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From | YANNAN SHEN <yannan2010@gmail.com> |
To | "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu> |
Subject | Re: st: time-series data identified by three variables |
Date | Fri, 30 Nov 2012 04:58:27 -0500 |
Hi Nick, There is one more thing I need your help with. Within each group where there is a patient return to treat the same disease, I want to calculate the duration between the repeat visit with his first visit . I wrote the following code: > bysort patient_id illness_id date: gen duration = date[_n]-date[1] but it returns all zeros. What is wrong? Sent from my iPhone On Nov 28, 2012, at 4:21 AM, Nick Cox <njcoxstata@gmail.com> wrote: > You want commands like > > bysort patient_id illness_id date of visit : egen meansev = mean(severity) > by patient_id illness_id : gen repeat = _n - 1 > > as you want to number 0 upwards. > > > Nick > > On Wed, Nov 28, 2012 at 6:28 AM, yannan shen <yannan2010@gmail.com> wrote: > >> I am working some panel data of hospital visits and I want to learn >> the severity of various disease. >> The variables I have in the dataset are: patient_id, illness_id, >> date_of_visit, severity >> each observation contains: patient_id, illness_id, date_of_visit, severity. >> >> For each patient (identified by patient_id), I want to know how many >> of times he has visited for the same illness (illness_id ). >> I use the duple command to to label the observation of patients who >> have visited hospital more than once. >> >>> duplicates tag patient_id illness_id , generate(duple) >> >> However, duple does not give information for any time series >> information. If a patient has 5 visiting records, I want to be able to >> know which is the 0th repeat, 1st repeat, 2nd repeat, 3rd repeat, and >> 4th repeat...I have a vague feeling that I can order those variables >> via date_of_visit but I am still not sure how exactly that can be >> done. >> >> Furthermore, I want to create two new variables: one variable equals >> to the average severity of each disease (disease_id) being treated on >> the same date_of_visit. The other variable equals the highest severity >> of a certain disease being treated on that day. (Ideally, I want to >> create additional variables for each observation) >> >> I have used “bysort” in the past but since now the type is a >> combination of illness_id and date_of_visit, I am a little confused. > > * > * 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/ * * 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/