Читать книгу Health Psychology - Michael Murray - Страница 148

A key issue in designing and reporting research studies in health psychology is transparency. This refers to the ability to accurately and openly describe in full detail the participants or patient population (P), intervention (I), comparison (C) and outcome (O) (‘PICO’). Above, we have mentioned the CONSORT and TREND guidelines that were designed to improve transparency of the descriptions of interventions. Intervention studies are typically designed to compare one, two or, at most, three treatments with a control condition consisting of standard care, a waiting list control, a placebo, or no treatment.

The standard designs are simple because precious resources must be stretched across a large number of trials. Rarely, if ever, does an intervention include only one technique, with practically all trials including two or more techniques in combination. If an intervention domain such as smoking has, say, 500 techniques, then there would be 2.5 million possible two-technique combinations, 124 million three-technique combinations and 62 billion four-technique combinations! These eye-watering figures may help to explain why replication so often fails. Which specific combination is used in any individual case, and in what order, depends on the subjective choices of the practitioner. Only if the ‘PICO’ description is fully detailed and transparent can an independent investigator have the opportunity to reproduce a replica of the study.