Cost-effectiveness of four parenting programs and bibliotherapy for parents of children with conduct problems

Background: Parenting programs and self-help parenting interventions employing written materials are effective in reducing child conduct problems (CP) in the short-Term compared to control groups, however evidence on the cost-effectiveness of such interventions is insufficient. Few studies have looked at the differences in effects between interventions in the same study design. Aim: This study aimed to determine the cost-effectiveness of four parenting programs: Comet, Incredible Years (IY), Cope and Connect, and bibliotherapy, compared to a waitlist control (WC), with a time horizon of 4 months, targeting CP in children aged 3-12 years. Methods: This economic evaluation was conducted alongside an RCT of the four parenting interventions and bibliotherapy compared to a WC. The study sample consisted of 961 parents of 3-12 yearold children with CP. CP was measured by the Eyberg Child Behavior Inventory. Effectiveness was expressed as the proportion of "recovered" cases of CP. The time horizon of the study was four months with a limited health sector perspective, including parents' time costs. We performed an initial comparative cost analysis for interventions whose outcomes differed significantly from the WC, and later a cost-effectiveness analysis of interventions whose outcomes differed significantly from both the WC and each other. Secondary analyses were performed: (i) joint outcome "recovered and improved", (ii) intervention completers, (iii) exclusion of parents' time costs, (iv) exclusion of training costs. Results: All interventions apart from Connect significantly reduced CP compared to the WC. Of the other interventions Comet resulted in a significantly higher proportion of recovered cases compared to bibliotherapy. A comparative cost analysis of the effective interventions rendered an average cost per recovered case for bibliotherapy of US$ 483, Cope US$ 1972, Comet US$ 3741, and IY US$ 6668. Furthermore, Comet had an ICER of US$ 8375 compared to bibliotherapy. Secondary analyses of "recovered and improved" and of intervention completers held Cope as the cheapest alternative. Exclusion of parents' time and training costs did not change the cost-effectiveness results. Discussion: The time horizon for this evaluation is very short. This study also had a limited costing perspective. Results may be interpreted with caution when considering decision-making about value for money. The inclusion of a multi-Attribute utility instrument sensitive to domains of quality-of-life impacted by CP in children would be valuable so that pragmatic value for money estimations can be made. Implications for Future Research: Further studies are needed with longer follow-up periods to ascertain on the sustainability of the effects, and fuller economic evaluations and economic modeling to provide insights on longer-Term cost-effectiveness. These results also raise the need to investigate the cost-effectiveness of the provision of these interventions as a "stepped care" approach. Conclusions: The results suggest the delivery of different programs according to budget constraints and the outcome desired. In the absence of a WTP threshold, bibliotherapy could be a cheap and effective option to initially target CP within a limited budget, whereas Comet could be offered to achieve greater effects based on decision-makers' willingness to make larger investments. In its turn, Cope could be offered when targeting broader outcomes, such as symptom improvement, rather than clinical caseness.