Study designs of evaluations included in the review
The review includes RCTs and case-control studies. Inclusion criteria for the RCTs were randomisation, placebo control and a measure of vaccine efficacy. For case-control studies the inclusion criteria were English language articles, as well as adult patients for pneumococcoal vaccine.
Specific interventions included in the review
Pneumococcal polysaccharide and Hib-PRP vaccines.
Participants included in the review
Participants in the review of pneumococcal polysaccharide varied in age (young to over 55 years), setting (South African and New Guinea gold mines to Veterans Administration clinics and hospitals in USA) and level of risk as defined by medical condition (high, medium and low). In the review of Hib-PRP vaccine, participants differed in age (18 to 72 months) and setting (day care facilities in USA to children in Finland).
Outcomes assessed in the review
The review focuses on the efficacy of the vaccines in preventing pneumococcal pneumonia and Haemophilus influenzae type B. As such, the randomised controlled trials (RCTs) assess the number of vaccine and placebo patients infected with the disease, whilst the case-control studies the number of cases and controls retrospectively exposed to the vaccine.
How were decisions on the relevance of primary studies made?
The authors do not state how the papers were selected for the review, or how many of the authors performed the selection.