorship in North America or Europe and Australia, focusing on subspecialties like hip & knee, sports, or shoulder, utilizing a comparative or randomized clinical trial study design, and having a larger sample size increased the odds of receiving more citations. Conclusions: Clinical studies related to hand surgery published in general orthopedic journals are most often of lower quality study design. Having a larger sample size or using a comparative study or randomized clinical trial design can improve the quality of study and may ultimately increase the impact factor of hand surgery journals.

scholarly journals Clinical Outcomes After Anterior Cruciate Ligament Reconstruction: A Meta-Analysis of Autograft Versus Allograft Tissue

2009 ◽  
Vol 2 (1) ◽  
pp. 56-72 ◽  
Author(s):  
Lisa M. Tibor ◽  
Joy L. Long ◽  
Peter L. Schilling ◽  
Ryan J. Lilly ◽  
James E. Carpenter ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Anterior Cruciate Ligament ◽  
Sample Size ◽  
Randomized Clinical Trial ◽  
Acl Reconstruction ◽  
Outcome Measures ◽  
Cruciate Ligament ◽  
Allograft Reconstruction ◽  
Kt 1000 ◽  
Anterior Cruciate

Background: Clinical outcomes of autograft and allograft anterior cruciate ligament (ACL) reconstructions are mixed, with some reports of excellent to good outcomes and other reports of early graft failure or significant donor site morbidity. Objective: To determine if there is a difference in functional outcomes, failure rates, and stability between autograft and allograft ACL reconstructions. Data Sources: Medline, Cochrane Central Register of Controlled Trials (Evidence Based Medicine Reviews Collection), Cochrane Database of Systematic Reviews, Web of Science, CINAHL, and SPORTDiscus were searched for articles on ACL reconstruction. Abstracts from annual meetings of the American Academy of Orthopaedic Surgeons, American Orthopaedic Society for Sports Medicine, and Arthroscopy Association of North America were searched for relevant studies. Study Selection: Inclusion criteria for studies were as follows: primary unilateral ACL injuries, mean patient age less than 41 years, and follow-up for at least 24 months postreconstruction. Exclusion criteria for studies included the following: skeletally immature patients, multiligament injuries, and publication dates before 1990. Data Extraction: Joint stability measures included Lachman test, pivot-shift test, KT-1000 arthrometer assessment, and frequency of graft failures. Functional outcome measures included Tegner activity scores, Cincinnati knee scores, Lysholm scores, and IKDC (International Knee Documentation Committee) total scores. Results: More than 5000 studies were identified. After full text review of 576 studies, 56 were included, of which only 1 directly compared autograft and allograft reconstruction. Allograft ACL reconstructions were more lax when assessed by the KT-1000 arthrometer. For all other outcome measures, there was no statistically significant difference between autograft and allograft ACL reconstruction. For all outcome measures, there was strong evidence of statistical heterogeneity between studies. The sample size necessary for a randomized clinical trial to detect a difference between autograft and allograft reconstruction varied, depending on the outcome. Conclusions: With the current literature, only KT-1000 arthrometer assessment demonstrated more laxity with allograft reconstruction. A randomized clinical trial directly comparing allograft to autograft ACL reconstruction is warranted, but a multicenter study would be required to obtain an adequate sample size.

scholarly journals Effect of Non Surgical Periodontal Therapy on Salivary Ph in Periodontal Disease: A Randomized Clinical Trial

2021 ◽  
pp. 12-17
Author(s):  
Stuti Gupta ◽  
. Shradha ◽  
Ejya Sharma ◽  
Himani Sharma ◽  
Saransh Srivastava ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Sample Size ◽  
Randomized Clinical Trial ◽  
Periodontal Therapy ◽  
Statistical Testing ◽  
Research Centre ◽  
Clinical Parameters ◽  
College Hospital ◽  
Significant Difference ◽  
Salivary Ph

The aim of the study is to assess the effect of pre and post Non Surgical Periodontal Therapy on Salivary pH in patients suffering with Chronic Periodontits. Patients reporting to the Department of Periodontics, I.T.S Dental College, Hospital & Research Centre, Greater Noida, Uttar Pradesh are included in the study. It is a randomized clinical trial where patients are randomized into two groups of Generalized Chronic Gingivitis and Generalized Chronic Periodontitis. The study are performed with the Sample size of 30 patients and 2 months Period were included. Unstimulated Saliva is collected at the first visit when patient reports to the OPD for NSPT. Clinical Parameters are recorded and NSPT is performed for the patient. Post 14 days of the treatment, saliva is collected and analysed for pH and clinical parameters are recorded again. pH is determined using a pH meter. Data is collected and statistically interpreted. The statistical testing to be used in this study are Mann Whitney U Test, Chi- square test and Paired t-test. There was statistically significant difference in plaque index, gingival index and oral hygiene index between two groups. There was a definite reduction in pH post SRP but it was statistically non significant due to relatively smaller sample size. Further research is required to substantiate the results for the same.

scholarly journals Performance of repeated measures of (1-3)-β-D-glucan, mannan antigen and anti-mannan antibodies for the diagnosis of Invasive Candidiasis in ICU patients: a preplanned ancillary analysis of the EMPIRICUS Randomized Clinical Trial

2021 ◽  
Author(s):  
Claire Dupuis ◽  
Clément Le bihan ◽  
Daniele Maubon ◽  
Laure Calvet ◽  
Stéphane Ruckly ◽  
...  
Keyword(s):  
Clinical Trial ◽  
High Risk ◽  
Randomized Clinical Trial ◽  
Invasive Candidiasis ◽  
Repeated Measures ◽  
Cumulative Risk ◽  
Empirical Therapy ◽  
Multiple Organ ◽  
Repeated Measurements ◽  
Increased Risk

Abstract Background We aimed to assess the prognostic value of repeated measurements of serum (1-3)-β-D-glucan(BDG), mannan-antigen(mannan-Ag) and anti-mannan antibodies(anti-mannan-Ab) on the occurrence of Invasive Candidiasis(IC) in a high risk non-immunocompromised population. Methods It is a preplanned ancillary analysis of the EMPIRICUS Randomized Clinical Trial, including non-immunocompromised critically ill patients with ICU-acquired sepsis, multiple Candida colonization, multiple organ failure, exposed to broad-spectrum antibacterial agents. BDG(>80 and >250 pg/mL), mannan-Ag(>125 pg/mL) and anti-mannan-Ab(>10 AU) were collected repeatedly. We used cause-specific hazard models. Biomarkers were assessed at baseline in the whole cohort(cohort 1). Baseline covariates and/or repeated measurements and/or increased of biomarkers were then studied in the subgroup of patients who were still alive at day 3 and free of IC(cohort 2). Results 234 patients were included and 215 were still alive and free of IC at day 3. IC developed in 27(11.5%) and day-28 mortality was 29.1%. Finally, only BDG>80 pg/ml at inclusion was associated with an increased risk of IC(CSHR[IC]=4.67, CI95% 1.61-13.5) but not death (CSHR[death]=1.20, CI95% 0.71-2.02). Conclusions Among high risk patients, a first measurement of BDG over 80 pg/mL was strongly associated with the occurrence of IC. Neither a cut off-of 250 pg/mL nor repeated measurements of fungal biomarkers seemed to be useful to predict the occurrence of IC. The cumulative risk of IC in the placebo group if BDG>80 pg/ml was 25.39% questioning about the potential interest of empirical therapy in this subgroup.

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