Effects of Decision Aids for Menorrhagia on Treatment Choices, Health Outcomes, and Costs: A Randomized Controlled Trial

Context Decision aids can increase patient involvement in treatment decision making. However, questions remain regarding their effects and cost implications.

Objective To evaluate the effects of information, with and without a structured preference elicitation interview, on treatment choices, health outcomes, and costs.

Design, Setting, and Participants A randomized controlled trial with 2 years of follow-up. Between October 1996 and February 1998, 894 women with uncomplicated menorrhagia were recruited from 6 hospitals in southwest England. Women were randomized to the control group, information alone group (information), or information plus interview group (interview).

Interventions Women in both intervention groups were sent an information pack (a booklet and complementary videotape) 6 weeks before their specialist consultation. Immediately before their consultation, women in the interview group underwent structured interview, to clarify and elicit their preferences.

Main Outcome Measures Self-reported health status was the main outcome; secondary outcomes included treatments received and costs. Cost analyses adopted a UK health service (payer) perspective, and were based on patient-reported resource use data and are reported in 1999-2000 US dollars.

Results The interventions had no consistent effect on health status. Hysterectomy rates were lower for women in the interview group (38%) (adjusted odds ratio [OR], 0.60; 95% confidence interval [CI], 0.38-0.96) than in the control group (48%) and women who received the information alone (48%) (adjusted OR, 0.52; 95% CI, 0.33-0.82). The interview group had lower mean costs ($1566) than the control group ($2751) (mean difference, $1184; 95% CI, $684-$2110) and the information group $2026 (mean difference, $461; 95% CI, $236-$696).

Conclusions Neither intervention had an effect on health status. Providing women with information alone did not affect treatment choices; however, the addition of an interview to clarify values and elicit preferences had a significant effect on women's management and resulted in reduced costs.

The call for increased patient participation in treatment decision making has come from a range of different perspectives.^1-12 Methods to achieve these aims have included the development of patient decision aids. These can provide evidence-based information on treatment options and outcomes, help patients consider the personal value they place on benefits vs harms, and participate in decisions about their care. Decision aids come in a variety of formats including leaflets, audiotapes, decision boards, computer programs, videos, Web sites, and structured interviews.^13,14 Systematic reviews have shown that they increase patients' knowledge of available management choices without increasing anxiety or decisional conflict.¹³ They reduce the number of patients who are uncertain about what to do and assist in promoting participative decision making.¹³ However, the effect on treatment choices, health outcomes, satisfaction, and costs is less understood.

The clinical context of this study is menorrhagia, or heavy menstrual bleeding. Around a third of all menstruating women report heavy periods,¹⁵ and it is a common reason for consultation with a family physician.¹⁶ Referral to specialist care is common, with 35% of those consulting their family physician receiving a referral within a year.¹⁷ The condition is not life threatening, but it can have a considerable effect on a woman's quality of life.¹⁸

A woman requiring treatment for menorrhagia faces a number of treatment options, including provision of advice and reassurance, addressing possible iatrogenic causes, drug therapy, or referral to a gynecologist for possible surgery, typically hysterectomy or endometrial destruction.¹⁹ Women are faced with clear trade-offs between treatments, and their preferences must be taken into account in decision making.^8,10,20 Decision aids were developed to help women with menorrhagia determine and articulate their treatment preferences, and to enable them to play a more active role in treatment decision making. The aids used in this study were: (1) an information pack consisting of a specially designed booklet and linear video; and (2) a structured interview with a research nurse to clarify and elicit a woman's treatment preferences. This study evaluated these aids in terms of their effects on outcomes, patient management, and costs.

The content of the information pack drew on epidemiological studies, a systematic review of treatment efficacy published in the Effective Health Care series,¹⁹ and research into patients' information needs, including 4 specially commissioned focus groups.²¹ The 28-page booklet included an introductory section emphasizing the importance of a woman's preference in deciding on treatment, together with chapters describing menorrhagia and its causes, investigations, treatment options (medical and surgical), and the benefits and risks of surgery. It also included a section entitled "personal treatment plan" in which the reader was prompted to write down her preferences in response to a series of questions. The 30-minute video was presented by a female physician and included clips of interviews with women who had experienced different treatments for menorrhagia. The materials were pilot tested with patients before final production.

The structured interview drew on material derived from patient surveys^22,23 and interviews with women with menorrhagia.²¹ It was comprehensively piloted with 32 women during the development phase. The purpose of the interview was to help patients clarify and articulate their preferences, and to give them the chance to provide information that they might not have the opportunity or inclination to reveal to their physician. The interviews were conducted by a trained research nurse immediately before the woman's first specialist consultation for menorrhagia. Information on the woman's attitudes toward the clinical and lifestyle characteristics of possible treatments, the extent to which she wanted to become involved in the decision-making process, and her treatment preference were summarized on a form. The woman was encouraged to give the form to her physician during the consultation, after which it was added to her medical record.

A total of 28 consultant gynecologists from 6 hospitals in southwest England took part in the study. Institutional review board approval was granted by each of the centers. All women who were referred from primary to secondary care with uncomplicated menorrhagia, which was deemed nonurgent by their consultant, were considered for trial entry if their referral related to a new episode of menorrhagia. Women were identified by a research nurse from inspection of referral letters sent from general practitioners to the participating consultants. All women identified from referral letters were registered and written consent was requested.

For those consenting, random allocation to 1 of the 3 groups was then performed using a form of random permuted blocks, with block size randomly set to 3, 6, or 9 to avoid any possibility of selection bias.²⁴ The allocation sequence was generated by computer and stratified by consultant and the age at which the woman left full-time education. Secure randomization was ensured by using a central telephone randomization system. It was not possible to blind women or their physicians to allocation group. Women were randomized to (1) a standard practice control group with no intervention; (2) an information group, which received the booklet and videotape, sent to their homes 6 weeks before their consultations; and (3) an interview group, which received the same materials as the information group and who underwent an interview immediately before their consultation. The interview attempted to explicitly clarify values and elicit treatment preferences.

Before randomization, participants completed a baseline questionnaire, which included generic and condition-specific health status measures, and elicited clinical and sociodemographic characteristics, treatment knowledge, and treatment preferences. Women randomized to an intervention arm were asked to complete a questionnaire about their use of the information pack. Women in the interview group were asked to arrive 30 minutes before their scheduled outpatient appointment to participate in the interview. Follow-up questionnaires were sent at 6, 12, and 24 months postconsultation. The questionnaires focused on outcomes and health service contacts. Women who did not respond to the 24-month questionnaire after receiving 2 reminder letters were asked to take part in a short telephone interview covering key items from the follow-up questionnaire.

Outcomes were measured using standard validated scales when available. The primary outcome was general health status measured using the SF-36 (36-item Short Form Health Survey).²⁵ It was considered important to use a generic health status measure to permit comparisons with other uses of health care resources. Secondary outcomes included treatments received during follow-up, severity of menorrhagia,²⁶ and patient satisfaction.

Nonresponse bias was assessed using t and χ² tests. Multiple regression methods were used to analyze health status, logistic regression to analyze treatments, and ordinal regression to analyze satisfaction. To allow for potential clustering, both consultant (when methods were available) the consultant-intervention interaction were modeled as random effects.²⁷ A pool of covariates, selected from the baseline characteristics and treatment preferences summarized in Table 1, were defined for each analytical model a priori.

The primary outcome of the study was health status as measured by the SF-36. The sample size of 900 participants was calculated to detect differences between study groups of 5 points, with a power of 80% at the .05 significance level. This applied to all domains except the 2 role-related scales, which have SDs more than a third greater than the other scales.²⁸

For the cost analysis, unit costs were estimated from published sources.^29-33 We took a UK National Health Service perspective based on 1999-2000 UK prices and converted them to US dollars using the average exchange rate for 2000 (£1 = $1.52). For purposes of costing, we recorded resources associated with the development and production of the interventions; duration of time devoted by the nurse to the interview; and a woman's use of health services (therapeutic and diagnostic procedures and medications for menorrhagia; inpatient days in hospital for any reason; and outpatient and family physician visits for any reason during follow-up). These data were collected using questionnaires sent to women at 6, 12, and 24 months.

Given that the time horizon of the analysis was only 2 years, total costs are not discounted. To account for the skewed nature of the data, 95% confidence intervals (CIs) for differential costs have been calculated using bias-corrected and accelerated nonparametric bootstrapping (based on the 25th and 75th percentiles).³⁴ For some patients, resource use data were wholly or partially missing. We have addressed this problem using multivariate multiple imputation methods to impute the missing observations for these patients, under the assumption that these data were missing at random.³⁵

Between October 1996 and February 1998, 1301 eligible women were invited to partipate in the study—894 (69%) gave their consent (Figure 1). There were no exclusions after randomization. Recruitment at the 5 main hospitals ranged from 147 to 202 women; a further 48 women were recruited from a smaller hospital that joined the trial during the first year of recruitment. There was no significant difference in age between those granting (mean [SD], 40 [7.0] years) and refusing (41 [7.7] years) consent (P = .56).

Table 1 gives baseline descriptive statistics for the 3 groups. The educational background of the sample was close to population averages.³⁶ The 3 groups were generally well matched but there were small between-group differences in the duration of menorrhagia, and also in previous experience of hormonal and nonhormonal drug treatments. For women's treatment preferences, there were differences between the groups in terms of whether a preference was held and whether there was a preference for individual treatments. Few women expressed a preference for endometrial destruction, unspecified surgery, no treatment, or any other possible treatment.

Information pack questionnaires were returned by 519 (87%) women in the intervention groups. All but 4 women reported watching or reading at least some of the video or booklet. The interview, which lasted a mean (SD) of 20 (6.2) minutes, was conducted with 240 (80%) of the women randomized to that group. Clinicians' perceptions of consultation length differed between the groups (P = .01). The clinicians perceived consultations with women in the interview group to be "longer than usual" (28.5%) more often than those for women in the other 2 groups (18.9% for control and 16.9% for information).

The response rate to the 2-year follow-up was 70% (Figure 1) with a mean duration of follow-up of 26 months for each group. The rates of loss to follow-up varied between the groups, but these differences were not statistically significant (P = .69). Nonresponders were significantly younger than responders at baseline (mean [SD] age: 39 [7.8] vs 41 [6.5] years; P<.001); had more cases of severe menorrhagia (50 [15.7] vs 46 [13.8]; P = .001); had a lower level of knowledge (63 [21.4] vs 68 [21.0]; P = .002), and were less likely to have had previous treatment with nonhormonal drugs (66 [25.0%] vs 241 [38.8%]; P<.005). There were no between-group differences.

The role physical dimension of the SF-36 shows a significant difference between the interview and control groups (P = .04). None of the other differences reached statistical significance. Figure 2 shows the adjusted mean health status scores for the 3 groups, and illustrates the lack of a consistent effect across the dimensions. However, the considerable improvement in health status from baseline for all 3 groups is evident.

Treatment data were reported by 81% of women during the 2 years of follow-up. This rate was similar for all 3 groups (82% for control; 78% for information; and 84% for interview) (P = .17). The treatments reported by women are summarized in Table 2. Among women who underwent treatment, the interview group showed significant reductions in hysterectomy rate in comparison with the control group (P = .04) and the information group (adjusted odds [OR], 0.52; 95% CI, 0.33-0.82; P = .008) equivalent to relative reductions of 26% and 32%, respectively.³⁷ There was no difference between the information and control groups (P = .53). No other treatments showed a significant between-group difference, although the numbers of women who received endometrial destruction or other treatment were too small to rule out an effect. The intervention groups may have been more likely to undergo drug therapy, but the differences did not reach statistical significance (information vs control: P = .17; interview vs control: P = .11). The observed difference in hysterectomy rates between the interview group and the others was maintained when women reporting that they were waiting for hysterectomy were included in the analysis (interview vs control: P = .008; information vs interview: adjusted OR, 0.52; 95% CI, 0.34-0.80; P = .005).

The interview group rated both the opportunities they had been given to take part in treatment decision making (adjusted OR, 1.49; 95% CI, 1.11-2.01; P = .008) and the overall results of their treatments (adjusted OR, 1.44; 95% CI, 1.03-2.01; P = .03) significantly higher than the control group did. The differences between the information group and the controls were smaller and not significant (opportunities to take part in decision making: adjusted OR, 1.24 [95% CI, 0.91-1.69]; results of treatment: adjusted OR, 1.16 [95% CI, 0.85-1.60]). The differences between the intervention groups were not statistically significant.

Resource use is reported in Table 3. Total fixed intervention costs for the development and production of the booklet and videotape (including expert input) came to $121 904, which gave a cost per patient of $0.20. This assumed that the effective life of the interventions was 3 years, and the population for whom the interventions would be applicable was all women in England and Wales aged 25 to 52 years, who are referred from primary to secondary care with uncomplicated menorrhagia.^17,38 A total cost per patient of $21 for information and $27 for interview included the costs of the booklet and videotape and 20 minutes of an experienced nurse's time for the interview.³⁹

Table 4 presents the mean costs and the mean between-group differences in these costs. The main factors that influenced costs were surgery and other procedures, and inpatient and outpatient costs. Lower surgery costs in the interview group came from the reduction in hysterectomy rates, but this was partially offset by the greater number who received endometrial destruction and the levonorgestrel-releasing intrauterine contraceptive device. The higher rates of nongynecology health service contacts had the greatest influence over the between-group differences in inpatient and outpatient costs.

In terms of overall costs, both intervention groups showed major mean cost savings in comparison with the control group. The interview group also showed a savings in comparison with the information group. However, the overall cost was greatly influenced by the number of hospital contacts.

Overall costs were sensitive to the costs associated with health service contacts and were particularly high for a small number of women with high levels of resource use (Table 3). However, even when unrelated and inpatient costs were excluded, interview remained less costly than the other 2 groups (Table 4). Further sensitivity analyses were undertaken to explore the implications of varying the fixed costs of the interventions and the cost implications of the perceived additional length of the initial specialist consultation for women in the interview group. Halving the population for whom the interventions would be applicable, reducing the effective life of the interventions from 3 years to 1 year, and increasing the length of the initial consultation by 50% did not affect the conclusions of the cost analysis.

Among studies evaluating decision aids, this is the largest, with the longest period of follow-up. This has enabled a number of questions to be addressed that previous studies have been unable to answer. These include the effects on health status, satisfaction, and long-term effects on treatments. In addition, few studies have examined the effect of decision aids on costs.

A potential limitation of the study design is the possibility of contamination bias, in which clinicians could have applied the experience gained from consultations with the intervention groups in their consultations with the control group. This bias would have the effect of reducing any observed differences in outcome between the intervention groups and the control group, so our conclusions may be considered conservative. Another bias could have been introduced if there was a clustering effect in terms of the consultation style of particular consultants or the types of patients referred to them. This has been dealt with by incorporating consultants as a random effect in the statistical analysis. A further potential bias could have resulted from the inability to ensure that clinicians were blind to the allocation group. They were not told which patients were randomized to the control or information only groups, but we could not be certain that patients did not mention this fact in the subsequent consultation. Patients in the interview group were given a summary sheet to take into the consultation, so clinicians would have been aware of the allocation in this case.

The rate of loss to follow-up is within the range of other studies in the field,^40-42 although these studies cover just 1 year of follow-up. There were differences in baseline characteristics between responders and nonresponders. The statistical analyses ensure that these differences will not affect the comparisons between trial groups, but they should be noted when attempting to generalize the findings.

Neither intervention had a major impact on health status. The role physical dimension of the SF-36 did differ between the interview and control groups, but there was no consistent differential effect across the other dimensions, and this finding is consistent with previous studies.⁴³ Considering the major improvements in health status from baseline levels for women in all 3 groups, the impact of the decision aid is likely to be less important than the effectiveness of the available treatments.

In terms of the effects on treatment received, women who received the interview (plus information) were considerably less likely to undergo hysterectomy in comparison with those who received standard care and those who received information alone. This study confirms the effect identified in a recently updated systematic review.⁴³ Five studies showed reduced relative rates of surgery (ranging from 21% to 42%) and a nonsignificant trend when decision aids were compared with standard practice or less complex decision aids. These studies concerned decisions relating to treatment for benign prostatic hyperplasia,⁴⁰ ischemic heart disease,^44,45 low back pain,⁴¹ and breast cancer.⁴⁶ As in this study, all these decisions relate to conditions with a choice between radical surgery and more conservative options, but the results both support and contrast the findings reported in this article. They are consistent with the reduction in the rate of radical surgery reported here, and the additional effect of complex decision aids in comparison with simple decision aids. However, the effect sizes reported across the studies remain similar irrespective of the content of the interventions, which range from relatively simple to complex decision aids. A major strength of this article is that these effects have been compared within the same study.

The effect of the interview on satisfaction, in which women were more satisfied with the opportunities they had been given to be involved in making treatment decisions, is in contrast with results in the literature.⁴³ No effect was detected in 4 of 5 studies measuring satisfaction with the decision-making process, or 5 of 6 studies looking at satisfaction with the decision. It should be noted, however, that these earlier studies had limited power to detect between-group differences in satisfaction.

The results of the cost analysis suggest that information plus interview has lower costs than information alone and standard practice within secondary care treatment of menorrhagia. The study indicates important reductions in hysterectomy and inpatient and outpatient costs. Even if the cost of lowered inpatient days and outpatient and family physician visits unrelated to menorrhagia, which are heavily influenced by a small number of women with high costs, is excluded from the analysis, interview remains a less costly intervention compared with both control and information alone.

The model of information and interview used in this study could easily be adapted for use in other settings. However, the interventions were aimed at patients and did not involve their physicians. Future decision aids should incorporate training for clinicians in the principles and practice of involving patients in treatment decision making, alongside evidence-based information, value clarification, and preference elicitation for patients. Further research is required into which aspects of the interview contribute to the observed effects; when in the decision-making process such interventions should be integrated; and in which clinical settings these methods would be the most effective and the most cost-effective.

In conclusion, providing women with evidence-based information alone did not affect health outcomes, satisfaction, or treatments, although it may have lowered costs. However, the addition of a structured interview helped women to use the information to clarify their values and preferences. These were summarized on a pro forma and given to the patients to give to their clinicians to expedite the consultation and for inclusion in their medical record. This process reduced costs and had a significant effect on women's subsequent management and long-term satisfaction.