# Meta-SPSS

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 | META-SPSS DISCLAIMER ---------- META-SPSS is provided "as is" without warranty of any kind. The entire risk as to the quality, performance, and fitness for intended purpose is with you. You assume responsibility for the selection of the program and for the use of results obtained from that program. DESCRIPTION ----------- This collection of files adds meta-analytic facilities to SPSS: 1. Meta-analysis of P values (see 'MetaPValues-Info.txt' for technical details). 2. Meta-analysis of binary outcomes: RD, OR and RR, with both fixed & random effects (DerSimonian-Laird) models. Raw data (counts) or summary data (adjusted OR, RR or RD) can be used as input. Different fixed effects models: inverse variance (Woolf method), Mantel-Haenszel and Peto (this last only for OR) are available for raw data (counts); for summary data only the first. 3. Meta-analysis of continuous outcomes: unstandardised & standardised (Hedges, Cohen & Glass) mean differences, with both fixed (inverse variance) & random effects (DerSimonian-Laird) methods. Means, SD & N or Cohen's d can be used for input (except for Glass method, which requires means, SD & N). Orwin's Fail Safe N is computed for significant results. 4. Meta-analysis of correlation coefficients: Hedges-Olkin fixed & random effects models (inverse variance & Dersimonian-Laird). Orwin's Fail Safe N is computed for significant results. 5. Meta-analysis of correlation coefficients: Schmidt-Hunter method (simplified, unreliability or range departure correction methods are not included). See Larry Lyons paper & website (details in folder "Documents") for details. For methods 1 to 4, Higgins' I2 with its 95%CI is calculated (see 'Higgins I2 formula.txt' for details and a reference). For methods 2, 3 & 4, forest plots are also included (see below for a limitation). You must know meta-analysis before using them, although some short documents with meta-analysis theory & formulae are included in the folder "Documents". I recommend reading Andy Field's papers (Meta1.pdf, Metar.pdf & Metad.pdf)and taking a look at his website. A text file with useful references (mainly from British Medical Journal) and tutorials is also included. A very good book on the topic is 'Systematic Reviews in Health Care' Edited by Mathias Egger, George Davey Smith & Douglas G Altman. BMJ Books, 2nd Ed (2001). (ISBN: 0-7279-1488-X). Feel free to edit & modify every file. If you improve the code, I would like to have a copy. Questions can be sent to me: Marta Garcia-Granero (biostatistics@terra.es). SPSS files included: ------------------- - MetaDatasets.SPS: creates in drive A: a collection of datasets from published meta-analysis, mainly from British Medical Journal. Must be run once to obtain the datasets that MetaTests.SPS requires. - MetaAnalysisOfxxxxxxx.SPS: Syntax files for meta-analytic methods 1 to 5. The name, a bit long, it's related to the method: Method File ---------------------------------------------------------- Odds Ratio: Peto MetaAnalysisOfBinOutcomes(OR-Peto).SPS M-H MetaAnalysisOfBinOutcomes(OR-MH).SPS Inv Var MetaAnalysisOfBinOutcomes(OR-IV).SPS DerS-Laird MetaAnalysisOfBinOutcomes(OR-DL).SPS Summary data MetaAnalysisOfBinOutcomes(SumOR-IV).SPS MetaAnalysisOfBinOutcomes(SumOR-DL).SPS Risk Ratio: M-H MetaAnalysisOfBinOutcomes(RR-MH).SPS Inv Var MetaAnalysisOfBinOutcomes(RR-IV).SPS DerS-Laird MetaAnalysisOfBinOutcomes(RR-DL).SPS Summary data MetaAnalysisOfBinOutcomes(SumRR-IV).SPS MetaAnalysisOfBinOutcomes(SumRR-DL).SPS Risk Diff: M-H MetaAnalysisOfBinOutcomes(RD-MH).SPS Inv Var MetaAnalysisOfBinOutcomes(RD-IV).SPS DerS-Laird MetaAnalysisOfBinOutcomes(RD-DL).SPS Summary data MetaAnalysisOfBinOutcomes(SumRD-IV).SPS MetaAnalysisOfBinOutcomes(SumRD-DL).SPS Mean Difference: Inv Var MetaAnalysisOfContOutcomes(WM-IV).SPS DerS-Laird MetaAnalysisOfContOutcomes(WM-DL).SPS Hedges G (Stand. Mean Difference): Inv Var MetaAnalysisOfContOutcomes(G-IV).SPS DerS-Laird MetaAnalysisOfContOutcomes(G-DL).SPS Summary data MetaAnalysisOfContOutcomes(SumG-IV).SPS MetaAnalysisOfContOutcomes(SumG-DL).SPS Cohen d (Stand. Mean Difference): Inv Var MetaAnalysisOfContOutcomes(D-IV).SPS DerS-Laird MetaAnalysisOfContOutcomes(D-DL).SPS Summary data MetaAnalysisOfContOutcomes(SumD-IV).SPS MetaAnalysisOfContOutcomes(SumD-DL).SPS Glass delta (Stand. Mean Difference): Inv Var MetaAnalysisOfContOutcomes(Delta-IV).SPS DerS-Laird MetaAnalysisOfContOutcomes(Delta-DL).SPS Correlation (Hedges-Olkin): Inv Var MetaAnalysisOfCorrCoef(HO-IV).SPS DerS-Laird MetaAnalysisOfCorrCoef(HO-DL).SPS Correlation (Schmidt-Hunter): MetaAnalysisOfCorrCoef(SH).SPS P Values: MetaAnalysisOfPvalues.SPS ---------------------------------------------------------- - ForOR.SPS: For binary outcomes the information included assumes that RR and RD are the summary data of interest. This syntax has to be run after loading binary outcomes files if OR is the summary measure of interest. ForOR.SPS creates 4 extra variables, called: caex, canex, coex & conex. - MetaTests.SPS: a syntax file that shows the use of the different method files. - XXXXXX.sct: several chart templates that work with SPSS 11.5 or older. - Two SAV files in "Temp" folder: they are created by files of methods 2-4. They were originally included in the ZIP file to be sure that the "Temp" folder is created during installation, because several syntax files store information in Temp and it must exist to avoid errors. INSTALLATION ------------ - Download META-SPSS.ZIP and unzip its contents to a floppy disk (drive A:). - Run MetaDatasets.SPS once to create the 12 example datasets. - Open MetaTests.SPS and run it to see how the files work. ACCURACY OF THE METHODS ----------------------- I have tried to check the output with published datasets and other programs (Review Manager, Meta, Easy Meta Analysis, Combine...) and, to my knowledge, everything is OK. An extra check was performed comparing META-SPSS output with tables 15.4 & 15.6 of 'Systematic Reviews in Health Care' (p 303-306), using the same datasets. If you want to check that results with META-SPSS are correct, the datasets are included as 'MetaDataset(XII).sav' (binary outcomes) & 'MetaDataset(XIII).sav' (continuous outcomes). Table 15.4 Method Estimate (95% CI) Sig of effect(*) Heterogeneity --------------------------------------------------------------------------- Odds Ratio: Peto 0.59 (0.51 to 0.69) z=7.05 (p<0.001) X2=38.5 (p<0.001) M-H 0.59 (0.51 to 0.69) z=6.98 (p<0.001) X2=38.9 (p<0.001) Inv Var 0.60 (0.52 to 0.70) z=6.70 (p<0.001) X2=38.8 (p<0.001) DerS-Laird 0.54 (0.34 to 0.85) z=2.64 (p=0.008) Risk Ratio: M-H 0.79 (0.74 to 0.85) z=6.95 (p<0.001) X2=29.8 (p<0.001) Inv Var 0.80 (0.75 to 0.85) z=7.14 (p<0.001) X2=29.7 (p<0.001) DerS-Laird 0.77 (0.64 to 0.92) z=2.93 (p=0.003) Risk Diff: M-H -0.117 (-0.149 to -0.085) z=7.13 (p<0.001) X2=33.1 (p<0.001) Inv Var -0.127 (-0.158 to -0.095) z=7.86 (p<0.001) X2=32.7 (p<0.001) DerS-Laird -0.124 (-0.211 to -0.038) z=2.81 (p=0.005) --------------------------------------------------------------------------- Table 15.6 Method Estimate (95% CI) Sig of effect(*) Heterogeneity --------------------------------------------------------------------------- Fixed effect models: Cohen's d -0.16 (-0.41 to 0.08) z=1.29 (p=0.20) X2=2.34 (p=0.31) Hedges' g -0.16 (-0.41 to 0.08) z=1.29 (p=0.20) X2=2.31 (p=0.32) Glass's d -0.16 (-0.40 to 0.09) z=1.24 (p=0.21) X2=2.28 (p=0.32) Random effects models: Cohen's d -0.15 (-0.42 to 0.12) z=1.12 (p=0.26) Hedges' g -0.15 (-0.42 to 0.11) z=1.12 (p=0.26) Glass's d -0.15 (-0.42 to 0.12) z=1.10 (p=0.27) --------------------------------------------------------------------------- (*) META-SPSS gives a X2 test, mathematically equivalent (X2=(Z)2). --------------------------------------------------------------------------- LIMITATIONS & KNOWN BUGS ------------------------ Cumulative meta-analysis is not possible... yet (I'm working on that). Check this website from time to time to see if I have updated META-SPSS. The syntax files assume that everything runs from a floppy disk (A:). You will have to edit every 'Meta...SPS' file (including MetaTests.SPS & MetaDatasets.SPS) and replace every "A:" by a suitable drive&path if you want to run them from other location. This code was developed before SPSS 12 was released, and the chart templates included will only work with SPSS 11.5 or older. The graphs will need formatting if SPSS 12 is used (good luck, I never succeeded trying to apply chart templates in v12, and some options, available in older versions, have dissapeared). |

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