33 Some trials reported only malignancies.
Some trials reported the median values of this outcome.
This proved not to be possible because few trials reported dispersion (standard deviation, standard error, or interquartile range).
However, it has been suggested that the absolute benefit is more modest [ 79], because most trials reported on oestrogen receptor-positive women with early disease, whereas about one-third of women are negative for the oestrogen receptor, and many women with breast cancer do not present with early stage disease.
Sex is an important risk factor for laryngeal oedema after extubation and subsequent reintubation, but we could not do a subgroup analysis because so few trials reported results separately by sex.
Consensus within the literature about the efficacy of different lock solutions is limited because the methodology of trials reported is often poor, with frequent use of historical controls, or reports in the form of case series with no control group.
Because majority of the trials reported very limited details of study design and performance, we attempted to contact authors by letters or e-mails for additional information, but we got a few responses.
Two trials reported some resource information suggesting a cost-beneficial saving when comparing therapeutic communities to a prison alternative.
14 We were unable to examine the effect of different treatments according to predominant stool pattern reported by the patients, however, because few of the eligible trials reported these data as many predate the use of these subgroups, making it difficult to assign people to these categories retrospectively.
However, definite conclusions on the efficacy of secondary prophylaxis cannot be drawn from these observations because many trials report a decline in the incidence of FN in later cycles without administering prophylaxis (Hupperets and Tjan-Heijnen, 2006).
