# st: dstdize

 From "Claus Dethlefsen / Aalborg Sygehus" To Subject st: dstdize Date Wed, 3 Aug 2005 15:02:07 +0200

```Dear list

I am having some trouble with dstdize and hope that someone can help.

My dataset consists of a grouping variable "elderly" on 3 levels, "female" on 2 levels and a binary outcome variable (outc30). I wish to calculate standardized mortality-rates using the first group in "elderly" as reference.

I can almost accomplish this using dstdize, but I have trouble using the population variable. I set this to 1 just to get started and called the command as below (with output).

However, my wish is to use weights relating to the first group "elderly=60", that is 81/171 and 70/151 for male and female, respectively. These weights should be used in the other two groups and in the calculation of adjusted rates. How do I tell Stata to do this?

gen all=1
. dstdize outc30 all female, by(elderly)

----------------------------------------------------------
-> elderly= 60
Pop.  Stratum  Pop.
Stratum       Pop.     Cases  Dist. Rate[s] Dst[P]  s*P
----------------------------------------------------------
0         81        22  0.536 0.2716  0.550 0.1495
1         70        12  0.464 0.1714  0.450 0.0771
----------------------------------------------------------
Totals:          151        34    Adjusted Cases:     34.2
Crude Rate:   0.2252
95% Conf. Interval: [0.1601, 0.2930]

----------------------------------------------------------
-> elderly= 80
Pop.  Stratum  Pop.
Stratum       Pop.     Cases  Dist. Rate[s] Dst[P]  s*P
----------------------------------------------------------
0         96        35  0.565 0.3646  0.550 0.2006
1         74        25  0.435 0.3378  0.450 0.1519
----------------------------------------------------------
Totals:          170        60    Adjusted Cases:     59.9
Crude Rate:   0.3529
95% Conf. Interval: [0.2808, 0.4244]

----------------------------------------------------------
-> elderly= 110
Pop.  Stratum  Pop.
Stratum       Pop.     Cases  Dist. Rate[s] Dst[P]  s*P
----------------------------------------------------------
0         20        13  0.541 0.6500  0.550 0.3577
1         17         7  0.459 0.4118  0.450 0.1852
----------------------------------------------------------
Totals:           37        20    Adjusted Cases:     20.1
Crude Rate:   0.5405
95% Conf. Interval: [0.3870, 0.6987]

Summary of Study Populations:
elderly             N      Crude     Adj_Rate       Confidence Interval
--------------------------------------------------------------------------
60           151   0.225166     0.226554    [  0.160089,    0.293018]
80           170   0.352941     0.352555    [  0.280752,    0.424359]
110            37   0.540541     0.542861    [  0.386972,    0.698749]

_______________________________

Claus Dethlefsen, Msc, PhD
Klinisk Epidemiologisk Afdeling

Aalborg Sygehus Nord
9000 Aalborg

Tlf:   9932 1086
9932 1094 (direkte)
Fax:   9932 1088
email: aas.claus.dethlefsen@nja.dk

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```