{'fraction_non_alphanumeric': 0.025210084033613446, 'fraction_numerical': 0.0, 'mean_word_length': 4.686567164179104, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Review: Working in collaboration with young people and health professionals: a staged approach to the implementation of a randomised controlled trial

Simple treatments, such as a pill that is thought to treat a condition, can easily be compared using a standard randomised controlled trial (RCT) by giving one group of subjects the pill and the other group a placebo. If the patients are randomly allocated to either group A (treatment) or group B (control) then there will probably be no significant differences between the groups (for example age, gender, ethnicity etc.). Thus, if there is a difference in outcomes (say group A gives better outcomes), then that difference is likely to be due to the treatment. It is crucial that the treatment is double blind, i.e. neither the subject nor investigator knows whether group A or B is the treatment group. If the subject knows they are receiving a treatment, then the placebo effect makes measuring any treatment effect impossible. Subjects may improve even after being given a placebo (sugar pill say) if they believe in its efficacy. Indeed they may suffer side effects known to be associated with the treatment, even if they are receiving the placebo. Such is the strength of the placebo effect, and the associated Hawthorn effect (things get better when they are being investigated) that whenever possible a double-blind RCT should be conducted. However, this is not always possible or even desirable. In my first study, which was of barrier creams in incontinence dermatitis, patients were randomised into two groups; it was double blind, but there was no control. That is because there is no such thing as a cream that can be applied to a patient that could not act as a barrier cream. Failing to apply anything would give a control, but it would not then be double blind or even single blind. We therefore conducted a parallel trial comparing an