Introduction

Top Abstract Introduction Participants and methods Results Discussion References

The rationale for decision aids is addressed in the accompanying paper.¹ Unlike hormone replacement therapy, prostate surgery is a "Rubicon" procedurethat 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 involvement of patients in decision making and the influence that this had on treatment choices and health outcomes.

	Participants and methods

Top Abstract Introduction Participants and methods Results Discussion References

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.

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; a copy was also sent to their general practitioners.

Randomisation
Patients randomised to the control group received normal care from their general practitioner. The randomisation schedule 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,⁹ and prostatic symptoms.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.

View larger version (34K): [in this window] [in a new window]   Progress of patients through trial

Economic evaluation
We recorded the resources used by each patient over the trial period. The unit costs were attached to resource volumes to obtain a total cost per patient.

Sample size
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 at the 5% level of significance. Allowing for a 30% dropout rate, we planned to recruit 210 patients.

Statistical analysis
We present the results for those who completed the assessment at nine months, as the intention to treat analysis did not alter the results. We performed Mann-Whitney U tests when data for outcome measures were skewed. We present the means and standard deviations for resource use and costs; confidence intervals around mean differences between study groups are based on t tests assuming unequal variances.

	Results

Top Abstract Introduction Participants and methods Results Discussion References

Recruitment
Overall, 33 general practices agreed to participate, and 112 men were recruited between January 1996 and September 1998 (figure). The intervention and control groups were comparable at baseline (table 1).

Impact on decision making
Patients reacted positively to the decision aid. At three months, patients in the intervention group showed lower decisional conflict on all three subscales and on their total score (table 2); this significant difference was maintained at the final assessment (total score at nine months). 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 3).

Anxiety and other health status outcomes
The anxiety scores were similar at the final assessment in the two groups. The amount of change in American Urological Association scores was not significantly different in the two groups (median change in score 1 in intervention group, 2 in control group; 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
No significant differences were detected in resource volumes used per patient between patient groups. When costs of the video sessions were excluded, groups did not differ significantly in total or individual costs of the components (table 4).

	Discussion

Top Abstract Introduction Participants and methods Results Discussion References

The decision aid on benign prostatic hypertrophy seemed to increase patients' participation in decision making. 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.¹²

The intervention did not reduce costs. It is 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.

	Acknowledgments

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.

	Footnotes

Funding: NHS national research and development programme, the BUPA Foundation, and the Kings's Fund.

Competing interests: None declared.

The full version of this paper is available on the BMJ's website

	References

Top Abstract Introduction Participants and methods Results Discussion References

1.	Murray E, Davis H, See Tai S, Gray A, Coulter A, Haines A. Randomised controlled trial of an interactive multimedia decision aid on hormone replacement therapy in primary care. BMJ 2001; 323: 490-493[Medline].
2.	Barry MJ, Fowler FJJ, Mulley AGJ, Henderson JVJ, Wennberg JE. Patient reactions to a program designed to facilitate patient participation in treatment decisions for benign prostatic hyperplasia. Med Care 1995; 33: 771-782[Medline].
3.	Barry MJ, Cherkin DC, Chang Y, Fowler FJJ, Skates S. A randomized trial of a multimedia shared decision-making program for men facing a treatment decision for benign prostatic hyperplasia. Dis Manage Clin Outcomes 1997; 1/1: 5-14.
4.	Kasper JF, Mulley AGJ, Wennberg JE. Developing shared decision-making programs to improve the quality of health care. Qual Rev Bull 1992; 18: 183-190[Medline].
5.	McConnell JD, Barry MJ, Bruskewitz RC. Benign prostatic hyperplasia: diagnosis and treatment. Rockville, MD: Agency for Health Care Policy and Research, 1994. (Clinical practice guideline No 8.)
6.	O'Connor AM. Validation of a decisional conflict scale. Med Decis Making 1995; 15: 25-30[Medline].
7.	Brazier JE, Harper R, Jones NM, O'Cathain A, Thomas KJ, Usherwood T, et al. Validating the SF-36 health survey questionnaire: new outcome measure for primary care. BMJ 1992; 305: 160-164[Medline].
8.	Euroqol Group. EuroQol: a new facility for the measurement of health-related quality of life. Health Policy 1990; 16: 199-208[Medline].
9.	Marteau TM, Bekker H. The development of a six-item short-form of the state scale of the Spielberger State-Trait Anxiety Inventory (STAI). Br J Clin Psychol 1992; 31: 301-306[Medline].
10.	Barry MJ, Fowler FJJ, O'Leary MP, Bruskewitz RC, Holtgrewe HL, Mebust WK, et al. The American Urological Association symptom index for benign prostatic hyperplasia. The Measurement Committee of the American Urological Association. J Urol 1992; 148: 1549-1557[Medline].
11.	Dolan P, Gudex C, Kind P, Williams A. The time trade-off method: results from a general population study. Health Econ 1996; 5: 141-154[Medline].
12.	Elwyn G, Edwards A, Gwyn R, Grol R. Towards a feasible model for shared decision making: focus group study with general practice registrars. BMJ 1999; 319: 753-756[Abstract/Full Text].

(Accepted 6 April 2001)