# Evidence-based assessment/Process phase/Brinley plots

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Both researchers and clinicians struggle with how to measure clinical change. A nomothetic approach, which favors examining group outcomes and universal laws, is the typical method of assessing clinical change in large-scale trials, but an idiographic approach, which favors assessment of individual outcomes, may be more appropriate for practicing clinicians, who are typically working with small and diverse samples. One such idiographic approach involves the use of modified Brinley plots.

# Description of Modified Brinley plots

Modified Brinley plots provide a graphical depiction of individual change that considers individual variation in treatment response and clinically significant improvement or deterioration. While a treatment may be empirically supported and effective at the group level, using Brinley plots allows a practicing clinician to see if a given treatment works for a given individual. Furthermore, calculation of the Reliable Change Index allows the clinician to compare their client’s scores to standardized data from previous trials, to assess if a change in score is statistically and/or clinically meaningful. Collecting the appropriate standardized data for a given client and measure can be challenging and time-consuming, however.

### Advantages of Brinley Plots

Advantages include that each patient's individual response is visible. Brinley plots also show whether the change is large enough to be reliable, usually pegged to the Reliable Change Index.

### Limitations

There are several limitations to Brinley plots. One is that they are not familiar to a wide audience (although having information on Wikiversity may help address that concern!). A second is that the orientation is not intuitive -- desirable change usually follows a diagonal sweep, and moving straight up counter-intuitively would mean problems were getting worse. A third issue is that the plot only shows two time points per person, whereas some progress measures may be tracked every session, every week, or even more frequently. Static Brinley plots would not be able to show trajectories or changes over time.

## Proposal to Build Tables and Template Figures

We are therefore proposing a repository of tables populated with relevant standardized information, into which clinicians could easily enter a client’s data in order to ascertain their level of clinical change. The repository could also include templates of modified Brinley plots, into which clinicians could enter individual client’s data to generate a graphical depiction of their client’s change. Such resources would allow practicing clinicians outside of academia to use evidence-based methods to assess their clients’ progress and response to treatment.
* ↑ Barlow, D. H., Nock, M. K., & Hersen, M. (2009). Single case experimental designs: Strategies for studying behavioral change (3rd ed.). Pearson.
* ↑ Blampied, Neville M. (2017-01). "Analyzing Therapeutic Change Using Modified Brinley Plots: History, Construction, and Interpretation". Behavior Therapy 48 (1): 115–127. doi:10.1016/j.beth.2016.09.002. https://linkinghub.elsevier.com/retrieve/pii/S0005789416300776.
* ↑ Youngstrom, Eric A.; Langfus, Joshua A. (2019-03). "Where do Brinley plots fit in the toolkit for clinical data visualization?". Clinical Psychology: Science and Practice 26 (1): e12275. doi:10.1111/cpsp.12275. http://doi.wiley.com/10.1111/cpsp.12275.