scholarly journals Matching the Statistical Model to the Research Question for Dental Caries Indices with Many Zero Counts

2017 ◽  
Vol 51 (3) ◽  
pp. 198-208 ◽  
Author(s):  
John S. Preisser ◽  
D. Leann Long ◽  
John W. Stamm
Keyword(s):  
Clinical Trial ◽  
Dental Caries ◽  
Statistical Model ◽  
Randomized Clinical Trial ◽  
Count Data ◽  
Treatment Effects ◽  
Negative Binomial ◽  
Research Question ◽  
Model Class ◽  
Zero Counts

Marginalized zero-inflated count regression models have recently been introduced for the statistical analysis of dental caries indices and other zero-inflated count data as alternatives to traditional zero-inflated and hurdle models. Unlike the standard approaches, the marginalized models directly estimate overall exposure or treatment effects by relating covariates to the marginal mean count. This article discusses model interpretation and model class choice according to the research question being addressed in caries research. Two data sets, one consisting of fictional dmft counts in 2 groups and the other on DMFS among schoolchildren from a randomized clinical trial comparing 3 toothpaste formulations to prevent incident dental caries, are analyzed with negative binomial hurdle, zero-inflated negative binomial, and marginalized zero-inflated negative binomial models. In the first example, estimates of treatment effects vary according to the type of incidence rate ratio (IRR) estimated by the model. Estimates of IRRs in the analysis of the randomized clinical trial were similar despite their distinctive interpretations. The choice of statistical model class should match the study's purpose, while accounting for the broad decline in children's caries experience, such that dmft and DMFS indices more frequently generate zero counts. Marginalized (marginal mean) models for zero-inflated count data should be considered for direct assessment of exposure effects on the marginal mean dental caries count in the presence of high frequencies of zero counts.

scholarly journals Randomized clinical trial to evaluate two methods of caries risk assessment in schoolchildren: the CARDEC-PEL 04 study protocol

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Aryane Marques Menegaz ◽  
Thays Torres do Vale Oliveira ◽  
Mariana Minatel Braga ◽  
Daniela Prócida Raggio ◽  
Maximiliano Sergio Cenci ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Clinical Trial ◽  
Dental Caries ◽  
Randomized Clinical Trial ◽  
Negative Binomial ◽  
Essential Element ◽  
Caries Experience ◽  
Caries Risk ◽  
Caries Risk Assessment ◽  
Multivariate Method

Abstract Background Caries risk assessment is an essential element for managing and preventing dental caries in children. Individual caries risk assessment can be conducted to evaluate the presence or absence of single factors, or using multivariate models, a combination of factors. The subject has been extensively studied, but no previous research has compared whether a more elaborate and individualized method of caries risk benefits the patient than more straightforward strategies. Thus, this protocol evaluates the efficacy of two risk assessment methods for caries control in children, a simplified method based on caries experience evaluation and a multivariate method described in the literature. Methods This is a randomized, double-blind, controlled, parallel-treatment trial protocol. Two groups will be tested for two forms of caries risk assessment: an individualized and detailed multivariate method based on the guidelines of the Caries Care International 4D and another simplified process, based only on caries experience in primary and/or permanent dentition, considering the presence of decayed, missing and filled teeth using the DMFT/dmft index. Participants will be children aged 8 to 11 years, followed up at 12 and 24 months. The primary outcome will be a composite outcome representing the number of tooth surfaces requiring operative intervention (account variable). In addition, the Shapiro–Wilk normality test and Student's t-test will be performed. A multivariate analysis using negative binomial regression will compare groups in the intention-to-treat population, considering a two-tailed significance level of 5%. Discussion This is the first randomized clinical trial aiming to compare dental caries-related treatment and follow-up based on a detailed, multivariate and individualized assessment of caries risk in school-age children to a simpler risk assessment strategy based on caries experience. This study will define whether there are essential benefits to the patient that justify the choice of one method over the other. Trial registration Clinicaltrials.gov registration: NCT03969628. Registered on May 31th, 2019.

Benefits of immediate versus delayed palliative care to informal family caregivers of persons with advanced cancer: Outcomes from the ENABLE III randomized clinical trial.

2014 ◽  
Vol 32 (18_suppl) ◽  
pp. LBA9513-LBA9513 ◽  
Author(s):  
J Nicholas Dionne-Odom ◽  
Andres Azuero ◽  
Kathleen Lyons ◽  
Zhongze Li ◽  
Tor Tosteson ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Palliative Care ◽  
Randomized Clinical Trial ◽  
Family Caregivers ◽  
Advanced Cancer ◽  
Treatment Effects ◽  
Subjective Burden ◽  
Patient Death ◽  
Burden Scale ◽  
Cancer Experience

LBA9513 Background: Family caregivers of individuals with advanced cancer experience significant burden and diminished QOL; few interventions have been found to reduce these outcomes. Methods: Randomized clinical trial conducted from 10/11/2010 to 9/5/2013 of immediate versus delayed (initiated 12 weeks after randomization) entry patients (n=207) and caregivers (n=122) into ENABLE (Educate, Nurture, Advise, Before Life Ends), a phone-based concurrent oncology palliative care intervention. QOL (Caregiver Quality of Life-Cancer, lower scores=better QOL), depression (Center for Epidemiological Study-Depression) and burden (Montgomery Borgatta Caregiver Burden Scale; subjective burden [SB], objective burden [OB]; demand burden [DB]) measures were collected at baseline, 6, 12, 18, and 24 weeks, and every 12 weeks until patient death or study completion. Results: Estimated treatment effects (immediate minus delayed) for caregivers from randomization to 12 weeks were (mean [SE]): -3.1 [2.3] for QOL (P=.17), -4.1 [1.3] for depression (P=.003), -1.0 [0.4] for SB (P=.02), 0.3 [0.6] for OB (P=.60), and -0.5 [0.6] for DB (P=.39). Estimated treatment effects (immediate minus delayed) from intervention initiation to 12 weeks were (mean [SE]): -6.4 [3.4] for QOL (P=.06), -7.4 [2] for depression (P<.001), -1.0 [0.6] for SB (P=.08), -0.6 [0.7] for OB (P=.44), and -0.5 [0.8] for DB (P=.50). Estimated treatment effects (immediate minus delayed) measured backwards from the time of patient’s death were (mean [SE]): of -4.9 [2.6] for QOL (P=.07), -3.8 [1.5] for depression (P=.02), -1.1 [0.4] for SB (P=.01), -0.6 [0.6] for OB (P=.26), and -0.7 [0.6] for DB (P=.22). Conclusions: Caregivers in the immediate group had lower depression, SB, and trends towards better QOL in comparisons up to 12 weeks, following initiation of the intervention in both groups, and in the terminal decline analysis. These results suggest that concurrent oncology palliative care should be initiated as early as possible to maximize benefit to caregivers. Clinical trial information: NCT01245621.

Mentalization as a moderator of treatment effects: Findings from a randomized clinical trial for personality disorders

2013 ◽  
Vol 23 (6) ◽  
pp. 674-689 ◽  
Author(s):  
Frida Slagstad Gullestad ◽  
Merete Selsbakk Johansen ◽  
Per Høglend ◽  
Sigmund Karterud ◽  
Theresa Wilberg
Keyword(s):  
Clinical Trial ◽  
Personality Disorders ◽  
Randomized Clinical Trial ◽  
Treatment Effects

The short-term treatment effects on the microbiota at the dorsum of the tongue in intra-oral halitosis patients—a randomized clinical trial

2012 ◽  
Vol 17 (2) ◽  
pp. 463-473 ◽  
Author(s):  
Seida Erovic Ademovski ◽  
G. Rutger Persson ◽  
Edwin Winkel ◽  
Albert Tangerman ◽  
Peter Lingström ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Randomized Clinical Trial ◽  
Treatment Effects ◽  
Term Treatment ◽  
Short Term ◽  
Short Term Treatment

scholarly journals A Randomized clinical trial of antioxidant therapy in patients with septic shock. Reference study to propose adjuvant therapy in patients with critical organic damage by COVID-19

2020 ◽  
Author(s):  
Alfredo Aisa-Alvarez ◽  
Israel Perez-Torres ◽  
Gilberto Camarena-Alejo ◽  
Juvenal Franco-Granillo ◽  
Enrique Martínez-Rodríguez ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Clinical Trial ◽  
Septic Shock ◽  
Organ Failure ◽  
Randomized Clinical Trial ◽  
Ischemia Reperfusion ◽  
Research Question ◽  
Antioxidant Therapy ◽  
Random Allocation ◽  
Vit C

Abstract Background: Oxidative stress (OS) participates in the pathophysiology of patients with septic shock having multiple organ failure (MOF), ischemia-reperfusion injury and acute respiratory failure syndrome (ARDS). Antioxidants have been proposed in their therapy.Objective: To evaluate the effect of antioxidant treatment in patients with septic shock with MOF and levels OS after treatment.Research question: Will the administration of specific antioxidant therapy decrease deregulatory factors of oxidative stress and organ failure in patients with septic shock?Study design and Methods: Double-blind, placebo-controlled randomized clinical trial run in 2 ICU in Mexico City between May 2018 and January 2020. The random allocation sequence was generated using computer methods. Patients older than 18 years of either sex, with septic shock were included, were excluded when informed consent could not be obtained, they received chronic or recent use of steroids, statins, or antioxidants or if they had contraindications to the use of antioxidants. All antioxidants were administered by mouth or nasogastric tube during 5 days and were added to standard.Results: 97 patients were included with median age of 66 years. 20 were treated with MT and 18 with Vit C and they showed post-treatment decreased SOFA scores [p=0.007 and p<0.001 respectively]. Also, total antioxidant capacity (TAC) was improved by NAC. All patients had decreased basal levels of Vit C and patients that received Vit C had decreased levels of the NO3−/NO2− (p=0.02) and RCP levels [p=0.045]. Procalcitonin (PCT) levels were reduced by Vit E, [p=0.047], NAC; [p=0.001] and MT [p=0.045]. LPO was reduced in patients that received MT p=0.042 Conclusion: In septic shock, antioxidant therapy associated with standard intensive care unit therapy reduces MOF, the oxidative and inflammatory state. These results could be a reference to use adjuvant antioxidant therapy in patients with septic shock in COVID19.Trial Registration: ClinicalTrials.gov Identifier: NCT 03557229

Endogenous switching regression model and treatment effects of count-data outcome

2020 ◽  
Vol 20 (3) ◽  
pp. 627-646
Author(s):  
Takuya Hasebe
Keyword(s):  
Regression Model ◽  
Count Data ◽  
Treatment Effects ◽  
Negative Binomial ◽  
Negative Binomial Regression ◽  
Negative Binomial Regression Model ◽  
Switching Regression ◽  
Latent Heterogeneity ◽  
Endogenous Switching ◽  
Binomial Regression

In this article, I describe the escount command, which implements the estimation of an endogenous switching model with count-data outcomes, where a potential outcome differs across two alternate treatment statuses. escount allows for either a Poisson or a negative binomial regression model with lognormal latent heterogeneity. After estimating the parameters of the switching regression model, one can estimate various treatment effects with the command teescount. I also describe the command lncount, which fits the Poisson or negative binomial regression model with lognormal latent heterogeneity.

Stochastic variable selection strategies for zero-inflated models

2017 ◽  
Vol 18 (1) ◽  
pp. 3-23 ◽  
Author(s):  
Eva Cantoni ◽  
Marie Auda
Keyword(s):  
Variable Selection ◽  
Count Data ◽  
Negative Binomial ◽  
Stochastic Search ◽  
Simulation Studies ◽  
Stochastic Variable ◽  
Selection Strategies ◽  
Selection For ◽  
A Chain ◽  
Zero Counts

When count data exhibit excess zero, that is more zero counts than a simpler parametric distribution can model, the zero-inflated Poisson (ZIP) or zero-inflated negative binomial (ZINB) models are often used. Variable selection for these models is even more challenging than for other regression situations because the availability of p covariates implies 4 p possible models. We adapt to zero-inflated models an approach for variable selection that avoids the screening of all possible models. This approach is based on a stochastic search through the space of all possible models, which generates a chain of interesting models. As an additional novelty, we propose three ways of extracting information from this rich chain and we compare them in two simulation studies, where we also contrast our approach with regularization (penalized) techniques available in the literature. The analysis of a typical dataset that has motivated our research is also presented, before concluding with some recommendations.

Sign in / Sign up

Export Citation Format

Share Document