Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
| From | Barth Riley <barthriley@comcast.net> |
| To | statalist@hsphsun2.harvard.edu |
| Subject | st: No observations in stcox models |
| Date | Fri, 08 Nov 2013 11:47:31 -0600 |
Dear listI am running a series of Cox regression models using stcox in Stat 11. I am obtaining the error message "No observations," despite the fact that the effective sample size (excluding missing values on all predictors and the failure variable) is between 150 and 550. There is also variability on all model variables. I should note that some of the predictors are categorical/ordinal and thus separate dummy variables for each category are being included in the model via the xi command. Could missing categories cause this error? Are there other factors to consider in determining the effective sample size for a Cox model?
Thanks in advance Barth * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/