I am trying to learn meta analysis and I am using an example from Bland, An Introduction to Medical Statistics:
When I use admetan, from SSC, I have no problem:
However when I try to use meta set from Stata 16 I get the following error message:
I appreciate from the Manual that the CI should be symmetric but I do not understand how I can resolve this error.
Thank you,
Janet
Code:
* Example generated by -dataex-. To install: ssc install dataex clear input float(or ll ul) .29 .03 3.12 5.09 .5 52.29 .35 .16 .74 .18 .08 .55 1.24 .52 2.96 .17 .07 .43 .71 .14 3.66 .58 .25 1.36 .4 .24 .66 .01 0 .21 .82 .27 2.54 1.44 .37 5.67 .61 .29 1.28 .59 .34 1.04 .46 .1 2.05 .5 .17 1.54 .98 .56 1.72 end
Code:
. admetan or ll ul Studies included: 17 Participants included: Unknown Meta-analysis pooling of aggregate data using the fixed-effect inverse-variance model -------------------------------------------------------------------- Study | Effect [95% Conf. Interval] % Weight ---------------------+---------------------------------------------- 1 | 0.290 0.030 3.120 0.21 2 | 5.090 0.500 52.290 0.00 3 | 0.350 0.160 0.740 6.00 4 | 0.180 0.080 0.550 9.14 5 | 1.240 0.520 2.960 0.34 6 | 0.170 0.070 0.430 15.57 7 | 0.710 0.140 3.660 0.16 8 | 0.580 0.250 1.360 1.64 9 | 0.400 0.240 0.660 11.44 10 | 0.010 0.000 0.210 45.76 11 | 0.820 0.270 2.540 0.39 12 | 1.440 0.370 5.670 0.07 13 | 0.610 0.290 1.280 2.06 14 | 0.590 0.340 1.040 4.12 15 | 0.460 0.100 2.050 0.53 16 | 0.500 0.170 1.540 1.08 17 | 0.980 0.560 1.720 1.50 ---------------------+---------------------------------------------- Overall effect | 0.193 0.122 0.264 100.00 -------------------------------------------------------------------- Test of overall effect = 0: z = 5.336 p = 0.000 Heterogeneity Measures --------------------------------------------------------- | Value df p-value ---------------------+----------------------------------- Cochran's Q | 39.61 16 0.001 I² (%) | 59.6% Modified H² | 1.475 tau² | 0.0420 --------------------------------------------------------- I² = between-study variance (tau²) as a percentage of total variance Modified H² = ratio of tau² to typical within-study variance
Code:
. meta set or ll ul confidence intervals not symmetric CIs defined by variables ll and ul must be symmetric and based on a normal distribution. If you are working with effect sizes such as odds ratios, risk ratios, or hazard ratios, the CIs should be specified on the log scale. r(459);
Thank you,
Janet
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