# Process evaluation of a complex intervention in augmentative and alternative communication care in Germany: a mixed methods study

## TL;DR

This study evaluates a new approach to improve communication care for people who use AAC in Germany, finding that it helps users apply AAC systems more effectively in daily life.

## Contribution

The study introduces and evaluates a complex intervention combining training, therapy, and case management to enhance AAC implementation.

## Key findings

- The intervention was positively rated and improved AAC system use in different contexts.
- Case management was especially helpful during care process challenges.
- Intervention group showed higher acceptance and use of AAC systems compared to the comparison group.

## Abstract

In Germany, clear care pathways for people without natural speech who require augmentative and alternative communication (AAC) are currently lacking. Therefore, AAC is often not sustainably implemented in everyday life. For this reason, a complex intervention was developed that supplements existing AAC consultation with additional AAC training, AAC therapy, and case management. This article presents the results of the process evaluation of the complex intervention. It examines (1) how caregivers and AAC consultants rate the intervention (2), which contextual factors influence its implementation, and (3) the acceptance, use competence, and use of the new AAC system.

The process evaluation used a mixed methods design. Quantitative data were collected with a longitudinal survey of caregivers of AAC users in the intervention and comparison groups at three time points (T0: after AAC consultation; T1: 4 weeks after AAC system receipt; T2: 4 months after AAC system receipt). Semi-structured focus group interviews were conducted with caregivers of AAC users and with AAC consultants. The quantitative data were analysed descriptively and with nonparametric mean value comparisons. The qualitative results were analysed using structured qualitative content analysis.

The evaluation and presentation of results were based on the Medical Research Council process evaluation guidance by Moore et al. The intervention elements were rated positively. AAC training and therapy enabled the participants to use the AAC system effectively in different contexts. Case management provided support, particularly in the event of problems in the care process. However, the results also show the heterogeneity of the intervention, as it depended on various contextual factors. Overall, acceptance, use competence, and use of the AAC system were rated higher in the intervention group than in the comparison group.

The process evaluation illustrates various contextual factors that can influence the implementation of the AAC intervention. The results highlight the potential of the intervention to improve AAC care and establish a sustainable use of AAC systems in everyday life. In addition, the process evaluation provides indications of how AAC interventions can be adapted for successful implementation.

Grant number 01NVF17019.

The online version contains supplementary material available at 10.1186/s12913-025-12452-y.