title: The WHO analgesic ladder for cancer pain control, twenty years of use. How much pain relief does one get from using it?
abstract: BACKGROUND
  Pain is a major problem in the treatment of patients with cancer. This article reviews studies concerning evaluation of patients with cancer pain treated according to The World Health Organization (WHO) analgesic ladder.
  
  
  METHODS
  Systematic search of PUBMED, MEDLINE, EMBASE, LILACS, BDENF, and OVID and a hand search of reference lists and textbooks from 1982 to 2004 were performed.
  
  
  RESULTS
  Analgesia was considered adequate in 45 to 100% of patients analyzed in the studies.
  
  
  CONCLUSIONS
  However, the evidence that they provide is insufficient to grant the effectiveness of the WHO guidelines because a controlled clinical trial of this intervention has never been published.
authors.affiliation: School of Nursing, University of São Paulo, Av Dr Enéas de Carvalho Aguiar, 419, 05403-0, São Paulo, SP, Brazil. karileao@usp.br
authors.forename: Karine
authors.initials: K
authors.lastname: Azevedo São Leão Ferreira
authors.forename: Miako
authors.initials: M
authors.lastname: Kimura
authors.forename: Manoel
authors.initials: M
authors.lastname: Jacobsen Teixeira
mesh_terms: D000700:Analgesics / Q000592:standards* / Q000627:therapeutic use*; D006801:Humans; D009369:Neoplasms / Q000150:complications*; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D010147:Pain Measurement; D011446:Prospective Studies; D012107:Research Design; D012189:Retrospective Studies; D016896:Treatment Outcome; D014944:World Health Organization
chemical_list: D000700:Analgesics