6,483 research outputs found
INTRODUCTORY REMARKS: NEW VALUE-ADDED LIVESTOCK AND POULTRY INITIATIVES
Livestock Production/Industries,
Effect of regression to the mean on decision making in health care
Knowledge of regression to the mean can help with everything from interpreting test results to improving your career prospects. All healthcare professionals should be aware of its implication
Comment on ``Experimental demonstration of the violation of local realism without Bell inequalities'' by Torgerson et al
We exhibit a local-hidden-variable model in agreement with the results of the
two-photon coincidence experiment made by Torgerson et al. [Phys. Lett. A 204
(1995) 323]. The existence of any such model shows that the experiment does not
exclude local realism.Comment: LaTeX, 5 page
Evidence for risk of bias in cluster randomised trials: review of recent trials published in three general medical journals
Objective To examine the prevalence of a risk of bias associated with the design and conduct of cluster randomised controlled trials among a sample of recently published studies. Design Retrospective review of cluster randomised trials published in the BMJ, Lancet, and New England Journal of Medicine from January 1997 to October 2002. Main outcome measures Prevalence of secure randomisation of clusters, identification of participants before randomisation (to avoid foreknowledge of allocation), differential recruitment between treatment arms, differential application of inclusion and exclusion criteria, and differential attrition. Results Of the 36 trials identified, 24 were published in the BMJ, I I in the Lancet, and a single trial in the New England journal of Medicine. At the cluster level, 15 (42%) trials provided evidence for secure allocation and 25 (69%) used stratified allocation. Few trials showed evidence of imbalance at the cluster level. However, some evidence of susceptibility to risk of bias at the individual level existed in 14 (39%) studies. Conclusions Some recently published cluster randomised trials may not have taken adequate precautions to guard against threats to the internal validity of their design
Hormone replacement therapy and prevention of vertebral fractures: a meta-analysis of randomised trials
BACKGROUND: Hormone replacement therapy (HRT) is often seen as the treatment of choice for preventing fractures in women. We undertook a recent meta-analysis of randomised trials which suggested that HRT reduced non-vertebral fractures by 30%. In this analysis we extend that analysis to vertebral fractures. METHODS: We searched the main electronic databases until the end of August 2001. We sought all randomised controlled trials (RCTs) of HRT where women had been randomised to at least 12 months of HRT or to no HRT. RESULTS: We found 13 RCTs. Overall there was a 33% reduction in vertebral factures (95% confidence interval (CI) 45% to 98%). CONCLUSIONS: This review and meta-analysis showed a significant reduction in vertebral fractures associated with HRT use
Influence of therapist competence and quantity of cognitive behavioural therapy on suicidal behaviour and inpatient hospitalisation in a randomised controlled trial in borderline personality disorder: Further analyses of treatment effects in the BOSCOT study
<br>Objectives. We investigated the treatment effects reported from a high-quality
randomized controlled trial of cognitive behavioural therapy (CBT) for 106 people with
borderline personality disorder attending community-based clinics in the UK National
Health Service â the BOSCOT trial. SpeciïŹcally, we examined whether the amount of
therapy and therapist competence had an impact on our primary outcome, the number of
suicidal acts, using instrumental variables regression modelling.
Design. Randomized controlled trial. Participants from across three sites (London,
Glasgow, and Ayrshire/Arran) were randomized equally to CBT for personality disorders
(CBTpd) plus Treatment as Usual or to Treatment as Usual. Treatment as Usual varied
between sites and individuals, but was consistent with routine treatment in the UK
National Health Service at the time. CBTpd comprised an average 16 sessions (range
0â35) over 12 months.</br>
<br>Method. We used instrumental variable regression modelling to estimate the impact of
quantity and quality of therapy received (recording activities and behaviours that took place after randomization) on number of suicidal acts and inpatient psychiatric
hospitalization.</br>
<br>Results. A total of 101 participants provided full outcome data at 2 years post
randomization. The previously reported intention-to-treat (ITT) results showed on
average a reduction of 0.91 (95% conïŹdence interval 0.15â1.67) suicidal acts over 2 years
for those randomized to CBT. By incorporating the inïŹuence of quantity of therapy and
therapist competence, we show that this estimate of the effect of CBTpd could be
approximately two to three times greater for those receiving the right amount of therapy from a competent therapist.</br>
<br>Conclusions. Trials should routinely control for and collect data on both quantity of
therapy and therapist competence, which can be used, via instrumental variable
regression modelling, to estimate treatment effects for optimal delivery of therapy. Such
estimates complement rather than replace the ITT results, which are properly the
principal analysis results from such trials.</br>
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