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1.
BMC Med Res Methodol ; 23(1): 267, 2023 11 11.
Article in English | MEDLINE | ID: mdl-37951877

ABSTRACT

BACKGROUND: Planning the design of a new trial comparing two treatments already in a network of trials with an a-priori plan to estimate the effect size using a network meta-analysis increases power or reduces the sample size requirements. However, when the comparison of interest is between a treatment already in the existing network (old treatment) and a treatment that hasn't been studied previously (new treatment), the impact of leveraging information from the existing network to inform trial design has not been extensively investigated. We aim to identify the most powerful trial design for a comparison of interest between an old treatment A and a new treatment Z, given a fixed total sample size. We consider three possible designs: a two-arm trial between A and Z ('direct two-arm'), a two-arm trial between another old treatment B and Z ('indirect two-arm'), and a three-arm trial among A, B, and Z. METHODS: We compare the standard error of the estimated effect size between treatments A and Z for each of the three trial designs using formulas. For continuous outcomes, the direct two-arm trial always has the largest power, while for a binary outcome, the minimum variances among the three trial designs are conclusive only when [Formula: see text]. Simulation studies are conducted to demonstrate the potential for the indirect two-arm and three-arm trials to outperform the direct two-arm trial in terms of power under the condition of [Formula: see text]. RESULTS: Based on the simulation results, we observe that the indirect two-arm and three-arm trials have the potential to be more powerful than a direct two-arm trial only when [Formula: see text]. This power advantage is influenced by various factors, including the risk of the three treatments, the total sample size, and the standard error of the estimated effect size from the existing network meta-analysis. CONCLUSIONS: The standard two-arm trial design between two treatments in the comparison of interest may not always be the most powerful design. Utilizing information from the existing network meta-analysis, incorporating an additional old treatment into the trial design through an indirect two-arm trial or a three-arm trial can increase power.


Subject(s)
Clinical Trials as Topic , Research Design , Humans , Computer Simulation , Network Meta-Analysis , Sample Size
2.
BMC Med Res Methodol ; 23(1): 79, 2023 04 03.
Article in English | MEDLINE | ID: mdl-37013490

ABSTRACT

BACKGROUND: In network meta-analysis, estimation of a comparative effect can be performed for treatments that are connected either directly or indirectly. However, disconnected trial networks may arise, which poses a challenge to comparing all available treatments of interest. Several modeling approaches attempt to compare treatments from disconnected networks but not without strong assumptions and limitations. Conducting a new trial to connect a disconnected network can enable calculation of all treatment comparisons and help researchers maximize the value of the existing networks. Here, we develop an approach to finding the best connecting trial given a specific comparison of interest. METHODS: We present formulas to quantify the variation in the estimation of a particular comparative effect of interest for any possible connecting two-arm trial. We propose a procedure to identify the optimal connecting trial that minimizes this variation in effect estimation. RESULTS: We show that connecting two treatments indirectly might be preferred to direct connection through a new trial, by leveraging information from the existing disconnected networks. Using a real network of studies on the use of vaccines in the treatment of bovine respiratory disease (BRD), we illustrate a procedure to identify the best connecting trial and confirm our findings via simulation. CONCLUSION: Researchers wishing to conduct a connecting two-arm study can use the procedure provided here to identify the best connecting trial. The choice of trial that minimizes the variance of a comparison of interest is network dependent and it is possible that connecting treatments indirectly may be preferred to direct connection.


Subject(s)
Research Design , Animals , Cattle , Humans , Network Meta-Analysis , Computer Simulation
3.
BMC Med Res Methodol ; 22(1): 299, 2022 11 22.
Article in English | MEDLINE | ID: mdl-36418960

ABSTRACT

BACKGROUND: A critical step in trial design is determining the sample size and sample allocation to ensure the proposed study has sufficient power to test the hypothesis of interest: superiority, equivalence, or non-inferiority. When data are available from prior trials and leveraged with the new trial to answer the scientific questions, the value of society's investment in prior research is increased. When prior information is available, the trial design including the sample size and allocation should be adapted accordingly, yet the current approach to trial design does not utilize such information. Ensuring we maximize the value of prior research is essential as there are always constraints on resources, either physical or financial, and designing a trial with adequate power can be a challenge. METHODS: We propose an approach to increasing the power of a new trial by incorporating evidence from a network meta-analysis into the new trial design and analysis. We illustrate the methodology through an example network meta-analysis, where the goal is to identify the optimal allocation ratio for the new three-arm trial, which involves the reference treatment, the new treatment, and the negative control. The primary goal of the new trial is to show that the new treatment is non-inferior to the reference treatment. It may also be of interest to know if the new treatment is superior to the negative control. We propose an optimal treatment allocation strategy which is derived from minimizing the standard error of the log odds ratio estimate of the comparison of interest. We conducted a simulation study to assess the proposed methods to design a new trial while borrowing information from the existing network meta-analysis and compare it to even allocation methods. RESULTS: Using mathematical derivation and simulations, we document that our proposed approach can borrow information from a network meta-analysis to modify the treatment allocation ratio and increase the power of the new trial given a fixed total sample size or to reduce the total sample size needed to reach a desired power. CONCLUSIONS: When prior evidence about the hypotheses of interest is available, the traditional equal allocation strategy is not the most powerful approach anymore. Our proposed methodology can improve the power of trial design, reduce the cost of trials, and maximize the utility of prior investments in research.


Subject(s)
Network Meta-Analysis , Humans , Odds Ratio , Sample Size , Computer Simulation
4.
J Dairy Sci ; 105(11): 8594-8608, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36055845

ABSTRACT

Clinical trials are a valuable study design for evaluating interventions when it is ethical and feasible for investigators to randomly allocate study animals to intervention groups. Researchers may choose to evaluate the comparative efficacy of intervention groups for their effect on outcomes that are relevant to the specific objectives of their trial. However, the results across multiple trials on the same intervention and with the same outcome should be considered when making decisions on whether to use an intervention, because the results of a single trial are subject to sampling error and do not reflect all biological variability. The objective of this review was to provide an overview of important concepts when selecting intervention groups and outcomes within a randomized controlled trial, and when building a body of evidence for intervention efficacy across multiple trials. Empirical evidence is presented to highlight that integrating and interpreting the efficacy of an intervention across trials is hindered by a lack of replication of interventions across trials. Inconsistency in the outcomes and their measurement among trials also limits the ability to build a body of evidence for the efficacy of interventions. The development of core outcome sets for specific topic areas in dairy science, updated as necessary, may improve consistency across trials and aid in the development of a body of evidence for evidence-based decision-making.


Subject(s)
Clinical Trials, Veterinary as Topic , Research Design , Animals , Cattle
5.
J Dairy Sci ; 105(7): 6155-6163, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35570046

ABSTRACT

Research allows for the discovery of new knowledge and is integral to evidence-based decision-making. However, research is only useful if it is available. The aim of this study was to explore publication and accessibility of full-text reports for controlled trials (experimental studies) conducted in dairy cattle. We determined the proportion of controlled trials presented as abstracts at the 2015 Joint Annual Meeting of the American Dairy Science Association and the American Society of Animal Science or the 2015 American Association of Bovine Practitioners Annual Conference that were subsequently published. Factors associated with publication or non-publication in a peer-reviewed journal were evaluated using risk ratios. For trials that were subsequently published, we compared the sample size, numerical results, and inference between the conference abstract and the subsequent publication. Approximately half of the trials (177 out of 380) reported at conferences were subsequently published. Source conference, whether the conference abstract results were described as preliminary, whether there was at least one positive outcome, author affiliation, whether the trial involved deliberate disease induction, and total sample size were not strongly associated with subsequent publication. For trials that were published, the sample size differed between the conference proceedings and full publications for 22%, the numerical results differed in 29%, and the inference differed for 11%. We also evaluated whether trials included in 9 recent systematic reviews were in English and were available without subscription or cost. Of the 390 trials included in recent systematic reviews, approximately 40% were available only through subscription or access fee. These results suggest that publication and accessibility of research results is suboptimal, representing an area of wastage in dairy cattle research. Researchers should ensure that they publish the results of trials comprehensively in searchable publications, even if the results are not novel or do not detect expected differences, and, when possible, make the results available freely.


Subject(s)
Research Report , Animals , Cattle , Sample Size , United States
6.
Vet Surg ; 51(4): 557-567, 2022 May.
Article in English | MEDLINE | ID: mdl-35383972

ABSTRACT

OBJECTIVE: To evaluate the use of mesenchymal stem cells (MSCs), autologous conditioned serum (ACS), platelet-rich plasma (PRP), and autologous protein solution (APS) for the treatment of equine musculoskeletal disease by diplomates of the American College of Veterinary Surgery (ACVS), and American College of Veterinary Sports Medicine and Rehabilitation (ACVSMR). STUDY DESIGN: Cross-sectional study. SAMPLE POPULATION: Diplomates (n = 423). METHODS: An email link was sent to ACVS and ACVMR diplomates. A survey contained 59 questions regarding demographics, as well as indications, frequency, adverse effects, and limitations of use. Responses were analyzed using Fisher's exact test. RESULTS: One hundred and fifty four surveys were analyzed. Years in practice and type of practice were not associated with biologic therapy use. PRP was the most used therapy (120/137; 87.5%). PRP and MSCs were most often administered intralesionally while ACS and APS were most often administered intra-articularly. ACS (50/104; 48.1%) treatment was repeated commonly within 2 weeks of initial injection. MSCs (39/90; 43.3%) and PRP (38/100; 38%) were commonly repeated 1-2 months after initial injection and APS was typically repeated >4 months after initial injection (21/53; 39.6%). Local inflammation and expense were the most common adverse effect and limitation of use. CONCLUSION: Diplomates most commonly utilized PRP and MSC intralesionally for soft-tissue injuries, and ACS and ACP intra-articularly for joint injury. Protocols for repeated administration varied widely. Local inflammation was a clinical concern with the use of biologics. CLINICAL SIGNIFICANCE: Biologic therapies are used commonly by ACVS and ACVSMR diplomates for soft tissue and joint disease.


Subject(s)
Horse Diseases , Musculoskeletal Diseases , Platelet-Rich Plasma , Animals , Biological Therapy/veterinary , Cross-Sectional Studies , Horse Diseases/therapy , Horses , Humans , Inflammation/veterinary , Musculoskeletal Diseases/therapy , Musculoskeletal Diseases/veterinary , Surveys and Questionnaires
7.
BMC Med Res Methodol ; 21(1): 186, 2021 09 20.
Article in English | MEDLINE | ID: mdl-34544374

ABSTRACT

BACKGROUND: The emergence of antimicrobial resistance across populations is a global threat to public health. Surveillance programs often monitor human and animal populations to evaluate trends of emergence in these populations. Many national level antibiotic resistance surveillance programs quantify the proportion of resistant bacteria as a means of monitoring emergence and control measures. The reason for monitoring these different populations are many, including interest in similar changes in resistance which might provide insight into emergence and control options. METHODS: In this research, we developed a method to quantify the correlation in antimicrobial resistance across populations, for the conventionally unnoticed mean shift of the susceptible bacteria. With the proposed Bayesian latent class mixture model with censoring and multivariate normal hierarchy, we address several challenges associated with analyzing the minimum inhibitory concentration data. RESULTS: Application of this approach to the surveillance data from National Antimicrobial Resistance Monitoring System led to a detection of positive correlation in the central tendency of azithromycin resistance of the susceptible populations from Salmonella serotype Typhimurium across food animal and human populations. CONCLUSIONS: Our proposed approach has been shown to be accurate and superior to the commonly used naïve estimation by simulation studies. Further implementation of this Bayesian model could serve as a useful tool to indicate the co-existence of antimicrobial resistance, and potentially a need of clinical intervention.


Subject(s)
Anti-Bacterial Agents , Drug Resistance, Bacterial , Animals , Anti-Bacterial Agents/pharmacology , Bayes Theorem , Humans , Microbial Sensitivity Tests
8.
J Dairy Sci ; 102(6): 4759-4771, 2019 Jun.
Article in English | MEDLINE | ID: mdl-31005322

ABSTRACT

Reproducibility is an essential element of the scientific process, and it requires clear and complete reporting of study design, conduct, and analysis. In the human and animal health literature, incomplete reporting is associated with biased effect estimates. Moreover, incomplete reporting precludes knowledge synthesis and undervalues the resources allocated to the primary research. The Reporting Guidelines for Randomized Controlled Trials for Livestock and Food Safety (REFLECT) statement, published in 2010, is a checklist developed by expert consensus to provide guidance on what study elements should be reported in any intervention trial (designed experiment) involving livestock. The Journal of Dairy Science (JDS) has recently endorsed the use of reporting guidelines. To assess the status of reporting of controlled experiments in JDS and to provide a baseline for future comparison, we evaluated the reporting of 18 items from the REFLECT statement checklist in a sample of 137 controlled trials published in JDS in 2017. Two reviewers independently screened titles and abstracts for relevance and then evaluated a sample of 120 papers reporting controlled trials (experimental studies involving at least one intervention and one comparison or control group), using yes or no questions. Although some items, such as treatment details and statistical analysis, were well reported, other areas, including sample size justification, allocation concealment, blinding, study flow, baseline data, and ancillary analyses, were often not reported or were incompletely described. This work highlights the need for authors and reviewers to take advantage of guidelines and checklists for reporting. Adherence to reporting guidelines can help improve the completeness of reporting of research, expedite and better inform the peer-review process, increase clarity for the reader, and allow for knowledge synthesis, such as meta-analysis, all of which serve to increase the value of the work conducted.


Subject(s)
Clinical Trials, Veterinary as Topic , Editorial Policies , Guidelines as Topic , Animals , Cross-Sectional Studies , Research Design , Research Report/standards
9.
Risk Anal ; 39(10): 2237-2258, 2019 10.
Article in English | MEDLINE | ID: mdl-31039285

ABSTRACT

The inclusion of deep tissue lymph nodes (DTLNs) or nonvisceral lymph nodes contaminated with Salmonella in wholesale fresh ground pork (WFGP) production may pose risks to public health. To assess the relative contribution of DTLNs to human salmonellosis occurrence associated with ground pork consumption and to investigate potential critical control points in the slaughter-to-table continuum for the control of human salmonellosis in the United States, a quantitative microbial risk assessment (QMRA) model was established. The model predicted an average of 45 cases of salmonellosis (95% CI = [19, 71]) per 100,000 Americans annually due to WFGP consumption. Sensitivity analysis of all stochastic input variables showed that cooking temperature was the most influential parameter for reducing salmonellosis cases associated with WFGP meals, followed by storage temperature and Salmonella concentration on contaminated carcass surface before fabrication. The input variables were grouped to represent three main factors along the slaughter-to-table chain influencing Salmonella doses ingested via WFGP meals: DTLN-related factors, factors at processing other than DTLNs, and consumer-related factors. The evaluation of the impact of each group of factors by second-order Monte Carlo simulation showed that DTLN-related factors had the lowest impact on the risk estimate among the three groups of factors. These findings indicate that interventions to reduce Salmonella contamination in DTLNs or to remove DTLNs from WFGP products may be less critical for reducing human infections attributable to ground pork than improving consumers' cooking habits or interventions of carcass decontamination at processing.


Subject(s)
Lymph Nodes/microbiology , Red Meat/microbiology , Salmonella Food Poisoning/epidemiology , Salmonella Infections/epidemiology , Salmonella/isolation & purification , Animals , Humans , Risk Assessment , Salmonella Food Poisoning/prevention & control , Swine
10.
Vet Ophthalmol ; 18(2): 147-51, 2015 Mar.
Article in English | MEDLINE | ID: mdl-24674456

ABSTRACT

OBJECTIVE: To describe Schirmer tear test I and rebound tonometry findings in healthy bovine calves. ANIMALS STUDIED: Thirty-three clinically normal dairy breed calves of mean (SD) 11 (1.1) weeks (range, 9.3-13.3 weeks) of age were evaluated. PROCEDURES: A Schirmer tear test I was performed on each eye followed by tonometry, using a TonoVet(®) without topical anesthesia. We report means (SD) and statistical analysis of data for each assay. RESULTS: For both Schirmer tear test (STT) I and tonometry, significant differences were not found between fellow eyes (P = 0.1536 and P = 0.83, respectively). The mean (SD) STT I value of all eyes was 20.4 (5.0) mm/min (range, 9-34 mm/min) while the mean (SD) intraocular pressure (IOP) value of all eyes was 15.2 (5.2) mmHg (range, 7-25 mmHg). CONCLUSIONS: This study reports normal data for the STT I and rebound tonometry in calves. This data may be useful in complete ophthalmic examinations of cattle, guiding diagnosis of glaucoma, uveitis, and keratoconjunctivitis sicca. However, results of these diagnostic modalities must be interpreted in light of clinical signs, given the wide range of normal values obtained in this study.


Subject(s)
Cattle/physiology , Tears/metabolism , Tonometry, Ocular/veterinary , Animals , Female , Male
11.
BMC Musculoskelet Disord ; 15: 54, 2014 Feb 24.
Article in English | MEDLINE | ID: mdl-24564877

ABSTRACT

BACKGROUND: To evaluate feasibility and potential effectiveness of a patient decision aid (PtDA) for patients and a preference report for surgeons to reduce wait times and improve decision quality in patients with osteoarthritis considering total knee replacement. METHODS: A prospective two-arm pilot randomized controlled trial. Patients with osteoarthritis were eligible if they understood English and were referred for surgical consultation about an initial total knee arthroplasty at a Canadian orthopaedic joint assessment clinic. Patients were randomized to the PtDA intervention or usual education. The intervention was an osteoarthritis PtDA for patients and a one-page preference report summarizing patients' clinical and decisional data for their surgeon. The main feasibility outcomes were rates of recruitment and questionnaire completion; the preliminary effectiveness outcomes were wait times and decision quality. RESULTS: Of 180 patients eligible for surgical consultation, 142 (79%) were recruited and randomized to the PtDA intervention (n = 71) or usual education (n = 71). Data collection yielded a 93% questionnaire completion rate with less than 1% missing items. After one year, 13% of patients remained on the surgical wait list. The median time from referral to being off the wait list (censored using survival analysis techniques) was 33.4 weeks for the PtDA group (n = 69, 95% CI: 26.0, 41.4) and 33.0 weeks for usual education (n = 71, 95% CI: 26.1, 39.9). Patients exposed to the PtDA had higher decision quality based on knowledge (71% versus 47%; p < 0.0001) and quality decision being an informed choice that is consistent with their values for option outcomes (56.4% versus 25.0%; p < 0.001). CONCLUSIONS: Recruitment of patients with osteoarthritis considering surgery and data collection were feasible. As some patients remained on the surgical waiting list after one year, follow-up should be extended to two years. Patients exposed to the PtDA achieved higher decision quality compared to those receiving usual education but there was no difference in wait for surgery. TRIALS REGISTRATION: ClinicalTrials.Gov NCT00743951.


Subject(s)
Arthroplasty, Replacement, Knee , Decision Support Techniques , Osteoarthritis, Knee/surgery , Patient Education as Topic , Patient Preference , Waiting Lists , Aged , Arthroplasty, Replacement, Knee/psychology , Choice Behavior , Feasibility Studies , Female , Health Knowledge, Attitudes, Practice , Humans , Male , Middle Aged , Osteoarthritis, Hip/complications , Osteoarthritis, Knee/psychology , Pamphlets , Patient Participation , Pilot Projects , Practice Guidelines as Topic , Prospective Studies , Referral and Consultation , Surveys and Questionnaires , Teaching Materials , Tertiary Care Centers , Video Recording
12.
BMC Med Inform Decis Mak ; 14: 112, 2014 Dec 12.
Article in English | MEDLINE | ID: mdl-25495552

ABSTRACT

BACKGROUND: Over 100 trials show that patient decision aids effectively improve patients' information comprehension and values-based decision making. However, gaps remain in our understanding of several fundamental and applied questions, particularly related to the design of interactive, personalized decision aids. This paper describes an interdisciplinary development process for, and early field testing of, a web-based patient decision support research platform, or virtual decision lab, to address these questions. METHODS: An interdisciplinary stakeholder panel designed the web-based research platform with three components: a) an introduction to shared decision making, b) a web-based patient decision aid, and c) interactive data collection items. Iterative focus groups provided feedback on paper drafts and online prototypes. A field test assessed a) feasibility for using the research platform, in terms of recruitment, usage, and acceptability; and b) feasibility of using the web-based decision aid component, compared to performance of a videobooklet decision aid in clinical care. RESULTS: This interdisciplinary, theory-based, patient-centered design approach produced a prototype for field-testing in six months. Participants (n = 126) reported that: the decision aid component was easy to use (98%), information was clear (90%), the length was appropriate (100%), it was appropriately detailed (90%), and it held their interest (97%). They spent a mean of 36 minutes using the decision aid and 100% preferred using their home/library computer. Participants scored a mean of 75% correct on the Decision Quality, Knowledge Subscale, and 74 out of 100 on the Preparation for Decision Making Scale. Completing the web-based decision aid reduced mean Decisional Conflict scores from 31.1 to 19.5 (p < 0.01). CONCLUSIONS: Combining decision science and health informatics approaches facilitated rapid development of a web-based patient decision support research platform that was feasible for use in research studies in terms of recruitment, acceptability, and usage. Within this platform, the web-based decision aid component performed comparably with the videobooklet decision aid used in clinical practice. Future studies may use this interactive research platform to study patients' decision making processes in real-time, explore interdisciplinary approaches to designing web-based decision aids, and test strategies for tailoring decision support to meet patients' needs and preferences.


Subject(s)
Consumer Health Information/methods , Decision Support Techniques , Osteoarthritis, Knee/therapy , Patient Preference , Patient-Centered Care/methods , Adolescent , Adult , Aged , Aged, 80 and over , Decision Making , Decision Support Systems, Clinical , Feasibility Studies , Female , Humans , Internet , Male , Medical Informatics/methods , Middle Aged , New Hampshire , Osteoarthritis, Knee/psychology , User-Computer Interface , Young Adult
13.
Vet Ophthalmol ; 17(4): 305-8, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24674385

ABSTRACT

OBJECTIVE: To evaluate corneal sensitivity as measured by the corneal touch threshold in healthy bovine calves. ANIMALS STUDIED: Twelve clinically normal male calves with predominantly Holstein genetics and a median age of 76.5 days (range, 67-92 days). PROCEDURES: Corneal touch threshold (CTT) of the central cornea was measured in both eyes of each calf using a Cochet-Bonnet aesthesiometer. RESULTS: The mean ± standard deviation corneal touch threshold of all eyes was 1.33 ± 1.1 g/mm(2) (range, 0.62-66.15 g/mm(2) ), corresponding to a filament length of 34.56 ± 8.02 mm (range, 14-47.5 mm). There was no significant difference between fellow eyes. CONCLUSIONS: Cochet-Bonnet aesthesiometry was well tolerated in all 12 calves using a modified head restraint. Calves in this study may have a relatively sensitive central cornea compared to adult cattle and some other species; however, wide variation among individuals and eyes may be possible. Studies utilizing larger calf populations are necessary to establish reference ranges.


Subject(s)
Cattle/physiology , Cornea/physiology , Touch/physiology , Animals , Male
14.
Front Vet Sci ; 11: 1402981, 2024.
Article in English | MEDLINE | ID: mdl-38835899

ABSTRACT

This study summarizes a presentation at the symposium for the Calvin Schwabe Award for Lifetime Achievement in Veterinary Epidemiology and Preventive Medicine, which was awarded to the first author. As epidemiologists, we are taught that "correlation does not imply causation." While true, identifying causes is a key objective for much of the research that we conduct. There is empirical evidence that veterinary epidemiologists are conducting observational research with the intent to identify causes; many studies include control for confounding variables, and causal language is often used when interpreting study results. Frameworks for studying causes include the articulation of specific hypotheses to be tested, approaches for the selection of variables, methods for statistical estimation of the relationship between the exposure and the outcome, and interpretation of that relationship as causal. When comparing observational studies in veterinary populations to those conducted in human populations, the application of each of these steps differs substantially. The a priori identification of exposure-outcome pairs of interest are less common in observational studies in the veterinary literature compared to the human literature, and prior knowledge is used to select confounding variables in most observational studies in human populations, whereas data-driven approaches are the norm in veterinary populations. The consequences of not having a defined exposure-outcome hypotheses of interest and using data-driven analytical approaches include an increased probability of biased results and poor replicability of results. A discussion by the community of researchers on current approaches to studying causes in observational studies in veterinary populations is warranted.

15.
Avian Dis ; 57(1): 22-8, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23678725

ABSTRACT

While real-time-polymerase chain reaction (RT PCR) has been used as a rapid test for detection of Salmonella Enteritidis in recent years, little research has been done to assess the feasibility of pooling poultry environmental samples with a Salmonella Enteritidis-specific RT PCR assay. Therefore the objective of this study was to compare RT PCR Salmonella Enteritidis detection in individual and pooled (in groups of two, three, and four) poultry environmental drag swab samples to traditional cultural methods. The drag swabs were collected from poultry facilities previously confirmed positive for Salmonella Enteritidis and were cultured according to National Poultry Improvement Plan guidelines. Initial, Salmonella Enteritidis-specific RT PCR assay threshold cycle cutoff values of < or = 36, < or = 30, and < or = 28 were evaluated in comparison to culture. The average limit of detection of the RT PCR assay was 2.4 x 10(3) colony-forming units (CFUs)/ml, which corresponded to an average threshold cycle value of 36.6. Before enrichment, samples inoculated with concentrations from 10(2) to 10(5) CFUs/ml were detected by RT PCR, while after enrichment, samples inoculated from 10(0) to 10(5) CFUs/ml were detected by RT PCR. Threshold cycle cutoff values were used in the subsequent field trial from which Salmonella Enteritidis was cultured in 7 of 208 environmental samples (3.4%). Individual samples were 99.0%, 100%, and 100% in agreement with the RT PCR at threshold cycle (C(t)) cutoff values of < or = 36, < or = 30, and < or = 28 respectively. The agreement for pooled samples also followed the same trend with highest agreement at C(t) < or = 28 (pool of 2 = 100.0%, pool of 3 = 100.0%, pool of 4 = 100.0%), midrange agreement at C(t) < or = 30 (pool of 2 = 99.0%, pool of 3 = 100.0%, pool of 4 = 100.0%), and lowest agreement at C(t) < or = 36 (pool of 2 = 98.1%, pool of 3 = 97.1%, pool of 4 = 98.1%). In conclusion, regardless of the level of pooling after tetrathionate enrichment, sensitivity was very good, and results would be comparable to what would have been found with individual culture or individual RT PCR at C(t) < or = 36.


Subject(s)
Chickens/microbiology , Colony Count, Microbial/methods , Environmental Microbiology , Real-Time Polymerase Chain Reaction/methods , Salmonella enteritidis/isolation & purification , Animals , Housing, Animal , Limit of Detection , ROC Curve , Salmonella enteritidis/genetics , Salmonella enteritidis/growth & development , Sensitivity and Specificity
16.
Front Pharmacol ; 14: 1157708, 2023.
Article in English | MEDLINE | ID: mdl-37188261

ABSTRACT

Introduction: To achieve higher power or increased precision for a new trial, methods based on updating network meta-analysis (NMA) have been proposed by researchers. However, this approach could potentially lead to misinterpreted results and misstated conclusions. This work aims to investigate the potential inflation of type I error risk when a new trial is conducted only when, based on a p-value of the comparison in the existing network, a "promising" difference between two treatments is noticed. Methods: We use simulations to evaluate the scenarios of interest. In particular, a new trial is to be conducted independently or depending on the results from previous NMA in various scenarios. Three analysis methods are applied to each simulation scenario: with the existing network, sequential analysis and without the existing network. Results: For the scenario that the new trial will be conducted only when a promising finding (p-value <5%) is indicated by the existing network, the type I error risk increased dramatically (38.5% in our example data) when analyzed with the existing network and sequential analysis. The type I error is controlled at 5% when analyzing the new trial without the existing network. Conclusion: If the intention is to combine a trial result with an existing network of evidence, or if it is expected that the trial will eventually be included in a network meta-analysis, then the decision that a new trial is performed should not depend on a statistically "promising" finding indicated by the existing network.

17.
PLoS One ; 18(12): e0296020, 2023.
Article in English | MEDLINE | ID: mdl-38128003

ABSTRACT

Randomized clinical trials (RCTs) are designed for measuring the effectiveness of the treatments and testing a hypothesis regarding the relative effect between two or more treatments. Trial designers are often interested in maximizing power when the total sample size is fixed or minimizing the required total sample size to reach a pre-specified power. One approach to maximizing power proposed by previous researchers is to leverage prior evidence using meta-analysis (NMA) to inform the sample size determination of a new trial. For example, researchers may be interested in designing a two-arm trial comparing treatments A and B which are already in the existing trial network but do not have any direct comparison. The researchers' intention is to incorporate the result into an existing network for meta-analysis. Here we develop formulas to address these options and use simulations to validate our formula and evaluate the performance of different analysis methods in terms of power. We also implement our proposed method into the R package OssaNMA and publish an R Shiny app for the convenience of the application. The goal of the package is to enable researchers to readily adopt the proposed approach which can improve the power of an RCT and is therefore resource-saving. In the R Shiny app, We also provide the option to include the cost of each treatment which would enable researchers to compare the total treatment cost associated with each design and analysis approach. Further, we explore the effect of allocation to treatment group on study power when the a priori plan is to incorporate the new trial result into an existing network for meta-analysis.


Subject(s)
Network Meta-Analysis , Sample Size , Randomized Controlled Trials as Topic
18.
Front Vet Sci ; 10: 1137774, 2023.
Article in English | MEDLINE | ID: mdl-37065218

ABSTRACT

Background: Reporting of clinical trials conducted in client- and shelter-owned dog and cat populations is not optimal, which inhibits the ability to assess the reliability and validity of trial findings and precludes the ability to include some trials in evidence synthesis. Objective: To develop a reporting guideline for parallel group and crossover trials that addresses the unique features and reporting requirements for trials conducted in client- and shelter-owned dog and cat populations. Design: Consensus statement. Setting: Virtual. Participants: Fifty-six experts from North America, the United Kingdom, Europe, and Australia working in academia, government (research and regulatory agencies), industry, and clinical veterinary practice. Methods: A steering committee created a draft checklist for reporting criteria based upon the CONSORT statement and the CONSORT extensions for reporting of abstracts and crossover trials. Each item was presented to the expert participants and was modified and presented again until >85% of participants were in agreement about the inclusion and wording of each item in the checklist. Results: The final PetSORT checklist consists of 25 main items with several sub-items. Most items were modifications of items contained in the CONSORT 2010 checklist or the CONSORT extension for crossover trials, but 1 sub-item pertaining to euthanasia was created de novo. Conclusion: The methods and processes used to develop this guideline represent a novel departure from those used to create other reporting guidelines, by using a virtual format. The use of the PetSORT statement should improve reporting of trials conducted in client- and shelter-owned dogs and cats and published in the veterinary research literature.

19.
Front Vet Sci ; 10: 1137781, 2023.
Article in English | MEDLINE | ID: mdl-37065227

ABSTRACT

Well-designed randomized controlled trials (RCTs) provide the best evidence of the primary research designs for evaluating the effectiveness of interventions. However, if RCTs are incompletely reported, the methodological rigor with which they were conducted cannot be reliably evaluated and it may not be possible to replicate the intervention. Missing information also may limit the reader's ability to evaluate the external validity of a trial. Reporting guidelines are available for clinical trials in human healthcare (CONSORT), livestock populations (REFLECT), and preclinical experimental research involving animals (ARRIVE 2.0). The PetSORT guidelines complement these existing guidelines, providing recommendations for reporting controlled trials in pet dogs and cats. The rationale and scientific background are explained for each of the 25 items in the PetSORT reporting recommendations checklist, with examples from well-reported trials.

20.
Dis Colon Rectum ; 55(9): 970-5, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22874604

ABSTRACT

BACKGROUND: Previous research in colorectal cancer has focused on survival, recurrence, and functional outcomes. Few have assessed the decisional needs of patients or the information patients are retaining from the informed consent process. OBJECTIVES: The aims of this study were to describe the decisional needs of adult patients with rectal cancer when deciding on the surgical treatment of their disease and to identify gaps in patients' recollection of the informed consent discussion. DESIGN: Face-to-face interviews were conducted with the use of a questionnaire based on the validated Ottawa Decision Support Framework Needs Assessment. SETTING: This study was performed at a university-based academic Cancer Assessment Center, in Ottawa, Ontario, Canada. PATIENTS: Adult patients with rectal cancer treated with low anterior resection or abdominoperineal resection were included. MAIN OUTCOME MEASURES: The primary outcomes measured were patients' knowledge and understanding of decision and their decisional needs. RESULTS: Thirty patients were interviewed between November 2009 and July 2010. Eighty percent were male, with a median age of 65. None of the patients perceived having a choice of surgical options. When questioned about the main outcomes of rectal cancer surgery, 47% could not recall a preoperative discussion of risks to bowel function, 47% could not recall a preoperative discussion of risks to sexual function, and 57% could not recall a preoperative discussion of risks to urinary function. Patients would like information regarding functional outcomes, body image, and the immediate postoperative period. A minority of patients desire information regarding cure rate, need for a second surgery, or the ability of surgery to treat their symptoms. Patients would like information that is portable and trusted by their health care team that they can review at their own time. LIMITATIONS: To avoid introducing decisional conflict before surgery, patients were interviewed at the first postoperative visit. Preoperative informed consent discussions were not standardized. CONCLUSION: Despite a comprehensive educational oncology pathway, patients retain little of the informed consent discussion. This study highlights the dichotomy between the outcomes that surgeons and patients value most. The results of this study will guide future efforts to improve informed consent.


Subject(s)
Comprehension , Decision Making , Digestive System Surgical Procedures/psychology , Informed Consent/psychology , Mental Recall , Rectal Neoplasms/surgery , Adult , Aged , Aged, 80 and over , Female , Health Knowledge, Attitudes, Practice , Humans , Male , Middle Aged , Rectal Neoplasms/psychology , Rectum/surgery
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