previous post). I've just looked at a recent lecture from David Clark (see video). He's still making claims about outcomes based on lack of comparative data. How do we know that so-called recoveries in the IAPT programme are not due to the placebo effect or spontaneous improvement?
For example, in the lecture Clark makes much of the changes in Buckinghamshire Healthy Minds following a review of notes of the unrecovered patients to identify themes and recurrent patterns in the data (see powerpoint presentation). National figures are that 46% of people are said to recover and a further 15% improve. These are average figures and there is considerable variability by Clinical Commissioning Groups (CCGs). Buckinghamshire was below 50% and by telling staff to increase recovery rates to 65%, lo and behold they did! Isn't this just a Hawthorne effect?
There's a lot of money invested in IAPT so I'm sure Clark doesn't want to think about whether IAPT therapists are mere placebologists. There will always be a problem with assessing the effectiveness of psychotherapy because of the issue of the adequacy of control groups (eg. see my BMJ letter). Psychotherapy trials cannot be conducted double-blind because subjects always know whether they have received the therapy under investigation or a control intervention.