Longitudinal results of a randomized, placebo-controlled trial of botulinum toxin type B (BotB) in 109 subjects across 9 sites. (more details available below the variable definitions).
Format
A data frame with 631 observations and 7 variables
- week
week of measurement; type: numeric
- site
study site, levels: 1-9; type: double
- id
patient id at each site (not unique across sites); type: numeric 1-19
- treat
treatment assignment: levels: 1 = placebo, 2 = botox B 5000 units, 3 = botox B 10,000 units; type: double 1-3)
- age
age in years, range 26-83; type: numeric
- sex
sex of participant, 1 = F, 2 = M; type: double
- twstrs
total score of Toronto Western Spasmodic Torticollis Rating Scale, range 0-87; type: numeric
Source
This data set is from a study published in 1999 in the journal Neurology,
A. Brashear, M.F. Lew, D.D. Dykstra, C.L. Comella, S.A. Factor, R.L. Rodnitzky, R. Trosch, C. Singer, M.F. Brin, J.J. Murray, J.D. Wallace, A. Willmer–Hulme, M. Koller (1999), Safety and efficacy of NeuroBloc (botulinum toxin type B) in type A–responsive cervical dystonia. Neurology, 53(7), 1439.
This dataset has been passed through Statistical Methods for the Analysis of Repeated Measurements by Charles S. Davis, pp. 161-163 (Springer, 2002) and can also be found at Frank Harrell's website here.
Details
Cervical dystonia, also called spasmodic torticollis, is a painful condition in which your neck muscles contract involuntarily, causing your head to twist or turn to one side. Cervical dystonia can also cause your head to uncontrollably tilt forward or backward.
A rare disorder that can occur at any age, cervical dystonia most often occurs in middle-aged people, women more than men. Symptoms generally begin gradually and then reach a point where they don't get substantially worse.
109 subjects across 9 sites were randomized to placebo (N = 36), 5000 units of botulinum toxin B (N = 36), or 10,000 units of botulinum toxin B (N = 37), injected once at baseline into the affected muscle to partially paralyze it and make it relax, releasing the spasmed side of the neck and head.
The response variable is the score on the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS-Total on a 0-87 scale), which measures the severity, pain, and disability of cervical dystonia (higher scores mean more impairment) at weeks 0 (baseline), 2, 4, 8, 12, and 16. It is expected that the single botox injection at week 0 may wear off over time.