st: kappa agreement standard errors

 From "Weichle, Thomas" To Subject st: kappa agreement standard errors Date Tue, 8 Dec 2009 13:24:16 -0600

```Hi Statalisters,
I am wondering why the calculation of the standard errors is different
for the kap command vs. the kapci command.

. kapci dual_15_85_6mp_dx dual_15_85_dx_12mth, tab

Health |
Care Dual |
User | Health Care Dual User
(15%<=VA |       (15%<=VA
Reliance<= |    Reliance<=85%)
85%) |         0          1 |     Total
-----------+----------------------+----------
0 |     1,395        118 |     1,513
1 |       261        158 |       419
-----------+----------------------+----------
Total |     1,656        276 |     1,932

N=1932
------------------------------------------------
Kappa (95% CI) = 0.341 (0.290 - 0.393)    (A)
------------------------------------------------
A = analytical

. help r()

. return list

scalars:
r(kappa) =  .3411969207847029
r(lb_an) =  .2896667786271169
r(ub_an) =  .3927270629422889
r(prop_e) =  .7022330671398995
r(prop_o) =  .8038302277432712
r(se) =  .0262913719660408
r(z) =  1.959963984540054
r(N) =  1932

. kap dual_15_85_6mp_dx dual_15_85_dx_12mth

Expected
Agreement   Agreement     Kappa   Std. Err.         Z      Prob>Z
-----------------------------------------------------------------
80.38%      70.22%     0.3412     0.0220      15.48      0.0000

. return list

scalars:
r(se) =  .0220367175735475
r(z) =  15.48310993440647
r(kappa) =  .3411969207847029
r(prop_e) =  .7022330671398995
r(prop_o) =  .8038302277432712
r(N) =  1932

Tom Weichle
Math Statistician
Center for Management of Complex Chronic Care (CMC3)
Hines VA Hospital, Bldg 1, C202
708-202-8387 ext. 24261
Thomas.Weichle@va.gov

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```