topic How to get standard error and confidence limit of parameter in proc nlin in New SAS User

How to get standard error and confidence limit of parameter in proc nlin

linlin87 — Fri, 21 Jul 2023 13:49:14 GMT

Hello to Sas community,

I would like help to get into table - like outest table - the confidence interval and standard error for the variables from proc nlin. How do you do?

I have statement like this so I am get parameter for every by variable patient. I will get the estimate for a,...,f out in parameters_out but the confidence limits I do not get. I see PROC REG has some TABLEOUT - is similar in PROC NLIN? I cannot find.

Help would be really good thank you!

proc nlin data = datafull_2016_2022 plots = fit maxiter = 200 save outest = parameters_final;
by prtcpt;
parameters a=-10 / pdata=parameters_init;
model y = a*exp(x/b) + c*exp(x/d) + e*x + f;
run;

Re: How to get standard error and confidence limit of parameter in proc nlin

ballardw — Fri, 21 Jul 2023 14:31:11 GMT

I think you want the OUTPUT statement to get the confidence limits. The OUTEST is different than overall parameters.

Output out=yourdatasetname <options>=<variablenames>;

I don't suggest a specific syntax because you do not indicate whether you want confidence limits of predicted values L95 and U95, LCL and UCL or of the mean L95M / U95M and LCLM/ UCLM.

Similarly there are multiple standard error options: STDI (individual predicted value) STDP (mean predicted value) STDR (standard error of residuals)

The out= dataset name would have to be different than the OUTEST name. If you want both sets of values in one dataset then you need to combine the two sets.

Re: How to get standard error and confidence limit of parameter in proc nlin

linlin87 — Fri, 21 Jul 2023 19:34:05 GMT

Thank you @ballardw for helping. I will try this but I think your suggesting get confidence and prediction interval for data? I want confidence intervals of the parameter values.

Re: How to get standard error and confidence limit of parameter in proc nlin

FreelanceReinh — Sat, 22 Jul 2023 11:19:58 GMT

Hello @linlin87,

Use the ODS OUTPUT statement

ods output ParameterEstimates=want;

before or in the PROC NLIN step. For each BY group and parameter, dataset WANT will contain the estimate (variable Estimate) and the confidence limits (LowerCL, UpperCL).

Re: How to get standard error and confidence limit of parameter in proc nlin

linlin87 — Mon, 24 Jul 2023 07:46:56 GMT

Thank you @ballardw and @FreelanceReinh for your helping me!