Investigating aspects of treatment fidelity in a new conversation-based therapy for people with agrammatic aphasia and their conversation partners

Abstract

Background: When conducting a speech and language therapy intervention study, one essential part lies in the evaluation of the outcomes. The underlying therapy itself and its delivery are aspects which are mostly done in the background. There is little focus on the question: Was therapy delivered with fidelity, i.e. to what extent does the actual therapy delivery correspond to the planned delivery? If treatment fidelity (TF) is discussed in a paper, researchers often report on therapy manuals, training and supervision of therapists, or adherence to the therapeutic techniques. However, according to Cherney et al. (2013), TF is regarded as a crucial component of any behavioural treatment study (ibid.) and should therefore be assessed in a speech and language therapy intervention study. Aim: The present thesis is part of a wider research project in which a new conversation-based therapy - called Better Conversations with Aphasia (BCA; Beeke et al., 2011; Beeke et al., submitted; Beckley et al., 2013) – was designed. The therapy was provided to eight people with agrammatism and their conversation partners (CPs), together called a dyad. It is an adaptation of a conversation training programme called SPPARC (Supporting Partners of People with Aphasia in Relationships and Conversation; Lock et al., 2001a). Every dyad was treated by the same speech and language therapist (SLT) and all therapy sessions were videotaped. The aim of the present thesis is to examine aspects of TF retrospectively and thereby assess the degree of uniform therapy delivery as planned. Methods: The multifaceted concept of TF is introduced and applied to the wider research project. Using this concept, the degree to which the BCA therapy programme was delivered as planned, can be measured. This can be achieved by developing a pilot fidelity tool, which is based on a conceptual framework of TF (Carroll et al., 2007), on practices reported in the TF literature and on the generic session plans of the BCA therapy. The first step was to observe 23% of the therapy sessions and rate them with the tool. These observations were conducted on data of seven dyads. In addition, descriptive data were collected to enlarge the fidelity evaluation. In a last step, inter-rater reliability (IRR) of parts of the fidelity tool was also assessed with the help of a second observer who rated 20% of the sessions already used for the fidelity check. Results: The results indicate that, in terms of therapy content, a high fidelity level of 91.9% was reached for the BCA therapy programme. Dyad-specific fidelity scores thereby ranged between 86% and 97%, which shows a certain degree of variability, even when only one therapist was delivering the intervention. It also suggests that each dyad received a satisfactorily equivalent intervention. The duration and frequency of the therapy sessions varied across the dyads. However, this reflects the individual and interactive nature of a conversation-based therapy. Qualitatively, the therapist showed a high degree of desired behaviour associated with the delivery of the BCA therapy programme (averaged across the dyads: 96.7%). Other potential moderators of fidelity, such as the acceptance of components of the therapy programme and the clients’ motivation, were also investigated in the present thesis, providing a multifaceted evaluation of TF. In terms of the inter-rater reliability of the designed fidelity tool, acceptable levels have been reached for almost all of the sessions observed by two qualified SLTs. Future directions: For future investigations, the procedural section of the fidelity tool could be refined in terms of fewer, essential elements of the BCA therapy. Moreover, clearer rating guidelines are necessary for rating the fidelity tool reliably. A potential next step for future research might be to identify potential essential components of the BCA therapy and to relate the outcomes of the main BCA research project to TF data. However, the importance and value of a fidelity evaluation is already being demonstrated in the present thesis.