Dropping dupliate dates by person

[Jake Magel]

Hello, I am working with claims data and trying to drop duplicate dates by person in order to identify a single date for a group of claims
I have tried to generate an tag id by date and drop based on 0s but, so far, I am unable to get this to work. Would sure appreciate help with this. Thanks. Jake


I have also tried the following:

sort unique_person_id pert_service_start_dt
capture drop dup
quietly by pert_service_start_dt (unique_person_id): gen dup = cond(_N==1,0,_n)

clear
input long unique_person_id str10 pert_service_start_dt
1 "2013-07-12"
1 "2014-04-28"
1 "2014-10-17"
1 "2014-12-05"
1 "2014-12-22"
1 "2015-02-23"
1 "2015-03-05"
1 "2015-03-10"
1 "2015-04-28"
1 "2015-05-16"
1 "2015-07-19"
1 "2015-09-27"
1 "2015-09-28"
1 "2015-09-28"
1 "2015-12-01"
2 "2013-07-20"
2 "2013-10-14"
2 "2013-10-14"
2 "2013-10-14"
2 "2013-10-14"
2 "2013-10-14"
2 "2013-11-03"
2 "2013-11-03"
2 "2013-11-22"
2 "2013-11-24"
2 "2013-11-24"
2 "2013-11-24"
2 "2013-11-24"
2 "2013-11-24"
2 "2013-12-11"
2 "2013-12-11"
2 "2013-12-14"
2 "2013-12-14"
2 "2013-12-18"
2 "2013-12-28"
2 "2014-02-07"
2 "2014-03-03"
2 "2014-03-20"
2 "2014-03-31"
2 "2014-03-31"
2 "2014-03-31"
2 "2014-03-31"
2 "2014-04-06"
2 "2014-04-17"
2 "2014-04-17"
2 "2014-04-20"
2 "2014-04-20"
2 "2014-04-20"
2 "2014-04-20"
2 "2014-04-20"
2 "2014-04-30"
2 "2014-04-30"
2 "2014-04-30"
2 "2014-04-30"
2 "2014-04-30"
2 "2014-05-01"
2 "2014-05-01"
2 "2014-05-01"
2 "2014-05-01"
2 "2014-05-01"
2 "2014-05-02"
2 "2014-05-02"
2 "2014-05-02"
2 "2014-07-03"
2 "2014-07-03"
2 "2014-07-03"
2 "2014-07-19"
2 "2014-07-29"
2 "2014-07-30"
2 "2014-07-30"
2 "2014-08-17"
2 "2014-09-14"
2 "2014-09-22"
2 "2014-09-22"
2 "2014-09-22"
2 "2014-09-27"
2 "2014-10-02"
2 "2014-10-02"
2 "2014-10-07"
2 "2014-10-21"
2 "2014-10-21"
2 "2014-10-21"
2 "2014-10-21"
2 "2014-10-24"
2 "2014-10-24"
2 "2014-10-24"
2 "2014-10-24"
2 "2014-10-29"
2 "2014-10-29"
2 "2014-10-29"
2 "2014-10-29"
2 "2014-10-30"
2 "2014-12-05"
2 "2014-12-05"
2 "2014-12-12"
2 "2014-12-12"
2 "2014-12-12"
2 "2014-12-31"
2 "2015-01-26"
2 "2015-01-26"
end
[/CODE]

[Joro Kolev]

Can you say a bit more how the tagging strategy failed?

Is this not what you want?

. sort unique pert

. egen tag = tag(unique pert)

. keep if tag
(49 observations deleted)

. list

     +-----------------------------+
     | unique~d   pert_ser~t   tag |
     |-----------------------------|
  1. |        1   2013-07-12     1 |
  2. |        1   2014-04-28     1 |
  3. |        1   2014-10-17     1 |
  4. |        1   2014-12-05     1 |
  5. |        1   2014-12-22     1 |
     |-----------------------------|
  6. |        1   2015-02-23     1 |
  7. |        1   2015-03-05     1 |
  8. |        1   2015-03-10     1 |
  9. |        1   2015-04-28     1 |
 10. |        1   2015-05-16     1 |
     |-----------------------------|
 11. |        1   2015-07-19     1 |
 12. |        1   2015-09-27     1 |
 13. |        1   2015-09-28     1 |
 14. |        1   2015-12-01     1 |
 15. |        2   2013-07-20     1 |
     |-----------------------------|
 16. |        2   2013-10-14     1 |
 17. |        2   2013-11-03     1 |
 18. |        2   2013-11-22     1 |
 19. |        2   2013-11-24     1 |
 20. |        2   2013-12-11     1 |
     |-----------------------------|
 21. |        2   2013-12-14     1 |
 22. |        2   2013-12-18     1 |
 23. |        2   2013-12-28     1 |
 24. |        2   2014-02-07     1 |
 25. |        2   2014-03-03     1 |
     |-----------------------------|
 26. |        2   2014-03-20     1 |
 27. |        2   2014-03-31     1 |
 28. |        2   2014-04-06     1 |
 29. |        2   2014-04-17     1 |
 30. |        2   2014-04-20     1 |
     |-----------------------------|
 31. |        2   2014-04-30     1 |
 32. |        2   2014-05-01     1 |
 33. |        2   2014-05-02     1 |
 34. |        2   2014-07-03     1 |
 35. |        2   2014-07-19     1 |
     |-----------------------------|
 36. |        2   2014-07-29     1 |
 37. |        2   2014-07-30     1 |
 38. |        2   2014-08-17     1 |
 39. |        2   2014-09-14     1 |
 40. |        2   2014-09-22     1 |
     |-----------------------------|
 41. |        2   2014-09-27     1 |
 42. |        2   2014-10-02     1 |
 43. |        2   2014-10-07     1 |
 44. |        2   2014-10-21     1 |
 45. |        2   2014-10-24     1 |
     |-----------------------------|
 46. |        2   2014-10-29     1 |
 47. |        2   2014-10-30     1 |
 48. |        2   2014-12-05     1 |
 49. |        2   2014-12-12     1 |
 50. |        2   2014-12-31     1 |
     |-----------------------------|
 51. |        2   2015-01-26     1 |
     +-----------------------------+

.

[Jake Magel]

Exactly. Thanks.

[Joro Kolev]

You are welcome.

egen, tag

selects one observation in the group identified by the varlist within parenthesis in tag().

And btw my sorting in

 
 . sort unique pert

is redundant, no need to sort like that.