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Elizabeth Murray a Department of
Primary Care and Population Sciences, Royal Free and University College
Medical School, University College London, London N19 3UA, b Picker Institute Europe,
Oxford OX1 1RX, c Health Economics Research Centre, University of
Oxford, Oxford OX3 7LF Correspondence to: E Murray
elizabeth.murray{at}pcps.ucl.ac.uk
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Abstract |
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Objective:
To determine whether a decision aid on
benign prostatic hypertrophy influences decision making, health
outcomes, and resource use.
Design:
Randomised controlled trial.
Setting:
33 general practices in the United Kingdom.
Participants:
112 men with benign prostatic hypertrophy.
Intervention:
Patients' decision aid consisting of an
interactive multimedia programme with booklet and printed summary.
Outcome measures:
Patients' and general
practitioners' perceptions of who made the decision, decisional
conflict scores, treatment choice and prostatectomy rate, American
Urological Association symptom scale, costs, anxiety, utility, and
general health status.
Results:
Both patients and general practitioners found the decision aid acceptable. A higher proportion of patients (32% v 4%; mean difference 28%, 95% confidence interval 14%
to 41%) and their general practitioners (46% v 25%; 21%,
3% to 40%) perceived that treatment decisions had been made mainly or
only by patients in the intervention group compared with the control
group. Patients in the intervention group had significantly lower
decisional conflict scores than those in the control group at three
months (2.3 v 2.6;
0.3,
0.5 to
0.1, P<0.01) and
this was maintained at nine months. No differences were found between
the groups for anxiety, general health status, prostatic symptoms,
utility, or costs (excluding costs associated with the video disc equipment).
Conclusions:
The decision aid reduced decisional
conflict in men with benign prostatic hypertrophy, and the patients
played a more active part in decision making. Such programmes could be delivered cheaply by the internet, and there are good arguments for
coordinated investment in them, particularly for conditions in which
patient utilities are important.
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What is already known on this topic
What this study adds
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Introduction |
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The rationale for decision aids is addressed in the
accompanying paper.1 Unlike hormone replacement therapy,
prostate surgery is a "Rubicon" procedure
that is, once undertaken
it cannot be reversed. In the United States, a pilot study on the
impact of a programme to aid in decisions about benign prostatic
hyperplasia showed a 40% decrease in surgery rates.2 This
finding was not replicated in a subsequent randomised controlled
trial.3
We aimed to determine whether an interactive multimedia decision aid in
primary care would promote greater patient involvement in decision
making and what influence this had on treatment choices and health
outcomes. We also aimed to determine the acceptability of such a system
to patients and general practitioners and the impact on a general
practitioner's workload and to undertake an economic analysis.
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Participants and methods |
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Patient recruitment
We invited general practitioners in two urban areas (Oxford
and London), one suburban area (Harrow), and one semirural area (Thame
and the Chilterns) to participate in our study.1 We asked
participating doctors to recruit men with benign prostatic hypertrophy
opportunistically. The doctors were asked to retain their normal
clinical practice in diagnosing or managing the condition but to refer
patients to the study as soon as they were confident about the
diagnosis. The men needed a sufficient understanding of English to be
able to consult without an interpreter. Men were excluded if there was
any clinical suggestion of carcinoma of the prostate or if they had
chronic retention of urine, recent urinary tract infection, a history
of acute urinary retention or prostate surgery, severe visual or
hearing impairment, or severe learning difficulties or mental illness.
Ethical approval was obtained from local research ethics
committees.
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Example of printout given to each patient after viewing the
programme
Benign Prostatic Hyperplasia: Choosing Surgical or Non Surgical Treatment Summary for: John Smith The treatment options discussed in this program you have just seen are: 1. Surgical Treatment, which includes three approaches:
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Intervention
The intervention, developed by the Foundation for Informed
Medical Decision Making,4 comprised an interactive multimedia programme with booklet and printed summary. Information was
obtained from studies by the Patient Outcome Research Team and other
published trials.
1 5
Treatment options discussed were
surgery (prostatectomy or transurethral prostatectomy), balloon dilatation of the prostate, drugs (
2 blockers and
5
reductase inhibitors), and watchful waiting. Information comprised
probabilities of the risks and benefits of each treatment, calculated
on the basis of information on age, severity of symptoms, and general health entered by the patient at the beginning of the session. After
viewing the programme the patients were given a summary of the
information (box); a copy was also sent to their general practitioners.
Randomisation
Patients randomised to the control group received normal
care from their general practitioner. Randomisation was performed after
informed consent had been obtained. The randomisation schedule,
stratified according to recruitment centre, was generated by computer.
Allocations were sealed in opaque numbered envelopes, opened by the
study nurse after collection of the baseline data.
Data collection
We collected baseline data before randomisation. Follow up
data were collected by postal questionnaire from patients three and
nine months after baseline. Outcome measures included personal details,
patients' and general practitioners' perceptions of who made the
decision about treatment, patient's satisfaction with the choice of
treatment, decisional conflict scores,6 choice of
treatment and prostatectomy rate, health status and physical function
(SF-36),7 health states and valuation of health states
(Euroqol EQ-5D),8 anxiety (Spielberger state trait anxiety
inventory short form),9 and prostatic symptoms (American
Urological Association symptom scale).10 Patients in the
intervention group completed a questionnaire immediately after viewing
the programme. All patients were asked to see their doctor to reach a
treatment decision.
Economic evaluation
We recorded the resources used by each patient over the
trial period. These were the equipment and staff time associated with
video sessions, the number and duration of consultations with the
general practitioners, referrals to urologists, other referrals, drugs
related to benign prostatic hypertrophy, tests, and diagnostic and
surgical procedures. The unit costs were attached to resource volumes
to obtain a total cost per patient. Table 1 shows the unit costs
used in the analysis and the sources of information. To aid
generalisability of the results we obtained unit costs from national
sources where possible.
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Costs of trial technology
Video disc systems were installed in five locations. The video hardware systems were obtained at a cost of £24 300. No insurance or maintenance costs were incurred, but each system had to be kept in a secured room, a locked cupboard, or a combination of these. Arrangements for use of space to store and use the equipment varied between centres, but a total of £3070 was paid over the five centres for storage and room rental. Software for the disc players was obtained from the Foundation for Informed Decision Making. The cost of software was $1900 (£1118) per video disc, giving a total cost of $9500 (£5590) plus £400 for shipping and insurance. Because of technological change during the study, the equipment had no residual value by the end of the study. However, the equipment was shared with another trial,1 and in terms of patient numbers only 36% of the costs for equipment were attributable to the current study. The total equipment and storage costs were therefore £15 840. Trial research nurses took patients to the video rooms, set up the equipment and explained its operation, and returned at the end of the session to put the equipment away. Diaries were maintained at one site for a sample period of one month, and from these it was estimated that 25 minutes of staff time was involved per viewing session. Based on a research nurse being on F grade, the cost of this time was £5.85 per session. A total of 57 patients in the current trial used the equipment across the five centres. The cost per patient was therefore £278 for the equipment plus £5.85 for staff time, a total of £283.85 per video session. |
Sample size
We postulated that patients with more information would
tolerate greater intensity of symptoms without seeking active treatment, as preliminary results from the United States showed a
reduced uptake of surgery in the intervention group.2
Additionally, a concern commonly voiced by general practitioners during
the developmental phase of the trial was that the intervention could raise patients' anxiety. A sample size of 160 patients (80 in each group) would have given us 90% power to detect a difference of
3.7 points (from 15 to 18.7) in the mean scores on the American Urological Association symptom scale for the two groups and 6 points
(from the baseline mean score of 32 to 38) on the Spielberger state
trait anxiety inventory at the 5% level of significance. Allowing for
a 30% dropout rate, we planned to recruit 210 patients; however, both
recruitment and dropout rates were less than expected (figure). A
retrospective calculation determined that the power to detect the
observed difference in decisional conflict score between the two groups
at the final assessment was 85% at the 5% significance
level.
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Statistical analysis
We analysed data for all outcomes for those patients who
completed all the assessments. We also performed an intention to treat
analysis to allow for those patients who did not complete the study and
who were therefore unable to provide data at the nine months'
assessment. For that analysis we assumed no change in score on any
outcome from the beginning of the study, and we substituted baseline
data for the missing data at the final assessment. Where data for
resource use were missing for the second follow up only or for
individual resource items, we took the mean value for that item in that
arm of the study. We present the results for those who completed the
nine months' assessment, as the intention to treat analysis did not
alter the results.
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Results |
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Recruitment
Overall, 33 general practices agreed to participate; 12 from Oxford and the Chilterns and 21 from London and Harrow. Between
January 1996 and September 1998, 112 men were recruited (figure). Table
2 presents the baseline data on the two groups.
Impact on decision making
Patients reacted positively to the decision aid (table 3).
At three months, patients in the intervention group showed lower
decisional conflict on all three subscales and on their total score
(table 4); this significant difference was maintained at the final
assessment (total score at nine months: mean (SD) scores, intervention
group 2.23 (0.38), control group 2.55 (0.50); mean difference
0.33,
95% confidence interval for mean difference
0.51 to
0.14). A
higher proportion of both general practitioners and patients perceived
that treatment decisions had been made mainly or only by the patients
in the intervention group (table
5).
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Anxiety and other health status outcomes
The Spielberger scores were similar at the final assessment
in the two groups (Mann-Whitney U test). The American Urological
Association scores in both groups improved over the study period. The
amount of change was not significantly different in the two groups
(median change in score
1 in intervention group,
2 in control
group; Mann-Whitney U test, P=0.8). We found no difference between the
two groups in the trends over time in the EQ-5D responses nor in the
SF-36 scores.
Economic evaluation
Missing data were replaced by conditional means in less
than 4% of resource use items. No significant differences were
detected in resource volumes used per patient between the groups (table
6).
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Discussion |
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The decision aid on benign prostatic hypertrophy seemed to increase patients' participation in decision making. A higher proportion of both patients and general practitioners thought that patients had "mainly or only" made the treatment decisions themselves in the intervention group than in the control group. Patients who viewed the programme had reduced decisional conflict scores (indicating reduced uncertainty about the decision) at three months, and this was maintained at nine months. The intervention was acceptable to both the patients and the doctors. The general practitioners were, however, likely to have had a prior interest in shared decision making. Recently, general practice registrars reported not being trained in the skills required to involve patients in clinical decisions.13
The intervention did not reduce costs; six out of seven completed or planned prostatectomies were in the intervention group. These results make it unlikely that the intervention reduced prostatectomy rates in a UK general practice population, but the study was underpowered to determine whether it caused an increase in the surgical rate.
Methodological considerations
The low recruitment rate prevented us from definitively
determining that there was no increase in anxiety in the intervention
group; however, the intervention had no noticeable impact on anxiety.
The low recruitment rate did not seem to be due to bias in recruiting
patients into the trial, as we were unable to detect the non-referral
of suitable patients attending the study practices. Moreover, as
randomisation occurred after referral it would be unlikely to affect
the main conclusion of the study. Although the technology used in these
trials is now outdated, this does not affect the main findings, which
relate to the interactive multimedia nature of the decision aid. The cost of delivering such programmes by the internet to standard personal
computers would be small: equipment costs of £1500 over three years,
with a low utilisation rate (two users per weekday) and lower space and
staff costs commensurate with a less dedicated technology would bring
the cost per session, excluding software, down from £177 to about £5
(£1 equipment, £2.50 staff time, £1.50 space).
Implications for the NHS
Internet sites for people seeking information on health
care are proliferating, but many are of low quality. The NHS has the
opportunity to provide high quality patient information and decision
aids through outlets such as NHS Direct Online, with the potential to
enhance patient care through informed patient choice. Accessible
evidence based information for patients could play an important part in
the drive to promote evidence based health care.
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Acknowledgments |
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We thank Jo Burns for administrative support, research staff Liz Redfern, Sue Davis, Jean Catterson, and Marjorie Talbot, and the general practitioners. AH is currently based at the London School of Hygiene and Tropical Medicine, London WC1E 7HT.
Contributors: AC and AH developed the idea for the study, participated in the design of the trial, and helped write the paper. AG initiated the health economic component of the study, determined the health economic data to be collected, participated in the analysis, and helped write the paper. HD coordinated the project, collected the data, participated in the analysis, and helped write the paper. SST participated in the study design and analysis of the data and helped write the paper. EM, the principal investigator, participated in the research design, coordinated the project, participated in data analysis, and helped write the paper; she will act as guarantor for the paper.
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Footnotes |
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Funding: NHS national research and development programme, the BUPA Foundation, and the Kings's Fund.
Competing interests: None declared.
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References |
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(Accepted 6 April 2001)
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