Addressing Participation in Adults With Postconcussive Symptoms Using Cognitive Strategy Training: A Feasibility Trial

Design

A single-group, prospective design was used, with outcomes gathered pre- and postintervention. A small-scale design for feasibility evaluation is recommended early in intervention evaluation to be fiscally conservative and to inform intervention refinement should a large-scale study be warranted (Bowen et al., 2009). All study procedures were approved by the University of Missouri Institutional Review Board. All participants provided written informed consent.

Participants

Participants (n = 15) were recruited through colleague referral and through a university-based e-mail communication that reaches the campus and members of the community. Interested people contacted researchers by phone or e-mail and were asked to complete a prescreening survey. Those who met the initial eligibility criteria completed screening procedures (i.e., Patient Health Questionnaire–9; PHQ–9) and baseline testing in a university research laboratory. Participants were included if they had

▪ a concussion diagnosis,

Participants were excluded if they had

▪ severe neurological or psychiatric conditions;

Data Collection

Intervention

Participants engaged in 10 weekly, 45-min CO-OP sessions with a trained interventionist. Five goals were identified using the COPM. One goal was not discussed within the intervention (i.e., the untrained goal), to serve as a measure of skill transfer. CO-OP is a metacognitive strategy training intervention with a primary purpose of improving occupational performance (Dawson et al., 2017). The client and therapist collaborate to identify areas of performance breakdown within client-chosen goals. The foundation of the CO-OP process is the learning of the Goal–Plan– Do–Check metacognitive strategy. Client use of this broad strategy can increase the likelihood of skill transfer, because it can be applied in a range of occupations and environments. Clients identify a specific goal to address and then develop a plan to address areas of performance breakdown. The plan is then trialed in the do phase within the intervention session as appropriate and in everyday life. Finally, the client checks whether the plan was successful or whether modifications are needed for improved performance (Figure 1). The Goal–Plan–Do–Check global strategy is used to develop more tailored, domain-specific strategies that are used within the Plan. During this process, the therapist facilitates gradual client independence in application of the Goal–Plan–Do–Check strategy, including opportunities for generalization of learned cognitive strategies through a process called guided discovery. Guided discovery takes the form of methods such as asking a series of probing questions or modeling for the client. For a more thorough description of the CO-OP Approach^TM, please see prior CO-OP literature (Dawson et al., 2017; Polatajko et al., 2001).

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Figure 1.

CO-OP process example.

Data Analysis

We calculated descriptive statistics for sample demographics, intervention acceptability, and performance at pre- and postintervention for each preliminary effect outcome measure. Additionally, recruitment rate, retention rate, and adherence rate were calculated as outlined in Table 1. To determine change from pre- to postintervention, we calculated effect sizes (Hedge’s g) with associated 95% confidence intervals. Hedge’s g was calculated on the basis of a paired sample calculation in which the mean change from pre- to postintervention is divided by the standard deviation of the difference. Hedge’s g is a more conservative estimate of effect for small sample sizes (Borenstein et al., 2021). Effect sizes were interpreted as 0.2 indicating small; 0.5, medium; and 0.8, large (Cohen, 1988). Null hypothesis significance testing was not conducted, because it is not recommended for feasibility designs (Bowen et al., 2009; Lancaster et al., 2004).

Feasibility

There was a recruitment rate of 32% and a retention rate of 93% (Figure 2). There was a 100% adherence rate to intervention sessions. Finally, CO-OP was seen as highly acceptable as indicated by an average score of 3.85 (SD = 0.25) on the Client Satisfaction Questionnaire–8. All feasibility criteria set a priori were met, with the exception of recruitment rate, which fell short of the intended benchmark by 17% (Figure 2).

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Figure 2.

Study flow diagram.

Preliminary Effect

From pre- to postintervention, large improvements were demonstrated for performance (Hedge’s g = 1.97) and satisfaction (Hedge’s g = 2.59) scores for trained COPM goals (Table 3). Large improvement was also noted for satisfaction (Hedge’s g = 0.81), and medium improvement was noted in performance levels (Hedge’s g = 0.58) for untrained goals. Overall, larger gains were observed for goals that were directly trained compared with untrained goals. Large effects were noted for the affective and cognitive domains of the NSI (Hedge’s gs = 1.14 and 0.85, respectively), sleep outcomes per the PSQI (Hedge’s g = 0.87), and perceived executive function in daily life per the DEX (Hedge’s g = 0.80).

Medium-sized effects were observed for visual symptoms in daily life (Hedge’s g = 0.54). The sample demonstrated large gains in fluid cognitive abilities on the NIH Toolbox (Hedge’s g = 1.08). Changes were negligible for functional cognition, as measured by the WCPA accuracy scores, time to completion, or efficiency; however, medium effects were present for time spent planning before the task (Hedge’s g = 0.72) and for the number of rules followed during task performance (Hedge’s g = 0.52).