eLetters

709 e-Letters

  • Hypnotics' association with mortality or cancer: bias related to the study design and analysis
    Morten Andersen (1)

    In BMJ Open, Kripke et al have presented a study on risks associated with the use of hypnotics (1). In their two-in-one study, the authors report an about fourfold increased risk of death and a 35% increased risk of cancer when comparing users of hypnotics with non-users. The authors present the analyses as a cohort study using a survival analysis model with Cox regression. However, several approaches in both the study d...

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  • Low serum 25-hydroxyvitamin D concentrations may explain the association between dental plaque and cancer mortality
    Wililam B. Grant

    The finding that dental plaque is directly associated with 1.79 times the odds ratio of cancer mortality rates [1] is interesting. However, the conclusion that the bacterial load on tooth surfaces and gingival pockets may play a role in carcinogenesis is most likely incorrect. It is not clear how oral bacteria would cause cancer.

    An alternative explanation for the association is that high dental plaque is a mar...

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  • Is it hypnotics that kill, or is it psychiatric illness?
    Kenneth G Terkelsen, MD

    Is it hypnotics that kill, or is it psychiatric illness? * Kenneth G. Terkelsen, M.D. General Psychiatrist, Assistant Director * James P. McGuire, M.D. Child and Adolescent Psychiatrist Behavioral Health Services Community Health Center of Cape Cod Mashpee, Massachusetts, USA

    * Michael B. Friedman, Adjunct Associate Professor Columbia School of Social Work and Mailman School of Public Health New York, New York, US...

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  • May Systemic Atherosclerotic Risk Classification Bring a Different Glance to the CORONARY Study?
    Sinan Demirtas

    May Systemic Atherosclerotic Risk Classification Bring a Different Glance to the CORONARY Study?

    Running Title; the CORONARY Study and Atherosclerosis Classification ? Sinan DEMIRTAS, Medical School of Dicle University, Department of Cardiovascular Surgery celalyav@hotmail.com Oguz KARAHAN, Medical School of Dicle University, Department of Cardiovascular Surgery oguzk2002@gmail.com ?

    Corresponding Autho...

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  • bias and confounding
    Ingrid Muehlhauser

    There are major concerns related to confounding and bias in this study. More intensive medication in the obese subjects is obviously mainly due to twice as high prevalence rates of hypertension and diabetes compared to subjects with normal BMI. Do the authors suggest that diabetes and hypertension improve life expectancy? Statin use was apparently not different across BMI categories. On the other hand, antidabetic drug t...

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  • Re:Adjustment or over-adjustment for 'TB incidence in the country of birth'?
    Guy B. Marks

    We thank the correspondents Min and Gyorkos for their comments on our paper, which focus on the appropriateness of adjustment for confounding in the analysis. We do not agree that the analysis suffers from over- adjustment for confounding. Over-adjustment occurs when a factor that is on the casual pathway between the main effect (exposure of interest) and the outcome is included as covariate. The decision about whether a fa...

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  • Re:Conflict of interest: response to Ms Colella
    Daniel F. Kripke

    Please note that my co-authors have approved our manuscript, but Dr. Langer and Dr. Kline have no previous publications about hypnotic drugs and no affiliation with the www.DarkSideOfSleepingPills.com web site. Some people would think it scientifically proper that I participated in a new study which overcomes some of the limitations of my previous scientific studies, along with co-authors who have no previous biases or...

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  • Conflict of interest
    Angela M Colella

    Dear Editor: I appreciated and read Dr. Kripke's manuscript with interest. He and his co-authors present many considerations healthcare providers should acknowledge when prescribing hypnotics. Hypnotics, like all medications, have inherent risks. I was disappointed however, to read about Dr. Kripke's affiliation, or hosting, of the website www.DarkSideOfSleepingPills.com. In my opinion, this affiliation casts a signi...

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  • Things May Not Be As They Seem
    Jose Maria Lopez Lozano

    Sir, In their recent study from Oxfordshire, Wyllie and colleagues questioned the role that intensive infection control measures have played in controlling the epidemic of MRSA in hospitals in their region. [1] The authors suggest that effects of introducing intensive interventions for MRSA may have been limited, given that stabilization and subsequent declines in rates of MRSA occurred prior to such measures, and were...

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  • Response to Article: Baby knows best? The impact of weaning style on food preferences and body mass index in early childhood in a case-controlled sample
    Smita Nambiar

    Dear Madam,

    This letter is in response to the article entitled 'Baby knows best? The impact of weaning style on food preferences and body mass index in early childhood in a case-controlled sample' (doi 10.1136/bmjopen-2011- 000298).

    In this article, the impact of the 'how' of introduction to solid feeding (self-feeding finger foods versus spoon-feeding), on food preference, food consumption, BMI and p...

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