Pub Date : 2023-07-18DOI: 10.54103/2282-0930/20637
I. Nesteruk
The media is reporting tens of millions of new daily Covid-19 cases in China in the final days of 2022. However, official statistics have recorded in mainland China only 1.9 million cases since the start of the pandemic and stopped providing data after December 21, 2022. Results of SIR simulations showed that daily numbers of new cases stated to decline in December 2022. The contradictions in statistics and estimations are discussed. Millions of new daily cases in China look very unlikely.
{"title":"What is wrong with Chinese COVID-19 statistics?","authors":"I. Nesteruk","doi":"10.54103/2282-0930/20637","DOIUrl":"https://doi.org/10.54103/2282-0930/20637","url":null,"abstract":"The media is reporting tens of millions of new daily Covid-19 cases in China in the final days of 2022. However, official statistics have recorded in mainland China only 1.9 million cases since the start of the pandemic and stopped providing data after December 21, 2022. Results of SIR simulations showed that daily numbers of new cases stated to decline in December 2022. The contradictions in statistics and estimations are discussed. Millions of new daily cases in China look very unlikely.","PeriodicalId":45811,"journal":{"name":"Epidemiology Biostatistics and Public Health","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89974373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-18DOI: 10.54103/2282-0930/20639
Zahra Arab Borzu, A. Baghestani, E. Talebi Ghane, Aliakbar Khadem Maboudi, A. Akhavan, A. Saeedi
The observations of repeated or recurrent events occur in many longitudinal studies. Furthermore, sometimes there may exist a terminal event such as death, which is strongly correlated with recurrent events. In many situations, a fraction of subjects who will never experience the event of interest during a long follow-up period is considered to be cured. In this article, we proposed a joint frailty model in the presence of cure fraction. The dependency is modeled by shared frailty that is contained in both the recurrent andterminal events hazard functions. It allows to estimate two separate sets of parameters on the recurrent, death, and cure model. We applied the maximum likelihood method under a piecewise constant hazard function for model fitting. The proposed model is evaluated by simulation studies and an application to a breast cancer data is provided.
{"title":"Joint frailty model for recurrent events and a terminal event in the presence of cure fraction","authors":"Zahra Arab Borzu, A. Baghestani, E. Talebi Ghane, Aliakbar Khadem Maboudi, A. Akhavan, A. Saeedi","doi":"10.54103/2282-0930/20639","DOIUrl":"https://doi.org/10.54103/2282-0930/20639","url":null,"abstract":"The observations of repeated or recurrent events occur in many longitudinal studies. Furthermore, sometimes there may exist a terminal event such as death, which is strongly correlated with recurrent events. In many situations, a fraction of subjects who will never experience the event of interest during a long follow-up period is considered to be cured. In this article, we proposed a joint frailty model in the presence of cure fraction. The dependency is modeled by shared frailty that is contained in both the recurrent andterminal events hazard functions. It allows to estimate two separate sets of parameters on the recurrent, death, and cure model. We applied the maximum likelihood method under a piecewise constant hazard function for model fitting. The proposed model is evaluated by simulation studies and an application to a breast cancer data is provided.","PeriodicalId":45811,"journal":{"name":"Epidemiology Biostatistics and Public Health","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87955690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-07-18DOI: 10.54103/2282-0930/20638
D. De Martini
The rate of phase III trials failures is approximately 42-45%, and most of them are due to a lack of efficacy. Some of the failures for a lack of efficacy are expected, due to type I errors in phase II and type II errors in phase III. However, the rate of these failures is far from saturating the global failure rate due to a lack of efficacy.In this work, the probability of unexpected failure for a lack of efficacy in phase III trials is estimated to be about 14%, with credibility interval (9%, 18%). These failures can be recovered through an adequate planning/empowering of phase II, and by adopting conservative estimation for the sample size of phase III. The software SP4CT (a free web application available at www.sp4ct.com) allows these computations. This 14% rate of unexpected failures gives that every year approximately 270,000 patients uselessly undergo a phase III trial with a large damage in individual ethics; moreover, the unavailability of many effective treatments is a considerable damage for collective ethics. The 14% of unexpected failures also produces more than $11bn of pure waste, and generates a much higher lack of revenue given by drugs’ marketing.
{"title":"Phase III Failures for a Lack of Efficacy can be, in Significant Part, Recovered (Introducing Success Probability Estimation Quantitatively)","authors":"D. De Martini","doi":"10.54103/2282-0930/20638","DOIUrl":"https://doi.org/10.54103/2282-0930/20638","url":null,"abstract":"The rate of phase III trials failures is approximately 42-45%, and most of them are due to a lack of efficacy. Some of the failures for a lack of efficacy are expected, due to type I errors in phase II and type II errors in phase III. However, the rate of these failures is far from saturating the global failure rate due to a lack of efficacy.In this work, the probability of unexpected failure for a lack of efficacy in phase III trials is estimated to be about 14%, with credibility interval (9%, 18%). These failures can be recovered through an adequate planning/empowering of phase II, and by adopting conservative estimation for the sample size of phase III. The software SP4CT (a free web application available at www.sp4ct.com) allows these computations. This 14% rate of unexpected failures gives that every year approximately 270,000 patients uselessly undergo a phase III trial with a large damage in individual ethics; moreover, the unavailability of many effective treatments is a considerable damage for collective ethics. The 14% of unexpected failures also produces more than $11bn of pure waste, and generates a much higher lack of revenue given by drugs’ marketing.","PeriodicalId":45811,"journal":{"name":"Epidemiology Biostatistics and Public Health","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81450781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: nowadays Wikipedia is one of the main on-line sources of general information. It contains several items about nosocomial infections and their prevention, together of items on virtually every scientific topic. This study aims to assess whether Wikipedia can be considered a reliable source for professional updating, concerning Healthcare-associated Infections (HAI). Methods: Wikipedia has been searched in order to gather items on HAI. 387 items were found with a search string. The field of research was reduced at those articles (27 items) containing exhaustive information in relation to prevention of HAI. The messages contained in those articles were than compared with the recommendations of a selected guideline (NICE 2003), completed by a literature search, with the aim of testing their reliability and exhaustivity. Results: 15 Wiki items were found and 51 messages selected. NICE guidelines contained 119 recommendations and 52 more recommendations has been found in a further literature search. 45.1% of Wikipedia’s messages were even found in the guidelines. On this percentage, 21.6% completely agreed with the messages of the guidelines, 15.7% partially agreed, 3.9% disagreed and 3.9% showed different level of evidence in different articles. Moreover, 54.9% of Wikipedia’s messages were not included in the guidelines and 84.2% of the recommendations contained in the guidelines were not present in Wikipedia. Conclusions: Wikipedia should not be considered as a reliable source for professional updating on HAI.
{"title":"Risk factors and control of hospital acquired infections: a comparison between Wikipedia and scientific literature","authors":"E. Allara","doi":"10.2427/8744","DOIUrl":"https://doi.org/10.2427/8744","url":null,"abstract":"Background: nowadays Wikipedia is one of the main on-line sources of general information. It contains several items about nosocomial infections and their prevention, together of items on virtually every scientific topic. \u0000This study aims to assess whether Wikipedia can be considered a reliable source for professional updating, concerning Healthcare-associated Infections (HAI). \u0000Methods: Wikipedia has been searched in order to gather items on HAI. 387 items were found with a search string. The field of research was reduced at those articles (27 items) containing exhaustive information in relation to prevention of HAI. The messages contained in those articles were than compared with the recommendations of a selected guideline (NICE 2003), completed by a literature search, with the aim of testing their reliability and exhaustivity. \u0000Results: 15 Wiki items were found and 51 messages selected. NICE guidelines contained 119 recommendations and 52 more recommendations has been found in a further literature search. 45.1% of Wikipedia’s messages were even found in the guidelines. On this percentage, 21.6% completely agreed with the messages of the guidelines, 15.7% partially agreed, 3.9% disagreed and 3.9% showed different level of evidence in different articles. Moreover, 54.9% of Wikipedia’s messages were not included in the guidelines and 84.2% of the recommendations contained in the guidelines were not present in Wikipedia. \u0000Conclusions: Wikipedia should not be considered as a reliable source for professional updating on HAI.","PeriodicalId":45811,"journal":{"name":"Epidemiology Biostatistics and Public Health","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89405383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A common aim of epidemiological research is to estimate the causal effect of a particular exposure on a particular outcome. Towards this end, observed associations are often ‘adjusted’ for potential confounding variables. When the potential confounders are unmeasured, explicit adjustment becomes unfeasible. It has been demonstrated that causal effects can be estimated even in the presence of umeasured confounding, utilizing a method called ‘front-door blocking’. In this paper we generalize this method to longitudinal studies. We demonstrate that the method of front-door blocking poses a number of challenging statistical problems, analogous to the famous problems associ- ated with the method of ‘back-door blocking’.
{"title":"Confounding adjustment through front-door blocking in longitudinal studies","authors":"A. Sjölander, R. Bellocco","doi":"10.2427/8757","DOIUrl":"https://doi.org/10.2427/8757","url":null,"abstract":"A common aim of epidemiological research is to estimate the causal effect of a particular exposure on a particular outcome. Towards this end, observed associations are often ‘adjusted’ for potential confounding variables. When the potential confounders are unmeasured, explicit adjustment becomes unfeasible. It has been demonstrated that causal effects can be estimated even in the presence of umeasured confounding, utilizing a method called ‘front-door blocking’. In this paper we generalize this method to longitudinal studies. We demonstrate that the method of front-door blocking poses a number of challenging statistical problems, analogous to the famous problems associ- ated with the method of ‘back-door blocking’.","PeriodicalId":45811,"journal":{"name":"Epidemiology Biostatistics and Public Health","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75265101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Multiple imputation is a simulation-based approach for the analysis of data with missing observations. It is widely utilized in many set- tings and preeminent among general approaches when the analytical method does not involve a likelihood function or this is too complex. We consider a multiple imputation method based on the estimation of conditional quantiles of missing observations given the observed data. The method does not require modeling a likelihood and has desirable features that may be useful in some practical settings. It can also be applied to impute dependent, bounded, censored and count data. In a simulation study it shows some advantage over the alternative meth- ods considered in terms of mean squared error across all scenarios except when the data arise from a normal distribution where all meth- ods considered perform equally well. We present an application to the estimation of percentiles of body mass index conditional on physical activity assessed by accelerometers.
{"title":"Multiple Imputation Based on Conditional Quantile Estimation","authors":"M. Bottai, H. Zhen","doi":"10.2427/8758","DOIUrl":"https://doi.org/10.2427/8758","url":null,"abstract":"Multiple imputation is a simulation-based approach for the analysis of data with missing observations. It is widely utilized in many set- tings and preeminent among general approaches when the analytical method does not involve a likelihood function or this is too complex. We consider a multiple imputation method based on the estimation of conditional quantiles of missing observations given the observed data. The method does not require modeling a likelihood and has desirable features that may be useful in some practical settings. It can also be applied to impute dependent, bounded, censored and count data. In a simulation study it shows some advantage over the alternative meth- ods considered in terms of mean squared error across all scenarios except when the data arise from a normal distribution where all meth- ods considered perform equally well. We present an application to the estimation of percentiles of body mass index conditional on physical activity assessed by accelerometers.","PeriodicalId":45811,"journal":{"name":"Epidemiology Biostatistics and Public Health","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84207150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The aim of this work is to present the reflections and proposals derived from the first Workshop of the SISMEC STATDENT working group on statistical methods and applications in dentistry, held in Ancona (Italy) on 28th September 2011. STATDENT began as a forum of comparison and discussion for statisticians working in the field of dental research in order to suggest new and improve existing biostatistical and clinical epidemiological methods. During the meeting, we dealt with very important topics of statistical methodology for the analysis of dental data, covering the analysis of hierarchically structured and over-dispersed data, the issue of calibration and reproducibility, as well as some problems related to survey methodology, such as the design and construction of unbiased statistical indicators and of well conducted clinical trials. This paper gathers some of the methodological topics discussed during the meeting, concerning multilevel and zero-inflated models for the analysis of caries data and methods for the training and calibration of raters in dental epidemiology.
{"title":"Challenges in Dental Statistics: Data and Modelling","authors":"D. Matranga, G. Solinas, P. Castiglia","doi":"10.2427/8759","DOIUrl":"https://doi.org/10.2427/8759","url":null,"abstract":"The aim of this work is to present the reflections and proposals derived from the first Workshop of the SISMEC STATDENT working group on statistical methods and applications in dentistry, held in Ancona (Italy) on 28th September 2011. STATDENT began as a forum of comparison and discussion for statisticians working in the field of dental research in order to suggest new and improve existing biostatistical and clinical epidemiological methods. During the meeting, we dealt with very important topics of statistical methodology for the analysis of dental data, covering the analysis of hierarchically structured and over-dispersed data, the issue of calibration and reproducibility, as well as some problems related to survey methodology, such as the design and construction of unbiased statistical indicators and of well conducted clinical trials. This paper gathers some of the methodological topics discussed during the meeting, concerning multilevel and zero-inflated models for the analysis of caries data and methods for the training and calibration of raters in dental epidemiology.","PeriodicalId":45811,"journal":{"name":"Epidemiology Biostatistics and Public Health","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77139397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Boccia, C. Vito, C. Marzuillo, W. Ricciardi, P. Villari
After the political elections of February 2013, one of the tasks of the Ministry of Health of the new Government will be the development of the new edition – the third – of the National Prevention Plan (NPP), after the NPP 2005-2007 and the NPP 2010-2012. A brainstorming process about the recent experience of the NPP 2010-2012 is important not only to elaborate technical indications for new plan, but also to make some reflections on...
{"title":"The governance of prevention in Italy","authors":"A. Boccia, C. Vito, C. Marzuillo, W. Ricciardi, P. Villari","doi":"10.2427/8814","DOIUrl":"https://doi.org/10.2427/8814","url":null,"abstract":"After the political elections of February 2013, one of the tasks of the Ministry of Health of the new Government will be the development of the new edition – the third – of the National Prevention Plan (NPP), after the NPP 2005-2007 and the NPP 2010-2012. A brainstorming process about the recent experience of the NPP 2010-2012 is important not only to elaborate technical indications for new plan, but also to make some reflections on...","PeriodicalId":45811,"journal":{"name":"Epidemiology Biostatistics and Public Health","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72793577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Marranzano, R. Ragusa, M. Platania, G. Faro, M. A. Coniglio
Background: nurses’ knowledge, attitudes and practices towards patients with HIV/AIDS are of ongoing interest, especially in developing countries. Nothing or very little is known about Italian nurses. Methods: HIV/AIDS knowledge, attitudes and behaviours of the nurses (n=107) from one university hospital inCatania,Sicily, were documented. Comparisons among nurses belonging to different Operative Units (O.U.) were conducted by the chi-square test (P<0.05). Results: although HIV was nurses’ main concern in regard to contracting infections in the workplace (54%), the vast majority of them (98%) had never refused an HIV/AIDS patient care assignment. Moreover, despite their concern of being more at risk of contracting HIV than the general population (41%), a not negligible percentage of nurses did not use gloves routinely (21%) and only a few treated all patients as potentially HIV-positive (9%). The vast majority of the respondents knew the meaning of AIDS (87%) and of a positive serological test (78%). On the contrary, a relatively low percentage of them knew what is the ‘window period’ (62%) and were acquainted with HIV pathophysiology (65%). No statistically significant differences in terms of risk perception were found between nurses who had previously attended an HIV/AIDS workshop, lecture or specific course (43%) and nurses who did not (57%). Level of knowledge was positively associated to age (P=0.000) and to education (P=0.016), and it was found higher in nurses working in a O.U. of Infectious Diseases. Conclusions: data from our study show that also in developed countries, such as Italy, nurses could have some misconceptions and concerns about HIV/AIDS. The importance of examining the impact of continuing education on nurses’ preparedness to care for patients with HIV/AIDS and to prevent the risks of occupational HIV transmission is discussed.
{"title":"Knowledge, attitudes and practices towards patients with HIV/AIDS in staff nurses in one university hospital in Sicily","authors":"M. Marranzano, R. Ragusa, M. Platania, G. Faro, M. A. Coniglio","doi":"10.2427/8731","DOIUrl":"https://doi.org/10.2427/8731","url":null,"abstract":"\u0000Background: nurses’ knowledge, attitudes and practices towards patients with HIV/AIDS are of ongoing interest, especially in developing countries. Nothing or very little is known about Italian nurses. \u0000Methods: HIV/AIDS knowledge, attitudes and behaviours of the nurses (n=107) from one university hospital inCatania,Sicily, were documented. Comparisons among nurses belonging to different Operative Units (O.U.) were conducted by the chi-square test (P<0.05). \u0000Results: although HIV was nurses’ main concern in regard to contracting infections in the workplace (54%), the vast majority of them (98%) had never refused an HIV/AIDS patient care assignment. Moreover, despite their concern of being more at risk of contracting HIV than the general population (41%), a not negligible percentage of nurses did not use gloves routinely (21%) and only a few treated all patients as potentially HIV-positive (9%). The vast majority of the respondents knew the meaning of AIDS (87%) and of a positive serological test (78%). On the contrary, a relatively low percentage of them knew what is the ‘window period’ (62%) and were acquainted with HIV pathophysiology (65%). No statistically significant differences in terms of risk perception were found between nurses who had previously attended an HIV/AIDS workshop, lecture or specific course (43%) and nurses who did not (57%). Level of knowledge was positively associated to age (P=0.000) and to education (P=0.016), and it was found higher in nurses working in a O.U. of Infectious Diseases. \u0000Conclusions: data from our study show that also in developed countries, such as Italy, nurses could have some misconceptions and concerns about HIV/AIDS. The importance of examining the impact of continuing education on nurses’ preparedness to care for patients with HIV/AIDS and to prevent the risks of occupational HIV transmission is discussed. \u0000","PeriodicalId":45811,"journal":{"name":"Epidemiology Biostatistics and Public Health","volume":"352 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76589141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Gasparini, L. D. Scala, F. Bretz, A. Racine‐Poon
Predictive probability of success is a (subjective) Bayesian evaluation of the prob- ability of a future successful event in a given state of information. In the context of pharmaceutical clinical drug development, successful events relate to the accrual of positive evidence on the therapy which is being developed, like demonstration of su- perior efficacy or ascertainment of safety. Positive evidence will usually be obtained via standard frequentist tools, according to the regulations imposed in the world of pharmaceutical development.Within a single trial, predictive probability of success can be identified with expected power, i.e. the evaluation of the success probability of the trial. Success means, for example, obtaining a significant result of a standard superiority test.Across trials, predictive probability of success can be the probability of a successful completion of an entire part of clinical development, for example a successful phase III development in the presence of phase II data.Calculations of predictive probability of success in the presence of normal data with known variance will be illustrated, both for within-trial and across-trial predictions.
{"title":"Some uses of predictive probability of success in clinical drug development","authors":"M. Gasparini, L. D. Scala, F. Bretz, A. Racine‐Poon","doi":"10.2427/8760","DOIUrl":"https://doi.org/10.2427/8760","url":null,"abstract":"Predictive probability of success is a (subjective) Bayesian evaluation of the prob- ability of a future successful event in a given state of information. In the context of pharmaceutical clinical drug development, successful events relate to the accrual of positive evidence on the therapy which is being developed, like demonstration of su- perior efficacy or ascertainment of safety. Positive evidence will usually be obtained via standard frequentist tools, according to the regulations imposed in the world of pharmaceutical development.Within a single trial, predictive probability of success can be identified with expected power, i.e. the evaluation of the success probability of the trial. Success means, for example, obtaining a significant result of a standard superiority test.Across trials, predictive probability of success can be the probability of a successful completion of an entire part of clinical development, for example a successful phase III development in the presence of phase II data.Calculations of predictive probability of success in the presence of normal data with known variance will be illustrated, both for within-trial and across-trial predictions.","PeriodicalId":45811,"journal":{"name":"Epidemiology Biostatistics and Public Health","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75263834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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