ashina data frame has 16 rows and 3 columns. It contains
data from a crossover trial for the effect of an NO synthase inhibitor
on headaches. Visual analog scale recordings of pain levels were made
at baseline and at five time points after infusion of the drug or
placebo. A score was calculated as the sum of the differences from
baseline. Data were recorded during two sessions for each patient. Six
patients were given treatment on the first occasion and the placebo on
the second. Ten patients had placebo first and then treatment. The
order of treatment and the placebo was randomized.
This data frame contains the following columns:
a numeric vector, summary score when given active substance.
a numeric vector, summary score when given placebo treatment.
a numeric vector code, 1: placebo first, 2: active first.
M.Ashina et al. (1999), Effect of inhibition of nitric oxide synthase on chronic tension-type headache: a randomised crossover trial. Lancet 353, 287–289