My comments above may need some amendment as, although the published information is [limited], it would seem that the [only] source of subjects was referral from the study’s lead author’s own clinic.
The final [amended version of the] study write up (see
https://adc.bmj.com/content/103/2/155 “Clinical and cost-effectiveness of the Lightning Process in addition to specialist medical care for paediatric chronic fatigue syndrome: randomised controlled trial”) is unclear about subject recruitment and refers to the study protocol. The current amended version only says
A detailed description of the study protocol has been reported. Between September 2010 and September 2013 we recruited participants after clinical assessment by the Bath/Bristol paediatric CFS/ME service, a large regional and national National Health Service (NHS) specialist service.
However the preregistration protocol, published after the commencement of the study (see
https://trialsjournal.biomedcentral.com/articles/10.1186/1745-6215-14-444 “ ) says little more
Children and young people aged 12 to 18 years inclusive will be recruited after assessment by the Bath/Bristol paediatric CFS/ME service. This is a large regional and national service that currently provides assessment and treatment for over 250 children a year. The majority of referrals are from South Gloucestershire, Bristol, Somerset and West Wiltshire. Referrals are made by paediatricians, general practitioners and, in some cases, schools.
Potentially eligible children and their families will be identified by the clinician conducting the initial clinical assessment who will inform them about the study and give both the young person and their parents patient information sheets. The clinician will obtain consent from the young person and their family to be contacted by a researcher. If willing, the recruiting researcher will contact the family and arrange to visit them at a convenient location (usually at home) to discuss and provide further information about the study.
So the implication is that children were only referred by the Bath Service after they had been referred to that Service by ‘normal’ referral processes. It is always difficult to recruit participants in such studies and an open call for referrals can not guarantee random or unbiased patterns of referrals. One approach is to attempt to select all people diagnosed in a specific geographical area over a specific period of time, which the write ups might be taken to suggest.
Given recruitment took place over three years, when the Service would expect to see some 750 patients in that period. I am confused whether the initial appointment involving some 657 subjects, mentioned above by
@dreampop, is the initial appointment with the Bath Service or the initial visit with the researchers. The reasons given for drop out however would seem to suggest the former, that the 657 was the number of initial appointments with the Bath Service rather than initial appointments with the research team.
Either way the reliance on referrals from just one clinic introduces a risk of bias resulting from that clinics reputation and referral practices, especially given the controversy surrounding the head of the clinic who is also the lead researcher. Further given the distinction the study makes between the research team and the clinic, it would be helpful to know how many of the headline 657 figure were seen initially by individuals both working in the clinic and part of the research team. It also has implications for the power dynamics between the research team and the subjects, [especially] given there are potential issues relating to concerns on the part of the children/families about child protection issues, which in turn has implications for self reported subjective outcome measures. [Given the high level of inappropriate involvement of child protection teams with children with ME/CFS and the not infrequent comments by parents on forums that they feel obliged to tell clinicians what they want to hear, this should be a consideration, making objective outcome measures even more essential.]
One way round this [potential selection bias] would have been to draw in subjects from other sources.
On the basis of the information given we can not rule in or rule out that no children we referred to the Bath Service in order to take advantage of a chance of free access to the Lightning Process.
That 136 of those referred to the Bath Service, just over 20% of the total sample, turned out not to have ‘CFS’ which is not surprising given other studies report potential for misdiagnose of up to 40%.
However some 125, just under 20% of the total sample did not return their contact forms. Unfortunately we can not say that this was a consequence of just getting lost in the complexities of everyday life with a seriously ill child, or indication that they did not wish to participate in the study. Though we don’t know if they changed their minds after their initial appointment or if they had previously been too polite or unconfident at that appointment to say no. Again this is a potential source of bias into the sample. And as with nearly all studies into ME/CFS there is potentially exclusion of the more severely impaired, [14 were straight away excluded for being ‘severe’ and] with the 75 excluded because they live too far, we have no idea whether the clinic/researchers defined too far or the subjects/families did, too far being a potential subjective [judgement] and potentially related to the the severity of the child’s condition [what is too far for one family will not be too far for another].
There was a further 33 drop outs, some 5%, before the start of the study, their reasons are not reported. Presumably the researchers have no information on this.
[This may be an unfair comment, but seems potentially less so given the study’s initially undisclosed elision of a feasibility study subjects into the full final study, but rather feels like there has been some at least post hoc tidying up of subject categories to keep the numbers up, which is not strictly consistent with random allocation. This might be acceptable in a feasibility study, but not in a full prospectively registered trial.]
[edited - corrections of grammar, and alterations shown in square brackets]
