Figure 1.
PRISMA Flow Diagram of Included Studies.
A total of 318 abstracts were identified from the literature search. Hand-searching of articles included in previously published systematic reviews identified 1 relevant article. After removal of duplicate records, 259 abstracts were reviewed and 223 were excluded. Thirty-six articles were assessed in full-text, 31 of which were excluded and, ultimately, five comparative cohort studies were included in the final qualitative synthesis. Due to heterogeneity in reported outcomes and/or summary measures, pooling of data for meta-analysis was not possible.
Table 1.
Downs and Black Checklist for Quality Assessment.
Table 2.
Characteristics and Results of Included Studies.