1/ More than a few psychologists have asked just what is meant by "evidence-based practice" and "evidence based therapy." This thread is a response I gave to someone who asked this on a psychology listserv. Perhaps others will find it helpful. Thread

2/ Your question is reasonable but unanswerable as asked. I do not believe there is any such thing as "the evidence-based practice model." The term "evidence-based" has acquired too much marketing cachet to have any agreed-upon meaning. It is now simply an ideological football,

3/ with all sides seeking to define & redefine it to serve their own purposes.
The original term was "evidence-based medicine" and was meant to represent the intersection of clinical judgment, patient values & preferences, & relevant scientific evidence. Here's a primary source:

4/ Sackett DL, Rosenberg WM, Gray JA, et al. Evidence based medicine: what it is and what it isn’t. BMJ 1996;312(7023):71–2

Then psychology (ever-ready to be medicine’s handmaiden) sought to adopt the term, so psychology too could sound more evidence-y and science-y.

5/ Those promoting instruction-manual therapies and RCTs sought to claim the term for their own purposes, so “evidence-based therapy” became a de facto codeword for the same protocol-driven, manualized therapies that used to be called “Empirically Supported Therapies” and

6/ before that, “Empirically Validated Therapies.” (It is also used as a de facto codeword for "not psychodynamic"). In fact, the therapies labeled "evidence-based therapies" are fundamentally inconsistent with the three pillars of "evidence-based medicine," because both clinical

7/ judgment and patients' values and preferences take a distant back seat to manualization and RCT research designs.
This is why we now have the absurdity of the American Psychological Association @APA speaking out of two sides of its ass, simultaneously promoting

8/ brief, instruction-manual therapy as “evidence-based therapy,” while circulating a separate document defining “evidence-based practice” to mean something else. So we now enter the realm of linguistic sleight of hand, where “evidence-based” sometimes means one thing and

9/ sometimes means something else. The only thing everyone agrees on is “evidence based” sounds really good & science-y & should be used wherever possible (even if it results in different @APA policy documents using the term in fundamentally contradictory & irreconcilable ways).

10/ When the term “evidence based” moved from medicine & was adopted by psychology, battles over what it “really” meant started immediately. The battles were fought out within a 2005 Amercian Psychological Association @APA presidential task force on “evidence based practice.”

11/ Some on the task force wanted to promote exclusively protocol-driven, manualized therapy as “evidence based” & declare "unethical" (!) any other form of psychotherapy; those on the task force who valued psychodynamic approaches (i.e., therapy based on insight & relationship)

12/ fought for a more inclusive definition consistent with the original medical usage, which puts equal emphasis on clinical expertise and patient values/preferences.
The tension was inherent in the @APA's 2006 policy statement, "Evidence Based Practice in Psychology" which is

13/ available at this link: https://www.apa.org/pubs/journals/features/evidence-based-statement.pdf). Despite fierce infighting in the Task Force that produced it, the final document was reasonably balanced.

14/ But after the 2006 policy document, the same partisan factions in American Psychological Association @APA still tried to claim the term “evidence based” for their own proprietary use, specifically to promote instruction-manual therapies. Those factions won out, culminating in

15/ @APA's clinical practice guidelines (for PTSD & depression so far) which exclusively promote protocol-driven, manualized therapies as "evidence-based THERAPY." Followed by—in response to howls of protest from clinical practitioners—a separate “professional” practice guideline

16/ for “evidence-based PRACTICE." Which is somehow different & separate from “evidence-based THERAPY."
In fact, the two sets of guidelines—clinical practice vs. professional practice—advocate contradictory agenda, with the former exclusively promoting instruction-manual

17/ therapies & the latter consisting mostly of psychological pablum & bromides about the importance of clinical judgment & patients' values and preferences, expressing a very half-hearted return to something closer to the 2006 Task Force document on “Evidence-Based Practice.”

18/ But—why would a new Professional Practice Guideline document even be necessary if @APA APA had not already, de facto, disavowed the 2006 documents in the first place, by issuing practice guidelines that exclusively recommended instruction-manual therapies?

19/ So I think the answer to your question about what is meant by "evidence-based," in short, is: “evidence based” now means nothing and everything, and everyone wants a piece of the term’s marketing and PR cachet.

In the end, it's not science. It's PR and politics.