Download PDFPDF

Evidence of selection bias in preterm survival studies: a systematic review
Compose Response

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
Author Information
First or given name, e.g. 'Peter'.
Your last, or family, name, e.g. 'MacMoody'.
Your email address, e.g.
Your role and/or occupation, e.g. 'Orthopedic Surgeon'.
Your organization or institution (if applicable), e.g. 'Royal Free Hospital'.
Statement of Competing Interests


  • Responses are moderated before posting and publication is at the absolute discretion of BMJ, however they are not peer-reviewed
  • Once published, you will not have the right to remove or edit your response. Removal or editing of responses is at BMJ's absolute discretion
  • If patients could recognise themselves, or anyone else could recognise a patient from your description, please obtain the patient's written consent to publication and send them to the editorial office before submitting your response [Patient consent forms]
  • By submitting this response you are agreeing to our full [Response terms and requirements]

Vertical Tabs

Other responses

Jump to comment:

  • Published on:
    Treatment decisions and survival data

    Dear Editor,

    Evans and Levene have endeavoured to review the published survival data for infants born at less than 28 weeks, to identify bias and to make recommendations facilitating more accurate comparison of the published survival rates [1].

    Practices regarding resuscitation vary between institutions and may change over time. In one study from a large regional centre in British Columbia, not includ...

    Show More
    Conflict of Interest:
    None declared.
  • Published on:
    Selection bias in preterm survival studies
    Dear Editor,

    The systematic review by Evans and Levine[1] identifies sources of selection bias in reporting preterm survival and recommends cohort characteristics, which should be defined to avoid bias in future studies. To these should be added the more fundamental source of confounding; that of lack of uniformity in defining a ‘live birth’, particularly around the margins of viability. Statute law does not consiste...

    Show More
    Conflict of Interest:
    None declared.