505 research outputs found
Celebrating the Life and Work of Sir David Cox
No full textI was privileged to have David Cox as a supervisor for my PhD (1983–1986) on the flow of water in dry rivers. The topic provoked laughter in the United Kingdom, but was familiar to me as an African born and bred. I learned from David to think about assumptions, and check what mathematicians had already demonstrated on mathematical functions and integrals. I often went to the library to search through the classic volumes informally known to pre-internet mathematicians as Abramowitz and Stegun and Gradshteyn and Ryzhik. I still try to think how I might get an approximate analytical solution to a likelihood function or an estimator rather than immediately resorting to simulation. David’s phrase “with some regularity conditions,” in relation to properties of estimators stayed with me. The phrase was behind a minor but surprisingly controversial article I wrote (Hutton, 2000) on a measure of comparison of rates, “Number needed to treat: properties and problems.” The number needed to treat is the inverse of a difference between two estimated rates, such as cure rates for two treatments (Cook and Sackett, 1995). The authors recommended including ‘Confidence intervals’ formed by inverting the confidence intervals for the difference. If the interval spans zero, a basic condition is violated
Women and independence in the nineteenth century novel : a study of Austen, Trollope and James
No full text'Women
and
independence in the nineteenth century novel : a
study
of
Austen, Trollope
and
James', begins
with the
concept of
independence
and works through the three
most common usages of
the
word.
The first, financial independence (not
needing to
earn one's
livelihood)
appears to be
a necessary prerequisite
for the
second
and third forms
of
independence,
although it is by
no means an
unequivocal good
in
any of
the
novels.
The
second,
intellectual
independence (not
depending
on others
for
one's opinion or conduct;
unwilling
to be
under obligation
to
others),
is
a matter of asserting independence
while employing
terms
which society recognizes.
The third,
of
being independent, is
exemplified
by
an
inward
struggle
for
a
knowledge
of self.
In
order
to trace the development
of
the idea
of self
during the
nineteenth century,
I have
chosen a group of novels which seem
to be
representative of
the beginning, the
middle, and the
end of
the period.
Particular
attention
is
given
to the
characterizations of
Emma
Woodhouse, Glencora Palliser, Isabel Archer, Milly Theale and
Maggie
Verver. Whereas in Jane Austen's
novels
the self
has a
definite shape
which the heroine
must
discover, and
in Anthony Trollope's
novels
the
self
(reflecting
the idea
of socially-determined man) must
learn to
accommodate social and political changes,
in Henry James's
novels
the
self
determined by
external manifestations
(hollow
man)
is
posed
against
the exercise of
the free
spirit or soul.
Jane Austen's
novels
look backward,
as she reacts against
late
eighteenth century romanticism, and
forward,
with
the development
of
the heroine
who exemplifies
intellectual independence. Anthony
Trollope's
women characters are creatures of social and political
adaptation; although
they do
not
derive their
reason
for being
from
men,
they
must accommodate
themselves to
men's wishes.
And
Henry James looks backward,
wistfully, at
Austen's
solid, comforting,
innocent
self and
forward, despairingly, to the dark,
unknowable self
of
the twentieth
century
Modelling the rate of change in a longitudinal study with missing data, adjusting for contact attempts
No full textThe Collaborative Ankle Support Trial (CAST) is a longitudinal trial in which interest lies in the rate of
improvement, the effectiveness of reminders and potentially informative missingness. A model is proposed for
continuous longitudinal data with non-ignorable or informative missingness, taking into account the nature of
attempts made to contact initial non-responders. The model combines a non-linear mixed model for the outcome\ud
model with a logistic regression model for the reminder process. A sensitivity analysis is used to contrast this
model with the traditional selection model, where we adjust for missingness by modelling the missingness process
Ethical issues in implementation research: a discussion of the problems in achieving informed consent
No full textBackground: Improved quality of care is a policy objective of health care systems around the world. Implementation research is the scientific study of methods to promote the systematic uptake of clinical research findings into routine clinical practice, and hence to reduce inappropriate
care. It includes the study of influences on healthcare professionals' behaviour and methods to enable them to use research findings more effectively. Cluster randomized trials represent the optimal design for evaluating the effectiveness of implementation strategies. Various codes of
medical ethics, such as the Nuremberg Code and the Declaration of Helsinki inform medical research, but their relevance to cluster randomised trials in implementation research is unclear. This paper discusses the applicability of various ethical codes to obtaining consent in cluster trials in implementation research.
Discussion: The appropriate application of biomedical codes to implementation research is not obvious. Discussion of the nature and practice of informed consent in implementation research cluster trials must consider the levels at which consent can be sought, and for what purpose it can be sought. The level at which an intervention is delivered can render the idea of patient level
consent meaningless. Careful consideration of the ownership of information, and rights of access to and exploitation of data is required. For health care professionals and organizations, there is a balance between clinical freedom and responsibility to participate in research.
Summary: While ethical justification for clinical trials relies heavily on individual consent, for
implementation research aspects of distributive justice, economics, and political philosophy underlie the debate. Societies may need to trade off decisions on the choice between individualized consent and valid implementation research. We suggest that social sciences codes could usefully inform the consideration of implementation research by members of Research Ethics Committees
Natural childbirth in twentieth century England : a history of alternative approaches to birth from the 1940s to the 1990s.
No full textPhDIt is well-established that a medical model of childbirth shaped maternity policy
during the second half of the twentieth century. However, alongside this narrative of
medicalised childbirth, an idea emerged that was to challenge medical hegemony in
maternity care provision. In 1933 British doctor Grantly Dick-Read published his
first book, Natural Childbirth, detailing his theories on pain during childbirth and its
remedy. Natural childbirth was a controversial idea and was not well-received by the
medical profession. Nevertheless, some women were enthusiastic about the nonmedical
approach suggested by Dick-Read and by the 1950s natural childbirth was
recognised as a distinct method of coping with the rigours of labour and birth. The
term later became synonymous with a range of alternative ideas about the
management of childbirth. Such ideas were disseminated through literature advising
women about childbirth, and through antenatal education, which aimed to inform,
enlighten and empower childbearing women.
Childbirth alternatives were consistently regarded with scepticism and the medical
establishment remained critical of them. Midwifery was surprisingly ambivalent,
given that it shared some of its core values with the principles of natural childbirth.
Nevertheless, a vocal minority continued to enthuse about childbirth alternatives, and
a handful of consumer organisations committed to promoting them emerged. By the
1970s and 1980s, a backlash against medicalised childbirth in contemporary Britain
provided a platform for such organisations to push their agenda even further.
Natural childbirth discourse provided the means to express dissatisfaction with the
medical system of childbirth; it also helped to give form to disillusionment with
contemporary maternity services by shaping expectations. By the late 1980s, policy
makers attempted to address the groundswell of discontent amongst childbearing
women by alluding to childbirth alternatives and offering a choice of services. Still,
as their shared history suggests, the relationship between the medical and natural
models of childbirth remained complex and littered with paradoxes
Sensitivity models for missing covariates in the analysis of survival data from multiple surveys
No full textUsing individual patient data from five independent surveys, we evaluate regional
variations in survival in cerebral palsy. The influence of four important variables measuring disability,
which are only partially observed for many cases, are analysed. Results are compared
between a naive complete case analysis; a full likelihood model in which the covariates are
assumed to be missing at random and in which each of the binary predictor variables are modelled
as independent Bernoulli random variables; a model in which the covariates are modelled
by a conditionalwise sequence, accommodating dependencies between the likelihoods of having
various mixtures of disabilities; and a model in which the likelihood of a predictor variable
being observed is allowed to depend on the value of the covariate itself (NMAR). Fully parametric
survival regression models are used and analysis carried out in BUGS. Results suggest
that proportions recorded as having severe visual or cognitive impairments are substantially
lower than the actual proportions severely impaired. Associations between the likelihood of a
particular covariate being recorded and the likelihood of a more severe disability imply that life
expectancies for those who are very severely impaired may be up to 20% less than inferences
based on complete case analyses
sj-docx-1-jop-10.1177_02698811231182012 – Supplemental material for The New Zealand drug harms ranking study: A multi-criteria decision analysis
No full textSupplemental material, sj-docx-1-jop-10.1177_02698811231182012 for The New Zealand drug harms ranking study: A multi-criteria decision analysis by Rose Crossin, Lana Cleland, Chris Wilkins, Marta Rychert, Simon Adamson, Tuari Potiki, Adam C Pomerleau, Blair MacDonald, Dwaine Faletanoai, Fiona Hutton, Geoff Noller, Ian Lambie, Jane L Sheridan, Jason George, Kali Mercier, Kristen Maynard, Louise Leonard, Patricia Walsh, Rhys Ponton, Sue Bagshaw, Suresh Muthukumaraswamy, Tracey McIntosh, Edward Poot, Paul Gordon, Patrick Sharry, David Nutt and Joseph Boden in Journal of Psychopharmacology</p
Long-term survival for a cohort of adults with cerebral palsy
No full textThe aim of this study was to investigate long-term survival and examine causes of death in adult patients with cerebral palsy (CP). A 1940–1950 birth cohort based on paediatric case referral allows for long-term survival follow-up. Survival is analyzed by birth characteristics and severity of disability from age 20 years (and age 2y for a subset of the data). Survival outcome compared with that expected in the general population based on English life tables. The main cohort consisted of 341 individuals, with 193 males and 148 females. Conditional on surviving to age 20 years, almost 85% of the cohort survived to age 50 years (a comparable estimate for the general population is 96%). Very few deaths were attributed to CP for those people dying over 20 years of age. Females survived better than males. However, females faced a greater increase in risk relative to the general population than did males. We conclude that survival outlook is good though lower than in the general population. The relative risk of death compared with the UK population decreases with age, although it shows some indication of rising again after age 50 years. Many more deaths were caused by diseases of the respiratory system among those dying in their 20s and 30s than would be expected in the general population. Many fewer deaths than expected in this age group are caused by injuries and accidents. For those people who die in their 40s and 50s, an increase in deaths due to diseases of the circulatory system and neoplasms is observed. More deaths than expected in this age group are due to diseases of the nervous system
Analysing the rate of change in a longitudinal study with missing data, taking into account the number of contact attempts
No full textIn longitudinal and multivariate settings incomplete data, due to missed visits, dropouts or non-return of
questionnaires are quite common.
A longitudinal trial in which potentially informative missingness occurs is the Collaborative Ankle Support
Trial (CAST). The aim of this study is to estimate the clinical effectiveness of four different methods of
mechanical support after severe ankle sprain. The clinical status of multiple subjects was measured at four
points in time via a questionnaire and, based on this, a continuous and bounded outcome score was calculated.
Motivated by this study, a model is proposed for continuous longitudinal data with non-ignorable or
informative missingness, taking into account the number of attempts made to contact initial non-responders.
The model combines a non-linear mixed model for the underlying response model with a logistic regression
model for the reminder process.
The outcome model enables us to analyze the rate of improvement including the dependence on explanatory
variables. The non-linear mixed model is derived under the assumption that the rate of improvement in a given
time interval is proportional to the current score and the still achievable score. Based on this assumption a
differential equation is solved in order to obtain the model of interest.
The response model relates the probability of response at each contact attempt and point in time to
covariates and to observed and missing outcomes.
Using this model the impact of missingness on the rate of improvement is evaluated for different missingness
processes
Jane Luise Hutton's contribution to the Discussion of ‘Experimental evaluation of algorithm-assisted human decision-making : application to pretrial public safety assessment’ by Imai et al.
No full textI read this paper from a background in randomised controlled clinical trials, and I congratulate the authors on achieving randomised research in a legal system (Fernandez Lynch et al., 2020). Given the focus on judges’ decisions, I was puzzled that it was simply an individually randomised trial. I now appreciate that discussion of optimal cluster randomized designs is a future project. Deciding how to translate analyses which model parameters for judges, and perhaps the sessions and courts, as well as characteristics of arrestees, for a legal audience will be challenging. As an aside, I wonder whether a parameteric analysis would provide more precise estimates and clearer communication. You might find the CONSORT Consort—Cluster Trials (consort-statement.org) and cluster trials CONSORT statements useful in persuading lawyers to use the appropriate designs. The literature on evaluating complex health care interventions might also be relevant in considering wider judicial systems. New framework on complex interventions to improve health—UKRI. (https://www.ukri.org/news/new-framework-on-complex-interventions-to-improve-health/
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