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.