eLetters

769 e-Letters

  • Propensity score matching to minimize confounding by indication
    Sujit D Rathod
    The authors made a concerted effort to control for confounding in the design and analysis phase of this paper, and correctly stated that unmeasured confounding is a limiting feature of the results. Given the understandable concerns about confounding by indication, another approach the authors may wish to consider is propensity score matching for the analysis. Indeed, they should be able to show that a given hypnotic user had some...
    Show More
  • Adjustment or over-adjustment for 'TB incidence in the country of birth'?
    Sooyeon Min

    The recent paper by Dobler et al. (2012) highlights the challenge of variable selection and adjustment in multivariate analyses [1]. The authors state that including the potentially confounding variable 'TB incidence in the country of birth' was one of the major strengths of their study. TB incidence in the country of birth is indeed an important predictor of the risk of developing TB - but it may not be a true confounde...

    Show More
  • Re:Are we sure that baby-led weaning is nutritionally adequate and can prevent childhood obesity?
    Ellen Townsend

    In response to the letter from ECOG we would to like highlight that the criticisms levied against our research were already discussed explicitly in our paper and the limitations, for example, of parental self -report were mentioned up front in the article in the summary box. For precisely the reasons mentioned by the ECOG group we generated a matched sample from our total sample in which we controlled for age. The matched...

    Show More
  • Response: "Hypnotics' association with mortality or cancer: a matched cohort study"
    Devonne M Ryan

    Dr. Daniel Kripke,

    Thank you for you article entitled "Hypnotics' association with mortality or cancer: a matched cohort study," I enjoyed reading it and found it to be especially interesting. Nonetheless, I have a few comments and questions related to your research area and your article. Firstly, I thought the research design you choose was suitable for the nature of the research. The matched cohort study was...

    Show More
  • Are we sure that baby-led weaning is nutritionally adequate and can prevent childhood obesity?
    Andrea Vania
    Sir, we write you regarding the article "Baby knows best? The impact of weaning style on food preferences and body mass index in early childhood in a case e controlled sample" by Ellen Townsend and Nicola J Pitchfordby, published on BMJ Open 2012;2:e000298. doi:10.1136/ bmjopen-2011-000298 We strongly disagree from the results shown by the authors, as we think that the article has strong bias which do not allow such conclusions....
    Show More
  • Re:Hypnotics and mortality: A time for action
    Daniel F Kripke

    We apologize if we created confusion by saying we "adjusted" for prior cancer. Indeed, our method of adjustment was to exclude all patients with any diagnosis of major cancer prior to the interval of observation. Similarly, when examining non-melanoma skin cancers, we excluded patients with prior skin cancers.

    Unfortunately, only dichotomous responses concerning whether patients used alcohol were available in...

    Show More
  • Need for accessible non-drug treatments
    Daniel F Kripke
    As these distinguished authors write, efforts should be made to improve the accessibility of non-drug treatments for insomnia such as cognitive-behavioral approaches. By reducing the use of hypnotics, such treatments might be life-saving.

    Conflict of Interest:

    Please see our BMJ Open article

  • Insomnia in the UK: who cares?
    Colin A Espie

    Insomnia is twice as common in the UK as anxiety or depressive symptoms(1). Indeed, chronic insomnia is a risk factor for the development of such mental health problems(2). Yet in a week when new research shows that the prevalence of insomnia is increasing in England(3), and that even occasional hypnotic drug use continues to be associated with excess mortality(4), it is disappointing that after 21 months of waiting for a...

    Show More
  • Hypnotics and mortality: more evidence is needed
    Victor Vallejo-Garcia

    Dear Editor:

    We have read with great interest the recent article by Kripke DF, Langer RD and Kline LE that assessed the risk of all cause mortality and cancer incidence in patients using benzodiazepines or zolpidem. The article poses relevant questions about the use of these drugs and it is likely to have a very large influence on the decisions that health care practioners take, particularly because of the larg...

    Show More
  • richard link

    Why weren't people with insomnia who didn't take hypnotics included in the control group-could insomnia and not hypnotics be the factor causing excess death???Is the dose relationship just an indication of the severity of insomnia?

    Conflict of Interest:

    None declared

Pages