Review for 10.1186/1471-230X-12-13 (2012)

Reviewer's report
Title:Chronic fatigue syndrome after Giardia enteritis: clinical characteristics,
disability and long-term sickness absence.
Version: 1Date:1 April 2011
Reviewer: Naomi Swanson
Reviewer's report:
The question posed by the authors is well defined and the methods are
appropriate. The manuscript is generally well-written, with the discussion and
conclusions supported by the data. I have recommendations regarding the
reporting of the results that are detailed below. The study limitations are not
stated. Prior work is acknowledged, and the title and abstract are descriptive of
the study findings.
Minor Essential Revisions:
1) The authors need to mention what statistical tests they are reporting on in the
results section. E.g., Student's t-tests indicated that ... In reading this section, it is
difficult to determine what statistical tests were done and when they were done.
2) The authors also need to state what level of significance they were using for
their tests. Generally, a significance (p) value of less than or equal to .05 is used,
but it is unclear whether that convention is being followed by the authors.
3) I don't understand what the "P" column is in Tables 2 and 3. What statistical
test is being done here? The table legends need to state that and it should also
be stated in the results section.
4) All acronyms should be spelled out at the time of first use. Examples of where
this does not happen are in the next to last paragraph of the results section.
"AHAD" and "DHAD" are not defined prior to their use.
5) Study limitations need to be addressed before the conclusions in the
discussion section. A couple of potential limitations are a small study population
and subject recall issues.
6) The authors' use of English is generally very good, but the manuscript needs
to be examined for minor errors in spelling and grammar. For example, in
paragraph 2 of the background section, the initial word in the 4th sentence
should be "Patients" rather than "Patient." The first sentence in the methods
section should read, "From August 2005 to September 2007, 96 patients with..."
The second sentence should read, "Clinical, medical...were recorded." And since
CDC is a U.S. agency, the correct spelling for its name should be Centers (rather
than Centres) for Disease Control and Prevention. There are a few other similar
sorts of editorial changes that need to be made in the rest of the manuscript.
Discretionary Revisions
1) It would be useful to have a brief description of what the authors think could go
into a comprehensive rehabilitation program.
2) The authors may wish to include a reference to a newly published study with
relevance to their study:
Jones, DEJ, Gray, J, Frith, J, Newton, JL. (2011). Fatigue severity remains stable
over time and independently associated with orthostatic symptoms in chronic
fatigue syndrome: a longitudinal study. Journal of Internal Medicine, 269(2),
182-188.
Level of interest: An article of importance in its field
Quality of written English: Needs some language corrections before being
published
Statistical review: No, the manuscript does not need to be seen by a
statistician.
Declaration of competing interests:
I declare that I have no competing interests.