Loading in 5 sec....

The Conditional Random-Effects Variance Component in Meta-regressionPowerPoint Presentation

The Conditional Random-Effects Variance Component in Meta-regression

- 116 Views
- Uploaded on

Download Presentation
## PowerPoint Slideshow about ' The Conditional Random-Effects Variance Component in Meta-regression' - colton-suarez

**An Image/Link below is provided (as is) to download presentation**

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript

### The Conditional Random-Effects Variance Component in Meta-regression

Michael T. Brannick

Guy Cafri

University of South Florida

Background

- What is the random-effects variance component (REVC)?
- What is the conditional random-effects variance component (CREVC)?
- Who cares? (Tells whether we are done!)

Items of Interest

Point Estimators of the CREVC

Method of Moments (WLS)

Maximum Likelihood (iterated WLS)

Significance tests

Fixed chi-square

Random chi-square (2 of these)

Lower bound > 0 (3 of these)

Confidence Intervals (3 types)

ML, bootstrap, bootstrap adjusted

- Bias
- RMSE
- Type I error
- Power
- Coverage probability
- Width

Monte Carlo Method

- Effect size: d
- Conditions (based on literature)
- REVC: 0, .04, .10, .19, .35, .52
- Proportion A/C: 0, .02, .18, .50
- K studies: 13, 22, 30, 69, 112, 234
- Average N (skewed): 53, 231, 730

- Reps: 10k times each for 378 cells

Results – Point Estimates

Note: results are averages over cells

Method of moments is less biased than max like until k > 100

Results – Confidence Intervals

Bias corrected bootstrap has best coverage; similar width

Coverage

Width

Implications

- Slight preference for method of moments WLS when k is small
- Use the fixed-effects chi-square for testing the CREVC
- Use the bias-corrected bootstrap for constructing confidence intervals

Conclusions

- Please indicate the uncertainty of the estimates when reporting a meta-analysis (confidence intervals and/or standard errors of parameter estimates)
- Free software:
- http://luna.cas.usf.edu/~mbrannic/files/meta/MetaRegsMB1.sas

Download Presentation

Connecting to Server..