The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Lack of concealment may lead to selection bias in cluster randomized trials of palliative care

På svenska

Author

  • MS Jordhoy
  • PM Fayers
  • Marianne Ahlner-Elmqvist
  • S Kaasa

Summary, in English

Comprehensive palliative care programs are often implemented on a community level, and to evaluate such interventions, randomization by cluster (community) may be the only feasible method. In trials randomizing individual subjects, the importance of proper concealment has been stressed, In cluster randomized trials, however, concealment of individual patient allocation is often impossible. The following risk of selection bias has been given little attention. In the present study, comparing palliative care to conventional care, community health care districts were defined as clusters and randomized. The patients' treatment assignment was determined by the allocation of the cluster in which they resided, and hence predictable by their address. A biased selection based on practical considerations related to patients' diagnoses and hospital departments was suspected. To explore this, cancer diagnoses were grouped according to local tradition for sharing of treatment responsibility among hospital departments. A significant difference between trial arms in distribution of these groups was revealed and strongly supported our suspicion. The finding carries an important message to future researchers: when using cluster randomization, any evidence of selection bias should be carefully checked and reported.

Publishing year

2002

Language

English

Pages

43-49

Publication/Series

Palliative Medicine

Volume

16

Issue

1

Document type

Journal article

Publisher

SAGE Publications

Topic

  • Otorhinolaryngology

Keywords

  • concealment
  • selection bias
  • palliative care
  • cluster randomization

Status

Published

Research group

  • Laryngoesophagology, Allergy and Life Quality

ISBN/ISSN/Other

  • ISSN: 1477-030X