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help for ^metacum^                                               (STB-42: sbe22)
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Cumlative meta-analysis, with graphics
--------------------------------------

	^metacum^ { theta | exp(theta) } { se_theta | var_theta | ll ul [cl] }
		[^if^ exp] [^in^ range] [^, v^ar ^ci^ ^eff^ect^(f^|^r)^ ^efo^rm ^l^evel^(^#^)^
		^gr^aph ^id(^strvar^)^ ^cl^ine ^fm^ult^(^#^)^ ^cs^ize^(^#^)^
		^ltr^unc^(^#^)^ ^rtr^unc^(^#^)^]


Description
-----------

^metacum^ provides cumulative pooled estimates, confidence limits, and a test
that the true pooled effect is zero, obtained from fixed or random effects
meta-analysis and, optionally, plots the cumulative pooled estimates
in the style of Lau et al. (1992). 

The user provides the effect estimate as ^theta^ (i.e., a log risk ratio,
log odds ratio, or other measure of effect). Likewise, the user supplies a 
measure of theta's variability (i.e., its standard error, ^se_theta^, or
its variance, ^var_theta^). Alternatively,  the user provides ^exp(theta)^
(e.g. a risk ratio or odds ratio) and its confidence interval, ^(ll, ul)^.

Options
-------

^var^ means the user has specified a variable containing the variance of
the effect estimate.  If this option is not included, the command assumes
the standard error has been specified.

^ci^ means the user has specified the lower and upper confidence limits of
the effect estimate, which is assumed to be on the ratio scale (e.g. odds ratio
or risk ratio).

^effect(f^|^r)^ must be included. This specifies whether ^f^ixed or ^r^andom-effects
esimates are used in the output and graph.

^eform^ requests that the output is exponentiated. This is useful for effect
measures such as log odds ratios which are derived from generalized linear
models. If the ^eform^ and ^graph^ options are used, then the graph output is 
exponentiated, with a log scale for the x axis.

^level(^#^)^ specifies the level for the confidence intervals (default 95).

^id(^strvar^)^ is a character variable which is used to label the studies.  If
the data contains a labelled numeric variable then the @decode@ command can be
used to create a character variable

Options for graphing results
----------------------------

^graph^ requests a graph. Graph options are allowed, except for ^ylabel()^,
^symbol()^, ^xlog^, ^ytick^ and ^gap^.

^cline^ asks that a vertical dotted line be drawn at the combined estimate.

^csize(^#^)^ gives the size of the circles used in the graph (default 180).

^fmult(^#^)^ is a number greater than zero which can be used to scale 
the font size for the study labels. The font size is automatically
reduced if the maximum label length is greater than 8, or the number
of studies is greater than 20. However it may be possible to increase
it somewhat over the default size.

^ltrunc(^#^)^ truncates the left side of the graph at ^#^. This is used to truncate
very wide confidence intervals. However ^#^ must be less than each of the
individual study estimates.

^rtrunc(^#^)^ truncates the right side of the graph at ^#^, and must be greater than
each of the individual study estimates.


Required input variables
------------------------

  ^theta^        the effect estimate
  ^se_theta^     the corresponding standard error

 or

  ^theta^        the effect estimate
  ^var_theta^    the corresponding variance

 or

  ^exp(theta)^   the risk (or odds) ratio
  ^ll^           the lower limit of the risk ratio's confidence interval
  ^ul^           the upper limit of the risk ratio's confidence interval
 [^cl^]          optional (see below)


Optional input variable
-----------------------

^cl^ contains the confidence level of the confidence interval defined by
^ll^ and ^ul^.  If ^cl^ is not provided, the procedure assumes that
each confidence interval is at the 95% confidence level.  ^cl^ allows the
user to provide the confidence level, by study, when the confidence interval
is not at the default level.  ^cl^ can be specified with or without a 
decimal point.  For example, .90 and 90 are equivalent and may be mixed 
(i.e., 90, .95, 80, .90 etc.).


Examples
--------

   . ^metacum logor selogor, effect(f) eform graph cline^
              ^xline(1) id(trialnam) xlab^ 
   . ^metacum meandiff vardiff, effect(r) var graph^ 
   . ^metacum rr ll ul, ci effect(r) eform^


Note
----

The command @meta@ must be installed before running @metacum@.


Author
------

       Jonathan Sterne
       United Medical and Dental Schools, UK
       email: j.sterne@@umds.ac.uk


Reference
---------

Lau J., E. M. Antman, J. Jimenez-Silva, et al. 1992.
Cumulative meta-analysis of therapeutic trials for myocardial infarction.
New England Journal of Medicine 327: 248-54.


Also see
--------

    STB:  STB-42 sbe16.1, STB-38 sbe16
On-line:  help for @meta@ (if installed), @metareg@ (if installed), 
          @metabias@ (if installed)