How far does screening women for domestic (partner) - NIHR Health ...

DOI: 10.3310/hta13160 Health Technology Assessment 2009; Vol. 13: No. 16
PreDoVe pilot trial, and averaged across all women
in the arm. These directly recorded pilot data
were used to populate the model with the number
of women attending the practices, the number
who were asked about partner violence by GPs or
practice nurses, the number of women disclosing
partner violence, the number of subsequent
referrals to the advocate or psychologist, and the
number of women who declined to take up the
referral to these services.
Simplifying assumptions about current abuse
incidence included: 16 years as a woman’s
minimum age for first experiencing partner
violence; a lifetime prevalence of 40%; and that
moving to a state of abuse occurs at a constant
rate over a woman’s lifetime. Assessment rates at
intervention and control practices were assumed
to be 10.7% of abused women and 7.1% of nonabused
women, based on actual rates of asking
and extrapolation from the prevalence of partner
violence found in east London general practices.
Costs comprised health-care use in terms of
assessment, mental health and treatment costs
as well as other social costs. Social costs included
criminal justice costs, civil justice costs and cost of
divorce involving children, societal employment
loss, temporary housing costs and costs of social
services.
Quality of life was based on survey data using the
Short Form 12 (SF-12) measurement tool. SF-12
No
abuse
Abuse
unidentified
Psychologist
Advocate
Medium-term
improvement
Figure 3 Diagram of Markov model states of PreDoVe intervention.
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data were converted into quality of life utilities
between 0 (equivalent to death) and 1 (equivalent
to optimal health) for those with less severe and
more severe violence, based on the US study by
Wittenberg and colleagues. 272 See Appendix 10.3
for a summary of treatment cost sources, and
Appendix 10.4 for other costs and QALYs per
woman per year for each state.
The majority of women in the model are likely
to be in ‘No abuse’ (State 1) although a flow of
women will become ‘Abuse unidentified’ (State
2). Following assessment, women experiencing
partner violence can remain unidentified (State 2),
or be referred to a psychologist and/or advocate
(States 3 and 4), or disclose abuse to a health-care
professional but not be seeking intervention (State
5). If the psychologist and/or advocate intervention
is successful, the women can be termed as
‘Medium-term improvement’ (State 6) and, if this
does not worsen, can return to the ‘No abuse’
category.
Results
Univariate sensitivity analysis was carried out,
and model parameters were both increased and
decreased by 25%, unless these figures were
internally invalid (such as if probabilities were
less than zero or greater than one). For transition
probabilities for which the intervention was
assumed to be preferable to the control, the
sensitivity analysis was constrained to assume the
Disclosed abuse
to health-care
professional – not
seeking intervention
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