Il XV Convegno Italiano degli Utenti di Stata si terrà a Bologna il 15-16 Novembre 2018. Ogni anno il Convegno rappresenta un’occasione unica di scambio interdisciplinare fra gli utenti di Stata. Nelle edizioni precedenti, sono stati presentati una varietà di nuovi comandi scritti dagli utenti, nonché disparate applicazioni in economia, biostatistica, scienze sociali, psicologia e gestione dei dati. La sessione “invited speaker” e il corso di formazione tenuto nella seconda giornata del Convegno hanno costantemente offerto ai partecipanti l’occasione di aggiornarsi su nuove metodologie di recente sviluppo.
Il convegno si aprirà con la sessione dedicata ad un “invited speaker” (tenuta da Michael J. Crowther, Department of Health Sciences – University of Leicester) e proseguirà con una serie di sessioni che daranno la possibilità ai partecipanti di:
Conoscere nuove applicazioni che evidenziano le potenzialità di Stata su nuovi comandi e procedure
Incontrare ricercatori appartenenti a diverse aree disciplinari
Interagire direttamente con gli statistici della StataCorp
Scambiare informazioni e routine sviluppate per Stata
La seconda giornata sarà dedicata al corso di formazione “Joint Modelling of Survival and Longitudinal Data” tenuto da Michael J. Crowther.
COME SOTTOPORRE UN CONTRIBUTO
Gli autori interessati a presentare un contributo sono invitati a sottoporre un abstract in formato elettronico al comitato scientifico all’indirizzo e-mail statausers@tstat.it entro il 15.09.2018. Nell’e-mail dovranno essere inclusi nome, affiliazione, indirizzo e recapito telefonico. Saranno disponibili 25 minuti per ciascuna presentazione e 10 minuti per la relativa discussione. Eventuali contributi che dovessero richiedere tempi diversi, saranno ben accolti e per la pianificazione del programma sarà necessario segnalarne la durata prevista al momento dell’invio dell’abstract. Il comitato scientifico farà pervenire una risposta entro il 26.09.2018 e la versione definitiva del lavoro dovrà essere inoltrata al comitato scientifico entro e non oltre il 28.10.2018.
COMITATO SCIENTIFICO
Una-Louise Bell
Rino Bellocco
Giovanni Capelli
Maurizio Pisati
Anteprima Programma per scaricare il CALL FOR PAPER
15 Novembre 2018
9.00 – 9.30 Registrazione dei partecipanti
9.30 – 10.30 I SESSIONE – INVITED SPEAKER
Multi-state survival analysis in Stata • Michael J. Crowther , Department of Health Sciences University of Leicester
Multi-state models are increasingly being used to model complex disease profiles. By modelling transitions between disease states, accounting for competing events at each transition, we can gain a much richer understanding of patient trajectories and how risk factors impact over the entire disease pathway. In this talk, I’ll introduce some new Stata commands for the analysis of multi-state survival data. This includes –msset-, a data preparation tool which converts a dataset from wide (one observation per subject, multiple time and status variables) to long (one observation for each transition for which a subject is at risk for). –msaj– calculates the non-parametric Aalen-Johansen estimates of transition probabilities. –msboxes– creates a descriptive plot of the multi-state process through the transition matrix and numbers at risk. –stms– fits joint transition-specific survival models, allowing each transition to have a different parametric model, yet maximised jointly to enable sharing of covariate effects across transitions. –predictms– calculates a variety of predictions from a multi-state survival model, including transition probabilities, length of stay (restricted mean time in each state), the probability of ever visiting each state and more. Predictions are made at user-specified covariate patterns. Differences and ratios of predictions across covariate patterns can also be calculated. Standardised (population-averaged) predictions can be obtained. Confidence intervals for all quantities are available. Simulation or the Aalen-Johansen estimator are used to calculate all quantities. User-defined predictions can also be calculated by providing a user-written Mata function, to provide complete flexibility. –predictms– can be used with a general transition matrix (cyclic or acyclic) and allows the use of transition-specific timescales. I will illustrate the software using a dataset of patients with primary breast cancer.
10.30 – 10.50 Pausa caffè
10.50 – 12.15 II SESSIONE – COMMUNITY CONTRIBUTED, I
The Stata module CUB for fitting mixture models for ordinal data • Christopher F. Baum, Boston College; Giovanni Cerulli IRCrES-CNR; Francesca di Iorio, Domenico Piccolo e Rosaria Simone, Università degli Studi di Napoli Federico II
We present CUB, a Stata routine for modelling ordinal data via a class of finite mixture distributions accounting for both uncertainty and feeling components of an ordered decisional process. This routine allows for modelling also over-dispersion, inflated categories, and large heterogeneity occurrences. Model parameters are estimated by maximum likelihood. We explore various features of the package CUB, including simulation routines.
Two-part models, hurdle models and zero-inflated are robust to endogeneity among the parts • David M. Drukker, StataCorp.
There are many models for an outcome that a mass point at a boundary value an is continuously or discrete distributed over a large number of off-boundary values. Two-part models (TPMs), hurdle models (HMs), and zero-inflated models (ZIMs) use different approaches to combine distinct models for boundary and off-boundary values. Except for a few “cake debate” papers whose assertions were not accepted, the vast majority of the literature has either assumed that the process determining when the outcome is on or off the boundary must be exogenous or that any endogeneity must be modeled. Drukker (2017) showed that, contrary to conventional belief, TPMs are robust to endogeneity of the on-off-boundary process in that they identify the mean of the outcome conditional on covariates. This talk covers the following points: i) It reviews this literature and the argument that shows that TPMs are robust to the endogeneity of on-off-boundary process. ii) It discusses new results showing that HMs and ZIMs are also robust to the endogeneity of on-off-boundary process. iii) It presents a new Stata command that estimates the parameters of interest in endogenous TPMS and HMs and shows how to subsequently use -margins- to estimate the effects of interest.
Risk-adjustment procedures and graphical representations of outcome rates for institutional comparisons • Jacopo Lenzi, Università degli Studi di Bologna
An overriding goal of outcomes research is measuring and comparing hospital performance using readily available administrative data. Risk-adjustment techniques develop from conventional logistic regression analysis, but some precautions need to be taken to account for the positive correlation between observations from within the same hospital. These include the use of generalized estimating equations, which are available in Stata as xtgee. Two effective graphs that illustrate outcome measures across different providers and incorporate sample size information are the caterpillar plot and the funnel plot, which can be obtained using the eclplot and funnelcompar packages, respectively.
12.15 – 13.00 III SESSIONE – EXPLOITING THE POTENTIAL OF STATA 15, I
Efficient dynamic documents using Stata • Bill Rising, StataCorp.
Stata 15 includes three new commands for producing dynamic documents: –dyndoc-, –putdocx-, and –putpdf-. These commands have generated much interest in the user community; this has led to a large amount of community-contributed software. In this presentation, will give some tips about how to use the commands efficiently both with official Stata software and with some of these community-contributed tools.
13.00 – 14.00 Pranzo
14.00 – 14.50 IV SESSIONE – COMMUNITY CONTRIBUTED, II
Recurrent-event analysis with Stata: methods and applications • Francesca Ghilotti, Rino Bellocco, Karolinska Institutet, Università degli Studi di Milano-Bicocca
Often in medical studies the event of interest can recur in the same patient over time. Even if time-to-first event analysis or the use of Poisson regression are still possible, they prevent the use of data to its full potential. If the outcome can occur more than once, failure times are correlated within subject and methods accounting for lack of independence are needed. Different statistical models are available for analyzing such data, among which the Andersen and Gill (AG) model, the Prentice, Williams and Peterson Total Time (PWP-TT) model and frailty models. The aim of this presentation is to review statistical techniques for multiple-failure survival data, and to show how to implement them in Stata.
Le determinanti del voto referendario del 4 Dicembre 2016 • Mariano Bella e Giovanni Graziano, Ufficio Studi Confcommercio
This paper offers new evidence on the socio-economic-demographic determinants of the referendum of December 4, 2016 through the analysis of the vote in Italian municipalities. The results indicate a strong ideology of the vote, in the sense that the political orientation expressed in the 2014 elections significantly influences its orientation. Moreover, it is not so much the youth vote that has determined the rejection of the reform as the social unease, summarized through the unemployment rate and the share of commuters in the municipalities. This also involves a reduced explanatory capacity of the genuine territorial variables. Overall, the vote was determined mainly by political affiliation, then by the self-assessment of one’s socio-economic status and, only residually, by personal opinion on the contents of the reform. If democracy is a result built up by the exercise of “electoral profession”, then the revival of civic education, updated in the direction of enriching it with the economic implications of good institutions, can be an incentive to actually express preferences on the basic rules.
14.50 – 15.50 V SESSIONE – TRICKS AND TIPS
Simple Tools for Saving Time • Bill Rising, StataCorp.
This brief talk will show some simple tools for saving time when working with Stata. This will be a hodgepodge of items whose goal is to reduce the amount of thought, coordination, and human memory required of common tasks in a complex work environment while speeding up such tasks greatly.
Calling External Routines in Stata • Giovanni Cerulli e Antonio Zinilli, IRCrES-CNR
One of less well known functions in Stata, is the possibility to call external routines, written in other software, to perform specific tasks within Stata. This talk offers some insights on how to develop a Stata ADO file embedding an external software routine to execute in Stata using the Stata module stree, written to allow users to run regression trees (a Machine Learning technique currently unavailable in Stata).
Finding data embedded in text files: using -fileread()- and basic string functions to extract spatial coordinates from google map or counts in preformatted documents • Giovanni Capelli, Università degli Studi di Cassino e del Lazio Meridionale
From Stata 13 on, Stata supports the long string format strL. The programming function fileread() can be used to upload in a Stata long string field an entire text or binary file, found in a local directory or uploaded from a webpage. These long string fields can then be searched to extract specific numeric or categorical data. We illustrate the use of the fileread() programming function, coupled with the string functions strpos() and substr(), to solve the following issues: i) Extract spatial coordinates from a database of individual addresses using google map APIs calls; and ii) Extract count data from a non-anonymous version of multiple Word structured files and automatically rebuild an anonymous PDF version of the file through LaTeX.
15.50 – 16.00 Pausa caffè
16.00 – 17.00 VI SESSIONE – EXPLOITING THE POTENTIAL OF STATA 15, II
Estimating the average causal effect on an ordinal outcome of an endogenously assigned treatment from an endogenously selected sample • David M. Drukker, StataCorp.
This talk discusses the average causal effect (ACE) of an endogenous binary treatment on an ordinal outcome when the sample is subject to endogenous selection. It shows how to estimate the ACE using an extended regression model (ERM) command in Stata. It illustrates how to do regression adjustment in Stata and discusses standard errors for sample-averaged treatment effects and population-averaged treatment effects.
17.00 – 17.15 VII SESSIONE – REPORT TO USERS WISHES AND GRUMBLES • BILL RISING AND DAVID M. DRUKKER, STATACORP
La sessione “Wishes and Grumbles” offre ai partecipanti la possibilità di interagire direttamente con la StataCorp: sarà possibile evidenziare problemi o limitazioni del software nonché suggerire eventuali miglioramenti o comandi che potrebbero essere inclusi in Stata.
20.15 Cena Sociale (facoltativa)
Clicca QUI per scaricare la versione PDF del programma in Italiano
Click HERE to download the program in PDF format
16 Novembre 2018
Corso di Formazione Joint Modelling of Longitudinal and Survival Data
Come ogni anno proponiamo una serata insieme al termine del Convegno.
Quest’anno la cena sociale si terrà, la sera del 15 Novembre, presso il ristorante C’ERA UNA VOLTA…, Via Massimo D’Azeglio, 9.
Il ritrovo sarà direttamente al ristorante alle ore 20.15.
Le prenotazioni dovranno essere effettuate al momento dell’iscrizione al Convegno e la quota di partecipazione da corrispondere direttamente in loco.
La partecipazione è subordinata al pagamento della seguente quota di partecipazione:
Convegno:
Studenti / Dottorandi*: € 62.00
Altre categorie: € 95.00
Corso di Formazione:
Studenti / Dottorandi* € 227.00
Altre categorie: € 350.00
Convegno e Corso di Formazione:
Studenti / Dottorandi* € 244.00
Altre categorie: € 375.00
*Per usufruire dello status “studente” è necessario presentare copia del libretto universitario o un certificato di iscrizione (in carta semplice) all’Università ed essere studenti a tempo pieno. I prezzi si intendono IVA 22% esclusa. L’aliquota IVA non sarà applicata per Enti Pubblici soggetti ad esenzione a norma dell’art. 14 c. 10 della L. 537/93 per la partecipazione a corsi di formazione dei propri dipendenti.
La quota di iscrizione include il materiale didattico, pause caffè e pranzo.
CLICCA QUI PER SCARICARE IL MODULO DI REGISTRAZIONE
SCADENZA ISCRIZIONE:
La domanda di partecipazione dovrà avvenire, tramite il modulo di registrazione disponibile presso la segreteria organizzativa (statausers@tstat.it), entro il 5.11.2018.
Il XV Convegno Italiano degli Utenti di Stata si terrà a Bologna il 15-16 Novembre 2018. Il Convegno rappresenta un’occasione unica di scambio interdisciplinare fra gli utenti di Stata. Nelle edizioni precedenti, sono stati presentati una varietà di nuovi comandi scritti dagli utenti, nonché disparate applicazioni in economia, biostatistica, scienze sociali, psicologia e gestione dei dati. La sessione “invited speaker” e il corso di formazione tenuto nella seconda giornata del Convegno hanno costantemente offerto ai partecipanti l’occasione di aggiornarsi su nuove metodologie di recente sviluppo.
La seconda giornata sarà dedicata al corso di formazione “Joint Modelling of Survival and Longitudinal Data” tenuto da Michael J. Crowther, Department of Health Sciences – University of Leicester.
