Computed theoretical power for N=100 and N=200 scenarios

Modules/ado/plus/m/metannt.hlp

@@ -0,0 +1,86 @@
+.-
+help for ^metannt^
+.-
+
+Estimates of absolute benefit or risk from meta-analysis 
+--------------------------------------------------------
+
+
+ ^metannt , measure(^or|rr|rd^) size(^#^) confint(^#,#^) baseline(^#[,#...#]^)^ 
+
+
+Description
+-----------
+
+This program is intended to aid interpretation of meta-analyses of binary 
+data by presenting the effect sizes in absolute terms. Both the number 
+needed to treat (NNT) and the number of events avoided (or added) per 
+1000 are presented. 
+
+The ^Number Needed to Treat (NNT)^ is the number of individuals required 
+to experience the intervention in order to expect there to be one 
+additional event to be observed. Assuming the event is undesireable, this 
+is termed the "number needed to treat to benefit" (NNTB). If the 
+intervention arm experiences more events, this is commonly refered to as 
+the "number needed to treat to harm" (NNTH). 
+
+^metannt^ calculates this by deriving an effect size (e.g. a risk ratio), 
+applying it to a population with a given event prevalance, and from this 
+deriving a projected event rate if the population were to receive the 
+intervention. The NNT is equal to 
+1/(control group event rate - treatment group event rate).
+
+The ^number of avoided or excess events (respectively) per 1000 population^ 
+is the difference between the two event rates multiplied by 1000. The 
+intervention group event rate is calculated in the same manner as with 
+the NNT. Optionally a confidence interval is also presented, using the 
+confidence limits of the effect size applied to the control group event 
+rate.
+
+Options for ^metannt^
+-------------------
+
+^baseline()^ specifies the baseline (ie. control group) event rates, from 
+which the NNT and number of events avoided are computed from. More than 
+one baseline event rate may be specified.
+
+^measure(^rr|or|rd^)^ specifies whether the estimated effect size pooled is
+a risk ratio, odds ratio or (absolute) risk difference.
+
+^size(^#^)^ denotes the size of the effect
+
+^confint(^#,#^)^ denotes the confidence interval around the effect size. 
+
+By default the saved results from the r() macros within @metan@ are used to
+derive the control group event rate, the effect measure, the effect size and 
+its confidence interval. However, unless a recent version of metan (1.71 
+onwards) was used immediately beforehand, the first three options must be 
+specified. The confidence interval is optional.
+
+
+Examples
+--------
+
+  . ^metannt , measure(rr) size(0.2) baseline(0.1,0.2,0.3)^ 
+
+  . ^metan tdeath tnodeath cdeath cnodeath, or^
+  . ^metannt , baseline(0.15)^ 
+
+
+
+
+Authors
+-------
+
+    Michael J Bradburn, Jonathan J Deeks, Douglas G Altman.
+    Centre for Statistics in Medicine, Institute of Health Sciences, 
+    Old Road, Headington, Oxford OX3 7LF, UK. 
+
+    email mike.bradburn@@cancer.org.uk
+
+Also see
+--------
+
+On-line: help for @metan@ (if installed), @meta@ (if installed)
+
+