Communication tools for end-of-life decision-making in the intensive care unit: a systematic review and meta-analysis

Table 4 Risk of bias/quality assessment for observational studies

Study ID	Newcastle-Ottawa scale for cohort studies - selection	Newcastle-Ottawa scale for cohort studies - comparability	Newcastle-Ottawa scale for cohort studies - outcome	Overall Newcastle-Ottawa scale risk of bias
Ahrens 2003 [32]	★★★★	☆☆	★★★	Poor
Campbell 2003 [29]	★★★★	☆☆	★★★	Poor
Cox 2012 [15]	★★★★	☆☆	★★☆	Poor
Daly 2010 [16]	★★★★	★★	★★★	Good
Dowdy 1998 [17]	★★★★	★☆	★★★	Good
Hatler 2012 [18]	★★★★	☆☆	★★★	Poor
Holloran 1995 [28]	★★★☆	☆☆	★★★	Poor
Knaus 1990 [25]	★★★☆	★☆	★★★	Good
Lamba 2012 [27]	★★★★	☆☆	★★★	Poor
Lilly 2000 [26]	★★★★	★☆	★★★	Good
McCannon 2012 [30]	★★★★	☆☆	★★★	Poor
Norton 2007 [19]	★★★☆	☆☆	★★★	Poor
Quenot 2012 [31]	★★★★	☆☆	★★★	Poor
Shelton 2010 [20]	★★★★	☆☆	★★★	Poor

Using the Newcastle-Ottawa Scale, stars are awarded for each quaity item, with the maximum number of stars in the "Selection," "Comparability," and "Outcome" being four, two, and three, respectively. In the table, solid stars indicate stars awarded for quality items, while open stars indicate quality items which were absent

ISSN: 1364-8535