Several studies did not stratify patients based on severity of illness (for example, Child Pugh score and APACHE [Acute Physiology and Chronic Health Evaluation] score) and hence it is difficult to assess patient matching or the impact of underlying disease on patient mortality with or without treatment.
Six studies involving more than 2,000 CF patients demonstrated an association of MBL-deficient genotypes with more severe lung function, three studies reported earlier onset of P. aeruginosa infection, whereas several studies did not detect an association with lung disease and/or with age of infection with P. aeruginosa.
In addition, several studies did not report the specific injury and, therefore, analysis of injury type was not possible.
Furthermore, several studies did address the type and class of suture material as a possible cause for vaginal cuff dehiscence [11, 19, 22].
Data about possible gender differences are also scarce in our meta-analysis, since several studies did not report separate analyses by gender [48,50,54,55,60].
As several studies did not explain the nature of the evolution course, it is difficult to know the factors that explain these varied results.
And several studies did not appear to take into consideration major risk factors that influence life expectancy, such as socioeconomic status and overall health.
For example, in this study it was found that several studies did not specify that the diagnosis of migraine was made based on the IHS criteria even though this was highly possible as the investigators had used these criteria in all of their previous studies.
We observed, however, that several studies did not use the stringent culture-based outcome definitions such as Cure or Failed.
It should also be noted that several studies did not find any impact of inhibiting neurogenesis on anxiety- or depression-related behaviors [9], [82], [83], [84].
