I have longitudinal data on registered arthropathy diagnoses for my study subjects including main group and a comparison group. As the data include 22 years of follow up, I want to see the pattern of incidence across age groups. I am looking for a stata command/module that does it automatically for me. I know how to do it manually but that takes some time and is not the best choice for me. Any guidance from my experienced colleagues is very much appreciated.
I think its better to use some basic statistical software's like SPSS and SAS
Dear Mehdi,
I presume you have each patient followed from diagnosis until some event, and that the follow-up length varied for each patient, with right-censoring and late entry (ie, by longitudinal you mean the sample cohort being followed and not different samples being surveyed over time).
If yes, one way to do that is first:
1 - stset the data (by time or date, and other options)
2 - use the strate / stmh
For age-specific incidences, you split the data first
3 - Use the stsplit in agebands
4 - Use strate / stmh
Notes:
1 - when using stset, pay attention to each scale to you want, eg: scale(365.25) - year; scale(12) - months
2 - be carefull when using stsplit, it is very powerful, but you can messy things
3 - strate allows you to obtain rates per(1000) per(100000) and the unit depends on the scale in stset
I hope it helped
some tutorials in the links
http://www.pauldickman.com/survival/stset.pdf
http://biostat3.net/download/stataintro.pdf
http://www.pauldickman.com/teaching/veneto2005/labs.pdf
Dear Otavio, thank you very much. You have good knowledge of this filed! I am going to implement the analysis the way you have prposed. I will come back when I am done.
Thank all for useful conversation. Could you please tell us that if no follow up time is not available and data is available with number of incidence and if we know the population size and interested to calculate the rate per 100000 with 95% CI then what would be the STATA command
- Badges
- Science topic