<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div><blockquote style="border-left-width: 2px; border-left-style: solid; border-left-color: rgb(16, 16, 255); margin-left: 5px; padding-left: 5px; "><div style="font-family: 'times new roman', 'new york', times, serif; "><div style="font-family: 'times new roman', 'new york', times, serif; "><font><span class="Apple-style-span" style="font-size: 16px; ">#Boa tarde a todos, numa regressão logística múltipla, após a escolha de um ponto de corte,</span><br></font><div id="yiv2066124207" style="font-family: 'times new roman', 'new york', times, serif; font-size: 12pt; "><div><div style="color: rgb(0, 0, 0); background-color: rgb(255, 255, 255); font-size: 12pt; font-family: 'times new roman', 'new york', times, serif; "><div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times,
serif">#criei a tabela de classificação conforme CMR abaixo, e usei o </font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif">#comando dignosis do pacote DiagnosisMed</font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif">#para calcular a sensibilidade e especificidade !</font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif"><br></font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new
york', times, serif">require(DiagnosisMed)</font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif"><br></font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif">tab<-matrix(c(64,112,17,406),nrow=2,ncol=2,byrow=T,</font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif">dimnames=list(Classificado=c(" 1 "," 0 "),</font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif">Observado=c(" 1 "," 0 ")));tab</font></div><div><span class="yiv2066124207Apple-style-span" style="font-family: times, serif; "><br></span></div><div><span class="yiv2066124207Apple-style-span" style="font-family: times, serif; ">diagnosis(tab)[]</span><br></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times,
serif"><br></font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif">#Porém os valores estão trocados, o certo é </font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif">#Sensitividade =64 /(17+64) =79,01%</font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif">#Especificidade=406/(112+406)=78,378%</font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif">#Tentei usar o comando:</font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif"><br></font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif"><br></font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times,
serif">diagnosis(t(tab))[]</font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times,
serif"><br></font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif"><br></font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif">#Mas não deu certo. Sendo assim:</font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif">#1- o que ocorreu ?</font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif">#2- Tem alguma função nos pacotes epiR ou ROCR que</font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif">#calcula a sensibilidade e especificidade ?</font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif" style="background-color:rgb(255, 255, 255);" color="#7F7F00"><b>#3- para achar o ponto de corte "ideal" tenho que fazer várias
tabelas de classificação</b></font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif" style="background-color:rgb(255, 255, 255);" color="#7F7F00"><b>#e plotar a sens. x espec. </b></font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif" style="background-color:rgb(255, 255, 255);" color="#7F7F00"><b>#No "satanic", tem-se um comando do proc logistic que</b></font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif" style="background-color:rgb(255, 255, 255);" color="#7F7F00"><b>#mostra todas as sensibilidade e especificidade para diferentes pontos de cortes.</b></font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif" style="background-color:rgb(255, 255, 255);" color="#7F7F00"><b>#Tem algum comando similar no R para regressão
logística múltipla ?</b></font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new
york', times, serif">#no caso univariado tem-se:</font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif">y=c(0,1,0,0,1,1,1,0,0,0)</font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif">x=c(12,19,14,13,14,15,16,17,17,18)</font></div><div><font class="yiv2066124207Apple-style-span" face="'times new roman', 'new york', times, serif">require(DiagnosisMed);arearoc<-DiagnosisMed::ROC(y,x,Full=TRUE) </font></div><div style="font-size: 12pt; font-family: times, serif; "><br></div><div style="font-size: 12pt; font-family: times, serif; "><br></div><div style="font-size: 12pt; font-family: times, serif; ">########### <font class="yiv2066124207Apple-style-span" color="#C00000">MUITO OBRIGADO</font> ###########</div><div style="font-size: 12pt; font-family: times, serif;
">#Alex</div></div></div></div></div></div></div></blockquote></div></div></body></html>