Dear Ethan,
The denominator of DUM should be in the standard deviation level, not variance, so it should be W = SQRT(THETA(7)**2*FLAG+THETA(8)**2*(1-FLAG)+THETA(9)**2*IPRED**2) IF (TYPE.EQ.2.AND.CMT.EQ.2) DUM=(LOQ-IPRED)/W Note that the way you coded DUM is equivalent to DUM=(LOQ-IPRED)/W**2 In your code for log-transformed data, I see that the denominator is specified as a standard deviation. However, it is not clear to me whether you want to use a different magnitude of proportional error or additive error for studies whose number is greater than 3. In the code for natural DV, THETA(8) is for the different additive error of such studies, whereas THETA(8) in the log DV corresponds to the different proportional error. Best regards, Jae Eun ________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of Ethan Wu Sent: Thursday, February 11, 2010 10:53 AM To: [email protected] Subject: [NMusers] help on diagnostic of a problem -- about M3 method for LLOQ: Dear users, I am working on a dataset with not small percentage below LLOQ. when I implemented M3 method to account for this, I always getting this error message: 0PROGRAM TERMINATED BY OBJ ERROR IN CLIK WITH INDIVIDUAL 2 ID=0.19000000E+02 CONDITIONAL LIKELIHOOD FOR SOME OBSERVATION ESTIMATED TO BE NEGLIGIBLE note that ID 19 is the first subject in the dataset. this is how I specify the $ERR (a combinative erro) and $EST: __________ $ERROR IPRED = F IRES = DV-IPRED FLAG=1 IF(STDY.GT.3) FLAG=0 DEL=0 W = SQRT(THETA(7)**2*FLAG+THETA(8)**2*(1-FLAG)+THETA(9)**2*IPRED**2) IF(W.EQ.0)DEL=1 IWRES = IRES/(W+DEL) IF (TYPE.EQ.2.AND.CMT.EQ.2) DUM=(LOQ-IPRED)/(THETA(7)**2*FLAG+THETA(8)**2*(1-FLAG)+THETA(9)**2*IPRED **2) CUMD=PHI(DUM) IF (TYPE.EQ.2) THEN F_FLAG=1 Y=CUMD ENDIF IF (TYPE.EQ.1) THEN F_FLAG=0 Y = IPRED+W*EPS(1) ENDIF $ESTIMATION METHOD=1 LAPLACIAN MAXEVAL=9999 PRINT=10 NOABORT or this: $ESTIMATION METHOD=1 INT LAPLACIAN MAXEVAL=9999 PRINT=10 NOABORT _____ Interstingly, when I use Log-transformed data, the model would run fine. this is how I specify $ERR (an additive error) and $EST, all the other aspects of model are the same between two tries. Could someone help me understand what is happening? Thanks. _____ $ERROR DEL = 0 IF(F.LE.0) DEL = 1 IPRED = LOG(F+DEL) IRES = DV-IPRED FLAG=1 IF(STDY.GT.3) FLAG=0 W = SQRT(THETA(7)**2*FLAG+THETA(8)**2*(1-FLAG)) DEL1=0 IF(W.EQ.0)DEL1=1 IWRES = IRES/(W+DEL1) IF (TYPE.EQ.2.AND.CMT.EQ.2) DUM = (LOG(LOQ)-IPRED)/(THETA(7)*FLAG+THETA(8)*(1-FLAG)) CUMD=PHI(DUM) IF (TYPE.EQ.2) THEN F_FLAG=1 Y=CUMD ENDIF IF (TYPE.EQ.1) THEN F_FLAG=0 Y=IPRED +EPS(1)*W ENDIF $ESTIMATION METHOD=1 LAPLACIAN MAXEVAL=9999 PRINT=10 NOABORT
