Meta-Analysis Continuous

The Meta-Analysis Continuous procedure performs meta-analysis with continuous outcomes on raw data that are provided in the active dataset for the estimation of the effect size.

Refer to the following introductory video for a brief Meta-Analysis Continuous overview:

Example
Several research studies were conducted in history to investigate a faddish but debatable medicine to help treat type II diabetes. The oral medicine was claimed to be able to reduce the blood glucose level after meals. Data were collected from different research sites from 1979 to 1986.
A principal investigator would like to draw statistical inference about the effect of the oral medicine. Due to the fact that the data were generated from different studies, she proposed the idea of synthesizing the results across the studies to reach an overall understanding of the effect and to identify those underlying sources of variation in the outcomes.
Statistics
Confidence level, iterative method, step-halving, convergence tolerance, sample means, sample variance, standard deviation, estimated effect size, Cohen’s d, Hedges' g, Glass’s Delta, mean difference, cumulative analysis, estimation method, trim-and-fill, regression-based test, random-effects model, fixed-effects model, restricted maximum likelihood estimator, empirical Bayes estimator, Hedges estimator, Hunter-Schmidt estimator, DerSimonian-Laird estimator, Sidik-Jonkman estimator, Knapp-Hartung standard-error adjustment, truncated Knapp-Hartung standard-error adjustment, coefficients, EGGER’s regression-based test, intercept, multiplicative model, multiplicative dispersion parameter, quadratic estimator, homogeneity test, heterogeneity measures, prediction interval, estimated standard error, estimated p-value, cumulative overall effect size, estimated study weight.

Obtaining a Meta-Analysis Continuous analysis

  1. From the menus choose:

    Analyze > Meta Analysis > Continuous Outcomes > Raw Data...

  2. Under the Treatment Group section, select a Study Size variable to represent the sample size for the treatment group. The selected variable must be numeric (string variables are not supported).
  3. Select a Mean variable to represent the sample means for the treatment group. The selected variable must be numeric (string variables are not supported).
  4. Select either Standard deviation to specify the sample standard deviation, or Variance to specify the sample variance and then select a variable to represent the standard deviation/variance for the treatment group.
  5. Under the Control Group section, select a Study Size variable to represent the sample size for the control group. The selected variable must be numeric (string variables are not supported).
  6. Select a Mean variable to represent the sample means for the control group. The selected variable must be numeric (string variables are not supported).
  7. Select either Standard deviation to specify the sample standard deviation, or Variance to specify the sample variance and then select a variable to represent the standard deviation/variance for the control group.
  8. Optionally, select Study ID and/or Study Label variables. The selected Study ID variable cannot be the same as the selected Study Label variable.
  9. Optionally, select an Effect Size setting.
    Cohen's d
    The default setting estimates the Cohen’s d. When Adjusted standard error is selected, the setting estimates the Cohen’s d and its variance using an alternative formula divided by 2(Ntreatment + Ncontrol −2).
    Hedges' g
    Estimates the Hedges’ g. When Adjusted standard error is selected, the setting estimates the Hedges’ g and its variance using an alternative formula divided by 2(Ntreatment + Ncontrol −3.94).
    Glass's Delta
    Estimates the Glass’s Delta based on the control group. When Standardized based on treatment group is selected, Glass’s Delta is standardized based on the standard deviation of the treatment group.
    Unstandardized Mean Difference
    Estimates the mean difference by assuming the two population standard deviations are equal. When Unequal group variances is selected the mean difference is estimated by assuming the two population standard deviations are not equal.
  10. Optionally, select a Model setting. When Trim-and-Fill settings are enabled, the setting also controls the model that is used by pooling in the trim-and-fill analysis. When Bias settings are enabled, the setting also controls the model that is used by the regression-based test.
    Random-effects
    The default setting builds the random-effects model.
    Fixed-effects
    Builds the fixed-effects model.
  11. Optionally, you can:
    • Click Criteria... to specify the general criteria.
    • Click Analysis to specify the subgroup and cumulative analysis.
    • Click Inference to specify the estimation methods.
    • Click Contrast to control the contrast test.
    • Click Bias to access the publication bias by conducting the EGGER’s regression-based test.
    • Click Trim-and-Fill to implement the trim-and-fill analysis of publication bias.
    • Click Print to control the table outputs.
    • Click Save to save the estimated statistics to the active data set.
    • Click Plot to specify which plots to include in the output.
  12. Click OK.

This procedure pastes META CONTINUOUS command syntax.