Analysis of methotrexate treatment effect in a longitudinal observational study: utility of cluster analysis.

@article{Wolfe1991AnalysisOM,
  title={Analysis of methotrexate treatment effect in a longitudinal observational study: utility of cluster analysis.},
  author={Frederick Wolfe and M A Cathey},
  journal={The Journal of rheumatology},
  year={1991},
  volume={18 5},
  pages={672-7}
}
We studied 235 patients with rheumatoid arthritis (RA) beginning therapy with methotrexate utilizing a k-means clustering algorithm. Four groups were identified: mild RA (Group 3), very severe RA (Group 4), and 2 groups intermediate in severity (Groups 1 and 2). Group 2, the largest of the clusters (n = 89), appeared to have greater tolerability of RA as measured by severity and psychological variables, and took the drug almost twice as long as other groups, although improvement was not greater… CONTINUE READING