Nick
[email protected]
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]]On Behalf Of Jinseok Kim
> Sent: 21 November 2006 15:09
> To: [email protected]
> Subject: st: person-period data using prsnperd command
>
>
> dear statalisters.
> I created a person-period data set using prsnperd command to conduct a
> discrete time hazard model and found a potential error in the data set
> created. Here's the syntax I used:
>
> . prsnperd childid minccage1 censored, t(72)
> No variation in event occurence for period 22!
> No variation in event occurence for period 32!
> No variation in event occurence for period 66!
> No variation in event occurence for period 68!
> No variation in event occurence for period 72!
>
> If I understand correctly, _period variable created by prsnperd should
> have values ranging from 1 to 72 because minccage1, my length-to-event
> variable in the model, has a maximum value of 72. And here's what I
> found strange:
>
> . tab _period if _period>72&_period<100, miss
>
> _period | Freq. Percent Cum.
> ------------+-----------------------------------
> 73 | 12 3.86 3.86
> 74 | 12 3.86 7.72
> 75 | 12 3.86 11.58
> 76 | 12 3.86 15.43
> 77 | 12 3.86 19.29
> 78 | 12 3.86 23.15
> 79 | 12 3.86 27.01
> 80 | 12 3.86 30.87
> 81 | 12 3.86 34.73
> 82 | 12 3.86 38.59
>
> *** I intentionally cut here to save the space...*******
>
> 94 | 11 3.54 82.32
> 95 | 11 3.54 85.85
> 96 | 11 3.54 89.39
> 97 | 11 3.54 92.93
> 98 | 11 3.54 96.46
> 99 | 11 3.54 100.00
> ------------+-----------------------------------
> Total | 311 100.00
>
> . tab _period if _period>1000, miss
>
> _period | Freq. Percent Cum.
> ------------+-----------------------------------
> 1001 | 1 0.20 0.20
> 1002 | 1 0.20 0.40
> 1003 | 1 0.20 0.60
> 1004 | 1 0.20 0.81
> 1005 | 1 0.20 1.01
> 1006 | 1 0.20 1.21
> 1007 | 1 0.20 1.41
> 1008 | 1 0.20 1.61
> 1009 | 1 0.20 1.81
> 1010 | 1 0.20 2.02
> 1011 | 1 0.20 2.22
> 1012 | 1 0.20 2.42
>
> I like to hear from you all regarding whether I missed something while
> I use it, or it is a known glitch. Thanks.
>
>
>
> Jinseok Kim, Ph.D.
> Assistant Professor
> College of Social Work
> University of South Carolina
> Columbia, SC 29208
>
> Tel: 803-576-6082
> Fax: 803-777-3498
> e-mail: [email protected]
>
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>
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